refactor: improve name handling in shm_posix.cpp to match semaphore pattern

Check if name already starts with '/' before adding prefix, consistent
with the pattern used in semaphore_impl.h. This avoids duplicate prefix
when users provide names in the correct format.

.gitignore

@@ -28,6 +28,7 @@ ui_*.h
 *.jsc
 Makefile*
 *build-*
+*build_*
 
 # Qt unit tests
 target_wrapper.*

3rdparty/gtest/src/gtest-death-test.cc

@@ -1296,8 +1296,8 @@ static void StackLowerThanAddress(const void* ptr, bool* result) {
 GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
 GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
 static bool StackGrowsDown() {
-  int dummy;
-  bool result;
+  int dummy {};
+  bool result {};
   StackLowerThanAddress(&dummy, &result);
   return result;
 }

CMakeLists.txt

@@ -59,6 +59,13 @@ if (LIBIPC_BUILD_DEMOS)
     add_subdirectory(demo/chat)
     add_subdirectory(demo/msg_que)
     add_subdirectory(demo/send_recv)
+    if (MSVC)
+        add_subdirectory(demo/win_service/service)
+        add_subdirectory(demo/win_service/client)
+    else()
+        add_subdirectory(demo/linux_service/service)
+        add_subdirectory(demo/linux_service/client)
+    endif()
 endif()
 
 install(

README.md

@@ -1,21 +1,20 @@
-# cpp-ipc(libipc) - C++ IPC Library
+# cpp-ipc (libipc) - C++ IPC Library
 
 [![MIT licensed](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/mutouyun/cpp-ipc/blob/master/LICENSE)
 [![Build Status](https://github.com/mutouyun/cpp-ipc/actions/workflows/c-cpp.yml/badge.svg)](https://github.com/mutouyun/cpp-ipc/actions)
 [![Build status](https://ci.appveyor.com/api/projects/status/github/mutouyun/cpp-ipc?branch=master&svg=true)](https://ci.appveyor.com/project/mutouyun/cpp-ipc)
 [![Vcpkg package](https://img.shields.io/badge/Vcpkg-package-blueviolet)](https://github.com/microsoft/vcpkg/tree/master/ports/cpp-ipc)
 
-A high-performance inter-process communication using shared memory on Linux/Windows.  
-使用共享内存的跨平台（Linux/Windows，x86/x64/ARM）高性能IPC通讯库。
+## A high-performance inter-process communication library using shared memory on Linux/Windows/FreeBSD.
 
- * 推荐支持C++17的编译器（msvc-2017/gcc-7/clang-4）
- * 除STL外，无其他依赖
- * 无锁（lock-free）或轻量级spin-lock
- * 底层数据结构为循环数组（circular array）
- * `ipc::route`支持单写多读，`ipc::channel`支持多写多读【**注意：目前同一条通道最多支持32个receiver，sender无限制**】
- * 默认采用广播模式收发数据，支持用户任意选择读写方案
- * 不会长时间忙等（重试一定次数后会使用信号量进行等待），支持超时
- * 支持[Vcpkg](https://github.com/microsoft/vcpkg/blob/master/README_zh_CN.md)方式安装，如`vcpkg install cpp-ipc`
+ * Compilers with C++17 support are recommended (msvc-2017/gcc-7/clang-4)
+ * No other dependencies except STL.
+ * Only lock-free or lightweight spin-lock is used.
+ * Circular array is used as the underline data structure.
+ * `ipc::route` supports single write and multiple read. `ipc::channel` supports multiple read and write. (**Note: currently, a channel supports up to 32 receivers, but there is no such a limit for the sender.**) 
+ * Broadcasting is used by default, but user can choose any read/ write combinations.
+ * No long time blind wait. (Semaphore will be used after a certain number of retries.) 
+ * [Vcpkg](https://github.com/microsoft/vcpkg/blob/master/README.md) way of installation is supported. E.g. `vcpkg install cpp-ipc`
 
 ## Usage
 
@@ -31,7 +30,7 @@ See: [Wiki](https://github.com/mutouyun/cpp-ipc/wiki)
  OS | Windows 7 Ultimate x64
  Compiler | MSVC 2017 15.9.4
 
-UT & benchmark test function: [test](test)  
+Unit & benchmark tests: [test](test)  
 Performance data: [performance.xlsx](performance.xlsx)
 
 ## Reference
@@ -41,3 +40,42 @@ Performance data: [performance.xlsx](performance.xlsx)
  * [Lock-Free 编程 | 匠心十年 - 博客园](http://www.cnblogs.com/gaochundong/p/lock_free_programming.html)
  * [无锁队列的实现 | 酷 壳 - CoolShell](https://coolshell.cn/articles/8239.html)
  * [Implementing Condition Variables with Semaphores](https://www.microsoft.com/en-us/research/wp-content/uploads/2004/12/ImplementingCVs.pdf)
+
+------
+
+
+## 使用共享内存的跨平台（Linux/Windows/FreeBSD，x86/x64/ARM）高性能IPC通讯库
+
+ * 推荐支持C++17的编译器（msvc-2017/gcc-7/clang-4）
+ * 除STL外，无其他依赖
+ * 无锁（lock-free）或轻量级spin-lock
+ * 底层数据结构为循环数组（circular array）
+ * `ipc::route`支持单写多读，`ipc::channel`支持多写多读【**注意：目前同一条通道最多支持32个receiver，sender无限制**】
+ * 默认采用广播模式收发数据，支持用户任意选择读写方案
+ * 不会长时间忙等（重试一定次数后会使用信号量进行等待），支持超时
+ * 支持[Vcpkg](https://github.com/microsoft/vcpkg/blob/master/README_zh_CN.md)方式安装，如`vcpkg install cpp-ipc`
+
+## 使用方法
+
+详见：[Wiki](https://github.com/mutouyun/cpp-ipc/wiki)
+
+## 性能
+
+| 环境     | 值                               |
+| -------- | -------------------------------- |
+| 设备     | 联想 ThinkPad T450               |
+| CPU      | 英特尔® Core™ i5-4300U @ 2.5 GHz |
+| 内存     | 16 GB                            |
+| 操作系统 | Windows 7 Ultimate x64           |
+| 编译器   | MSVC 2017 15.9.4                 |
+
+单元测试和Benchmark测试: [test](test)  
+性能数据: [performance.xlsx](performance.xlsx)
+
+## 参考
+
+ * [Lock-Free Data Structures | Dr Dobb's](http://www.drdobbs.com/lock-free-data-structures/184401865)
+ * [Yet another implementation of a lock-free circular array queue | CodeProject](https://www.codeproject.com/Articles/153898/Yet-another-implementation-of-a-lock-free-circular)
+ * [Lock-Free 编程 | 匠心十年 - 博客园](http://www.cnblogs.com/gaochundong/p/lock_free_programming.html)
+ * [无锁队列的实现 | 酷 壳 - CoolShell](https://coolshell.cn/articles/8239.html)
+ * [Implementing Condition Variables with Semaphores](https://www.microsoft.com/en-us/research/wp-content/uploads/2004/12/ImplementingCVs.pdf)

demo/linux_service/client/CMakeLists.txt

@@ -0,0 +1,8 @@
+project(linux_client)
+
+file(GLOB SRC_FILES ./*.cpp)
+file(GLOB HEAD_FILES ./*.h)
+
+add_executable(${PROJECT_NAME} ${SRC_FILES} ${HEAD_FILES})
+
+target_link_libraries(${PROJECT_NAME} ipc)

demo/linux_service/client/main.cpp

@@ -0,0 +1,28 @@
+/// \brief To create a basic command line program.
+
+#include <stdio.h>
+#include <thread>
+#include <chrono>
+
+#include "libipc/ipc.h"
+
+int main(int argc, char *argv[]) {
+    printf("My Sample Client: Entry\n");
+    ipc::channel ipc_r{"service ipc r", ipc::receiver};
+    ipc::channel ipc_w{"service ipc w", ipc::sender};
+    while (1) {
+        auto msg = ipc_r.recv();
+        if (msg.empty()) {
+            printf("My Sample Client: message recv error\n");
+            return -1;
+        }
+        printf("My Sample Client: message recv: [%s]\n", (char const *)msg.data());
+        while (!ipc_w.send("Copy.")) {
+            printf("My Sample Client: message send error\n");
+            std::this_thread::sleep_for(std::chrono::seconds(1));
+        }
+        printf("My Sample Client: message send [Copy]\n");
+    }
+    printf("My Sample Client: Exit\n");
+    return 0;
+}

demo/linux_service/service/CMakeLists.txt

@@ -0,0 +1,8 @@
+project(linux_service)
+
+file(GLOB SRC_FILES ./*.cpp)
+file(GLOB HEAD_FILES ./*.h)
+
+add_executable(${PROJECT_NAME} ${SRC_FILES} ${HEAD_FILES})
+
+target_link_libraries(${PROJECT_NAME} ipc)

demo/linux_service/service/main.cpp

@@ -0,0 +1,34 @@
+/// \brief To create a basic command line program.
+
+#include <stdio.h>
+#include <string>
+#include <thread>
+#include <chrono>
+
+#include "libipc/ipc.h"
+
+int main(int argc, char *argv[]) {
+    printf("My Sample Service: Main: Entry\n");
+
+    ipc::channel ipc_r{"service ipc r", ipc::sender};
+    ipc::channel ipc_w{"service ipc w", ipc::receiver};
+
+    while (1) {
+        if (!ipc_r.send("Hello, World!")) {
+            printf("My Sample Service: send failed.\n");
+        }
+        else {
+            printf("My Sample Service: send [Hello, World!]\n");
+            auto msg = ipc_w.recv(1000);
+            if (msg.empty()) {
+                printf("My Sample Service: recv error\n");
+            } else {
+                printf("%s\n", (std::string{"My Sample Service: recv ["} + msg.get<char const *>() + "]").c_str());
+            }
+        }
+        std::this_thread::sleep_for(std::chrono::seconds(3));
+    }
+
+    printf("My Sample Service: Main: Exit\n");
+    return 0;
+}

demo/win_service/client/CMakeLists.txt

@@ -0,0 +1,8 @@
+project(win_client)
+
+file(GLOB SRC_FILES ./*.cpp)
+file(GLOB HEAD_FILES ./*.h)
+
+add_executable(${PROJECT_NAME} ${SRC_FILES} ${HEAD_FILES})
+
+target_link_libraries(${PROJECT_NAME} ipc)

demo/win_service/client/main.cpp

@@ -0,0 +1,45 @@
+/// \brief To create a basic Windows command line program.
+
+#if defined(__MINGW32__)
+#include <windows.h>
+#else
+#include <Windows.h>
+#endif
+#include <tchar.h>
+#include <stdio.h>
+
+#include "libipc/ipc.h"
+
+int _tmain (int argc, TCHAR *argv[]) {
+    _tprintf(_T("My Sample Client: Entry\n"));
+    ipc::channel ipc_r{ipc::prefix{"Global\\"}, "service ipc r", ipc::receiver};
+    ipc::channel ipc_w{ipc::prefix{"Global\\"}, "service ipc w", ipc::sender};
+    while (1) {
+        if (!ipc_r.reconnect(ipc::receiver)) {
+            Sleep(1000);
+            continue;
+        }
+        auto msg = ipc_r.recv();
+        if (msg.empty()) {
+            _tprintf(_T("My Sample Client: message recv error\n"));
+            ipc_r.disconnect();
+            continue;
+        }
+        printf("My Sample Client: message recv: [%s]\n", (char const *)msg.data());
+        for (;;) {
+            if (!ipc_w.reconnect(ipc::sender)) {
+                Sleep(1000);
+                continue;
+            }
+            if (ipc_w.send("Copy.")) {
+                break;
+            }
+            _tprintf(_T("My Sample Client: message send error\n"));
+            ipc_w.disconnect();
+            Sleep(1000);
+        }
+        _tprintf(_T("My Sample Client: message send [Copy]\n"));
+    }
+    _tprintf(_T("My Sample Client: Exit\n"));
+    return 0;
+}

demo/win_service/service/CMakeLists.txt

@@ -0,0 +1,8 @@
+project(win_service)
+
+file(GLOB SRC_FILES ./*.cpp)
+file(GLOB HEAD_FILES ./*.h)
+
+add_executable(${PROJECT_NAME} ${SRC_FILES} ${HEAD_FILES})
+
+target_link_libraries(${PROJECT_NAME} ipc)

demo/win_service/service/main.cpp

@@ -0,0 +1,193 @@
+/// \brief To create a basic Windows Service in C++.
+/// \see https://www.codeproject.com/Articles/499465/Simple-Windows-Service-in-Cplusplus
+
+#if defined(__MINGW32__)
+#include <windows.h>
+#else
+#include <Windows.h>
+#endif
+#include <tchar.h>
+#include <string>
+
+#include "libipc/ipc.h"
+
+SERVICE_STATUS        g_ServiceStatus = {0};
+SERVICE_STATUS_HANDLE g_StatusHandle = NULL;
+HANDLE                g_ServiceStopEvent = INVALID_HANDLE_VALUE;
+
+VOID WINAPI ServiceMain (DWORD argc, LPTSTR *argv);
+VOID WINAPI ServiceCtrlHandler (DWORD);
+DWORD WINAPI ServiceWorkerThread (LPVOID lpParam);
+
+#define SERVICE_NAME  _T("My Sample Service")
+
+int _tmain (int argc, TCHAR *argv[]) {
+    OutputDebugString(_T("My Sample Service: Main: Entry"));
+
+    SERVICE_TABLE_ENTRY ServiceTable[] = {
+        {SERVICE_NAME, (LPSERVICE_MAIN_FUNCTION) ServiceMain},
+        {NULL, NULL}
+    };
+
+    if (StartServiceCtrlDispatcher (ServiceTable) == FALSE) {
+        OutputDebugString(_T("My Sample Service: Main: StartServiceCtrlDispatcher returned error"));
+        return GetLastError ();
+    }
+
+    OutputDebugString(_T("My Sample Service: Main: Exit"));
+    return 0;
+}
+
+VOID WINAPI ServiceMain (DWORD argc, LPTSTR *argv) {
+    DWORD Status = E_FAIL;
+
+    OutputDebugString(_T("My Sample Service: ServiceMain: Entry"));
+
+    g_StatusHandle = RegisterServiceCtrlHandler (SERVICE_NAME, ServiceCtrlHandler);
+
+    if (g_StatusHandle == NULL) {
+        OutputDebugString(_T("My Sample Service: ServiceMain: RegisterServiceCtrlHandler returned error"));
+        goto EXIT;
+    }
+
+    // Tell the service controller we are starting
+    ZeroMemory (&g_ServiceStatus, sizeof (g_ServiceStatus));
+    g_ServiceStatus.dwServiceType = SERVICE_WIN32_OWN_PROCESS;
+    g_ServiceStatus.dwControlsAccepted = 0;
+    g_ServiceStatus.dwCurrentState = SERVICE_START_PENDING;
+    g_ServiceStatus.dwWin32ExitCode = 0;
+    g_ServiceStatus.dwServiceSpecificExitCode = 0;
+    g_ServiceStatus.dwCheckPoint = 0;
+
+    if (SetServiceStatus (g_StatusHandle, &g_ServiceStatus) == FALSE) {
+        OutputDebugString(_T("My Sample Service: ServiceMain: SetServiceStatus returned error"));
+    }
+
+    /* 
+     * Perform tasks neccesary to start the service here
+     */
+    OutputDebugString(_T("My Sample Service: ServiceMain: Performing Service Start Operations"));
+
+    // Create stop event to wait on later.
+    g_ServiceStopEvent = CreateEvent (NULL, TRUE, FALSE, NULL);
+    if (g_ServiceStopEvent == NULL) {
+        OutputDebugString(_T("My Sample Service: ServiceMain: CreateEvent(g_ServiceStopEvent) returned error"));
+
+        g_ServiceStatus.dwControlsAccepted = 0;
+        g_ServiceStatus.dwCurrentState = SERVICE_STOPPED;
+        g_ServiceStatus.dwWin32ExitCode = GetLastError();
+        g_ServiceStatus.dwCheckPoint = 1;
+
+        if (SetServiceStatus (g_StatusHandle, &g_ServiceStatus) == FALSE) {
+            OutputDebugString(_T("My Sample Service: ServiceMain: SetServiceStatus returned error"));
+        }
+        goto EXIT; 
+    }    
+
+    // Tell the service controller we are started
+    g_ServiceStatus.dwControlsAccepted = SERVICE_ACCEPT_STOP;
+    g_ServiceStatus.dwCurrentState = SERVICE_RUNNING;
+    g_ServiceStatus.dwWin32ExitCode = 0;
+    g_ServiceStatus.dwCheckPoint = 0;
+
+    if (SetServiceStatus (g_StatusHandle, &g_ServiceStatus) == FALSE) {
+        OutputDebugString(_T("My Sample Service: ServiceMain: SetServiceStatus returned error"));
+    }
+
+    // Start the thread that will perform the main task of the service
+    HANDLE hThread = CreateThread (NULL, 0, ServiceWorkerThread, NULL, 0, NULL);
+
+    OutputDebugString(_T("My Sample Service: ServiceMain: Waiting for Worker Thread to complete"));
+
+    // Wait until our worker thread exits effectively signaling that the service needs to stop
+    WaitForSingleObject (hThread, INFINITE);
+    
+    OutputDebugString(_T("My Sample Service: ServiceMain: Worker Thread Stop Event signaled"));
+    
+    
+    /* 
+     * Perform any cleanup tasks
+     */
+    OutputDebugString(_T("My Sample Service: ServiceMain: Performing Cleanup Operations"));
+
+    CloseHandle (g_ServiceStopEvent);
+
+    g_ServiceStatus.dwControlsAccepted = 0;
+    g_ServiceStatus.dwCurrentState = SERVICE_STOPPED;
+    g_ServiceStatus.dwWin32ExitCode = 0;
+    g_ServiceStatus.dwCheckPoint = 3;
+
+    if (SetServiceStatus (g_StatusHandle, &g_ServiceStatus) == FALSE) {
+        OutputDebugString(_T("My Sample Service: ServiceMain: SetServiceStatus returned error"));
+    }
+    
+EXIT:
+    OutputDebugString(_T("My Sample Service: ServiceMain: Exit"));
+    return;
+}
+
+VOID WINAPI ServiceCtrlHandler (DWORD CtrlCode) {
+    OutputDebugString(_T("My Sample Service: ServiceCtrlHandler: Entry"));
+
+    switch (CtrlCode) {
+    case SERVICE_CONTROL_STOP :
+
+        OutputDebugString(_T("My Sample Service: ServiceCtrlHandler: SERVICE_CONTROL_STOP Request"));
+
+        if (g_ServiceStatus.dwCurrentState != SERVICE_RUNNING)
+           break;
+
+        /* 
+         * Perform tasks neccesary to stop the service here 
+         */
+        
+        g_ServiceStatus.dwControlsAccepted = 0;
+        g_ServiceStatus.dwCurrentState = SERVICE_STOP_PENDING;
+        g_ServiceStatus.dwWin32ExitCode = 0;
+        g_ServiceStatus.dwCheckPoint = 4;
+
+        if (SetServiceStatus (g_StatusHandle, &g_ServiceStatus) == FALSE) {
+            OutputDebugString(_T("My Sample Service: ServiceCtrlHandler: SetServiceStatus returned error"));
+        }
+
+        // This will signal the worker thread to start shutting down
+        SetEvent (g_ServiceStopEvent);
+
+        break;
+
+    default:
+        break;
+    }
+
+    OutputDebugString(_T("My Sample Service: ServiceCtrlHandler: Exit"));
+}
+
+DWORD WINAPI ServiceWorkerThread (LPVOID lpParam) {
+    OutputDebugString(_T("My Sample Service: ServiceWorkerThread: Entry"));
+    ipc::channel ipc_r{ipc::prefix{"Global\\"}, "service ipc r", ipc::sender};
+    ipc::channel ipc_w{ipc::prefix{"Global\\"}, "service ipc w", ipc::receiver};
+
+    //  Periodically check if the service has been requested to stop
+    while (WaitForSingleObject(g_ServiceStopEvent, 0) != WAIT_OBJECT_0) {        
+        /* 
+         * Perform main service function here
+         */
+        if (!ipc_r.send("Hello, World!")) {
+            OutputDebugString(_T("My Sample Service: send failed."));
+        }
+        else {
+            OutputDebugString(_T("My Sample Service: send [Hello, World!]"));
+            auto msg = ipc_w.recv(1000);
+            if (msg.empty()) {
+                OutputDebugString(_T("My Sample Service: recv error"));
+            } else {
+                OutputDebugStringA((std::string{"My Sample Service: recv ["} + msg.get<char const *>() + "]").c_str());
+            }
+        }
+        Sleep(3000);
+    }
+
+    OutputDebugString(_T("My Sample Service: ServiceWorkerThread: Exit"));
+
+    return ERROR_SUCCESS;
+}

include/libipc/buffer.h

@@ -17,14 +17,16 @@ public:
     buffer();
 
     buffer(void* p, std::size_t s, destructor_t d);
-    buffer(void* p, std::size_t s, destructor_t d, void* additional);
+    // mem_to_free: pointer to be passed to destructor (if different from p)
+    // Use case: when p points into a larger allocated block that needs to be freed
+    buffer(void* p, std::size_t s, destructor_t d, void* mem_to_free);
     buffer(void* p, std::size_t s);
 
     template <std::size_t N>
-    explicit buffer(byte_t const (& data)[N])
+    explicit buffer(byte_t (& data)[N])
         : buffer(data, sizeof(data)) {
     }
-    explicit buffer(char const & c);
+    explicit buffer(char & c);
 
     buffer(buffer&& rhs);
     ~buffer();

include/libipc/condition.h

@@ -26,6 +26,9 @@ public:
     bool open(char const *name) noexcept;
     void close() noexcept;
 
+    void clear() noexcept;
+    static void clear_storage(char const * name) noexcept;
+
     bool wait(ipc::sync::mutex &mtx, std::uint64_t tm = ipc::invalid_value) noexcept;
     bool notify(ipc::sync::mutex &mtx) noexcept;
     bool broadcast(ipc::sync::mutex &mtx) noexcept;

include/libipc/def.h

@@ -65,4 +65,9 @@ struct relat_trait<wr<Rp, Rc, Ts>> {
 template <template <typename> class Policy, typename Flag>
 struct relat_trait<Policy<Flag>> : relat_trait<Flag> {};
 
+// the prefix tag of a channel
+struct prefix {
+    char const *str;
+};
+
 } // namespace ipc

include/libipc/ipc.h

@@ -19,14 +19,25 @@ enum : unsigned {
 
 template <typename Flag>
 struct IPC_EXPORT chan_impl {
+    static ipc::handle_t init_first();
+
     static bool connect   (ipc::handle_t * ph, char const * name, unsigned mode);
+    static bool connect   (ipc::handle_t * ph, prefix, char const * name, unsigned mode);
     static bool reconnect (ipc::handle_t * ph, unsigned mode);
     static void disconnect(ipc::handle_t h);
     static void destroy   (ipc::handle_t h);
 
     static char const * name(ipc::handle_t h);
 
-    static std::size_t recv_count(ipc::handle_t h);
+    // Release memory without waiting for the connection to disconnect.
+    static void release(ipc::handle_t h) noexcept;
+
+    // Force cleanup of all shared memory storage that handles depend on.
+    static void clear(ipc::handle_t h) noexcept;
+    static void clear_storage(char const * name) noexcept;
+    static void clear_storage(prefix, char const * name) noexcept;
+
+    static std::size_t recv_count   (ipc::handle_t h);
     static bool        wait_for_recv(ipc::handle_t h, std::size_t r_count, std::uint64_t tm);
 
     static bool   send(ipc::handle_t h, void const * data, std::size_t size, std::uint64_t tm);
@@ -41,7 +52,7 @@ class chan_wrapper {
 private:
     using detail_t = chan_impl<Flag>;
 
-    ipc::handle_t h_ = nullptr;
+    ipc::handle_t h_ = detail_t::init_first();
     unsigned mode_   = ipc::sender;
     bool connected_  = false;
 
@@ -52,6 +63,10 @@ public:
         : connected_{this->connect(name, mode)} {
     }
 
+    chan_wrapper(prefix pref, char const * name, unsigned mode = ipc::sender)
+        : connected_{this->connect(pref, name, mode)} {
+    }
+
     chan_wrapper(chan_wrapper&& rhs) noexcept
         : chan_wrapper{} {
         swap(rhs);
@@ -76,6 +91,28 @@ public:
         return detail_t::name(h_);
     }
 
+    // Release memory without waiting for the connection to disconnect.
+    void release() noexcept {
+        detail_t::release(h_);
+        h_ = nullptr;
+    }
+
+    // Clear shared memory files under opened handle.
+    void clear() noexcept {
+        detail_t::clear(h_);
+        h_ = nullptr;
+    }
+
+    // Clear shared memory files under a specific name.
+    static void clear_storage(char const * name) noexcept {
+        detail_t::clear_storage(name);
+    }
+
+    // Clear shared memory files under a specific name with a prefix.
+    static void clear_storage(prefix pref, char const * name) noexcept {
+        detail_t::clear_storage(pref, name);
+    }
+
     ipc::handle_t handle() const noexcept {
         return h_;
     }
@@ -100,6 +137,11 @@ public:
         detail_t::disconnect(h_); // clear old connection
         return connected_ = detail_t::connect(&h_, name, mode_ = mode);
     }
+    bool connect(prefix pref, char const * name, unsigned mode = ipc::sender | ipc::receiver) {
+        if (name == nullptr || name[0] == '\0') return false;
+        detail_t::disconnect(h_); // clear old connection
+        return connected_ = detail_t::connect(&h_, pref, name, mode_ = mode);
+    }
 
     /**
      * Try connecting with new mode flags.
@@ -167,26 +209,22 @@ template <relat Rp, relat Rc, trans Ts>
 using chan = chan_wrapper<ipc::wr<Rp, Rc, Ts>>;
 
 /**
- * class route
+ * \class route
  *
- * You could use one producer/server/sender for sending messages to a route,
+ * \note You could use one producer/server/sender for sending messages to a route,
  *       then all the consumers/clients/receivers which are receiving with this route,
  *       would receive your sent messages.
- *
- * A route could only be used in 1 to N
- * (one producer/writer to multi consumers/readers)
+ *       A route could only be used in 1 to N (one producer/writer to multi consumers/readers).
 */
-
 using route = chan<relat::single, relat::multi, trans::broadcast>;
 
 /**
- * class channel
+ * \class channel
  *
- * You could use multi producers/writers for sending messages to a channel,
+ * \note You could use multi producers/writers for sending messages to a channel,
  *       then all the consumers/readers which are receiving with this channel,
  *       would receive your sent messages.
 */
-
 using channel = chan<relat::multi, relat::multi, trans::broadcast>;
 
 } // namespace ipc

include/libipc/mutex.h

@@ -26,6 +26,9 @@ public:
     bool open(char const *name) noexcept;
     void close() noexcept;
 
+    void clear() noexcept;
+    static void clear_storage(char const * name) noexcept;
+
     bool lock(std::uint64_t tm = ipc::invalid_value) noexcept;
     bool try_lock() noexcept(false); // std::system_error
     bool unlock() noexcept;

include/libipc/pool_alloc.h

@@ -11,8 +11,8 @@ namespace mem {
 
 class IPC_EXPORT pool_alloc {
 public:
-    static void* alloc(std::size_t size);
-    static void  free (void* p, std::size_t size);
+    static void* alloc(std::size_t size) noexcept;
+    static void  free (void* p, std::size_t size) noexcept;
 };
 
 ////////////////////////////////////////////////////////////////

include/libipc/rw_lock.h

@@ -6,6 +6,7 @@
 #include <limits>
 #include <type_traits>
 #include <utility>
+#include <cstdint>
 
 ////////////////////////////////////////////////////////////////
 /// Gives hint to processor that improves performance of spin-wait loops.
@@ -98,7 +99,7 @@ inline void sleep(K& k) {
 namespace ipc {
 
 class spin_lock {
-    std::atomic<unsigned> lc_ { 0 };
+    std::atomic<std::uint32_t> lc_ { 0 };
 
 public:
     void lock(void) noexcept {
@@ -113,13 +114,13 @@ public:
 };
 
 class rw_lock {
-    using lc_ui_t = unsigned;
+    using lc_ui_t = std::uint32_t;
 
     std::atomic<lc_ui_t> lc_ { 0 };
 
     enum : lc_ui_t {
-        w_mask = (std::numeric_limits<std::make_signed_t<lc_ui_t>>::max)(), // b 0111 1111
-        w_flag = w_mask + 1                                                 // b 1000 0000
+        w_mask = (std::numeric_limits<std::make_signed_t<lc_ui_t>>::max)(), // b 0111 1111 ...
+        w_flag = w_mask + 1                                                 // b 1000 0000 ...
     };
 
 public:

include/libipc/semaphore.h

@@ -25,6 +25,9 @@ public:
     bool open(char const *name, std::uint32_t count = 0) noexcept;
     void close() noexcept;
 
+    void clear() noexcept;
+    static void clear_storage(char const * name) noexcept;
+
     bool wait(std::uint64_t tm = ipc::invalid_value) noexcept;
     bool post(std::uint32_t count = 1) noexcept;
 

include/libipc/shm.h

@@ -17,9 +17,31 @@ enum : unsigned {
 
 IPC_EXPORT id_t         acquire(char const * name, std::size_t size, unsigned mode = create | open);
 IPC_EXPORT void *       get_mem(id_t id, std::size_t * size);
-IPC_EXPORT std::int32_t release(id_t id);
-IPC_EXPORT void         remove (id_t id);
-IPC_EXPORT void         remove (char const * name);
+
+// Release shared memory resource and clean up disk file if reference count reaches zero.
+// This function decrements the reference counter. When the counter reaches zero, it:
+// 1. Unmaps the shared memory region
+// 2. Removes the backing file from disk (shm_unlink on POSIX)
+// 3. Frees the id structure
+// After calling this function, the id becomes invalid and must not be used again.
+// Returns: The reference count before decrement, or -1 on error.
+IPC_EXPORT std::int32_t release(id_t id) noexcept;
+
+// Release shared memory resource and force cleanup of disk file.
+// This function calls release(id) internally, then unconditionally attempts to
+// remove the backing file. WARNING: Do NOT call this after release(id) on the
+// same id, as the id is already freed by release(). Use this function alone,
+// not in combination with release().
+// Typical use case: Force cleanup when you want to ensure the disk file is removed
+// regardless of reference count state.
+IPC_EXPORT void         remove (id_t id) noexcept;
+
+// Remove shared memory backing file by name.
+// This function only removes the disk file and does not affect any active memory
+// mappings or id structures. Use this for cleanup of orphaned files or for explicit
+// file removal without affecting runtime resources.
+// Safe to call at any time, even if shared memory is still in use elsewhere.
+IPC_EXPORT void         remove (char const * name) noexcept;
 
 IPC_EXPORT std::int32_t get_ref(id_t id);
 IPC_EXPORT void sub_ref(id_t id);
@@ -45,6 +67,10 @@ public:
     bool acquire(char const * name, std::size_t size, unsigned mode = create | open);
     std::int32_t release();
 
+    // Clean the handle file.
+    void clear() noexcept;
+    static void clear_storage(char const * name) noexcept;
+
     void* get() const;
 
     void attach(id_t);

src/CMakeLists.txt

@@ -1,5 +1,7 @@
 project(ipc)
 
+set (PACKAGE_VERSION 1.3.0)
+
 aux_source_directory(${LIBIPC_PROJECT_DIR}/src/libipc SRC_FILES)
 aux_source_directory(${LIBIPC_PROJECT_DIR}/src/libipc/sync SRC_FILES)
 aux_source_directory(${LIBIPC_PROJECT_DIR}/src/libipc/platform SRC_FILES)
@@ -34,11 +36,13 @@ set_target_properties(${PROJECT_NAME}
 # set version
 set_target_properties(${PROJECT_NAME}
     PROPERTIES
-    VERSION 1.2.0
+    VERSION ${PACKAGE_VERSION}
     SOVERSION 3)
 
 target_include_directories(${PROJECT_NAME}
-  PUBLIC  ${LIBIPC_PROJECT_DIR}/include
+  PUBLIC  
+    "$<BUILD_INTERFACE:${LIBIPC_PROJECT_DIR}/include>"
+    "$<INSTALL_INTERFACE:include>"
   PRIVATE ${LIBIPC_PROJECT_DIR}/src
           $<$<BOOL:UNIX>:${LIBIPC_PROJECT_DIR}/src/libipc/platform/linux>)
 
@@ -50,6 +54,28 @@ endif()
 
 install(
   TARGETS ${PROJECT_NAME}
+  EXPORT cpp-ipc-targets
   RUNTIME DESTINATION bin
   LIBRARY DESTINATION lib
   ARCHIVE DESTINATION lib)
+
+install(EXPORT cpp-ipc-targets
+	FILE cpp-ipc-targets.cmake
+	NAMESPACE cpp-ipc::
+	DESTINATION share/cpp-ipc
+)
+
+file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/cpp-ipc-config.cmake.in"
+[[include(CMakeFindDependencyMacro)
+include("${CMAKE_CURRENT_LIST_DIR}/cpp-ipc-targets.cmake")
+]])
+configure_file("${CMAKE_CURRENT_BINARY_DIR}/cpp-ipc-config.cmake.in" "${CMAKE_CURRENT_BINARY_DIR}/cpp-ipc-config.cmake" @ONLY)
+install(FILES ${CMAKE_CURRENT_BINARY_DIR}/cpp-ipc-config.cmake DESTINATION share/cpp-ipc)
+
+include(CMakePackageConfigHelpers)
+write_basic_package_version_file(
+	cppIpcConfigVersion.cmake
+	VERSION ${PACKAGE_VERSION}
+	COMPATIBILITY AnyNewerVersion
+)
+install(FILES ${CMAKE_CURRENT_BINARY_DIR}/cppIpcConfigVersion.cmake DESTINATION share/cpp-ipc)

src/libipc/buffer.cpp

@@ -38,16 +38,16 @@ buffer::buffer(void* p, std::size_t s, destructor_t d)
     : p_(p_->make(p, s, d, nullptr)) {
 }
 
-buffer::buffer(void* p, std::size_t s, destructor_t d, void* additional)
-    : p_(p_->make(p, s, d, additional)) {
+buffer::buffer(void* p, std::size_t s, destructor_t d, void* mem_to_free)
+    : p_(p_->make(p, s, d, mem_to_free)) {
 }
 
 buffer::buffer(void* p, std::size_t s)
     : buffer(p, s, nullptr) {
 }
 
-buffer::buffer(char const & c)
-    : buffer(const_cast<char*>(&c), 1) {
+buffer::buffer(char & c)
+    : buffer(&c, 1) {
 }
 
 buffer::buffer(buffer&& rhs)

src/libipc/circ/elem_array.h

@@ -37,8 +37,8 @@ private:
     elem_t   block_[elem_max] {};
 
     /**
-     * @remarks 'warning C4348: redefinition of default parameter' with MSVC.
-     * @see
+     * \remarks 'warning C4348: redefinition of default parameter' with MSVC.
+     * \see
      *  - https://stackoverflow.com/questions/12656239/redefinition-of-default-template-parameter
      *  - https://developercommunity.visualstudio.com/content/problem/425978/incorrect-c4348-warning-in-nested-template-declara.html
     */

src/libipc/circ/elem_def.h

@@ -60,7 +60,7 @@ public:
         for (unsigned k = 0;; ipc::yield(k)) {
             cc_t curr = this->cc_.load(std::memory_order_acquire);
             cc_t next = curr | (curr + 1); // find the first 0, and set it to 1.
-            if (next == 0) {
+            if (next == curr) {
                 // connection-slot is full.
                 return 0;
             }
@@ -74,6 +74,10 @@ public:
         return this->cc_.fetch_and(~cc_id, std::memory_order_acq_rel) & ~cc_id;
     }
 
+    bool connected(cc_t cc_id) const noexcept {
+        return (this->connections() & cc_id) != 0;
+    }
+
     std::size_t conn_count(std::memory_order order = std::memory_order_acquire) const noexcept {
         cc_t cur = this->cc_.load(order);
         cc_t cnt; // accumulates the total bits set in cc
@@ -100,6 +104,11 @@ public:
         }
     }
 
+    bool connected(cc_t cc_id) const noexcept {
+        // In non-broadcast mode, connection tags are only used for counting.
+        return (this->connections() != 0) && (cc_id != 0);
+    }
+
     std::size_t conn_count(std::memory_order order = std::memory_order_acquire) const noexcept {
         return this->connections(order);
     }

src/libipc/ipc.cpp

@@ -9,6 +9,7 @@
 #include <vector>
 #include <array>
 #include <cassert>
+#include <mutex>
 
 #include "libipc/ipc.h"
 #include "libipc/def.h"
@@ -69,6 +70,23 @@ ipc::buff_t make_cache(T& data, std::size_t size) {
     return { ptr, size, ipc::mem::free };
 }
 
+acc_t *cc_acc(ipc::string const &pref) {
+    static ipc::unordered_map<ipc::string, ipc::shm::handle> handles;
+    static std::mutex lock;
+    std::lock_guard<std::mutex> guard {lock};
+    auto it = handles.find(pref);
+    if (it == handles.end()) {
+        ipc::string shm_name {ipc::make_prefix(pref, {"CA_CONN__"})};
+        ipc::shm::handle h;
+        if (!h.acquire(shm_name.c_str(), sizeof(acc_t))) {
+            ipc::error("[cc_acc] acquire failed: %s\n", shm_name.c_str());
+            return nullptr;
+        }
+        it = handles.emplace(pref, std::move(h)).first;
+    }
+    return static_cast<acc_t *>(it->second.get());
+}
+
 struct cache_t {
     std::size_t fill_;
     ipc::buff_t buff_;
@@ -85,10 +103,70 @@ struct cache_t {
     }
 };
 
-auto cc_acc() {
-    static ipc::shm::handle acc_h("__CA_CONN__", sizeof(acc_t));
-    return static_cast<acc_t*>(acc_h.get());
-}
+struct conn_info_head {
+
+    ipc::string prefix_;
+    ipc::string name_;
+    msg_id_t    cc_id_; // connection-info id
+    ipc::detail::waiter cc_waiter_, wt_waiter_, rd_waiter_;
+    ipc::shm::handle acc_h_;
+
+    conn_info_head(char const * prefix, char const * name)
+        : prefix_{ipc::make_string(prefix)}
+        , name_  {ipc::make_string(name)}
+        , cc_id_ {} {}
+
+    void init() {
+        if (!cc_waiter_.valid()) cc_waiter_.open(ipc::make_prefix(prefix_, {"CC_CONN__", name_}).c_str());
+        if (!wt_waiter_.valid()) wt_waiter_.open(ipc::make_prefix(prefix_, {"WT_CONN__", name_}).c_str());
+        if (!rd_waiter_.valid()) rd_waiter_.open(ipc::make_prefix(prefix_, {"RD_CONN__", name_}).c_str());
+        if (!acc_h_.valid()) acc_h_.acquire(ipc::make_prefix(prefix_, {"AC_CONN__", name_}).c_str(), sizeof(acc_t));
+        if (cc_id_ != 0) {
+            return;
+        }
+        acc_t *pacc = cc_acc(prefix_);
+        if (pacc == nullptr) {
+            // Failed to obtain the global accumulator.
+            return;
+        }
+        cc_id_ = pacc->fetch_add(1, std::memory_order_relaxed) + 1;
+        if (cc_id_ == 0) {
+            // The identity cannot be 0.
+            cc_id_ = pacc->fetch_add(1, std::memory_order_relaxed) + 1;
+        }
+    }
+
+    void clear() noexcept {
+        cc_waiter_.clear();
+        wt_waiter_.clear();
+        rd_waiter_.clear();
+        acc_h_.clear();
+    }
+
+    static void clear_storage(char const * prefix, char const * name) noexcept {
+        auto p = ipc::make_string(prefix);
+        auto n = ipc::make_string(name);
+        ipc::detail::waiter::clear_storage(ipc::make_prefix(p, {"CC_CONN__", n}).c_str());
+        ipc::detail::waiter::clear_storage(ipc::make_prefix(p, {"WT_CONN__", n}).c_str());
+        ipc::detail::waiter::clear_storage(ipc::make_prefix(p, {"RD_CONN__", n}).c_str());
+        ipc::shm::handle::clear_storage(ipc::make_prefix(p, {"AC_CONN__", n}).c_str());
+    }
+
+    void quit_waiting() {
+        cc_waiter_.quit_waiting();
+        wt_waiter_.quit_waiting();
+        rd_waiter_.quit_waiting();
+    }
+
+    auto acc() {
+        return static_cast<acc_t*>(acc_h_.get());
+    }
+
+    auto& recv_cache() {
+        thread_local ipc::unordered_map<msg_id_t, cache_t> tls;
+        return tls;
+    }
+};
 
 IPC_CONSTEXPR_ std::size_t align_chunk_size(std::size_t size) noexcept {
     return (((size - 1) / ipc::large_msg_align) + 1) * ipc::large_msg_align;
@@ -130,17 +208,32 @@ struct chunk_info_t {
 
 auto& chunk_storages() {
     class chunk_handle_t {
-        ipc::shm::handle handle_;
+        ipc::unordered_map<ipc::string, ipc::shm::handle> handles_;
+        std::mutex lock_;
 
-    public:
-        chunk_info_t *get_info(std::size_t chunk_size) {
-            if (!handle_.valid() &&
-                !handle_.acquire( ("__CHUNK_INFO__" + ipc::to_string(chunk_size)).c_str(), 
+        static bool make_handle(ipc::shm::handle &h, ipc::string const &shm_name, std::size_t chunk_size) {
+            if (!h.valid() &&
+                !h.acquire( shm_name.c_str(), 
                             sizeof(chunk_info_t) + chunk_info_t::chunks_mem_size(chunk_size) )) {
                 ipc::error("[chunk_storages] chunk_shm.id_info_.acquire failed: chunk_size = %zd\n", chunk_size);
+                return false;
+            }
+            return true;
+        }
+
+    public:
+        chunk_info_t *get_info(conn_info_head *inf, std::size_t chunk_size) {
+            ipc::string pref {(inf == nullptr) ? ipc::string{} : inf->prefix_};
+            ipc::string shm_name {ipc::make_prefix(pref, {"CHUNK_INFO__", ipc::to_string(chunk_size)})};
+            ipc::shm::handle *h;
+            {
+                std::lock_guard<std::mutex> guard {lock_};
+                h = &(handles_[pref]);
+                if (!make_handle(*h, shm_name, chunk_size)) {
                     return nullptr;
                 }
-            auto info = static_cast<chunk_info_t*>(handle_.get());
+            }
+            auto *info = static_cast<chunk_info_t*>(h->get());
             if (info == nullptr) {
                 ipc::error("[chunk_storages] chunk_shm.id_info_.get failed: chunk_size = %zd\n", chunk_size);
                 return nullptr;
@@ -148,29 +241,35 @@ auto& chunk_storages() {
             return info;
         }
     };
-    static ipc::map<std::size_t, chunk_handle_t> chunk_hs;
+    using deleter_t = void (*)(chunk_handle_t*);
+    using chunk_handle_ptr_t = std::unique_ptr<chunk_handle_t, deleter_t>;
+    static ipc::map<std::size_t, chunk_handle_ptr_t> chunk_hs;
     return chunk_hs;
 }
 
-chunk_info_t *chunk_storage_info(std::size_t chunk_size) {
+chunk_info_t *chunk_storage_info(conn_info_head *inf, std::size_t chunk_size) {
     auto &storages = chunk_storages();
     std::decay_t<decltype(storages)>::iterator it;
     {
         static ipc::rw_lock lock;
         IPC_UNUSED_ std::shared_lock<ipc::rw_lock> guard {lock};
         if ((it = storages.find(chunk_size)) == storages.end()) {
-            using chunk_handle_t = std::decay_t<decltype(storages)>::value_type::second_type;
+            using chunk_handle_ptr_t = std::decay_t<decltype(storages)>::value_type::second_type;
+            using chunk_handle_t     = chunk_handle_ptr_t::element_type;
             guard.unlock();
             IPC_UNUSED_ std::lock_guard<ipc::rw_lock> guard {lock};
-            it = storages.emplace(chunk_size, chunk_handle_t{}).first;
+            it = storages.emplace(chunk_size, chunk_handle_ptr_t{
+                ipc::mem::alloc<chunk_handle_t>(), [](chunk_handle_t *p) {
+                    ipc::mem::destruct(p);
+                }}).first;
         }
     }
-    return it->second.get_info(chunk_size);
+    return it->second->get_info(inf, chunk_size);
 }
 
-std::pair<ipc::storage_id_t, void*> acquire_storage(std::size_t size, ipc::circ::cc_t conns) {
+std::pair<ipc::storage_id_t, void*> acquire_storage(conn_info_head *inf, std::size_t size, ipc::circ::cc_t conns) {
     std::size_t chunk_size = calc_chunk_size(size);
-    auto info = chunk_storage_info(chunk_size);
+    auto info = chunk_storage_info(inf, chunk_size);
     if (info == nullptr) return {};
 
     info->lock_.lock();
@@ -185,24 +284,24 @@ std::pair<ipc::storage_id_t, void*> acquire_storage(std::size_t size, ipc::circ:
     return { id, chunk->data() };
 }
 
-void *find_storage(ipc::storage_id_t id, std::size_t size) {
+void *find_storage(ipc::storage_id_t id, conn_info_head *inf, std::size_t size) {
     if (id < 0) {
         ipc::error("[find_storage] id is invalid: id = %ld, size = %zd\n", (long)id, size);
         return nullptr;
     }
     std::size_t chunk_size = calc_chunk_size(size);
-    auto info = chunk_storage_info(chunk_size);
+    auto info = chunk_storage_info(inf, chunk_size);
     if (info == nullptr) return nullptr;
     return info->at(chunk_size, id)->data();
 }
 
-void release_storage(ipc::storage_id_t id, std::size_t size) {
+void release_storage(ipc::storage_id_t id, conn_info_head *inf, std::size_t size) {
     if (id < 0) {
         ipc::error("[release_storage] id is invalid: id = %ld, size = %zd\n", (long)id, size);
         return;
     }
     std::size_t chunk_size = calc_chunk_size(size);
-    auto info = chunk_storage_info(chunk_size);
+    auto info = chunk_storage_info(inf, chunk_size);
     if (info == nullptr) return;
     info->lock_.lock();
     info->pool_.release(id);
@@ -229,13 +328,13 @@ bool sub_rc(ipc::wr<Rp, Rc, ipc::trans::broadcast>,
 }
 
 template <typename Flag>
-void recycle_storage(ipc::storage_id_t id, std::size_t size, ipc::circ::cc_t curr_conns, ipc::circ::cc_t conn_id) {
+void recycle_storage(ipc::storage_id_t id, conn_info_head *inf, std::size_t size, ipc::circ::cc_t curr_conns, ipc::circ::cc_t conn_id) {
     if (id < 0) {
         ipc::error("[recycle_storage] id is invalid: id = %ld, size = %zd\n", (long)id, size);
         return;
     }
     std::size_t chunk_size = calc_chunk_size(size);
-    auto info = chunk_storage_info(chunk_size);
+    auto info = chunk_storage_info(inf, chunk_size);
     if (info == nullptr) return;
 
     auto chunk = info->at(chunk_size, id);
@@ -250,7 +349,7 @@ void recycle_storage(ipc::storage_id_t id, std::size_t size, ipc::circ::cc_t cur
 }
 
 template <typename MsgT>
-bool clear_message(void* p) {
+bool clear_message(conn_info_head *inf, void* p) {
     auto msg = static_cast<MsgT*>(p);
     if (msg->storage_) {
         std::int32_t r_size = static_cast<std::int32_t>(ipc::data_length) + msg->remain_;
@@ -258,45 +357,12 @@ bool clear_message(void* p) {
             ipc::error("[clear_message] invalid msg size: %d\n", (int)r_size);
             return true;
         }
-        release_storage(
-            *reinterpret_cast<ipc::storage_id_t*>(&msg->data_),
-            static_cast<std::size_t>(r_size));
+        release_storage(*reinterpret_cast<ipc::storage_id_t*>(&msg->data_),
+                        inf, static_cast<std::size_t>(r_size));
     }
     return true;
 }
 
-struct conn_info_head {
-
-    ipc::string name_;
-    msg_id_t    cc_id_; // connection-info id
-    ipc::detail::waiter cc_waiter_, wt_waiter_, rd_waiter_;
-    ipc::shm::handle acc_h_;
-
-    conn_info_head(char const * name)
-        : name_     {name}
-        , cc_id_    {(cc_acc() == nullptr) ? 0 : cc_acc()->fetch_add(1, std::memory_order_relaxed)}
-        , cc_waiter_{("__CC_CONN__" + name_).c_str()}
-        , wt_waiter_{("__WT_CONN__" + name_).c_str()}
-        , rd_waiter_{("__RD_CONN__" + name_).c_str()}
-        , acc_h_    {("__AC_CONN__" + name_).c_str(), sizeof(acc_t)} {
-    }
-
-    void quit_waiting() {
-        cc_waiter_.quit_waiting();
-        wt_waiter_.quit_waiting();
-        rd_waiter_.quit_waiting();
-    }
-
-    auto acc() {
-        return static_cast<acc_t*>(acc_h_.get());
-    }
-
-    auto& recv_cache() {
-        thread_local ipc::unordered_map<msg_id_t, cache_t> tls;
-        return tls;
-    }
-};
-
 template <typename W, typename F>
 bool wait_for(W& waiter, F&& pred, std::uint64_t tm) {
     if (tm == 0) return !pred();
@@ -322,11 +388,32 @@ struct queue_generator {
     struct conn_info_t : conn_info_head {
         queue_t que_;
 
-        conn_info_t(char const * name)
-            : conn_info_head{name}
-            , que_{("__QU_CONN__" +
-                    ipc::to_string(DataSize) + "__" +
-                    ipc::to_string(AlignSize) + "__" + name).c_str()} {
+        conn_info_t(char const * pref, char const * name)
+            : conn_info_head{pref, name} { init(); }
+
+        void init() {
+            conn_info_head::init();
+            if (!que_.valid()) {
+                que_.open(ipc::make_prefix(prefix_, {
+                          "QU_CONN__", 
+                          this->name_, 
+                          "__", ipc::to_string(DataSize), 
+                          "__", ipc::to_string(AlignSize)}).c_str());
+            }
+        }
+
+        void clear() noexcept {
+            que_.clear();
+            conn_info_head::clear();
+        }
+
+        static void clear_storage(char const * prefix, char const * name) noexcept {
+            queue_t::clear_storage(ipc::make_prefix(ipc::make_string(prefix), {
+                                   "QU_CONN__", 
+                                   ipc::make_string(name), 
+                                   "__", ipc::to_string(DataSize), 
+                                   "__", ipc::to_string(AlignSize)}).c_str());
+            conn_info_head::clear_storage(prefix, name);
         }
 
         void disconnect_receiver() {
@@ -357,6 +444,18 @@ constexpr static queue_t* queue_of(ipc::handle_t h) noexcept {
 
 /* API implementations */
 
+static bool connect(ipc::handle_t * ph, ipc::prefix pref, char const * name, bool start_to_recv) {
+    assert(ph != nullptr);
+    if (*ph == nullptr) {
+        *ph = ipc::mem::alloc<conn_info_t>(pref.str, name);
+    }
+    return reconnect(ph, start_to_recv);
+}
+
+static bool connect(ipc::handle_t * ph, char const * name, bool start_to_recv) {
+    return connect(ph, {nullptr}, name, start_to_recv);
+}
+
 static void disconnect(ipc::handle_t h) {
     auto que = queue_of(h);
     if (que == nullptr) {
@@ -374,6 +473,7 @@ static bool reconnect(ipc::handle_t * ph, bool start_to_recv) {
     if (que == nullptr) {
         return false;
     }
+    info_of(*ph)->init();
     if (start_to_recv) {
         que->shut_sending();
         if (que->connect()) { // wouldn't connect twice
@@ -389,16 +489,7 @@ static bool reconnect(ipc::handle_t * ph, bool start_to_recv) {
     return que->ready_sending();
 }
 
-static bool connect(ipc::handle_t * ph, char const * name, bool start_to_recv) {
-    assert(ph != nullptr);
-    if (*ph == nullptr) {
-        *ph = ipc::mem::alloc<conn_info_t>(name);
-    }
-    return reconnect(ph, start_to_recv);
-}
-
-static void destroy(ipc::handle_t h) {
-    disconnect(h);
+static void destroy(ipc::handle_t h) noexcept {
     ipc::mem::free(info_of(h));
 }
 
@@ -445,15 +536,16 @@ static bool send(F&& gen_push, ipc::handle_t h, void const * data, std::size_t s
         return false;
     }
     // calc a new message id
-    auto acc = info_of(h)->acc();
+    conn_info_t *inf = info_of(h);
+    auto acc = inf->acc();
     if (acc == nullptr) {
         ipc::error("fail: send, info_of(h)->acc() == nullptr\n");
         return false;
     }
     auto msg_id   = acc->fetch_add(1, std::memory_order_relaxed);
-    auto try_push = std::forward<F>(gen_push)(info_of(h), que, msg_id);
+    auto try_push = std::forward<F>(gen_push)(inf, que, msg_id);
     if (size > ipc::large_msg_limit) {
-        auto   dat = acquire_storage(size, conns);
+        auto   dat = acquire_storage(inf, size, conns);
         void * buf = dat.second;
         if (buf != nullptr) {
             std::memcpy(buf, data, size);
@@ -484,7 +576,7 @@ static bool send(F&& gen_push, ipc::handle_t h, void const * data, std::size_t s
 }
 
 static bool send(ipc::handle_t h, void const * data, std::size_t size, std::uint64_t tm) {
-    return send([tm](auto info, auto que, auto msg_id) {
+    return send([tm](auto *info, auto *que, auto msg_id) {
         return [tm, info, que, msg_id](std::int32_t remain, void const * data, std::size_t size) {
             if (!wait_for(info->wt_waiter_, [&] {
                     return !que->push(
@@ -493,7 +585,7 @@ static bool send(ipc::handle_t h, void const * data, std::size_t size, std::uint
                 }, tm)) {
                 ipc::log("force_push: msg_id = %zd, remain = %d, size = %zd\n", msg_id, remain, size);
                 if (!que->force_push(
-                        clear_message<typename queue_t::value_t>,
+                        [info](void* p) { return clear_message<typename queue_t::value_t>(info, p); },
                         info->cc_id_, msg_id, remain, data, size)) {
                     return false;
                 }
@@ -505,7 +597,7 @@ static bool send(ipc::handle_t h, void const * data, std::size_t size, std::uint
 }
 
 static bool try_send(ipc::handle_t h, void const * data, std::size_t size, std::uint64_t tm) {
-    return send([tm](auto info, auto que, auto msg_id) {
+    return send([tm](auto *info, auto *que, auto msg_id) {
         return [tm, info, que, msg_id](std::int32_t remain, void const * data, std::size_t size) {
             if (!wait_for(info->wt_waiter_, [&] {
                     return !que->push(
@@ -530,18 +622,22 @@ static ipc::buff_t recv(ipc::handle_t h, std::uint64_t tm) {
         // hasn't connected yet, just return.
         return {};
     }
-    auto& rc = info_of(h)->recv_cache();
+    conn_info_t *inf = info_of(h);
+    auto& rc = inf->recv_cache();
     for (;;) {
         // pop a new message
-        typename queue_t::value_t msg;
-        if (!wait_for(info_of(h)->rd_waiter_, [que, &msg] {
+        typename queue_t::value_t msg {};
+        if (!wait_for(inf->rd_waiter_, [que, &msg, &h] {
+                if (!que->connected()) {
+                    reconnect(&h, true);
+                }
                 return !que->pop(msg);
             }, tm)) {
             // pop failed, just return.
             return {};
         }
-        info_of(h)->wt_waiter_.broadcast();
-        if ((info_of(h)->acc() != nullptr) && (msg.cc_id_ == info_of(h)->cc_id_)) {
+        inf->wt_waiter_.broadcast();
+        if ((inf->acc() != nullptr) && (msg.cc_id_ == inf->cc_id_)) {
             continue; // ignore message to self
         }
         // msg.remain_ may minus & abs(msg.remain_) < data_length
@@ -554,14 +650,18 @@ static ipc::buff_t recv(ipc::handle_t h, std::uint64_t tm) {
         // large message
         if (msg.storage_) {
             ipc::storage_id_t buf_id = *reinterpret_cast<ipc::storage_id_t*>(&msg.data_);
-            void* buf = find_storage(buf_id, msg_size);
+            void* buf = find_storage(buf_id, inf, msg_size);
             if (buf != nullptr) {
                 struct recycle_t {
                     ipc::storage_id_t storage_id;
+                    conn_info_t *     inf;
                     ipc::circ::cc_t   curr_conns;
                     ipc::circ::cc_t   conn_id;
                 } *r_info = ipc::mem::alloc<recycle_t>(recycle_t{
-                    buf_id, que->elems()->connections(std::memory_order_relaxed), que->connected_id()
+                    buf_id, 
+                    inf, 
+                    que->elems()->connections(std::memory_order_relaxed), 
+                    que->connected_id()
                 });
                 if (r_info == nullptr) {
                     ipc::log("fail: ipc::mem::alloc<recycle_t>.\n");
@@ -572,7 +672,11 @@ static ipc::buff_t recv(ipc::handle_t h, std::uint64_t tm) {
                         IPC_UNUSED_ auto finally = ipc::guard([r_info] {
                             ipc::mem::free(r_info);
                         });
-                        recycle_storage<flag_t>(r_info->storage_id, size, r_info->curr_conns, r_info->conn_id);
+                        recycle_storage<flag_t>(r_info->storage_id, 
+                                                r_info->inf, 
+                                                size, 
+                                                r_info->curr_conns, 
+                                                r_info->conn_id);
                     }, r_info};
                 }
             } else {
@@ -630,11 +734,22 @@ using policy_t = ipc::policy::choose<ipc::circ::elem_array, Flag>;
 
 namespace ipc {
 
+template <typename Flag>
+ipc::handle_t chan_impl<Flag>::init_first() {
+    ipc::detail::waiter::init();
+    return nullptr;
+}
+
 template <typename Flag>
 bool chan_impl<Flag>::connect(ipc::handle_t * ph, char const * name, unsigned mode) {
     return detail_impl<policy_t<Flag>>::connect(ph, name, mode & receiver);
 }
 
+template <typename Flag>
+bool chan_impl<Flag>::connect(ipc::handle_t * ph, prefix pref, char const * name, unsigned mode) {
+    return detail_impl<policy_t<Flag>>::connect(ph, pref, name, mode & receiver);
+}
+
 template <typename Flag>
 bool chan_impl<Flag>::reconnect(ipc::handle_t * ph, unsigned mode) {
     return detail_impl<policy_t<Flag>>::reconnect(ph, mode & receiver);
@@ -647,15 +762,42 @@ void chan_impl<Flag>::disconnect(ipc::handle_t h) {
 
 template <typename Flag>
 void chan_impl<Flag>::destroy(ipc::handle_t h) {
+    disconnect(h);
+    detail_impl<policy_t<Flag>>::destroy(h);
+}
+
+template <typename Flag>
+void chan_impl<Flag>::release(ipc::handle_t h) noexcept {
     detail_impl<policy_t<Flag>>::destroy(h);
 }
 
 template <typename Flag>
 char const * chan_impl<Flag>::name(ipc::handle_t h) {
-    auto info = detail_impl<policy_t<Flag>>::info_of(h);
+    auto *info = detail_impl<policy_t<Flag>>::info_of(h);
     return (info == nullptr) ? nullptr : info->name_.c_str();
 }
 
+template <typename Flag>
+void chan_impl<Flag>::clear(ipc::handle_t h) noexcept {
+    disconnect(h);
+    using conn_info_t = typename detail_impl<policy_t<Flag>>::conn_info_t;
+    auto conn_info_p = static_cast<conn_info_t *>(h);
+    if (conn_info_p == nullptr) return;
+    conn_info_p->clear();
+    destroy(h);
+}
+
+template <typename Flag>
+void chan_impl<Flag>::clear_storage(char const * name) noexcept {
+    chan_impl<Flag>::clear_storage({nullptr}, name);
+}
+
+template <typename Flag>
+void chan_impl<Flag>::clear_storage(prefix pref, char const * name) noexcept {
+    using conn_info_t = typename detail_impl<policy_t<Flag>>::conn_info_t;
+    conn_info_t::clear_storage(pref.str, name);
+}
+
 template <typename Flag>
 std::size_t chan_impl<Flag>::recv_count(ipc::handle_t h) {
     return detail_impl<policy_t<Flag>>::recv_count(h);

src/libipc/memory/alloc.h

@@ -19,17 +19,17 @@ namespace mem {
 
 class static_alloc {
 public:
-    static void swap(static_alloc&) {}
+    static void swap(static_alloc&) noexcept {}
 
-    static void* alloc(std::size_t size) {
+    static void* alloc(std::size_t size) noexcept {
         return size ? std::malloc(size) : nullptr;
     }
 
-    static void free(void* p) {
+    static void free(void* p) noexcept {
         std::free(p);
     }
 
-    static void free(void* p, std::size_t /*size*/) {
+    static void free(void* p, std::size_t /*size*/) noexcept {
         free(p);
     }
 };

src/libipc/memory/resource.h

@@ -87,4 +87,24 @@ ipc::string to_string(T val) {
     return {};
 }
 
+/// \brief Check string validity.
+constexpr bool is_valid_string(char const *str) noexcept {
+    return (str != nullptr) && (str[0] != '\0');
+}
+
+/// \brief Make a valid string.
+inline ipc::string make_string(char const *str) {
+    return is_valid_string(str) ? ipc::string{str} : ipc::string{};
+}
+
+/// \brief Combine prefix from a list of strings.
+inline ipc::string make_prefix(ipc::string prefix, std::initializer_list<ipc::string> args) {
+    prefix += "__IPC_SHM__";
+    for (auto const &txt: args) {
+        if (txt.empty()) continue;
+        prefix += txt;
+    }
+    return prefix;
+}
+
 } // namespace ipc

src/libipc/platform/detail.h

@@ -9,6 +9,8 @@
 #   define IPC_OS_WINDOWS_
 #elif defined(__linux__) || defined(__linux)
 #   define IPC_OS_LINUX_
+#elif defined(__FreeBSD__)
+#   define IPC_OS_FREEBSD_
 #elif defined(__QNX__)
 #   define IPC_OS_QNX_
 #elif defined(__APPLE__)
@@ -70,15 +72,9 @@
 
 #if __cplusplus >= 201703L
 
-namespace std {
 
-// deduction guides for std::unique_ptr
-template <typename T>
-unique_ptr(T* p) -> unique_ptr<T>;
-template <typename T, typename D>
-unique_ptr(T* p, D&& d) -> unique_ptr<T, std::decay_t<D>>;
-
-} // namespace std
+// C++17 and later: std library already provides deduction guides
+// No need to add custom ones, just use the standard ones directly
 
 namespace ipc {
 namespace detail {

src/libipc/platform/linux/condition.h

@@ -27,7 +27,7 @@ public:
                 return false;
             }
         } else {
-            auto ts = detail::make_timespec(tm);
+            auto ts = linux_::detail::make_timespec(tm);
             int eno = A0_SYSERR(a0_cnd_timedwait(native(), static_cast<a0_mtx_t *>(mtx.native()), {ts}));
             if (eno != 0) {
                 if (eno != ETIMEDOUT) {

src/libipc/platform/linux/get_wait_time.h

@@ -10,6 +10,7 @@
 #include "a0/err_macro.h"
 
 namespace ipc {
+namespace linux_ {
 namespace detail {
 
 inline bool calc_wait_time(timespec &ts, std::uint64_t tm /*ms*/) noexcept {
@@ -43,4 +44,5 @@ inline timespec make_timespec(std::uint64_t tm /*ms*/) noexcept(false) {
 }
 
 } // namespace detail
+} // namespace linux_
 } // namespace ipc

src/libipc/platform/linux/mutex.h

@@ -25,7 +25,7 @@ public:
     bool lock(std::uint64_t tm) noexcept {
         if (!valid()) return false;
         for (;;) {
-            auto ts = detail::make_timespec(tm);
+            auto ts = linux_::detail::make_timespec(tm);
             int eno = A0_SYSERR(
                 (tm == invalid_value) ? a0_mtx_lock(native()) 
                                       : a0_mtx_timedlock(native(), {ts}));
@@ -56,7 +56,7 @@ public:
 
     bool try_lock() noexcept(false) {
         if (!valid()) return false;
-        int eno = A0_SYSERR(a0_mtx_timedlock(native(), {detail::make_timespec(0)}));
+        int eno = A0_SYSERR(a0_mtx_timedlock(native(), {linux_::detail::make_timespec(0)}));
         switch (eno) {
         case 0:
             return true;
@@ -125,23 +125,27 @@ class mutex {
         IPC_UNUSED_ std::lock_guard<std::mutex> guard {info.lock};
         auto it = info.mutex_handles.find(name);
         if (it == info.mutex_handles.end()) {
-            it = curr_prog::get().mutex_handles.emplace(name, 
-                              curr_prog::shm_data::init{name}).first;
+            it = info.mutex_handles
+                   .emplace(std::piecewise_construct, 
+                            std::forward_as_tuple(name),
+                            std::forward_as_tuple(curr_prog::shm_data::init{name}))
+                   .first;
         }
         mutex_ = &it->second.mtx;
         ref_   = &it->second.ref;
     }
 
     template <typename F>
-    void release_mutex(ipc::string const &name, F &&clear) {
+    static void release_mutex(ipc::string const &name, F &&clear) {
         if (name.empty()) return;
-        IPC_UNUSED_ std::lock_guard<std::mutex> guard {curr_prog::get().lock};
-        auto it = curr_prog::get().mutex_handles.find(name);
-        if (it == curr_prog::get().mutex_handles.end()) {
+        auto &info = curr_prog::get();
+        IPC_UNUSED_ std::lock_guard<std::mutex> guard {info.lock};
+        auto it = info.mutex_handles.find(name);
+        if (it == info.mutex_handles.end()) {
             return;
         }
         if (clear()) {
-            curr_prog::get().mutex_handles.erase(it);
+            info.mutex_handles.erase(it);
         }
     }
 
@@ -149,6 +153,11 @@ public:
     mutex() = default;
     ~mutex() = default;
 
+    static void init() {
+        // Avoid exception problems caused by static member initialization order.
+        curr_prog::get();
+    }
+
     a0_mtx_t const *native() const noexcept {
         return valid() ? mutex_->native() : nullptr;
     }
@@ -183,6 +192,25 @@ public:
         ref_   = nullptr;
     }
 
+    void clear() noexcept {
+        if (mutex_ != nullptr) {
+            if (mutex_->name() != nullptr) {
+                release_mutex(mutex_->name(), [this] {
+                    mutex_->clear();
+                    return true;
+                });
+            } else mutex_->clear();
+        }
+        mutex_ = nullptr;
+        ref_   = nullptr;
+    }
+
+    static void clear_storage(char const *name) noexcept {
+        if (name == nullptr) return;
+        release_mutex(name, [] { return true; });
+        robust_mutex::clear_storage(name);
+    }
+
     bool lock(std::uint64_t tm) noexcept {
         if (!valid()) return false;
         return mutex_->lock(tm);

src/libipc/platform/linux/sync_obj_impl.h

@@ -62,6 +62,15 @@ public:
         shm_.release();
         h_ = nullptr;
     }
+
+    void clear() noexcept {
+        shm_.clear(); // Make sure the storage is cleaned up.
+        h_ = nullptr;
+    }
+
+    static void clear_storage(char const *name) noexcept {
+        ipc::shm::handle::clear_storage(name);
+    }
 };
 
 } // namespace sync

src/libipc/platform/platform.c

@@ -7,7 +7,7 @@
 #include "libipc/platform/linux/a0/strconv.c"
 #include "libipc/platform/linux/a0/tid.c"
 #include "libipc/platform/linux/a0/time.c"
-#elif defined(IPC_OS_QNX_)
+#elif defined(IPC_OS_QNX_) || defined(IPC_OS_FREEBSD_)
 #else/*IPC_OS*/
 #   error "Unsupported platform."
 #endif

src/libipc/platform/platform.cpp

@@ -2,7 +2,7 @@
 #include "libipc/platform/detail.h"
 #if defined(IPC_OS_WINDOWS_)
 #include "libipc/platform/win/shm_win.cpp"
-#elif defined(IPC_OS_LINUX_) || defined(IPC_OS_QNX_)
+#elif defined(IPC_OS_LINUX_) || defined(IPC_OS_QNX_) || defined(IPC_OS_FREEBSD_)
 #include "libipc/platform/posix/shm_posix.cpp"
 #else/*IPC_OS*/
 #   error "Unsupported platform."

src/libipc/platform/posix/condition.h

@@ -88,6 +88,21 @@ public:
         cond_ = nullptr;
     }
 
+    void clear() noexcept {
+        if ((shm_.ref() <= 1) && cond_ != nullptr) {
+            int eno;
+            if ((eno = ::pthread_cond_destroy(cond_)) != 0) {
+                ipc::error("fail pthread_cond_destroy[%d]\n", eno);
+            }
+        }
+        shm_.clear(); // Make sure the storage is cleaned up.
+        cond_ = nullptr;
+    }
+
+    static void clear_storage(char const *name) noexcept {
+        ipc::shm::handle::clear_storage(name);
+    }
+
     bool wait(ipc::sync::mutex &mtx, std::uint64_t tm) noexcept {
         if (!valid()) return false;
         switch (tm) {
@@ -100,7 +115,7 @@ public:
             }
             break;
         default: {
-                auto ts = detail::make_timespec(tm);
+                auto ts = posix_::detail::make_timespec(tm);
                 int eno;
                 if ((eno = ::pthread_cond_timedwait(cond_, static_cast<pthread_mutex_t *>(mtx.native()), &ts)) != 0) {
                     if (eno != ETIMEDOUT) {

src/libipc/platform/posix/get_wait_time.h

@@ -10,6 +10,7 @@
 #include "libipc/utility/log.h"
 
 namespace ipc {
+namespace posix_ {
 namespace detail {
 
 inline bool calc_wait_time(timespec &ts, std::uint64_t tm /*ms*/) noexcept {
@@ -36,4 +37,5 @@ inline timespec make_timespec(std::uint64_t tm /*ms*/) noexcept(false) {
 }
 
 } // namespace detail
+} // namespace posix_
 } // namespace ipc

src/libipc/platform/posix/mutex.h

@@ -55,8 +55,12 @@ class mutex {
         IPC_UNUSED_ std::lock_guard<std::mutex> guard {info.lock};
         auto it = info.mutex_handles.find(name);
         if (it == info.mutex_handles.end()) {
-            it = curr_prog::get().mutex_handles.emplace(name, 
-                              curr_prog::shm_data::init{name, sizeof(pthread_mutex_t)}).first;
+          it = info.mutex_handles
+                   .emplace(std::piecewise_construct,
+                            std::forward_as_tuple(name),
+                            std::forward_as_tuple(curr_prog::shm_data::init{
+                                name, sizeof(pthread_mutex_t)}))
+                   .first;
         }
         shm_ = &it->second.shm;
         ref_ = &it->second.ref;
@@ -67,22 +71,34 @@ class mutex {
     }
 
     template <typename F>
-    void release_mutex(ipc::string const &name, F &&clear) {
+    static void release_mutex(ipc::string const &name, F &&clear) {
         if (name.empty()) return;
-        IPC_UNUSED_ std::lock_guard<std::mutex> guard {curr_prog::get().lock};
-        auto it = curr_prog::get().mutex_handles.find(name);
-        if (it == curr_prog::get().mutex_handles.end()) {
+        auto &info = curr_prog::get();
+        IPC_UNUSED_ std::lock_guard<std::mutex> guard {info.lock};
+        auto it = info.mutex_handles.find(name);
+        if (it == info.mutex_handles.end()) {
             return;
         }
         if (clear()) {
-            curr_prog::get().mutex_handles.erase(it);
+            info.mutex_handles.erase(it);
         }
     }
 
+    static pthread_mutex_t const &zero_mem() {
+        static const pthread_mutex_t tmp{};
+        return tmp;
+    }
+
 public:
     mutex() = default;
     ~mutex() = default;
 
+    static void init() {
+        // Avoid exception problems caused by static member initialization order.
+        zero_mem();
+        curr_prog::get();
+    }
+
     pthread_mutex_t const *native() const noexcept {
         return mutex_;
     }
@@ -92,9 +108,8 @@ public:
     }
 
     bool valid() const noexcept {
-        static const char tmp[sizeof(pthread_mutex_t)] {};
         return (shm_ != nullptr) && (ref_ != nullptr) && (mutex_ != nullptr)
-            && (std::memcmp(tmp, mutex_, sizeof(pthread_mutex_t)) != 0);
+            && (std::memcmp(&zero_mem(), mutex_, sizeof(pthread_mutex_t)) != 0);
     }
 
     bool open(char const *name) noexcept {
@@ -139,6 +154,15 @@ public:
                 release_mutex(shm_->name(), [this] {
                     auto self_ref = ref_->fetch_sub(1, std::memory_order_relaxed);
                     if ((shm_->ref() <= 1) && (self_ref <= 1)) {
+                        // Before destroying the mutex, try to unlock it.
+                        // This is important for robust mutexes on FreeBSD, which maintain
+                        // a per-thread robust list. If we destroy a mutex while it's locked
+                        // or still in the robust list, FreeBSD may encounter dangling pointers
+                        // later, leading to segfaults.
+                        // Only unlock here (when we're the last reference) to avoid
+                        // interfering with other threads that might be using the mutex.
+                        ::pthread_mutex_unlock(mutex_);
+                        
                         int eno;
                         if ((eno = ::pthread_mutex_destroy(mutex_)) != 0) {
                             ipc::error("fail pthread_mutex_destroy[%d]\n", eno);
@@ -154,10 +178,37 @@ public:
         mutex_ = nullptr;
     }
 
+    void clear() noexcept {
+        if ((shm_ != nullptr) && (mutex_ != nullptr)) {
+            if (shm_->name() != nullptr) {
+                release_mutex(shm_->name(), [this] {
+                    // Unlock before destroying, same reasoning as in close()
+                    ::pthread_mutex_unlock(mutex_);
+                    
+                    int eno;
+                    if ((eno = ::pthread_mutex_destroy(mutex_)) != 0) {
+                        ipc::error("fail pthread_mutex_destroy[%d]\n", eno);
+                    }
+                    shm_->clear();
+                    return true;
+                });
+            } else shm_->clear();
+        }
+        shm_   = nullptr;
+        ref_   = nullptr;
+        mutex_ = nullptr;
+    }
+
+    static void clear_storage(char const *name) noexcept {
+        if (name == nullptr) return;
+        release_mutex(name, [] { return true; });
+        ipc::shm::handle::clear_storage(name);
+    }
+
     bool lock(std::uint64_t tm) noexcept {
         if (!valid()) return false;
         for (;;) {
-            auto ts = detail::make_timespec(tm);
+            auto ts = posix_::detail::make_timespec(tm);
             int eno = (tm == invalid_value) 
                 ? ::pthread_mutex_lock(mutex_) 
                 : ::pthread_mutex_timedlock(mutex_, &ts);
@@ -167,21 +218,17 @@ public:
             case ETIMEDOUT:
                 return false;
             case EOWNERDEAD: {
-                    if (shm_->ref() > 1) {
-                        shm_->sub_ref();
-                    }
+                    // EOWNERDEAD means we have successfully acquired the lock,
+                    // but the previous owner died. We need to make it consistent.
                     int eno2 = ::pthread_mutex_consistent(mutex_);
                     if (eno2 != 0) {
                         ipc::error("fail pthread_mutex_lock[%d], pthread_mutex_consistent[%d]\n", eno, eno2);
                         return false;
                     }
-                    int eno3 = ::pthread_mutex_unlock(mutex_);
-                    if (eno3 != 0) {
-                        ipc::error("fail pthread_mutex_lock[%d], pthread_mutex_unlock[%d]\n", eno, eno3);
-                        return false;
+                    // After calling pthread_mutex_consistent(), the mutex is now in a
+                    // consistent state and we hold the lock. Return success.
+                    return true;
                 }
-                }
-                break; // loop again
             default:
                 ipc::error("fail pthread_mutex_lock[%d]\n", eno);
                 return false;
@@ -191,7 +238,7 @@ public:
 
     bool try_lock() noexcept(false) {
         if (!valid()) return false;
-        auto ts = detail::make_timespec(0);
+        auto ts = posix_::detail::make_timespec(0);
         int eno = ::pthread_mutex_timedlock(mutex_, &ts);
         switch (eno) {
         case 0:
@@ -199,21 +246,17 @@ public:
         case ETIMEDOUT:
             return false;
         case EOWNERDEAD: {
-                if (shm_->ref() > 1) {
-                    shm_->sub_ref();
-                }
+                // EOWNERDEAD means we have successfully acquired the lock,
+                // but the previous owner died. We need to make it consistent.
                 int eno2 = ::pthread_mutex_consistent(mutex_);
                 if (eno2 != 0) {
                     ipc::error("fail pthread_mutex_timedlock[%d], pthread_mutex_consistent[%d]\n", eno, eno2);
-                    break;
+                    throw std::system_error{eno2, std::system_category()};
                 }
-                int eno3 = ::pthread_mutex_unlock(mutex_);
-                if (eno3 != 0) {
-                    ipc::error("fail pthread_mutex_timedlock[%d], pthread_mutex_unlock[%d]\n", eno, eno3);
-                    break;
+                // After calling pthread_mutex_consistent(), the mutex is now in a
+                // consistent state and we hold the lock. Return success.
+                return true;
             }
-            }
-            break;
         default:
             ipc::error("fail pthread_mutex_timedlock[%d]\n", eno);
             break;

src/libipc/platform/posix/semaphore_impl.h

@@ -19,6 +19,7 @@ namespace sync {
 class semaphore {
     ipc::shm::handle shm_;
     sem_t *h_ = SEM_FAILED;
+    std::string sem_name_;  // Store the actual semaphore name used
 
 public:
     semaphore() = default;
@@ -38,9 +39,16 @@ public:
             ipc::error("[open_semaphore] fail shm.acquire: %s\n", name);
             return false;
         }
-        h_ = ::sem_open(name, O_CREAT, 0666, static_cast<unsigned>(count));
+        // POSIX semaphore names must start with "/" on some platforms (e.g., FreeBSD)
+        // Use a separate namespace for semaphores to avoid conflicts with shm
+        if (name[0] == '/') {
+            sem_name_ = std::string(name) + "_sem";
+        } else {
+            sem_name_ = std::string("/") + name + "_sem";
+        }
+        h_ = ::sem_open(sem_name_.c_str(), O_CREAT, 0666, static_cast<unsigned>(count));
         if (h_ == SEM_FAILED) {
-            ipc::error("fail sem_open[%d]: %s\n", errno, name);
+            ipc::error("fail sem_open[%d]: %s\n", errno, sem_name_.c_str());
             return false;
         }
         return true;
@@ -52,14 +60,40 @@ public:
             ipc::error("fail sem_close[%d]: %s\n", errno);
         }
         h_ = SEM_FAILED;
-        if (shm_.name() != nullptr) {
-            std::string name = shm_.name();
+        if (!sem_name_.empty() && shm_.name() != nullptr) {
             if (shm_.release() <= 1) {
-                if (::sem_unlink(name.c_str()) != 0) {
-                    ipc::error("fail sem_unlink[%d]: %s, name: %s\n", errno, name.c_str());
+                if (::sem_unlink(sem_name_.c_str()) != 0) {
+                    ipc::error("fail sem_unlink[%d]: %s, name: %s\n", errno, sem_name_.c_str());
                 }
             }
         }
+        sem_name_.clear();
+    }
+
+    void clear() noexcept {
+        if (valid()) {
+            if (::sem_close(h_) != 0) {
+                ipc::error("fail sem_close[%d]: %s\n", errno);
+            }
+            h_ = SEM_FAILED;
+        }
+        if (!sem_name_.empty()) {
+            ::sem_unlink(sem_name_.c_str());
+            sem_name_.clear();
+        }
+        shm_.clear(); // Make sure the storage is cleaned up.
+    }
+
+    static void clear_storage(char const *name) noexcept {
+        // Construct the semaphore name same way as open() does
+        std::string sem_name;
+        if (name[0] == '/') {
+            sem_name = std::string(name) + "_sem";
+        } else {
+            sem_name = std::string("/") + name + "_sem";
+        }
+        ::sem_unlink(sem_name.c_str());
+        ipc::shm::handle::clear_storage(name);
     }
 
     bool wait(std::uint64_t tm) noexcept {
@@ -70,7 +104,7 @@ public:
                 return false;
             }
         } else {
-            auto ts = detail::make_timespec(tm);
+            auto ts = posix_::detail::make_timespec(tm);
             if (::sem_timedwait(h_, &ts) != 0) {
                 if (errno != ETIMEDOUT) {
                     ipc::error("fail sem_timedwait[%d]: tm = %zd, tv_sec = %ld, tv_nsec = %ld\n",

src/libipc/platform/posix/shm_posix.cpp

@@ -45,11 +45,18 @@ namespace ipc {
 namespace shm {
 
 id_t acquire(char const * name, std::size_t size, unsigned mode) {
-    if (name == nullptr || name[0] == '\0') {
+    if (!is_valid_string(name)) {
         ipc::error("fail acquire: name is empty\n");
         return nullptr;
     }
-    ipc::string op_name = ipc::string{"__IPC_SHM__"} + name;
+    // For portable use, a shared memory object should be identified by name of the form /somename.
+    // see: https://man7.org/linux/man-pages/man3/shm_open.3.html
+    ipc::string op_name;
+    if (name[0] == '/') {
+        op_name = name;
+    } else {
+        op_name = ipc::string{"/"} + name;
+    }
     // Open the object for read-write access.
     int flag = O_RDWR;
     switch (mode) {
@@ -70,9 +77,15 @@ id_t acquire(char const * name, std::size_t size, unsigned mode) {
                                                S_IRGRP | S_IWGRP | 
                                                S_IROTH | S_IWOTH);
     if (fd == -1) {
-        ipc::error("fail shm_open[%d]: %s\n", errno, name);
+        // only open shm not log error when file not exist
+        if (open != mode || ENOENT != errno) {
+            ipc::error("fail shm_open[%d]: %s\n", errno, op_name.c_str());
+        }
         return nullptr;
     }
+    ::fchmod(fd, S_IRUSR | S_IWUSR | 
+                 S_IRGRP | S_IWGRP | 
+                 S_IROTH | S_IWOTH);
     auto ii = mem::alloc<id_info_t>();
     ii->fd_   = fd;
     ii->size_ = size;
@@ -151,7 +164,7 @@ void * get_mem(id_t id, std::size_t * size) {
     return mem;
 }
 
-std::int32_t release(id_t id) {
+std::int32_t release(id_t id) noexcept {
     if (id == nullptr) {
         ipc::error("fail release: invalid id (null)\n");
         return -1;
@@ -159,12 +172,16 @@ std::int32_t release(id_t id) {
     std::int32_t ret = -1;
     auto ii = static_cast<id_info_t*>(id);
     if (ii->mem_ == nullptr || ii->size_ == 0) {
-        ipc::error("fail release: invalid id (mem = %p, size = %zd)\n", ii->mem_, ii->size_);
+        ipc::error("fail release: invalid id (mem = %p, size = %zd), name = %s\n", 
+                    ii->mem_, ii->size_, ii->name_.c_str());
     }
     else if ((ret = acc_of(ii->mem_, ii->size_).fetch_sub(1, std::memory_order_acq_rel)) <= 1) {
         ::munmap(ii->mem_, ii->size_);
         if (!ii->name_.empty()) {
-            ::shm_unlink(ii->name_.c_str());
+            int unlink_ret = ::shm_unlink(ii->name_.c_str());
+            if (unlink_ret == -1) {
+                ipc::error("fail shm_unlink[%d]: %s\n", errno, ii->name_.c_str());
+            }
         }
     }
     else ::munmap(ii->mem_, ii->size_);
@@ -172,7 +189,7 @@ std::int32_t release(id_t id) {
     return ret;
 }
 
-void remove(id_t id) {
+void remove(id_t id) noexcept {
     if (id == nullptr) {
         ipc::error("fail remove: invalid id (null)\n");
         return;
@@ -181,16 +198,29 @@ void remove(id_t id) {
     auto name = std::move(ii->name_);
     release(id);
     if (!name.empty()) {
-        ::shm_unlink(name.c_str());
+        int unlink_ret = ::shm_unlink(name.c_str());
+        if (unlink_ret == -1) {
+            ipc::error("fail shm_unlink[%d]: %s\n", errno, name.c_str());
+        }
     }
 }
 
-void remove(char const * name) {
-    if (name == nullptr || name[0] == '\0') {
+void remove(char const * name) noexcept {
+    if (!is_valid_string(name)) {
         ipc::error("fail remove: name is empty\n");
         return;
     }
-    ::shm_unlink((ipc::string{"__IPC_SHM__"} + name).c_str());
+    // For portable use, a shared memory object should be identified by name of the form /somename.
+    ipc::string op_name;
+    if (name[0] == '/') {
+        op_name = name;
+    } else {
+        op_name = ipc::string{"/"} + name;
+    }
+    int unlink_ret = ::shm_unlink(op_name.c_str());
+    if (unlink_ret == -1) {
+        ipc::error("fail shm_unlink[%d]: %s\n", errno, op_name.c_str());
+    }
 }
 
 } // namespace shm

src/libipc/platform/win/condition.h

@@ -4,7 +4,11 @@
 #include <string>
 #include <mutex>
 
+#if defined(__MINGW32__)
+#include <windows.h>
+#else
 #include <Windows.h>
+#endif
 
 #include "libipc/utility/log.h"
 #include "libipc/utility/scope_guard.h"
@@ -44,15 +48,15 @@ public:
 
     bool open(char const *name) noexcept {
         close();
-        if (!sem_.open((std::string{"_cond_sem_"} + name).c_str())) {
+        if (!sem_.open((std::string{name} + "_COND_SEM_").c_str())) {
             return false;
         }
         auto finally_sem = ipc::guard([this] { sem_.close(); }); // close when failed
-        if (!lock_.open((std::string{"_cond_lock_"} + name).c_str())) {
+        if (!lock_.open((std::string{name} + "_COND_LOCK_").c_str())) {
             return false;
         }
         auto finally_lock = ipc::guard([this] { lock_.close(); }); // close when failed
-        if (!shm_.acquire((std::string{"_cond_shm_"} + name).c_str(), sizeof(std::int32_t))) {
+        if (!shm_.acquire((std::string{name} + "_COND_SHM_").c_str(), sizeof(std::int32_t))) {
             return false;
         }
         finally_lock.dismiss();
@@ -67,6 +71,16 @@ public:
         shm_.release();
     }
 
+    void clear() noexcept {
+        close();
+    }
+
+    static void clear_storage(char const *name) noexcept {
+        ipc::shm::handle::clear_storage(name);
+        ipc::sync::mutex::clear_storage(name);
+        ipc::sync::semaphore::clear_storage(name);
+    }
+
     bool wait(ipc::sync::mutex &mtx, std::uint64_t tm) noexcept {
         if (!valid()) return false;
         auto &cnt = counter();
@@ -76,7 +90,7 @@ public:
         }
         DWORD ms = (tm == invalid_value) ? INFINITE : static_cast<DWORD>(tm);
         /**
-         * @see
+         * \see
          *  - https://www.microsoft.com/en-us/research/wp-content/uploads/2004/12/ImplementingCVs.pdf
          *  - https://docs.microsoft.com/en-us/windows/win32/api/synchapi/nf-synchapi-signalobjectandwait
         */

src/libipc/platform/win/mutex.h

@@ -3,7 +3,11 @@
 #include <cstdint>
 #include <system_error>
 
+#if defined(__MINGW32__)
+#include <windows.h>
+#else
 #include <Windows.h>
+#endif
 
 #include "libipc/utility/log.h"
 
@@ -21,6 +25,8 @@ public:
     mutex() noexcept = default;
     ~mutex() noexcept = default;
 
+    static void init() {}
+
     HANDLE native() const noexcept {
         return h_;
     }
@@ -31,7 +37,7 @@ public:
 
     bool open(char const *name) noexcept {
         close();
-        h_ = ::CreateMutex(detail::get_sa(), FALSE, ipc::detail::to_tchar(name).c_str());
+        h_ = ::CreateMutex(detail::get_sa(), FALSE, detail::to_tchar(name).c_str());
         if (h_ == NULL) {
             ipc::error("fail CreateMutex[%lu]: %s\n", ::GetLastError(), name);
             return false;
@@ -45,6 +51,13 @@ public:
         h_ = NULL;
     }
 
+    void clear() noexcept {
+        close();
+    }
+
+    static void clear_storage(char const */*name*/) noexcept {
+    }
+
     bool lock(std::uint64_t tm) noexcept {
         DWORD ret, ms = (tm == invalid_value) ? INFINITE : static_cast<DWORD>(tm);
         for(;;) {

src/libipc/platform/win/semaphore.h

@@ -2,7 +2,11 @@
 
 #include <cstdint>
 
+#if defined(__MINGW32__)
+#include <windows.h>
+#else
 #include <Windows.h>
+#endif
 
 #include "libipc/utility/log.h"
 
@@ -32,7 +36,7 @@ public:
         close();
         h_ = ::CreateSemaphore(detail::get_sa(), 
                                static_cast<LONG>(count), LONG_MAX, 
-                               ipc::detail::to_tchar(name).c_str());
+                               detail::to_tchar(name).c_str());
         if (h_ == NULL) {
             ipc::error("fail CreateSemaphore[%lu]: %s\n", ::GetLastError(), name);
             return false;
@@ -46,6 +50,13 @@ public:
         h_ = NULL;
     }
 
+    void clear() noexcept {
+        close();
+    }
+
+    static void clear_storage(char const */*name*/) noexcept {
+    }
+
     bool wait(std::uint64_t tm) noexcept {
         DWORD ret, ms = (tm == invalid_value) ? INFINITE : static_cast<DWORD>(tm);
         switch ((ret = ::WaitForSingleObject(h_, ms))) {

src/libipc/platform/win/shm_win.cpp

@@ -1,6 +1,11 @@
 
+#if defined(__MINGW32__)
+#include <windows.h>
+#else
 #include <Windows.h>
+#endif
 
+#include <atomic>
 #include <string>
 #include <utility>
 
@@ -16,55 +21,89 @@
 
 namespace {
 
+struct info_t {
+    std::atomic<std::int32_t> acc_;
+};
+
 struct id_info_t {
     HANDLE      h_    = NULL;
     void*       mem_  = nullptr;
     std::size_t size_ = 0;
 };
 
+constexpr std::size_t calc_size(std::size_t size) {
+    return ((((size - 1) / alignof(info_t)) + 1) * alignof(info_t)) + sizeof(info_t);
+}
+
+inline auto& acc_of(void* mem, std::size_t size) {
+    return reinterpret_cast<info_t*>(static_cast<ipc::byte_t*>(mem) + size - sizeof(info_t))->acc_;
+}
+
 } // internal-linkage
 
 namespace ipc {
 namespace shm {
 
 id_t acquire(char const * name, std::size_t size, unsigned mode) {
-    if (name == nullptr || name[0] == '\0') {
+    if (!is_valid_string(name)) {
         ipc::error("fail acquire: name is empty\n");
         return nullptr;
     }
     HANDLE h;
-    auto fmt_name = ipc::detail::to_tchar(ipc::string{"__IPC_SHM__"} + name);
+    auto fmt_name = ipc::detail::to_tchar(name);
     // Opens a named file mapping object.
     if (mode == open) {
         h = ::OpenFileMapping(FILE_MAP_ALL_ACCESS, FALSE, fmt_name.c_str());
+        if (h == NULL) {
+          ipc::error("fail OpenFileMapping[%d]: %s\n", static_cast<int>(::GetLastError()), name);
+          return nullptr;
+        }
     }
     // Creates or opens a named file mapping object for a specified file.
     else {
+        std::size_t alloc_size = calc_size(size);
         h = ::CreateFileMapping(INVALID_HANDLE_VALUE, detail::get_sa(), PAGE_READWRITE | SEC_COMMIT,
-                                0, static_cast<DWORD>(size), fmt_name.c_str());
+                                0, static_cast<DWORD>(alloc_size), fmt_name.c_str());
+        DWORD err = ::GetLastError();
         // If the object exists before the function call, the function returns a handle to the existing object 
         // (with its current size, not the specified size), and GetLastError returns ERROR_ALREADY_EXISTS.
-        if ((mode == create) && (::GetLastError() == ERROR_ALREADY_EXISTS)) {
-            ::CloseHandle(h);
+        if ((mode == create) && (err == ERROR_ALREADY_EXISTS)) {
+            if (h != NULL) ::CloseHandle(h);
             h = NULL;
         }
-    }
         if (h == NULL) {
-        ipc::error("fail CreateFileMapping/OpenFileMapping[%d]: %s\n", static_cast<int>(::GetLastError()), name);
+          ipc::error("fail CreateFileMapping[%d]: %s\n", static_cast<int>(err), name);
           return nullptr;
         }
+    }
     auto ii = mem::alloc<id_info_t>();
     ii->h_    = h;
     ii->size_ = size;
     return ii;
 }
 
-std::int32_t get_ref(id_t) {
+std::int32_t get_ref(id_t id) {
+    if (id == nullptr) {
         return 0;
+    }
+    auto ii = static_cast<id_info_t*>(id);
+    if (ii->mem_ == nullptr || ii->size_ == 0) {
+        return 0;
+    }
+    return acc_of(ii->mem_, calc_size(ii->size_)).load(std::memory_order_acquire);
 }
 
-void sub_ref(id_t) {
-    // Do Nothing.
+void sub_ref(id_t id) {
+    if (id == nullptr) {
+        ipc::error("fail sub_ref: invalid id (null)\n");
+        return;
+    }
+    auto ii = static_cast<id_info_t*>(id);
+    if (ii->mem_ == nullptr || ii->size_ == 0) {
+        ipc::error("fail sub_ref: invalid id (mem = %p, size = %zd)\n", ii->mem_, ii->size_);
+        return;
+    }
+    acc_of(ii->mem_, calc_size(ii->size_)).fetch_sub(1, std::memory_order_acq_rel);
 }
 
 void * get_mem(id_t id, std::size_t * size) {
@@ -91,31 +130,42 @@ void * get_mem(id_t id, std::size_t * size) {
         ipc::error("fail VirtualQuery[%d]\n", static_cast<int>(::GetLastError()));
         return nullptr;
     }
+    std::size_t actual_size = static_cast<std::size_t>(mem_info.RegionSize);
+    if (ii->size_ == 0) {
+        // Opening existing shared memory
+        ii->size_ = actual_size - sizeof(info_t);
+    }
+    // else: Keep user-requested size (already set in acquire)
     ii->mem_ = mem;
-    ii->size_ = static_cast<std::size_t>(mem_info.RegionSize);
     if (size != nullptr) *size = ii->size_;
+    // Initialize or increment reference counter
+    acc_of(mem, calc_size(ii->size_)).fetch_add(1, std::memory_order_release);
     return static_cast<void *>(mem);
 }
 
-std::int32_t release(id_t id) {
+std::int32_t release(id_t id) noexcept {
     if (id == nullptr) {
         ipc::error("fail release: invalid id (null)\n");
         return -1;
     }
+    std::int32_t ret = -1;
     auto ii = static_cast<id_info_t*>(id);
     if (ii->mem_ == nullptr || ii->size_ == 0) {
         ipc::error("fail release: invalid id (mem = %p, size = %zd)\n", ii->mem_, ii->size_);
     }
-    else ::UnmapViewOfFile(static_cast<LPCVOID>(ii->mem_));
+    else {
+        ret = acc_of(ii->mem_, calc_size(ii->size_)).fetch_sub(1, std::memory_order_acq_rel);
+        ::UnmapViewOfFile(static_cast<LPCVOID>(ii->mem_));
+    }
     if (ii->h_ == NULL) {
         ipc::error("fail release: invalid id (h = null)\n");
     }
     else ::CloseHandle(ii->h_);
     mem::free(ii);
-    return 0;
+    return ret;
 }
 
-void remove(id_t id) {
+void remove(id_t id) noexcept {
     if (id == nullptr) {
         ipc::error("fail release: invalid id (null)\n");
         return;
@@ -123,8 +173,8 @@ void remove(id_t id) {
     release(id);
 }
 
-void remove(char const * name) {
-    if (name == nullptr || name[0] == '\0') {
+void remove(char const * name) noexcept {
+    if (!is_valid_string(name)) {
         ipc::error("fail remove: name is empty\n");
         return;
     }

src/libipc/platform/win/to_tchar.h

@@ -1,6 +1,10 @@
 #pragma once
 
+#if defined(__MINGW32__)
+#include <windows.h>
+#else
 #include <Windows.h>
+#endif
 
 #include <type_traits>
 #include <string>
@@ -41,8 +45,8 @@ constexpr auto to_tchar(ipc::string &&str) -> IsSameChar<T, ipc::string, ipc::st
 }
 
 /**
- * @remarks codecvt_utf8_utf16/std::wstring_convert is deprecated
- * @see https://codingtidbit.com/2020/02/09/c17-codecvt_utf8-is-deprecated/
+ * \remarks codecvt_utf8_utf16/std::wstring_convert is deprecated
+ * \see https://codingtidbit.com/2020/02/09/c17-codecvt_utf8-is-deprecated/
  *      https://stackoverflow.com/questions/42946335/deprecated-header-codecvt-replacement
  *      https://en.cppreference.com/w/cpp/locale/codecvt/in
  *      https://docs.microsoft.com/en-us/windows/win32/api/stringapiset/nf-stringapiset-multibytetowidechar

src/libipc/pool_alloc.cpp

@@ -5,11 +5,11 @@
 namespace ipc {
 namespace mem {
 
-void* pool_alloc::alloc(std::size_t size) {
+void* pool_alloc::alloc(std::size_t size) noexcept {
     return async_pool_alloc::alloc(size);
 }
 
-void pool_alloc::free(void* p, std::size_t size) {
+void pool_alloc::free(void* p, std::size_t size) noexcept {
     async_pool_alloc::free(p, size);
 }
 

src/libipc/queue.h

@@ -18,6 +18,7 @@
 #include "libipc/utility/log.h"
 #include "libipc/platform/detail.h"
 #include "libipc/circ/elem_def.h"
+#include "libipc/memory/resource.h"
 
 namespace ipc {
 namespace detail {
@@ -29,7 +30,7 @@ protected:
 
     template <typename Elems>
     Elems* open(char const * name) {
-        if (name == nullptr || name[0] == '\0') {
+        if (!is_valid_string(name)) {
             ipc::error("fail open waiter: name is empty!\n");
             return nullptr;
         }
@@ -54,8 +55,17 @@ public:
     queue_conn(const queue_conn&) = delete;
     queue_conn& operator=(const queue_conn&) = delete;
 
-    bool connected() const noexcept {
-        return connected_ != 0;
+    void clear() noexcept {
+        elems_h_.clear();
+    }
+
+    static void clear_storage(char const *name) noexcept {
+        shm::handle::clear_storage(name);
+    }
+
+    template <typename Elems>
+    bool connected(Elems* elems) const noexcept {
+        return elems->connected(connected_);
     }
 
     circ::cc_t connected_id() const noexcept {
@@ -68,16 +78,16 @@ public:
      -> std::tuple<bool, bool, decltype(std::declval<Elems>().cursor())> {
         if (elems == nullptr) return {};
         // if it's already connected, just return
-        if (connected()) return {connected(), false, 0};
+        if (connected(elems)) return {connected(elems), false, 0};
         connected_ = elems->connect_receiver();
-        return {connected(), true, elems->cursor()};
+        return {connected(elems), true, elems->cursor()};
     }
 
     template <typename Elems>
     bool disconnect(Elems* elems) noexcept {
         if (elems == nullptr) return false;
         // if it's already disconnected, just return false
-        if (!connected()) return false;
+        if (!connected(elems)) return false;
         elems->disconnect_receiver(std::exchange(connected_, 0));
         return true;
     }
@@ -103,7 +113,7 @@ public:
 
     explicit queue_base(char const * name)
         : queue_base{} {
-        elems_ = open<elems_t>(name);
+        elems_ = queue_conn::template open<elems_t>(name);
     }
 
     explicit queue_base(elems_t * elems) noexcept
@@ -116,6 +126,17 @@ public:
         base_t::close();
     }
 
+    bool open(char const * name) noexcept {
+        base_t::close();
+        elems_ = queue_conn::template open<elems_t>(name);
+        return elems_ != nullptr;
+    }
+
+    void clear() noexcept {
+        base_t::clear();
+        elems_ = nullptr;
+    }
+
     elems_t       * elems()       noexcept { return elems_; }
     elems_t const * elems() const noexcept { return elems_; }
 
@@ -130,6 +151,10 @@ public:
         elems_->disconnect_sender();
     }
 
+    bool connected() const noexcept {
+        return base_t::connected(elems_);
+    }
+
     bool connect() noexcept {
         auto tp = base_t::connect(elems_);
         if (std::get<0>(tp) && std::get<1>(tp)) {

src/libipc/shm.cpp

@@ -5,6 +5,7 @@
 #include "libipc/shm.h"
 
 #include "libipc/utility/pimpl.h"
+#include "libipc/utility/log.h"
 #include "libipc/memory/resource.h"
 
 namespace ipc {
@@ -68,8 +69,21 @@ void handle::sub_ref() noexcept {
 }
 
 bool handle::acquire(char const * name, std::size_t size, unsigned mode) {
+    if (!is_valid_string(name)) {
+        ipc::error("fail acquire: name is empty\n");
+        return false;
+    }
+    if (size == 0) {
+        ipc::error("fail acquire: size is 0\n");
+        return false;
+    }
     release();
-    impl(p_)->id_ = shm::acquire((impl(p_)->n_ = name).c_str(), size, mode);
+    const auto id = shm::acquire(name, size, mode);
+    if (!id) {
+        return false;
+    }
+    impl(p_)->id_ = id;
+    impl(p_)->n_  = name;
     impl(p_)->m_  = shm::get_mem(impl(p_)->id_, &(impl(p_)->s_));
     return valid();
 }
@@ -79,6 +93,18 @@ std::int32_t handle::release() {
     return shm::release(detach());
 }
 
+void handle::clear() noexcept {
+    if (impl(p_)->id_ == nullptr) return;
+    shm::remove(detach());
+}
+
+void handle::clear_storage(char const * name) noexcept {
+    if (name == nullptr) {
+        return;
+    }
+    shm::remove(name);
+}
+
 void* handle::get() const {
     return impl(p_)->m_;
 }

src/libipc/sync/condition.cpp

@@ -2,13 +2,14 @@
 #include "libipc/condition.h"
 
 #include "libipc/utility/pimpl.h"
+#include "libipc/utility/log.h"
 #include "libipc/memory/resource.h"
 #include "libipc/platform/detail.h"
 #if defined(IPC_OS_WINDOWS_)
 #include "libipc/platform/win/condition.h"
 #elif defined(IPC_OS_LINUX_)
 #include "libipc/platform/linux/condition.h"
-#elif defined(IPC_OS_QNX_)
+#elif defined(IPC_OS_QNX_) || defined(IPC_OS_FREEBSD_)
 #include "libipc/platform/posix/condition.h"
 #else/*IPC_OS*/
 #   error "Unsupported platform."
@@ -49,6 +50,10 @@ bool condition::valid() const noexcept {
 }
 
 bool condition::open(char const *name) noexcept {
+    if (!is_valid_string(name)) {
+        ipc::error("fail condition open: name is empty\n");
+        return false;
+    }
     return impl(p_)->cond_.open(name);
 }
 
@@ -56,6 +61,14 @@ void condition::close() noexcept {
     impl(p_)->cond_.close();
 }
 
+void condition::clear() noexcept {
+    impl(p_)->cond_.clear();
+}
+
+void condition::clear_storage(char const * name) noexcept {
+    ipc::detail::sync::condition::clear_storage(name);
+}
+
 bool condition::wait(ipc::sync::mutex &mtx, std::uint64_t tm) noexcept {
     return impl(p_)->cond_.wait(mtx, tm);
 }

src/libipc/sync/mutex.cpp

@@ -2,13 +2,14 @@
 #include "libipc/mutex.h"
 
 #include "libipc/utility/pimpl.h"
+#include "libipc/utility/log.h"
 #include "libipc/memory/resource.h"
 #include "libipc/platform/detail.h"
 #if defined(IPC_OS_WINDOWS_)
 #include "libipc/platform/win/mutex.h"
 #elif defined(IPC_OS_LINUX_)
 #include "libipc/platform/linux/mutex.h"
-#elif defined(IPC_OS_QNX_)
+#elif defined(IPC_OS_QNX_) || defined(IPC_OS_FREEBSD_)
 #include "libipc/platform/posix/mutex.h"
 #else/*IPC_OS*/
 #   error "Unsupported platform."
@@ -49,6 +50,10 @@ bool mutex::valid() const noexcept {
 }
 
 bool mutex::open(char const *name) noexcept {
+    if (!is_valid_string(name)) {
+        ipc::error("fail mutex open: name is empty\n");
+        return false;
+    }
     return impl(p_)->lock_.open(name);
 }
 
@@ -56,6 +61,14 @@ void mutex::close() noexcept {
     impl(p_)->lock_.close();
 }
 
+void mutex::clear() noexcept {
+    impl(p_)->lock_.clear();
+}
+
+void mutex::clear_storage(char const * name) noexcept {
+    ipc::detail::sync::mutex::clear_storage(name);
+}
+
 bool mutex::lock(std::uint64_t tm) noexcept {
     return impl(p_)->lock_.lock(tm);
 }

src/libipc/sync/semaphore.cpp

@@ -2,11 +2,12 @@
 #include "libipc/semaphore.h"
 
 #include "libipc/utility/pimpl.h"
+#include "libipc/utility/log.h"
 #include "libipc/memory/resource.h"
 #include "libipc/platform/detail.h"
 #if defined(IPC_OS_WINDOWS_)
 #include "libipc/platform/win/semaphore.h"
-#elif defined(IPC_OS_LINUX_) || defined(IPC_OS_QNX_)
+#elif defined(IPC_OS_LINUX_) || defined(IPC_OS_QNX_) || defined(IPC_OS_FREEBSD_)
 #include "libipc/platform/posix/semaphore_impl.h"
 #else/*IPC_OS*/
 #   error "Unsupported platform."
@@ -47,6 +48,10 @@ bool semaphore::valid() const noexcept {
 }
 
 bool semaphore::open(char const *name, std::uint32_t count) noexcept {
+    if (!is_valid_string(name)) {
+        ipc::error("fail semaphore open: name is empty\n");
+        return false;
+    }
     return impl(p_)->sem_.open(name, count);
 }
 
@@ -54,6 +59,14 @@ void semaphore::close() noexcept {
     impl(p_)->sem_.close();
 }
 
+void semaphore::clear() noexcept {
+    impl(p_)->sem_.clear();
+}
+
+void semaphore::clear_storage(char const * name) noexcept {
+    ipc::detail::sync::semaphore::clear_storage(name);
+}
+
 bool semaphore::wait(std::uint64_t tm) noexcept {
     return impl(p_)->sem_.wait(tm);
 }

src/libipc/sync/waiter.cpp

@@ -0,0 +1,22 @@
+#include "libipc/waiter.h"
+
+#include "libipc/platform/detail.h"
+#if defined(IPC_OS_WINDOWS_)
+#include "libipc/platform/win/mutex.h"
+#elif defined(IPC_OS_LINUX_)
+#include "libipc/platform/linux/mutex.h"
+#elif defined(IPC_OS_QNX_) || defined(IPC_OS_FREEBSD_)
+#include "libipc/platform/posix/mutex.h"
+#else/*IPC_OS*/
+#   error "Unsupported platform."
+#endif
+
+namespace ipc {
+namespace detail {
+
+void waiter::init() {
+    ipc::detail::sync::mutex::init();
+}
+
+} // namespace detail
+} // namespace ipc

src/libipc/waiter.h

@@ -19,6 +19,8 @@ class waiter {
     std::atomic<bool>    quit_ {false};
 
 public:
+    static void init();
+
     waiter() = default;
     waiter(char const *name) {
         open(name);
@@ -34,10 +36,10 @@ public:
 
     bool open(char const *name) noexcept {
         quit_.store(false, std::memory_order_relaxed);
-        if (!cond_.open((std::string{"_waiter_cond_"} + name).c_str())) {
+        if (!cond_.open((std::string{name} + "_WAITER_COND_").c_str())) {
             return false;
         }
-        if (!lock_.open((std::string{"_waiter_lock_"} + name).c_str())) {
+        if (!lock_.open((std::string{name} + "_WAITER_LOCK_").c_str())) {
             cond_.close();
             return false;
         }
@@ -49,6 +51,16 @@ public:
         lock_.close();
     }
 
+    void clear() noexcept {
+        cond_.clear();
+        lock_.clear();
+    }
+
+    static void clear_storage(char const *name) noexcept {
+        ipc::sync::condition::clear_storage((std::string{name} + "_WAITER_COND_").c_str());
+        ipc::sync::mutex::clear_storage((std::string{name} + "_WAITER_LOCK_").c_str());
+    }
+
     template <typename F>
     bool wait_if(F &&pred, std::uint64_t tm = ipc::invalid_value) noexcept {
         IPC_UNUSED_ std::lock_guard<ipc::sync::mutex> guard {lock_};
@@ -62,12 +74,16 @@ public:
     }
 
     bool notify() noexcept {
-        std::lock_guard<ipc::sync::mutex>{lock_}; // barrier
+        {
+            IPC_UNUSED_ std::lock_guard<ipc::sync::mutex> barrier{lock_}; // barrier
+        }
         return cond_.notify(lock_);
     }
 
     bool broadcast() noexcept {
-        std::lock_guard<ipc::sync::mutex>{lock_}; // barrier
+        {
+            IPC_UNUSED_ std::lock_guard<ipc::sync::mutex> barrier{lock_}; // barrier
+        }
         return cond_.broadcast(lock_);
     }
 

test/CMakeLists.txt

@@ -15,11 +15,15 @@ include_directories(
     ${LIBIPC_PROJECT_DIR}/3rdparty
     ${LIBIPC_PROJECT_DIR}/3rdparty/gtest/include)
 
+# Collect only new test files (exclude archive directory)
 file(GLOB SRC_FILES
-    ${LIBIPC_PROJECT_DIR}/test/*.cpp
-    # ${LIBIPC_PROJECT_DIR}/test/profiler/*.cpp
+    ${LIBIPC_PROJECT_DIR}/test/test_*.cpp
     )
-file(GLOB HEAD_FILES ${LIBIPC_PROJECT_DIR}/test/*.h)
+file(GLOB HEAD_FILES ${LIBIPC_PROJECT_DIR}/test/test_*.h)
+
+# Ensure we don't include archived tests
+list(FILTER SRC_FILES EXCLUDE REGEX "archive")
+list(FILTER HEAD_FILES EXCLUDE REGEX "archive")
 
 add_executable(${PROJECT_NAME} ${SRC_FILES} ${HEAD_FILES})
 

test/archive/CMakeLists.txt.old

@@ -0,0 +1,28 @@
+project(test-ipc)
+
+if(NOT MSVC)
+  add_compile_options(
+    -Wno-attributes 
+    -Wno-missing-field-initializers 
+    -Wno-unused-variable 
+    -Wno-unused-function)
+endif()
+
+include_directories(
+    ${LIBIPC_PROJECT_DIR}/include 
+    ${LIBIPC_PROJECT_DIR}/src
+    ${LIBIPC_PROJECT_DIR}/test
+    ${LIBIPC_PROJECT_DIR}/3rdparty
+    ${LIBIPC_PROJECT_DIR}/3rdparty/gtest/include)
+
+file(GLOB SRC_FILES
+    ${LIBIPC_PROJECT_DIR}/test/*.cpp
+    # ${LIBIPC_PROJECT_DIR}/test/profiler/*.cpp
+    )
+file(GLOB HEAD_FILES ${LIBIPC_PROJECT_DIR}/test/*.h)
+
+add_executable(${PROJECT_NAME} ${SRC_FILES} ${HEAD_FILES})
+
+link_directories(${LIBIPC_PROJECT_DIR}/3rdparty/gperftools)
+target_link_libraries(${PROJECT_NAME} gtest gtest_main ipc)
+#target_link_libraries(${PROJECT_NAME} tcmalloc_minimal)

test/archive/test.h

@@ -14,6 +14,11 @@
 
 #include "thread_pool.h"
 
+#include "libipc/platform/detail.h"
+#ifdef IPC_OS_LINUX_
+#include <fcntl.h> // ::open
+#endif
+
 namespace ipc_ut {
 
 template <typename Dur>
@@ -83,4 +88,23 @@ inline static thread_pool & reader() {
     return pool;
 }
 
+#ifdef IPC_OS_LINUX_
+inline bool check_exist(char const *name) noexcept {
+    int fd = ::open((std::string{"/dev/shm/"} + name).c_str(), O_RDONLY);
+    if (fd == -1) {
+        return false;
+    }
+    ::close(fd);
+    return true;
+}
+#endif
+
+inline bool expect_exist(char const *name, bool expected) noexcept {
+#ifdef IPC_OS_LINUX_
+    return ipc_ut::check_exist(name) == expected;
+#else
+    return true;
+#endif
+}
+
 } // namespace ipc_ut

test/archive/test_ipc.cpp

@@ -151,11 +151,59 @@ void test_sr(char const * name, int s_cnt, int r_cnt) {
 
 } // internal-linkage
 
-TEST(IPC, basic) {
+TEST(IPC, clear) {
+    {
+        chan<relat::single, relat::single, trans::unicast> c{"ssu"};
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__AC_CONN__ssu", true));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__CC_CONN__ssu_WAITER_COND_", true));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__CC_CONN__ssu_WAITER_LOCK_", true));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__RD_CONN__ssu_WAITER_COND_", true));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__RD_CONN__ssu_WAITER_LOCK_", true));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__WT_CONN__ssu_WAITER_COND_", true));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__WT_CONN__ssu_WAITER_LOCK_", true));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__QU_CONN__ssu__64__16", true));
+        c.clear();
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__AC_CONN__ssu", false));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__CC_CONN__ssu_WAITER_COND_", false));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__CC_CONN__ssu_WAITER_LOCK_", false));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__RD_CONN__ssu_WAITER_COND_", false));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__RD_CONN__ssu_WAITER_LOCK_", false));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__WT_CONN__ssu_WAITER_COND_", false));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__WT_CONN__ssu_WAITER_LOCK_", false));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__QU_CONN__ssu__64__16", false));
+    }
+    {
+        chan<relat::single, relat::single, trans::unicast> c{"ssu"};
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__AC_CONN__ssu", true));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__CC_CONN__ssu_WAITER_COND_", true));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__CC_CONN__ssu_WAITER_LOCK_", true));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__RD_CONN__ssu_WAITER_COND_", true));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__RD_CONN__ssu_WAITER_LOCK_", true));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__WT_CONN__ssu_WAITER_COND_", true));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__WT_CONN__ssu_WAITER_LOCK_", true));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__QU_CONN__ssu__64__16", true));
+        chan<relat::single, relat::single, trans::unicast>::clear_storage("ssu");
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__AC_CONN__ssu", false));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__CC_CONN__ssu_WAITER_COND_", false));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__CC_CONN__ssu_WAITER_LOCK_", false));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__RD_CONN__ssu_WAITER_COND_", false));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__RD_CONN__ssu_WAITER_LOCK_", false));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__WT_CONN__ssu_WAITER_COND_", false));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__WT_CONN__ssu_WAITER_LOCK_", false));
+        EXPECT_TRUE(ipc_ut::expect_exist("__IPC_SHM__QU_CONN__ssu__64__16", false));
+        c.release(); // Call this interface to prevent destruction-time exceptions.
+    }
+}
+
+TEST(IPC, basic_ssu) {
     test_basic<relat::single, relat::single, trans::unicast  >("ssu");
-    //test_basic<relat::single, relat::multi , trans::unicast  >("smu");
-    //test_basic<relat::multi , relat::multi , trans::unicast  >("mmu");
+}
+
+TEST(IPC, basic_smb) {
     test_basic<relat::single, relat::multi , trans::broadcast>("smb");
+}
+
+TEST(IPC, basic_mmb) {
     test_basic<relat::multi , relat::multi , trans::broadcast>("mmb");
 }
 

test/archive/test_queue.cpp

@@ -302,3 +302,10 @@ TEST(Queue, prod_cons_NvN_broadcast) {
         test_sr(elems_t<ipc::relat::multi , ipc::relat::multi , ipc::trans::broadcast>{}, i, i, "mmb");
     }
 }
+
+TEST(Queue, clear) {
+    queue_t<ipc::relat::single, ipc::relat::single, ipc::trans::unicast> que{"test-queue-clear"};
+    EXPECT_TRUE(ipc_ut::expect_exist("test-queue-clear", true));
+    que.clear();
+    EXPECT_TRUE(ipc_ut::expect_exist("test-queue-clear", false));
+}

test/archive/test_shm.cpp

@@ -0,0 +1,134 @@
+#include <cstring>
+#include <cstdint>
+#include <thread>
+
+#include "libipc/shm.h"
+
+#include "test.h"
+
+using namespace ipc::shm;
+
+namespace {
+
+TEST(SHM, acquire) {
+    handle shm_hd;
+    EXPECT_FALSE(shm_hd.valid());
+
+    EXPECT_TRUE(shm_hd.acquire("my-test-1", 1024));
+    EXPECT_TRUE(shm_hd.valid());
+    EXPECT_STREQ(shm_hd.name(), "my-test-1");
+
+    EXPECT_TRUE(shm_hd.acquire("my-test-2", 2048));
+    EXPECT_TRUE(shm_hd.valid());
+    EXPECT_STREQ(shm_hd.name(), "my-test-2");
+
+    EXPECT_TRUE(shm_hd.acquire("my-test-3", 4096));
+    EXPECT_TRUE(shm_hd.valid());
+    EXPECT_STREQ(shm_hd.name(), "my-test-3");
+}
+
+TEST(SHM, release) {
+    handle shm_hd;
+    EXPECT_FALSE(shm_hd.valid());
+    shm_hd.release();
+    EXPECT_FALSE(shm_hd.valid());
+    EXPECT_TRUE(shm_hd.acquire("release-test-1", 512));
+    EXPECT_TRUE(shm_hd.valid());
+    shm_hd.release();
+    EXPECT_FALSE(shm_hd.valid());
+}
+
+TEST(SHM, get) {
+    handle shm_hd;
+    EXPECT_TRUE(shm_hd.get() == nullptr);
+    EXPECT_TRUE(shm_hd.acquire("get-test", 2048));
+
+    auto mem = shm_hd.get();
+    EXPECT_TRUE(mem != nullptr);
+    EXPECT_TRUE(mem == shm_hd.get());
+
+    std::uint8_t buf[1024] = {};
+    EXPECT_TRUE(memcmp(mem, buf, sizeof(buf)) == 0);
+
+    handle shm_other(shm_hd.name(), shm_hd.size());
+    EXPECT_TRUE(shm_other.get() != shm_hd.get());
+}
+
+TEST(SHM, hello) {
+    handle shm_hd;
+    EXPECT_TRUE(shm_hd.acquire("hello-test", 128));
+    auto mem = shm_hd.get();
+    EXPECT_TRUE(mem != nullptr);
+
+    constexpr char hello[] = "hello!";
+    std::memcpy(mem, hello, sizeof(hello));
+    EXPECT_STREQ((char const *)shm_hd.get(), hello);
+
+    shm_hd.release();
+    EXPECT_TRUE(shm_hd.get() == nullptr);
+    EXPECT_TRUE(shm_hd.acquire("hello-test", 1024));
+
+    mem = shm_hd.get();
+    EXPECT_TRUE(mem != nullptr);
+    std::uint8_t buf[1024] = {};
+    EXPECT_TRUE(memcmp(mem, buf, sizeof(buf)) == 0);
+
+    std::memcpy(mem, hello, sizeof(hello));
+    EXPECT_STREQ((char const *)shm_hd.get(), hello);
+}
+
+TEST(SHM, mt) {
+    handle shm_hd;
+    EXPECT_TRUE(shm_hd.acquire("mt-test", 256));
+    constexpr char hello[] = "hello!";
+    std::memcpy(shm_hd.get(), hello, sizeof(hello));
+
+    std::thread {
+        [&shm_hd] {
+            handle shm_mt(shm_hd.name(), shm_hd.size());
+            shm_hd.release();
+            constexpr char hello[] = "hello!";
+            EXPECT_STREQ((char const *)shm_mt.get(), hello);
+        }
+    }.join();
+
+    EXPECT_TRUE(shm_hd.get() == nullptr);
+    EXPECT_FALSE(shm_hd.valid());
+
+    EXPECT_TRUE(shm_hd.acquire("mt-test", 1024));
+    std::uint8_t buf[1024] = {};
+    EXPECT_TRUE(memcmp(shm_hd.get(), buf, sizeof(buf)) == 0);
+}
+
+TEST(SHM, remove) {
+    {
+        auto id = ipc::shm::acquire("hello-remove", 111);
+        EXPECT_TRUE(ipc_ut::expect_exist("hello-remove", true));
+        ipc::shm::remove(id);
+        EXPECT_TRUE(ipc_ut::expect_exist("hello-remove", false));
+    }
+    {
+        auto id = ipc::shm::acquire("hello-remove", 111);
+        EXPECT_TRUE(ipc_ut::expect_exist("hello-remove", true));
+        ipc::shm::release(id);
+        EXPECT_TRUE(ipc_ut::expect_exist("hello-remove", true));
+        ipc::shm::remove("hello-remove");
+        EXPECT_TRUE(ipc_ut::expect_exist("hello-remove", false));
+    }
+    {
+        handle shm_hd;
+        EXPECT_TRUE(shm_hd.acquire("mt-test", 256));
+        EXPECT_TRUE(ipc_ut::expect_exist("mt-test", true));
+        shm_hd.clear();
+        EXPECT_TRUE(ipc_ut::expect_exist("mt-test", false));
+    }
+    {
+        handle shm_hd;
+        EXPECT_TRUE(shm_hd.acquire("mt-test", 256));
+        EXPECT_TRUE(ipc_ut::expect_exist("mt-test", true));
+        shm_hd.clear_storage("mt-test");
+        EXPECT_TRUE(ipc_ut::expect_exist("mt-test", false));
+    }
+}
+
+} // internal-linkage

test/archive/test_sync.cpp

@@ -37,7 +37,11 @@ TEST(PThread, Robust) {
     pthread_mutex_destroy(&mutex);
 }
 #elif defined(IPC_OS_WINDOWS_)
+#if defined(__MINGW32__)
+#include <windows.h>
+#else
 #include <Windows.h>
+#endif
 #include <tchar.h>
 
 TEST(PThread, Robust) {
@@ -131,7 +135,7 @@ TEST(Sync, Condition) {
             {
                 std::lock_guard<ipc::sync::mutex> guard {lock};
                 while (que.empty()) {
-                    EXPECT_TRUE(cond.wait(lock, 1000));
+                    ASSERT_TRUE(cond.wait(lock, 1000));
                 }
                 val = que.front();
                 que.pop_front();

test/archive/test_waiter.cpp

@@ -4,8 +4,6 @@
 #include "libipc/waiter.h"
 #include "test.h"
 
-namespace {
-
 TEST(Waiter, broadcast) {
     for (int i = 0; i < 10; ++i) {
         ipc::detail::waiter waiter;
@@ -65,4 +63,23 @@ TEST(Waiter, quit_waiting) {
     std::cout << "quit... \n";
 }
 
-} // internal-linkage
+TEST(Waiter, clear) {
+    {
+        ipc::detail::waiter w{"my-waiter"};
+        ASSERT_TRUE(w.valid());
+        EXPECT_TRUE(ipc_ut::expect_exist("my-waiter_WAITER_COND_", true));
+        EXPECT_TRUE(ipc_ut::expect_exist("my-waiter_WAITER_LOCK_", true));
+        w.clear();
+        ASSERT_TRUE(!w.valid());
+        EXPECT_TRUE(ipc_ut::expect_exist("my-waiter_WAITER_COND_", false));
+        EXPECT_TRUE(ipc_ut::expect_exist("my-waiter_WAITER_LOCK_", false));
+    }
+    {
+        ipc::detail::waiter w{"my-waiter"};
+        EXPECT_TRUE(ipc_ut::expect_exist("my-waiter_WAITER_COND_", true));
+        EXPECT_TRUE(ipc_ut::expect_exist("my-waiter_WAITER_LOCK_", true));
+        ipc::detail::waiter::clear_storage("my-waiter");
+        EXPECT_TRUE(ipc_ut::expect_exist("my-waiter_WAITER_COND_", false));
+        EXPECT_TRUE(ipc_ut::expect_exist("my-waiter_WAITER_LOCK_", false));
+    }
+}

test/test_buffer.cpp

@@ -0,0 +1,384 @@
+/**
+ * @file test_buffer.cpp
+ * @brief Comprehensive unit tests for ipc::buffer class
+ * 
+ * This test suite covers all public interfaces of the buffer class including:
+ * - Constructors (default, with pointer and destructor, from array, from char)
+ * - Move semantics
+ * - Copy operations through assignment
+ * - Basic operations (empty, data, size)
+ * - Conversion methods (to_tuple, to_vector, get<T>)
+ * - Comparison operators
+ */
+
+#include <gtest/gtest.h>
+#include <cstring>
+#include <vector>
+#include "libipc/buffer.h"
+
+using namespace ipc;
+
+namespace {
+
+// Custom destructor tracker for testing
+struct DestructorTracker {
+  static int count;
+  static void reset() { count = 0; }
+  static void destructor(void* p, std::size_t) {
+      ++count;
+      delete[] static_cast<char*>(p);
+  }
+};
+int DestructorTracker::count = 0;
+
+} // anonymous namespace
+
+class BufferTest : public ::testing::Test {
+protected:
+  void SetUp() override {
+      DestructorTracker::reset();
+  }
+};
+
+// Test default constructor
+TEST_F(BufferTest, DefaultConstructor) {
+  buffer buf;
+  EXPECT_TRUE(buf.empty());
+  EXPECT_EQ(buf.size(), 0u);
+  EXPECT_EQ(buf.data(), nullptr);
+}
+
+// Test constructor with pointer, size, and destructor
+TEST_F(BufferTest, ConstructorWithDestructor) {
+  const char* test_data = "Hello, World!";
+  std::size_t size = std::strlen(test_data) + 1;
+  char* data = new char[size];
+  std::strcpy(data, test_data);
+  
+  buffer buf(data, size, DestructorTracker::destructor);
+  
+  EXPECT_FALSE(buf.empty());
+  EXPECT_EQ(buf.size(), size);
+  EXPECT_NE(buf.data(), nullptr);
+  EXPECT_STREQ(static_cast<const char*>(buf.data()), test_data);
+}
+
+// Test destructor is called
+TEST_F(BufferTest, DestructorCalled) {
+  {
+      char* data = new char[100];
+      buffer buf(data, 100, DestructorTracker::destructor);
+      EXPECT_EQ(DestructorTracker::count, 0);
+  }
+  EXPECT_EQ(DestructorTracker::count, 1);
+}
+
+// Test constructor with mem_to_free parameter
+// Scenario: allocate a large block, but only use a portion as data
+TEST_F(BufferTest, ConstructorWithMemToFree) {
+  // Allocate a block of 100 bytes
+  char* allocated_block = new char[100];
+  
+  // But only use the middle 50 bytes as data (offset 25)
+  char* data_start = allocated_block + 25;
+  std::strcpy(data_start, "Offset data");
+  
+  // When destroyed, should free the entire allocated_block, not just data_start
+  buffer buf(data_start, 50, DestructorTracker::destructor, allocated_block);
+  
+  EXPECT_FALSE(buf.empty());
+  EXPECT_EQ(buf.size(), 50u);
+  EXPECT_EQ(buf.data(), data_start);
+  EXPECT_STREQ(static_cast<const char*>(buf.data()), "Offset data");
+  
+  // Destructor will be called with allocated_block (not data_start)
+  // This correctly frees the entire allocation
+}
+
+// Test constructor without destructor
+TEST_F(BufferTest, ConstructorWithoutDestructor) {
+  char stack_data[20] = "Stack data";
+  
+  buffer buf(stack_data, 20);
+  
+  EXPECT_FALSE(buf.empty());
+  EXPECT_EQ(buf.size(), 20u);
+  EXPECT_EQ(buf.data(), stack_data);
+}
+
+// Test constructor from byte array
+TEST_F(BufferTest, ConstructorFromByteArray) {
+  byte_t data[10] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+  
+  buffer buf(data);
+  
+  EXPECT_FALSE(buf.empty());
+  EXPECT_EQ(buf.size(), 10u);
+  
+  const byte_t* buf_data = buf.get<const byte_t*>();
+  for (int i = 0; i < 10; ++i) {
+      EXPECT_EQ(buf_data[i], i);
+  }
+}
+
+// Test constructor from single char
+TEST_F(BufferTest, ConstructorFromChar) {
+  char c = 'X';
+  
+  buffer buf(c);
+  
+  EXPECT_FALSE(buf.empty());
+  EXPECT_EQ(buf.size(), sizeof(char));
+  EXPECT_EQ(*buf.get<const char*>(), 'X');
+}
+
+// Test move constructor
+TEST_F(BufferTest, MoveConstructor) {
+  char* data = new char[30];
+  std::strcpy(data, "Move test");
+  
+  buffer buf1(data, 30, DestructorTracker::destructor);
+  void* original_ptr = buf1.data();
+  std::size_t original_size = buf1.size();
+  
+  buffer buf2(std::move(buf1));
+  
+  // buf2 should have the original data
+  EXPECT_EQ(buf2.data(), original_ptr);
+  EXPECT_EQ(buf2.size(), original_size);
+  EXPECT_FALSE(buf2.empty());
+  
+  // buf1 should be empty after move
+  EXPECT_TRUE(buf1.empty());
+  EXPECT_EQ(buf1.size(), 0u);
+}
+
+// Test swap
+TEST_F(BufferTest, Swap) {
+  char* data1 = new char[20];
+  char* data2 = new char[30];
+  std::strcpy(data1, "Buffer 1");
+  std::strcpy(data2, "Buffer 2");
+  
+  buffer buf1(data1, 20, DestructorTracker::destructor);
+  buffer buf2(data2, 30, DestructorTracker::destructor);
+  
+  void* ptr1 = buf1.data();
+  void* ptr2 = buf2.data();
+  std::size_t size1 = buf1.size();
+  std::size_t size2 = buf2.size();
+  
+  buf1.swap(buf2);
+  
+  EXPECT_EQ(buf1.data(), ptr2);
+  EXPECT_EQ(buf1.size(), size2);
+  EXPECT_EQ(buf2.data(), ptr1);
+  EXPECT_EQ(buf2.size(), size1);
+}
+
+// Test assignment operator (move semantics)
+TEST_F(BufferTest, AssignmentOperator) {
+  char* data = new char[40];
+  std::strcpy(data, "Assignment test");
+  
+  buffer buf1(data, 40, DestructorTracker::destructor);
+  void* original_ptr = buf1.data();
+  
+  buffer buf2;
+  buf2 = std::move(buf1);
+  
+  EXPECT_EQ(buf2.data(), original_ptr);
+  EXPECT_FALSE(buf2.empty());
+}
+
+// Test empty() method
+TEST_F(BufferTest, EmptyMethod) {
+  buffer buf1;
+  EXPECT_TRUE(buf1.empty());
+  
+  char* data = new char[10];
+  buffer buf2(data, 10, DestructorTracker::destructor);
+  EXPECT_FALSE(buf2.empty());
+}
+
+// Test data() const method
+TEST_F(BufferTest, DataConstMethod) {
+  const char* test_str = "Const data test";
+  std::size_t size = std::strlen(test_str) + 1;
+  char* data = new char[size];
+  std::strcpy(data, test_str);
+  
+  const buffer buf(data, size, DestructorTracker::destructor);
+  
+  const void* const_data = buf.data();
+  EXPECT_NE(const_data, nullptr);
+  EXPECT_STREQ(static_cast<const char*>(const_data), test_str);
+}
+
+// Test get<T>() template method
+TEST_F(BufferTest, GetTemplateMethod) {
+  int* int_data = new int[5]{1, 2, 3, 4, 5};
+  
+  buffer buf(int_data, 5 * sizeof(int), [](void* p, std::size_t) {
+      delete[] static_cast<int*>(p);
+  });
+  
+  int* retrieved = buf.get<int*>();
+  EXPECT_NE(retrieved, nullptr);
+  EXPECT_EQ(retrieved[0], 1);
+  EXPECT_EQ(retrieved[4], 5);
+}
+
+// Test to_tuple() non-const version
+TEST_F(BufferTest, ToTupleNonConst) {
+  char* data = new char[25];
+  std::strcpy(data, "Tuple test");
+  
+  buffer buf(data, 25, DestructorTracker::destructor);
+  
+  // C++14 compatible: use std::get instead of structured binding
+  auto tuple = buf.to_tuple();
+  auto ptr = std::get<0>(tuple);
+  auto size = std::get<1>(tuple);
+  EXPECT_EQ(ptr, buf.data());
+  EXPECT_EQ(size, buf.size());
+  EXPECT_EQ(size, 25u);
+}
+
+// Test to_tuple() const version
+TEST_F(BufferTest, ToTupleConst) {
+  char* data = new char[30];
+  std::strcpy(data, "Const tuple");
+  
+  const buffer buf(data, 30, DestructorTracker::destructor);
+  
+  // C++14 compatible: use std::get instead of structured binding
+  auto tuple = buf.to_tuple();
+  auto ptr = std::get<0>(tuple);
+  auto size = std::get<1>(tuple);
+  EXPECT_EQ(ptr, buf.data());
+  EXPECT_EQ(size, buf.size());
+  EXPECT_EQ(size, 30u);
+}
+
+// Test to_vector() method
+TEST_F(BufferTest, ToVector) {
+  byte_t data_arr[5] = {10, 20, 30, 40, 50};
+  
+  buffer buf(data_arr, 5);
+  
+  std::vector<byte_t> vec = buf.to_vector();
+  ASSERT_EQ(vec.size(), 5u);
+  EXPECT_EQ(vec[0], 10);
+  EXPECT_EQ(vec[1], 20);
+  EXPECT_EQ(vec[2], 30);
+  EXPECT_EQ(vec[3], 40);
+  EXPECT_EQ(vec[4], 50);
+}
+
+// Test equality operator
+TEST_F(BufferTest, EqualityOperator) {
+  byte_t data1[5] = {1, 2, 3, 4, 5};
+  byte_t data2[5] = {1, 2, 3, 4, 5};
+  byte_t data3[5] = {5, 4, 3, 2, 1};
+  
+  buffer buf1(data1, 5);
+  buffer buf2(data2, 5);
+  buffer buf3(data3, 5);
+  
+  EXPECT_TRUE(buf1 == buf2);
+  EXPECT_FALSE(buf1 == buf3);
+}
+
+// Test inequality operator
+TEST_F(BufferTest, InequalityOperator) {
+  byte_t data1[5] = {1, 2, 3, 4, 5};
+  byte_t data2[5] = {1, 2, 3, 4, 5};
+  byte_t data3[5] = {5, 4, 3, 2, 1};
+  
+  buffer buf1(data1, 5);
+  buffer buf2(data2, 5);
+  buffer buf3(data3, 5);
+  
+  EXPECT_FALSE(buf1 != buf2);
+  EXPECT_TRUE(buf1 != buf3);
+}
+
+// Test size mismatch in equality
+TEST_F(BufferTest, EqualityWithDifferentSizes) {
+  byte_t data1[5] = {1, 2, 3, 4, 5};
+  byte_t data2[3] = {1, 2, 3};
+  
+  buffer buf1(data1, 5);
+  buffer buf2(data2, 3);
+  
+  EXPECT_FALSE(buf1 == buf2);
+  EXPECT_TRUE(buf1 != buf2);
+}
+
+// Test empty buffers comparison
+TEST_F(BufferTest, EmptyBuffersComparison) {
+  buffer buf1;
+  buffer buf2;
+  
+  EXPECT_TRUE(buf1 == buf2);
+  EXPECT_FALSE(buf1 != buf2);
+}
+
+// Test large buffer
+TEST_F(BufferTest, LargeBuffer) {
+  const std::size_t large_size = 1024 * 1024; // 1MB
+  char* large_data = new char[large_size];
+  
+  // Fill with pattern
+  for (std::size_t i = 0; i < large_size; ++i) {
+      large_data[i] = static_cast<char>(i % 256);
+  }
+  
+  buffer buf(large_data, large_size, [](void* p, std::size_t) {
+      delete[] static_cast<char*>(p);
+  });
+  
+  EXPECT_FALSE(buf.empty());
+  EXPECT_EQ(buf.size(), large_size);
+  
+  // Verify pattern
+  const char* data_ptr = buf.get<const char*>();
+  for (std::size_t i = 0; i < 100; ++i) { // Check first 100 bytes
+      EXPECT_EQ(data_ptr[i], static_cast<char>(i % 256));
+  }
+}
+
+// Test multiple move operations
+TEST_F(BufferTest, MultipleMoves) {
+  char* data = new char[15];
+  std::strcpy(data, "Multi-move");
+  void* original_ptr = data;
+  
+  buffer buf1(data, 15, DestructorTracker::destructor);
+  buffer buf2(std::move(buf1));
+  buffer buf3(std::move(buf2));
+  buffer buf4(std::move(buf3));
+  
+  EXPECT_EQ(buf4.data(), original_ptr);
+  EXPECT_TRUE(buf1.empty());
+  EXPECT_TRUE(buf2.empty());
+  EXPECT_TRUE(buf3.empty());
+  EXPECT_FALSE(buf4.empty());
+}
+
+// Test self-assignment safety
+TEST_F(BufferTest, SelfAssignment) {
+  char* data = new char[20];
+  std::strcpy(data, "Self-assign");
+  
+  buffer buf(data, 20, DestructorTracker::destructor);
+  void* original_ptr = buf.data();
+  std::size_t original_size = buf.size();
+  
+  buf = std::move(buf); // Self-assignment
+  
+  // Should remain valid
+  EXPECT_EQ(buf.data(), original_ptr);
+  EXPECT_EQ(buf.size(), original_size);
+}

test/test_condition.cpp

@@ -0,0 +1,550 @@
+/**
+ * @file test_condition.cpp
+ * @brief Comprehensive unit tests for ipc::sync::condition class
+ * 
+ * This test suite covers:
+ * - Condition variable construction (default and named)
+ * - Wait, notify, and broadcast operations
+ * - Timed wait with timeout
+ * - Integration with mutex
+ * - Producer-consumer patterns with condition variables
+ * - Resource cleanup
+ */
+
+#include <gtest/gtest.h>
+#include <thread>
+#include <chrono>
+#include <atomic>
+#include <vector>
+#include "libipc/condition.h"
+#include "libipc/mutex.h"
+#include "libipc/def.h"
+
+using namespace ipc;
+using namespace ipc::sync;
+
+namespace {
+
+std::string generate_unique_cv_name(const char* prefix) {
+  static int counter = 0;
+  return std::string(prefix) + "_cv_" + std::to_string(++counter);
+}
+
+} // anonymous namespace
+
+class ConditionTest : public ::testing::Test {
+protected:
+  void TearDown() override {
+      std::this_thread::sleep_for(std::chrono::milliseconds(10));
+  }
+};
+
+// Test default constructor
+TEST_F(ConditionTest, DefaultConstructor) {
+  condition cv;
+}
+
+// Test named constructor
+TEST_F(ConditionTest, NamedConstructor) {
+  std::string name = generate_unique_cv_name("named");
+  
+  condition cv(name.c_str());
+  EXPECT_TRUE(cv.valid());
+}
+
+// Test native() methods
+TEST_F(ConditionTest, NativeHandle) {
+  std::string name = generate_unique_cv_name("native");
+  
+  condition cv(name.c_str());
+  ASSERT_TRUE(cv.valid());
+  
+  const void* const_handle = static_cast<const condition&>(cv).native();
+  void* handle = cv.native();
+  
+  EXPECT_NE(const_handle, nullptr);
+  EXPECT_NE(handle, nullptr);
+}
+
+// Test valid() method
+TEST_F(ConditionTest, Valid) {
+  condition cv1;
+  
+  std::string name = generate_unique_cv_name("valid");
+  condition cv2(name.c_str());
+  EXPECT_TRUE(cv2.valid());
+}
+
+// Test open() method
+TEST_F(ConditionTest, Open) {
+  std::string name = generate_unique_cv_name("open");
+  
+  condition cv;
+  bool result = cv.open(name.c_str());
+  
+  EXPECT_TRUE(result);
+  EXPECT_TRUE(cv.valid());
+}
+
+// Test close() method
+TEST_F(ConditionTest, Close) {
+  std::string name = generate_unique_cv_name("close");
+  
+  condition cv(name.c_str());
+  ASSERT_TRUE(cv.valid());
+  
+  cv.close();
+  EXPECT_FALSE(cv.valid());
+}
+
+// Test clear() method
+TEST_F(ConditionTest, Clear) {
+  std::string name = generate_unique_cv_name("clear");
+  
+  condition cv(name.c_str());
+  ASSERT_TRUE(cv.valid());
+  
+  cv.clear();
+  EXPECT_FALSE(cv.valid());
+}
+
+// Test clear_storage() static method
+TEST_F(ConditionTest, ClearStorage) {
+  std::string name = generate_unique_cv_name("clear_storage");
+  
+  {
+      condition cv(name.c_str());
+      EXPECT_TRUE(cv.valid());
+  }
+  
+  condition::clear_storage(name.c_str());
+}
+
+// Test basic wait and notify
+TEST_F(ConditionTest, WaitNotify) {
+  std::string cv_name = generate_unique_cv_name("wait_notify");
+  std::string mtx_name = generate_unique_cv_name("wait_notify_mtx");
+  
+  condition cv(cv_name.c_str());
+  mutex mtx(mtx_name.c_str());
+  
+  ASSERT_TRUE(cv.valid());
+  ASSERT_TRUE(mtx.valid());
+  
+  std::atomic<bool> notified{false};
+  
+  std::thread waiter([&]() {
+      mtx.lock();
+      cv.wait(mtx);
+      notified.store(true);
+      mtx.unlock();
+  });
+  
+  std::this_thread::sleep_for(std::chrono::milliseconds(50));
+  
+  mtx.lock();
+  cv.notify(mtx);
+  mtx.unlock();
+  
+  waiter.join();
+  
+  EXPECT_TRUE(notified.load());
+}
+
+// Test broadcast to multiple waiters
+TEST_F(ConditionTest, Broadcast) {
+  std::string cv_name = generate_unique_cv_name("broadcast");
+  std::string mtx_name = generate_unique_cv_name("broadcast_mtx");
+  
+  condition cv(cv_name.c_str());
+  mutex mtx(mtx_name.c_str());
+  
+  ASSERT_TRUE(cv.valid());
+  ASSERT_TRUE(mtx.valid());
+  
+  std::atomic<int> notified_count{0};
+  const int num_waiters = 5;
+  
+  std::vector<std::thread> waiters;
+  for (int i = 0; i < num_waiters; ++i) {
+      waiters.emplace_back([&]() {
+          mtx.lock();
+          cv.wait(mtx);
+          ++notified_count;
+          mtx.unlock();
+      });
+  }
+  
+  std::this_thread::sleep_for(std::chrono::milliseconds(100));
+  
+  mtx.lock();
+  cv.broadcast(mtx);
+  mtx.unlock();
+  
+  for (auto& t : waiters) {
+      t.join();
+  }
+  
+  EXPECT_EQ(notified_count.load(), num_waiters);
+}
+
+// Test timed wait with timeout
+TEST_F(ConditionTest, TimedWait) {
+  std::string cv_name = generate_unique_cv_name("timed_wait");
+  std::string mtx_name = generate_unique_cv_name("timed_wait_mtx");
+  
+  condition cv(cv_name.c_str());
+  mutex mtx(mtx_name.c_str());
+  
+  ASSERT_TRUE(cv.valid());
+  ASSERT_TRUE(mtx.valid());
+  
+  auto start = std::chrono::steady_clock::now();
+  
+  mtx.lock();
+  bool result = cv.wait(mtx, 100); // 100ms timeout
+  mtx.unlock();
+  
+  auto end = std::chrono::steady_clock::now();
+  auto elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+  
+  EXPECT_FALSE(result); // Should timeout
+  EXPECT_GE(elapsed, 80); // Allow some tolerance
+}
+
+// Test wait with immediate notify
+TEST_F(ConditionTest, ImmediateNotify) {
+  std::string cv_name = generate_unique_cv_name("immediate");
+  std::string mtx_name = generate_unique_cv_name("immediate_mtx");
+  
+  condition cv(cv_name.c_str());
+  mutex mtx(mtx_name.c_str());
+  
+  ASSERT_TRUE(cv.valid());
+  ASSERT_TRUE(mtx.valid());
+  
+  std::atomic<bool> wait_started{false};
+  std::atomic<bool> notified{false};
+  
+  std::thread waiter([&]() {
+      mtx.lock();
+      wait_started.store(true);
+      cv.wait(mtx, 1000); // 1 second timeout
+      notified.store(true);
+      mtx.unlock();
+  });
+  
+  // Wait for waiter to start
+  while (!wait_started.load()) {
+      std::this_thread::sleep_for(std::chrono::milliseconds(1));
+  }
+  
+  std::this_thread::sleep_for(std::chrono::milliseconds(10));
+  
+  mtx.lock();
+  cv.notify(mtx);
+  mtx.unlock();
+  
+  waiter.join();
+  
+  EXPECT_TRUE(notified.load());
+}
+
+// Test producer-consumer with condition variable
+TEST_F(ConditionTest, ProducerConsumer) {
+  std::string cv_name = generate_unique_cv_name("prod_cons");
+  std::string mtx_name = generate_unique_cv_name("prod_cons_mtx");
+  
+  condition cv(cv_name.c_str());
+  mutex mtx(mtx_name.c_str());
+  
+  ASSERT_TRUE(cv.valid());
+  ASSERT_TRUE(mtx.valid());
+  
+  std::atomic<int> buffer{0};
+  std::atomic<bool> ready{false};
+  std::atomic<int> consumed_value{0};
+  
+  std::thread producer([&]() {
+      std::this_thread::sleep_for(std::chrono::milliseconds(50));
+      
+      mtx.lock();
+      buffer.store(42);
+      ready.store(true);
+      cv.notify(mtx);
+      mtx.unlock();
+  });
+  
+  std::thread consumer([&]() {
+      mtx.lock();
+      while (!ready.load()) {
+          cv.wait(mtx, 2000);
+      }
+      consumed_value.store(buffer.load());
+      mtx.unlock();
+  });
+  
+  producer.join();
+  consumer.join();
+  
+  EXPECT_EQ(consumed_value.load(), 42);
+}
+
+// Test multiple notify operations
+TEST_F(ConditionTest, MultipleNotify) {
+  std::string cv_name = generate_unique_cv_name("multi_notify");
+  std::string mtx_name = generate_unique_cv_name("multi_notify_mtx");
+  
+  condition cv(cv_name.c_str());
+  mutex mtx(mtx_name.c_str());
+  
+  ASSERT_TRUE(cv.valid());
+  ASSERT_TRUE(mtx.valid());
+  
+  std::atomic<int> notify_count{0};
+  const int num_notifications = 3;
+  
+  std::thread waiter([&]() {
+      for (int i = 0; i < num_notifications; ++i) {
+          mtx.lock();
+          cv.wait(mtx, 1000);
+          ++notify_count;
+          mtx.unlock();
+          std::this_thread::sleep_for(std::chrono::milliseconds(10));
+      }
+  });
+  
+  for (int i = 0; i < num_notifications; ++i) {
+      std::this_thread::sleep_for(std::chrono::milliseconds(50));
+      mtx.lock();
+      cv.notify(mtx);
+      mtx.unlock();
+  }
+  
+  waiter.join();
+  
+  EXPECT_EQ(notify_count.load(), num_notifications);
+}
+
+// Test notify vs broadcast
+TEST_F(ConditionTest, NotifyVsBroadcast) {
+  std::string cv_name = generate_unique_cv_name("notify_vs_broadcast");
+  std::string mtx_name = generate_unique_cv_name("notify_vs_broadcast_mtx");
+  
+  condition cv(cv_name.c_str());
+  mutex mtx(mtx_name.c_str());
+  
+  ASSERT_TRUE(cv.valid());
+  ASSERT_TRUE(mtx.valid());
+  
+  // Test notify (should wake one)
+  std::atomic<int> notify_woken{0};
+  
+  std::vector<std::thread> notify_waiters;
+  for (int i = 0; i < 3; ++i) {
+      notify_waiters.emplace_back([&]() {
+          mtx.lock();
+          cv.wait(mtx, 100);
+          ++notify_woken;
+          mtx.unlock();
+      });
+  }
+  
+  std::this_thread::sleep_for(std::chrono::milliseconds(50));
+  
+  mtx.lock();
+  cv.notify(mtx); // Wake one
+  mtx.unlock();
+  
+  std::this_thread::sleep_for(std::chrono::milliseconds(150));
+  
+  for (auto& t : notify_waiters) {
+      t.join();
+  }
+  
+  // At least one should be woken by notify
+  EXPECT_GE(notify_woken.load(), 1);
+}
+
+// Test condition variable with spurious wakeups pattern
+TEST_F(ConditionTest, SpuriousWakeupPattern) {
+  std::string cv_name = generate_unique_cv_name("spurious");
+  std::string mtx_name = generate_unique_cv_name("spurious_mtx");
+  
+  condition cv(cv_name.c_str());
+  mutex mtx(mtx_name.c_str());
+  
+  ASSERT_TRUE(cv.valid());
+  ASSERT_TRUE(mtx.valid());
+  
+  std::atomic<bool> predicate{false};
+  std::atomic<bool> done{false};
+  
+  std::thread waiter([&]() {
+      mtx.lock();
+      while (!predicate.load()) {
+          if (!cv.wait(mtx, 100)) {
+              // Timeout - check predicate again
+              if (predicate.load()) break;
+          }
+      }
+      done.store(true);
+      mtx.unlock();
+  });
+  
+  std::this_thread::sleep_for(std::chrono::milliseconds(50));
+  
+  mtx.lock();
+  predicate.store(true);
+  cv.notify(mtx);
+  mtx.unlock();
+  
+  waiter.join();
+  
+  EXPECT_TRUE(done.load());
+}
+
+// Test reopen after close
+TEST_F(ConditionTest, ReopenAfterClose) {
+  std::string name = generate_unique_cv_name("reopen");
+  
+  condition cv;
+  
+  ASSERT_TRUE(cv.open(name.c_str()));
+  EXPECT_TRUE(cv.valid());
+  
+  cv.close();
+  EXPECT_FALSE(cv.valid());
+  
+  ASSERT_TRUE(cv.open(name.c_str()));
+  EXPECT_TRUE(cv.valid());
+}
+
+// Test named condition variable sharing between threads
+TEST_F(ConditionTest, NamedSharing) {
+  std::string cv_name = generate_unique_cv_name("sharing");
+  std::string mtx_name = generate_unique_cv_name("sharing_mtx");
+  
+  std::atomic<int> value{0};
+  
+  std::thread t1([&]() {
+      condition cv(cv_name.c_str());
+      mutex mtx(mtx_name.c_str());
+      
+      ASSERT_TRUE(cv.valid());
+      ASSERT_TRUE(mtx.valid());
+      
+      mtx.lock();
+      cv.wait(mtx, 1000);
+      value.store(100);
+      mtx.unlock();
+  });
+  
+  std::thread t2([&]() {
+      std::this_thread::sleep_for(std::chrono::milliseconds(50));
+      
+      condition cv(cv_name.c_str());
+      mutex mtx(mtx_name.c_str());
+      
+      ASSERT_TRUE(cv.valid());
+      ASSERT_TRUE(mtx.valid());
+      
+      mtx.lock();
+      cv.notify(mtx);
+      mtx.unlock();
+  });
+  
+  t1.join();
+  t2.join();
+  
+  EXPECT_EQ(value.load(), 100);
+}
+
+// Test infinite wait
+TEST_F(ConditionTest, InfiniteWait) {
+  std::string cv_name = generate_unique_cv_name("infinite");
+  std::string mtx_name = generate_unique_cv_name("infinite_mtx");
+  
+  condition cv(cv_name.c_str());
+  mutex mtx(mtx_name.c_str());
+  
+  ASSERT_TRUE(cv.valid());
+  ASSERT_TRUE(mtx.valid());
+  
+  std::atomic<bool> woken{false};
+  
+  std::thread waiter([&]() {
+      mtx.lock();
+      cv.wait(mtx, invalid_value); // Infinite wait
+      woken.store(true);
+      mtx.unlock();
+  });
+  
+  std::this_thread::sleep_for(std::chrono::milliseconds(100));
+  
+  mtx.lock();
+  cv.notify(mtx);
+  mtx.unlock();
+  
+  waiter.join();
+  
+  EXPECT_TRUE(woken.load());
+}
+
+// Test broadcast with sequential waiters
+TEST_F(ConditionTest, BroadcastSequential) {
+  std::string cv_name = generate_unique_cv_name("broadcast_seq");
+  std::string mtx_name = generate_unique_cv_name("broadcast_seq_mtx");
+  
+  condition cv(cv_name.c_str());
+  mutex mtx(mtx_name.c_str());
+  
+  ASSERT_TRUE(cv.valid());
+  ASSERT_TRUE(mtx.valid());
+  
+  std::atomic<int> processed{0};
+  const int num_threads = 4;
+  
+  std::vector<std::thread> threads;
+  for (int i = 0; i < num_threads; ++i) {
+      threads.emplace_back([&]() {
+          mtx.lock();
+          cv.wait(mtx, 2000);
+          ++processed;
+          mtx.unlock();
+      });
+  }
+  
+  std::this_thread::sleep_for(std::chrono::milliseconds(100));
+  
+  mtx.lock();
+  cv.broadcast(mtx);
+  mtx.unlock();
+  
+  for (auto& t : threads) {
+      t.join();
+  }
+  
+  EXPECT_EQ(processed.load(), num_threads);
+}
+
+// Test operations after clear
+TEST_F(ConditionTest, AfterClear) {
+  std::string cv_name = generate_unique_cv_name("after_clear");
+  std::string mtx_name = generate_unique_cv_name("after_clear_mtx");
+  
+  condition cv(cv_name.c_str());
+  mutex mtx(mtx_name.c_str());
+  
+  ASSERT_TRUE(cv.valid());
+  
+  cv.clear();
+  EXPECT_FALSE(cv.valid());
+  
+  // Operations after clear should fail gracefully
+  mtx.lock();
+  EXPECT_FALSE(cv.wait(mtx, 10));
+  EXPECT_FALSE(cv.notify(mtx));
+  EXPECT_FALSE(cv.broadcast(mtx));
+  mtx.unlock();
+}

test/test_ipc_channel.cpp

@@ -0,0 +1,643 @@
+/**
+ * @file test_ipc_channel.cpp
+ * @brief Comprehensive unit tests for ipc::route and ipc::channel classes
+ * 
+ * This test suite covers:
+ * - Route (single producer, multiple consumer) functionality
+ * - Channel (multiple producer, multiple consumer) functionality
+ * - Construction, connection, and disconnection
+ * - Send and receive operations (blocking and non-blocking)
+ * - Timeout handling
+ * - Named channels with prefix
+ * - Resource cleanup and storage management
+ * - Clone operations
+ * - Wait for receiver functionality
+ * - Error conditions
+ */
+
+#include <gtest/gtest.h>
+#include <thread>
+#include <chrono>
+#include <atomic>
+#include <vector>
+#include <string>
+#include <cstring>
+#include <mutex>
+#include <condition_variable>
+#include "libipc/ipc.h"
+#include "libipc/buffer.h"
+
+using namespace ipc;
+
+namespace {
+
+// Simple latch implementation for C++14 (similar to C++20 std::latch)
+class latch {
+public:
+  explicit latch(std::ptrdiff_t count) : count_(count) {}
+  
+  void count_down() {
+      std::unique_lock<std::mutex> lock(mutex_);
+      if (--count_ <= 0) {
+          cv_.notify_all();
+      }
+  }
+  
+  void wait() {
+      std::unique_lock<std::mutex> lock(mutex_);
+      cv_.wait(lock, [this] { return count_ <= 0; });
+  }
+
+private:
+  std::ptrdiff_t count_;
+  std::mutex mutex_;
+  std::condition_variable cv_;
+};
+
+std::string generate_unique_ipc_name(const char* prefix) {
+  static int counter = 0;
+  return std::string(prefix) + "_ipc_" + std::to_string(++counter);
+}
+
+// Helper to create a test buffer with data
+buffer make_test_buffer(const std::string& data) {
+  char* mem = new char[data.size() + 1];
+  std::strcpy(mem, data.c_str());
+  return buffer(mem, data.size() + 1, [](void* p, std::size_t) {
+      delete[] static_cast<char*>(p);
+  });
+}
+
+// Helper to check buffer content
+bool check_buffer_content(const buffer& buf, const std::string& expected) {
+  if (buf.empty() || buf.size() != expected.size() + 1) {
+      return false;
+  }
+  return std::strcmp(static_cast<const char*>(buf.data()), expected.c_str()) == 0;
+}
+
+} // anonymous namespace
+
+// ========== Route Tests (Single Producer, Multiple Consumer) ==========
+
+class RouteTest : public ::testing::Test {
+protected:
+  void TearDown() override {
+      std::this_thread::sleep_for(std::chrono::milliseconds(10));
+  }
+};
+
+// Test default construction
+TEST_F(RouteTest, DefaultConstruction) {
+  route r;
+  EXPECT_FALSE(r.valid());
+}
+
+// Test construction with name
+TEST_F(RouteTest, ConstructionWithName) {
+  std::string name = generate_unique_ipc_name("route_ctor");
+  
+  route r(name.c_str(), sender);
+  EXPECT_TRUE(r.valid());
+  EXPECT_STREQ(r.name(), name.c_str());
+}
+
+// Test construction with prefix
+TEST_F(RouteTest, ConstructionWithPrefix) {
+  std::string name = generate_unique_ipc_name("route_prefix");
+  
+  route r(prefix{"my_prefix"}, name.c_str(), sender);
+  EXPECT_TRUE(r.valid());
+}
+
+// Test move constructor
+TEST_F(RouteTest, MoveConstructor) {
+  std::string name = generate_unique_ipc_name("route_move");
+  
+  route r1(name.c_str(), sender);
+  ASSERT_TRUE(r1.valid());
+  
+  const char* name_ptr = r1.name();
+  
+  route r2(std::move(r1));
+  
+  EXPECT_TRUE(r2.valid());
+  EXPECT_STREQ(r2.name(), name_ptr);
+}
+
+// Test assignment operator
+TEST_F(RouteTest, Assignment) {
+  std::string name = generate_unique_ipc_name("route_assign");
+  
+  route r1(name.c_str(), sender);
+  route r2;
+  
+  r2 = std::move(r1);
+  
+  EXPECT_TRUE(r2.valid());
+}
+
+// Test connect method
+TEST_F(RouteTest, Connect) {
+  std::string name = generate_unique_ipc_name("route_connect");
+  
+  route r;
+  bool connected = r.connect(name.c_str(), sender);
+  
+  EXPECT_TRUE(connected);
+  EXPECT_TRUE(r.valid());
+}
+
+// Test connect with prefix
+TEST_F(RouteTest, ConnectWithPrefix) {
+  std::string name = generate_unique_ipc_name("route_connect_prefix");
+  
+  route r;
+  bool connected = r.connect(prefix{"test"}, name.c_str(), sender);
+  
+  EXPECT_TRUE(connected);
+  EXPECT_TRUE(r.valid());
+}
+
+// Test reconnect
+TEST_F(RouteTest, Reconnect) {
+  std::string name = generate_unique_ipc_name("route_reconnect");
+  
+  route r(name.c_str(), sender);
+  ASSERT_TRUE(r.valid());
+  
+  bool reconnected = r.reconnect(sender | receiver);
+  EXPECT_TRUE(reconnected);
+}
+
+// Test disconnect
+TEST_F(RouteTest, Disconnect) {
+  std::string name = generate_unique_ipc_name("route_disconnect");
+  
+  route r(name.c_str(), sender);
+  ASSERT_TRUE(r.valid());
+  
+  r.disconnect();
+  // After disconnect, behavior depends on implementation
+}
+
+// Test clone
+TEST_F(RouteTest, Clone) {
+  std::string name = generate_unique_ipc_name("route_clone");
+  
+  route r1(name.c_str(), sender);
+  ASSERT_TRUE(r1.valid());
+  
+  route r2 = r1.clone();
+  
+  EXPECT_TRUE(r2.valid());
+  EXPECT_STREQ(r1.name(), r2.name());
+}
+
+// Test mode accessor
+TEST_F(RouteTest, Mode) {
+  std::string name = generate_unique_ipc_name("route_mode");
+  
+  route r(name.c_str(), sender);
+  EXPECT_EQ(r.mode(), sender);
+}
+
+// Test release
+TEST_F(RouteTest, Release) {
+  std::string name = generate_unique_ipc_name("route_release");
+  
+  route r(name.c_str(), sender);
+  ASSERT_TRUE(r.valid());
+  
+  r.release();
+  EXPECT_FALSE(r.valid());
+}
+
+// Test clear
+TEST_F(RouteTest, Clear) {
+  std::string name = generate_unique_ipc_name("route_clear");
+  
+  route r(name.c_str(), sender);
+  ASSERT_TRUE(r.valid());
+  
+  r.clear();
+  EXPECT_FALSE(r.valid());
+}
+
+// Test clear_storage static method
+TEST_F(RouteTest, ClearStorage) {
+  std::string name = generate_unique_ipc_name("route_clear_storage");
+  
+  {
+      route r(name.c_str(), sender);
+      EXPECT_TRUE(r.valid());
+  }
+  
+  route::clear_storage(name.c_str());
+}
+
+// Test clear_storage with prefix
+TEST_F(RouteTest, ClearStorageWithPrefix) {
+  std::string name = generate_unique_ipc_name("route_clear_prefix");
+  
+  {
+      route r(prefix{"test"}, name.c_str(), sender);
+      EXPECT_TRUE(r.valid());
+  }
+  
+  route::clear_storage(prefix{"test"}, name.c_str());
+}
+
+// Test send without receiver (should fail)
+TEST_F(RouteTest, SendWithoutReceiver) {
+  std::string name = generate_unique_ipc_name("route_send_no_recv");
+  
+  route r(name.c_str(), sender);
+  ASSERT_TRUE(r.valid());
+  
+  buffer buf = make_test_buffer("test");
+  bool sent = r.send(buf, 10); // 10ms timeout
+  
+  EXPECT_FALSE(sent); // Should fail - no receiver
+}
+
+// Test try_send without receiver
+TEST_F(RouteTest, TrySendWithoutReceiver) {
+  std::string name = generate_unique_ipc_name("route_try_send_no_recv");
+  
+  route r(name.c_str(), sender);
+  ASSERT_TRUE(r.valid());
+  
+  buffer buf = make_test_buffer("test");
+  bool sent = r.try_send(buf, 10);
+  
+  EXPECT_FALSE(sent);
+}
+
+// Test send and receive with buffer
+TEST_F(RouteTest, SendReceiveBuffer) {
+  std::string name = generate_unique_ipc_name("route_send_recv_buf");
+  
+  route sender_r(name.c_str(), sender);
+  route receiver_r(name.c_str(), receiver);
+  
+  ASSERT_TRUE(sender_r.valid());
+  ASSERT_TRUE(receiver_r.valid());
+  
+  buffer send_buf = make_test_buffer("Hello Route");
+  
+  std::thread sender_thread([&]() {
+      bool sent = sender_r.send(send_buf);
+      EXPECT_TRUE(sent);
+  });
+  
+  std::thread receiver_thread([&]() {
+      buffer recv_buf = receiver_r.recv();
+      EXPECT_TRUE(check_buffer_content(recv_buf, "Hello Route"));
+  });
+  
+  sender_thread.join();
+  receiver_thread.join();
+}
+
+// Test send and receive with string
+TEST_F(RouteTest, SendReceiveString) {
+  std::string name = generate_unique_ipc_name("route_send_recv_str");
+  
+  route sender_r(name.c_str(), sender);
+  route receiver_r(name.c_str(), receiver);
+  
+  ASSERT_TRUE(sender_r.valid());
+  ASSERT_TRUE(receiver_r.valid());
+  
+  std::string test_str = "Test String";
+  
+  std::thread sender_thread([&]() {
+      bool sent = sender_r.send(test_str);
+      EXPECT_TRUE(sent);
+  });
+  
+  std::thread receiver_thread([&]() {
+      buffer recv_buf = receiver_r.recv();
+      EXPECT_TRUE(check_buffer_content(recv_buf, test_str));
+  });
+  
+  sender_thread.join();
+  receiver_thread.join();
+}
+
+// Test send and receive with raw data
+TEST_F(RouteTest, SendReceiveRawData) {
+  std::string name = generate_unique_ipc_name("route_send_recv_raw");
+  
+  route sender_r(name.c_str(), sender);
+  route receiver_r(name.c_str(), receiver);
+  
+  ASSERT_TRUE(sender_r.valid());
+  ASSERT_TRUE(receiver_r.valid());
+  
+  const char* data = "Raw Data Test";
+  std::size_t size = std::strlen(data) + 1;
+  
+  std::thread sender_thread([&]() {
+      bool sent = sender_r.send(data, size);
+      EXPECT_TRUE(sent);
+  });
+  
+  std::thread receiver_thread([&]() {
+      buffer recv_buf = receiver_r.recv();
+      EXPECT_EQ(recv_buf.size(), size);
+      EXPECT_STREQ(static_cast<const char*>(recv_buf.data()), data);
+  });
+  
+  sender_thread.join();
+  receiver_thread.join();
+}
+
+// Test try_recv when empty
+TEST_F(RouteTest, TryRecvEmpty) {
+  std::string name = generate_unique_ipc_name("route_try_recv_empty");
+  
+  route r(name.c_str(), receiver);
+  ASSERT_TRUE(r.valid());
+  
+  buffer buf = r.try_recv();
+  EXPECT_TRUE(buf.empty());
+}
+
+// Test recv_count
+TEST_F(RouteTest, RecvCount) {
+  std::string name = generate_unique_ipc_name("route_recv_count");
+  
+  route sender_r(name.c_str(), sender);
+  route receiver_r(name.c_str(), receiver);
+  
+  ASSERT_TRUE(sender_r.valid());
+  ASSERT_TRUE(receiver_r.valid());
+  
+  std::size_t count = sender_r.recv_count();
+  EXPECT_GE(count, 0u);
+}
+
+// Test wait_for_recv
+TEST_F(RouteTest, WaitForRecv) {
+  std::string name = generate_unique_ipc_name("route_wait_recv");
+  
+  route sender_r(name.c_str(), sender);
+  
+  std::thread receiver_thread([&]() {
+      std::this_thread::sleep_for(std::chrono::milliseconds(50));
+      route receiver_r(name.c_str(), receiver);
+  });
+  
+  bool waited = sender_r.wait_for_recv(1, 500);
+  
+  receiver_thread.join();
+  
+  // Result depends on timing
+}
+
+// Test static wait_for_recv
+TEST_F(RouteTest, StaticWaitForRecv) {
+  std::string name = generate_unique_ipc_name("route_static_wait");
+  
+  std::thread receiver_thread([&]() {
+      std::this_thread::sleep_for(std::chrono::milliseconds(50));
+      route receiver_r(name.c_str(), receiver);
+  });
+  
+  bool waited = route::wait_for_recv(name.c_str(), 1, 500);
+  
+  receiver_thread.join();
+}
+
+// Test one sender, multiple receivers
+TEST_F(RouteTest, OneSenderMultipleReceivers) {
+  std::string name = generate_unique_ipc_name("route_1_to_n");
+  
+  route sender_r(name.c_str(), sender);
+  ASSERT_TRUE(sender_r.valid());
+  
+  const int num_receivers = 3;
+  std::vector<std::atomic<bool>> received(num_receivers);
+  for (auto& r : received) r.store(false);
+  
+  std::vector<std::thread> receivers;
+  for (int i = 0; i < num_receivers; ++i) {
+      receivers.emplace_back([&, i]() {
+          route receiver_r(name.c_str(), receiver);
+          buffer buf = receiver_r.recv(1000);
+          if (check_buffer_content(buf, "Broadcast")) {
+              received[i].store(true);
+          }
+      });
+  }
+  
+  std::this_thread::sleep_for(std::chrono::milliseconds(50));
+  
+  sender_r.send(std::string("Broadcast"));
+  
+  for (auto& t : receivers) {
+      t.join();
+  }
+  
+  // All receivers should receive the message (broadcast)
+  for (const auto& r : received) {
+      EXPECT_TRUE(r.load());
+  }
+}
+
+// ========== Channel Tests (Multiple Producer, Multiple Consumer) ==========
+
+class ChannelTest : public ::testing::Test {
+protected:
+  void TearDown() override {
+      std::this_thread::sleep_for(std::chrono::milliseconds(10));
+  }
+};
+
+// Test default construction
+TEST_F(ChannelTest, DefaultConstruction) {
+  channel ch;
+  EXPECT_FALSE(ch.valid());
+}
+
+// Test construction with name
+TEST_F(ChannelTest, ConstructionWithName) {
+  std::string name = generate_unique_ipc_name("channel_ctor");
+  
+  channel ch(name.c_str(), sender);
+  EXPECT_TRUE(ch.valid());
+  EXPECT_STREQ(ch.name(), name.c_str());
+}
+
+// Test send and receive
+TEST_F(ChannelTest, SendReceive) {
+  std::string name = generate_unique_ipc_name("channel_send_recv");
+  
+  channel sender_ch(name.c_str(), sender);
+  channel receiver_ch(name.c_str(), receiver);
+  
+  ASSERT_TRUE(sender_ch.valid());
+  ASSERT_TRUE(receiver_ch.valid());
+  
+  std::thread sender_thread([&]() {
+      sender_ch.send(std::string("Channel Test"));
+  });
+  
+  std::thread receiver_thread([&]() {
+      buffer buf = receiver_ch.recv();
+      EXPECT_TRUE(check_buffer_content(buf, "Channel Test"));
+  });
+  
+  sender_thread.join();
+  receiver_thread.join();
+}
+
+// Test multiple senders
+TEST_F(ChannelTest, MultipleSenders) {
+  std::string name = generate_unique_ipc_name("channel_multi_send");
+  
+  channel receiver_ch(name.c_str(), receiver);
+  ASSERT_TRUE(receiver_ch.valid());
+  
+  const int num_senders = 3;
+  std::atomic<int> received_count{0};
+  
+  std::vector<std::thread> senders;
+  for (int i = 0; i < num_senders; ++i) {
+      senders.emplace_back([&, i]() {
+          channel sender_ch(name.c_str(), sender);
+          std::string msg = "Sender" + std::to_string(i);
+          sender_ch.send(msg);
+      });
+  }
+  
+  std::thread receiver([&]() {
+      for (int i = 0; i < num_senders; ++i) {
+          buffer buf = receiver_ch.recv(1000);
+          if (!buf.empty()) {
+              ++received_count;
+          }
+      }
+  });
+  
+  for (auto& t : senders) {
+      t.join();
+  }
+  receiver.join();
+  
+  EXPECT_EQ(received_count.load(), num_senders);
+}
+
+// Test multiple senders and receivers
+TEST_F(ChannelTest, MultipleSendersReceivers) {
+  std::string name = generate_unique_ipc_name("channel_m_to_n");
+  
+  const int num_senders = 2;
+  const int num_receivers = 2;
+  const int messages_per_sender = 5;
+  const int total_messages = num_senders * messages_per_sender;  // Each receiver should get all messages
+  
+  std::atomic<int> sent_count{0};
+  std::atomic<int> received_count{0};
+  
+  // Use latch to ensure receivers are ready before senders start
+  latch receivers_ready(num_receivers);
+  
+  std::vector<std::thread> receivers;
+  for (int i = 0; i < num_receivers; ++i) {
+      receivers.emplace_back([&, i]() {
+          channel ch(name.c_str(), receiver);
+          receivers_ready.count_down();  // Signal this receiver is ready
+          
+          // Each receiver should receive ALL messages from ALL senders (broadcast mode)
+          for (int j = 0; j < total_messages; ++j) {
+              buffer buf = ch.recv(2000);
+              if (!buf.empty()) {
+                  ++received_count;
+              }
+          }
+      });
+  }
+  
+  // Wait for all receivers to be ready
+  receivers_ready.wait();
+  
+  std::vector<std::thread> senders;
+  for (int i = 0; i < num_senders; ++i) {
+      senders.emplace_back([&, i]() {
+          channel ch(name.c_str(), sender);
+          for (int j = 0; j < messages_per_sender; ++j) {
+              std::string msg = "S" + std::to_string(i) + "M" + std::to_string(j);
+              if (ch.send(msg, 1000)) {
+                  ++sent_count;
+              }
+              std::this_thread::sleep_for(std::chrono::milliseconds(10));
+          }
+      });
+  }
+  
+  for (auto& t : senders) {
+      t.join();
+  }
+  for (auto& t : receivers) {
+      t.join();
+  }
+  
+  EXPECT_EQ(sent_count.load(), num_senders * messages_per_sender);
+  // All messages should be received (broadcast mode)
+  EXPECT_EQ(received_count.load(), num_senders * messages_per_sender * num_receivers);
+}
+
+// Test try_send and try_recv
+TEST_F(ChannelTest, TrySendTryRecv) {
+  std::string name = generate_unique_ipc_name("channel_try");
+  
+  channel sender_ch(name.c_str(), sender);
+  channel receiver_ch(name.c_str(), receiver);
+  
+  ASSERT_TRUE(sender_ch.valid());
+  ASSERT_TRUE(receiver_ch.valid());
+  
+  bool sent = sender_ch.try_send(std::string("Try Test"));
+  
+  if (sent) {
+      buffer buf = receiver_ch.try_recv();
+      EXPECT_FALSE(buf.empty());
+  }
+}
+
+// Test timeout scenarios
+TEST_F(ChannelTest, SendTimeout) {
+  std::string name = generate_unique_ipc_name("channel_timeout");
+  
+  channel ch(name.c_str(), sender);
+  ASSERT_TRUE(ch.valid());
+  
+  // Send with very short timeout (may fail without receiver)
+  bool sent = ch.send(std::string("Timeout Test"), 1);
+}
+
+// Test clear and clear_storage
+TEST_F(ChannelTest, ClearStorage) {
+  std::string name = generate_unique_ipc_name("channel_clear");
+  
+  {
+      channel ch(name.c_str(), sender);
+      EXPECT_TRUE(ch.valid());
+  }
+  
+  channel::clear_storage(name.c_str());
+}
+
+// Test handle() method
+TEST_F(ChannelTest, Handle) {
+  std::string name = generate_unique_ipc_name("channel_handle");
+  
+  channel ch(name.c_str(), sender);
+  ASSERT_TRUE(ch.valid());
+  
+  handle_t h = ch.handle();
+  EXPECT_NE(h, nullptr);
+}

test/test_locks.cpp

@@ -0,0 +1,613 @@
+/**
+ * @file test_locks.cpp
+ * @brief Comprehensive unit tests for ipc::rw_lock and ipc::spin_lock classes
+ * 
+ * This test suite covers:
+ * - spin_lock: basic lock/unlock operations
+ * - rw_lock: read-write lock functionality
+ * - rw_lock: exclusive (write) locks
+ * - rw_lock: shared (read) locks
+ * - Concurrent access patterns
+ * - Reader-writer scenarios
+ */
+
+#include <gtest/gtest.h>
+#include <thread>
+#include <chrono>
+#include <atomic>
+#include <vector>
+#include "libipc/rw_lock.h"
+
+using namespace ipc;
+
+// ========== spin_lock Tests ==========
+
+class SpinLockTest : public ::testing::Test {
+protected:
+  void TearDown() override {
+      std::this_thread::sleep_for(std::chrono::milliseconds(5));
+  }
+};
+
+// Test basic lock and unlock
+TEST_F(SpinLockTest, BasicLockUnlock) {
+  spin_lock lock;
+  
+  lock.lock();
+  lock.unlock();
+  
+  // Should complete without hanging
+}
+
+// Test multiple lock/unlock cycles
+TEST_F(SpinLockTest, MultipleCycles) {
+  spin_lock lock;
+  
+  for (int i = 0; i < 100; ++i) {
+      lock.lock();
+      lock.unlock();
+  }
+}
+
+// Test critical section protection
+TEST_F(SpinLockTest, CriticalSection) {
+  spin_lock lock;
+  int counter = 0;
+  const int iterations = 1000;
+  
+  auto increment_task = [&]() {
+      for (int i = 0; i < iterations; ++i) {
+          lock.lock();
+          ++counter;
+          lock.unlock();
+      }
+  };
+  
+  std::thread t1(increment_task);
+  std::thread t2(increment_task);
+  
+  t1.join();
+  t2.join();
+  
+  EXPECT_EQ(counter, iterations * 2);
+}
+
+// Test mutual exclusion
+TEST_F(SpinLockTest, MutualExclusion) {
+  spin_lock lock;
+  std::atomic<bool> thread1_in_cs{false};
+  std::atomic<bool> thread2_in_cs{false};
+  std::atomic<bool> violation{false};
+  
+  auto cs_task = [&](std::atomic<bool>& my_flag, std::atomic<bool>& other_flag) {
+      for (int i = 0; i < 100; ++i) {
+          lock.lock();
+          
+          my_flag.store(true);
+          if (other_flag.load()) {
+              violation.store(true);
+          }
+          
+          std::this_thread::sleep_for(std::chrono::microseconds(10));
+          
+          my_flag.store(false);
+          lock.unlock();
+          
+          std::this_thread::yield();
+      }
+  };
+  
+  std::thread t1(cs_task, std::ref(thread1_in_cs), std::ref(thread2_in_cs));
+  std::thread t2(cs_task, std::ref(thread2_in_cs), std::ref(thread1_in_cs));
+  
+  t1.join();
+  t2.join();
+  
+  EXPECT_FALSE(violation.load());
+}
+
+// Test concurrent access
+TEST_F(SpinLockTest, ConcurrentAccess) {
+  spin_lock lock;
+  std::atomic<int> shared_data{0};
+  const int num_threads = 4;
+  const int ops_per_thread = 100;
+  
+  std::vector<std::thread> threads;
+  for (int i = 0; i < num_threads; ++i) {
+      threads.emplace_back([&]() {
+          for (int j = 0; j < ops_per_thread; ++j) {
+              lock.lock();
+              int temp = shared_data.load();
+              std::this_thread::yield();
+              shared_data.store(temp + 1);
+              lock.unlock();
+          }
+      });
+  }
+  
+  for (auto& t : threads) {
+      t.join();
+  }
+  
+  EXPECT_EQ(shared_data.load(), num_threads * ops_per_thread);
+}
+
+// Test rapid lock/unlock
+TEST_F(SpinLockTest, RapidLockUnlock) {
+  spin_lock lock;
+  
+  auto rapid_task = [&]() {
+      for (int i = 0; i < 10000; ++i) {
+          lock.lock();
+          lock.unlock();
+      }
+  };
+  
+  std::thread t1(rapid_task);
+  std::thread t2(rapid_task);
+  
+  t1.join();
+  t2.join();
+  
+  // Should complete without deadlock
+}
+
+// Test contention scenario
+TEST_F(SpinLockTest, Contention) {
+  spin_lock lock;
+  std::atomic<int> work_done{0};
+  const int num_threads = 8;
+  
+  std::vector<std::thread> threads;
+  for (int i = 0; i < num_threads; ++i) {
+      threads.emplace_back([&]() {
+          for (int j = 0; j < 50; ++j) {
+              lock.lock();
+              ++work_done;
+              std::this_thread::sleep_for(std::chrono::microseconds(100));
+              lock.unlock();
+              std::this_thread::yield();
+          }
+      });
+  }
+  
+  for (auto& t : threads) {
+      t.join();
+  }
+  
+  EXPECT_EQ(work_done.load(), num_threads * 50);
+}
+
+// ========== rw_lock Tests ==========
+
+class RWLockTest : public ::testing::Test {
+protected:
+  void TearDown() override {
+      std::this_thread::sleep_for(std::chrono::milliseconds(5));
+  }
+};
+
+// Test basic write lock and unlock
+TEST_F(RWLockTest, BasicWriteLock) {
+  rw_lock lock;
+  
+  lock.lock();
+  lock.unlock();
+  
+  // Should complete without hanging
+}
+
+// Test basic read lock and unlock
+TEST_F(RWLockTest, BasicReadLock) {
+  rw_lock lock;
+  
+  lock.lock_shared();
+  lock.unlock_shared();
+  
+  // Should complete without hanging
+}
+
+// Test multiple write cycles
+TEST_F(RWLockTest, MultipleWriteCycles) {
+  rw_lock lock;
+  
+  for (int i = 0; i < 100; ++i) {
+      lock.lock();
+      lock.unlock();
+  }
+}
+
+// Test multiple read cycles
+TEST_F(RWLockTest, MultipleReadCycles) {
+  rw_lock lock;
+  
+  for (int i = 0; i < 100; ++i) {
+      lock.lock_shared();
+      lock.unlock_shared();
+  }
+}
+
+// Test write lock protects data
+TEST_F(RWLockTest, WriteLockProtection) {
+  rw_lock lock;
+  int data = 0;
+  const int iterations = 500;
+  
+  auto writer_task = [&]() {
+      for (int i = 0; i < iterations; ++i) {
+          lock.lock();
+          ++data;
+          lock.unlock();
+      }
+  };
+  
+  std::thread t1(writer_task);
+  std::thread t2(writer_task);
+  
+  t1.join();
+  t2.join();
+  
+  EXPECT_EQ(data, iterations * 2);
+}
+
+// Test multiple readers can access concurrently
+TEST_F(RWLockTest, ConcurrentReaders) {
+  rw_lock lock;
+  std::atomic<int> concurrent_readers{0};
+  std::atomic<int> max_concurrent{0};
+  
+  const int num_readers = 5;
+  
+  std::vector<std::thread> readers;
+  for (int i = 0; i < num_readers; ++i) {
+      readers.emplace_back([&]() {
+          for (int j = 0; j < 20; ++j) {
+              lock.lock_shared();
+              
+              int current = ++concurrent_readers;
+              
+              // Track maximum concurrent readers
+              int current_max = max_concurrent.load();
+              while (current > current_max) {
+                  if (max_concurrent.compare_exchange_weak(current_max, current)) {
+                      break;
+                  }
+              }
+              
+              std::this_thread::sleep_for(std::chrono::microseconds(100));
+              
+              --concurrent_readers;
+              lock.unlock_shared();
+              
+              std::this_thread::yield();
+          }
+      });
+  }
+  
+  for (auto& t : readers) {
+      t.join();
+  }
+  
+  // Should have had multiple concurrent readers
+  EXPECT_GT(max_concurrent.load(), 1);
+}
+
+// Test writers have exclusive access
+TEST_F(RWLockTest, WriterExclusiveAccess) {
+  rw_lock lock;
+  std::atomic<bool> writer_in_cs{false};
+  std::atomic<bool> violation{false};
+  
+  auto writer_task = [&]() {
+      for (int i = 0; i < 50; ++i) {
+          lock.lock();
+          
+          if (writer_in_cs.exchange(true)) {
+              violation.store(true);
+          }
+          
+          std::this_thread::sleep_for(std::chrono::microseconds(50));
+          
+          writer_in_cs.store(false);
+          lock.unlock();
+          
+          std::this_thread::yield();
+      }
+  };
+  
+  std::thread t1(writer_task);
+  std::thread t2(writer_task);
+  
+  t1.join();
+  t2.join();
+  
+  EXPECT_FALSE(violation.load());
+}
+
+// Test readers and writers don't overlap
+TEST_F(RWLockTest, ReadersWritersNoOverlap) {
+  rw_lock lock;
+  std::atomic<int> readers{0};
+  std::atomic<bool> writer_active{false};
+  std::atomic<bool> violation{false};
+  
+  auto reader_task = [&]() {
+      for (int i = 0; i < 30; ++i) {
+          lock.lock_shared();
+          
+          ++readers;
+          if (writer_active.load()) {
+              violation.store(true);
+          }
+          
+          std::this_thread::sleep_for(std::chrono::microseconds(50));
+          
+          --readers;
+          lock.unlock_shared();
+          
+          std::this_thread::yield();
+      }
+  };
+  
+  auto writer_task = [&]() {
+      for (int i = 0; i < 15; ++i) {
+          lock.lock();
+          
+          writer_active.store(true);
+          if (readers.load() > 0) {
+              violation.store(true);
+          }
+          
+          std::this_thread::sleep_for(std::chrono::microseconds(50));
+          
+          writer_active.store(false);
+          lock.unlock();
+          
+          std::this_thread::yield();
+      }
+  };
+  
+  std::thread r1(reader_task);
+  std::thread r2(reader_task);
+  std::thread w1(writer_task);
+  
+  r1.join();
+  r2.join();
+  w1.join();
+  
+  EXPECT_FALSE(violation.load());
+}
+
+// Test read-write-read pattern
+TEST_F(RWLockTest, ReadWriteReadPattern) {
+  rw_lock lock;
+  int data = 0;
+  std::atomic<int> iterations{0};
+  
+  auto pattern_task = [&](int id) {
+      for (int i = 0; i < 20; ++i) {
+          // Write: increment based on thread id
+          lock.lock();
+          data += id;
+          lock.unlock();
+          
+          iterations.fetch_add(1);
+          std::this_thread::yield();
+          
+          // Read: verify data is consistent
+          lock.lock_shared();
+          int read_val = data;
+          EXPECT_GE(read_val, 0);  // Data should be non-negative
+          lock.unlock_shared();
+          
+          std::this_thread::yield();
+      }
+  };
+  
+  std::thread t1(pattern_task, 1);
+  std::thread t2(pattern_task, 2);
+  
+  t1.join();
+  t2.join();
+  
+  // Each thread increments by its id (1 or 2), 20 times each
+  // Total = 1*20 + 2*20 = 20 + 40 = 60
+  EXPECT_EQ(data, 60);
+  EXPECT_EQ(iterations.load(), 40);
+}
+
+// Test many readers, one writer
+TEST_F(RWLockTest, ManyReadersOneWriter) {
+  rw_lock lock;
+  std::atomic<int> data{0};
+  std::atomic<int> read_count{0};
+  
+  const int num_readers = 10;
+  
+  std::vector<std::thread> readers;
+  for (int i = 0; i < num_readers; ++i) {
+      readers.emplace_back([&]() {
+          for (int j = 0; j < 50; ++j) {
+              lock.lock_shared();
+              int val = data.load();
+              ++read_count;
+              lock.unlock_shared();
+              std::this_thread::yield();
+          }
+      });
+  }
+  
+  std::thread writer([&]() {
+      for (int i = 0; i < 100; ++i) {
+          lock.lock();
+          data.store(data.load() + 1);
+          lock.unlock();
+          std::this_thread::yield();
+      }
+  });
+  
+  for (auto& t : readers) {
+      t.join();
+  }
+  writer.join();
+  
+  EXPECT_EQ(data.load(), 100);
+  EXPECT_EQ(read_count.load(), num_readers * 50);
+}
+
+// Test rapid read lock/unlock
+TEST_F(RWLockTest, RapidReadLocks) {
+  rw_lock lock;
+  
+  auto rapid_read = [&]() {
+      for (int i = 0; i < 5000; ++i) {
+          lock.lock_shared();
+          lock.unlock_shared();
+      }
+  };
+  
+  std::thread t1(rapid_read);
+  std::thread t2(rapid_read);
+  std::thread t3(rapid_read);
+  
+  t1.join();
+  t2.join();
+  t3.join();
+}
+
+// Test rapid write lock/unlock
+TEST_F(RWLockTest, RapidWriteLocks) {
+  rw_lock lock;
+  
+  auto rapid_write = [&]() {
+      for (int i = 0; i < 2000; ++i) {
+          lock.lock();
+          lock.unlock();
+      }
+  };
+  
+  std::thread t1(rapid_write);
+  std::thread t2(rapid_write);
+  
+  t1.join();
+  t2.join();
+}
+
+// Test mixed rapid operations
+TEST_F(RWLockTest, MixedRapidOperations) {
+  rw_lock lock;
+  
+  auto rapid_read = [&]() {
+      for (int i = 0; i < 1000; ++i) {
+          lock.lock_shared();
+          lock.unlock_shared();
+      }
+  };
+  
+  auto rapid_write = [&]() {
+      for (int i = 0; i < 500; ++i) {
+          lock.lock();
+          lock.unlock();
+      }
+  };
+  
+  std::thread r1(rapid_read);
+  std::thread r2(rapid_read);
+  std::thread w1(rapid_write);
+  
+  r1.join();
+  r2.join();
+  w1.join();
+}
+
+// Test write lock doesn't allow concurrent readers
+TEST_F(RWLockTest, WriteLockBlocksReaders) {
+  rw_lock lock;
+  std::atomic<bool> write_locked{false};
+  std::atomic<bool> reader_entered{false};
+  
+  std::thread writer([&]() {
+      lock.lock();
+      write_locked.store(true);
+      std::this_thread::sleep_for(std::chrono::milliseconds(100));
+      write_locked.store(false);
+      lock.unlock();
+  });
+  
+  std::thread reader([&]() {
+      std::this_thread::sleep_for(std::chrono::milliseconds(20));
+      
+      lock.lock_shared();
+      if (write_locked.load()) {
+          reader_entered.store(true);
+      }
+      lock.unlock_shared();
+  });
+  
+  writer.join();
+  reader.join();
+  
+  // Reader should not have entered while writer held the lock
+  EXPECT_FALSE(reader_entered.load());
+}
+
+// Test multiple write lock upgrades
+TEST_F(RWLockTest, MultipleWriteLockPattern) {
+  rw_lock lock;
+  int data = 0;
+  
+  for (int i = 0; i < 100; ++i) {
+      // Read
+      lock.lock_shared();
+      int temp = data;
+      lock.unlock_shared();
+      
+      // Write
+      lock.lock();
+      data = temp + 1;
+      lock.unlock();
+  }
+  
+  EXPECT_EQ(data, 100);
+}
+
+// Test concurrent mixed operations
+TEST_F(RWLockTest, ConcurrentMixedOperations) {
+  rw_lock lock;
+  std::atomic<int> data{0};
+  std::atomic<int> reads{0};
+  std::atomic<int> writes{0};
+  
+  auto mixed_task = [&](int id) {
+      for (int i = 0; i < 50; ++i) {
+          if (i % 3 == 0) {
+              // Write operation
+              lock.lock();
+              data.store(data.load() + 1);
+              ++writes;
+              lock.unlock();
+          } else {
+              // Read operation
+              lock.lock_shared();
+              int val = data.load();
+              ++reads;
+              lock.unlock_shared();
+          }
+          std::this_thread::yield();
+      }
+  };
+  
+  std::thread t1(mixed_task, 1);
+  std::thread t2(mixed_task, 2);
+  std::thread t3(mixed_task, 3);
+  std::thread t4(mixed_task, 4);
+  
+  t1.join();
+  t2.join();
+  t3.join();
+  t4.join();
+  
+  EXPECT_GT(reads.load(), 0);
+  EXPECT_GT(writes.load(), 0);
+}

test/test_mutex.cpp

@@ -0,0 +1,501 @@
+/**
+ * @file test_mutex.cpp
+ * @brief Comprehensive unit tests for ipc::sync::mutex class
+ * 
+ * This test suite covers:
+ * - Mutex construction (default and named)
+ * - Lock/unlock operations
+ * - Try-lock functionality
+ * - Timed lock with timeout
+ * - Named mutex for inter-process synchronization
+ * - Resource cleanup (clear, clear_storage)
+ * - Native handle access
+ * - Concurrent access scenarios
+ */
+
+#include <gtest/gtest.h>
+#include <thread>
+#include <chrono>
+#include <atomic>
+#include <vector>
+#include "libipc/mutex.h"
+#include "libipc/def.h"
+
+using namespace ipc;
+using namespace ipc::sync;
+
+namespace {
+
+// Generate unique mutex names for tests
+std::string generate_unique_mutex_name(const char* prefix) {
+  static int counter = 0;
+  return std::string(prefix) + "_mutex_" + std::to_string(++counter);
+}
+
+} // anonymous namespace
+
+class MutexTest : public ::testing::Test {
+protected:
+  void TearDown() override {
+      // Allow time for cleanup
+      std::this_thread::sleep_for(std::chrono::milliseconds(10));
+  }
+};
+
+// Test default constructor
+TEST_F(MutexTest, DefaultConstructor) {
+  mutex mtx;
+  // Default constructed mutex may or may not be valid depending on implementation
+  // Just ensure it doesn't crash
+}
+
+// Test named constructor
+TEST_F(MutexTest, NamedConstructor) {
+  std::string name = generate_unique_mutex_name("named_ctor");
+  
+  mutex mtx(name.c_str());
+  EXPECT_TRUE(mtx.valid());
+}
+
+// Test native() const method
+TEST_F(MutexTest, NativeConst) {
+  std::string name = generate_unique_mutex_name("native_const");
+  
+  const mutex mtx(name.c_str());
+  const void* native_handle = mtx.native();
+  
+  EXPECT_NE(native_handle, nullptr);
+}
+
+// Test native() non-const method
+TEST_F(MutexTest, NativeNonConst) {
+  std::string name = generate_unique_mutex_name("native_nonconst");
+  
+  mutex mtx(name.c_str());
+  void* native_handle = mtx.native();
+  
+  EXPECT_NE(native_handle, nullptr);
+}
+
+// Test valid() method
+TEST_F(MutexTest, Valid) {
+  mutex mtx1;
+  // May or may not be valid without open
+  
+  std::string name = generate_unique_mutex_name("valid");
+  mutex mtx2(name.c_str());
+  EXPECT_TRUE(mtx2.valid());
+}
+
+// Test open() method
+TEST_F(MutexTest, Open) {
+  std::string name = generate_unique_mutex_name("open");
+  
+  mutex mtx;
+  bool result = mtx.open(name.c_str());
+  
+  EXPECT_TRUE(result);
+  EXPECT_TRUE(mtx.valid());
+}
+
+// Test close() method
+TEST_F(MutexTest, Close) {
+  std::string name = generate_unique_mutex_name("close");
+  
+  mutex mtx(name.c_str());
+  ASSERT_TRUE(mtx.valid());
+  
+  mtx.close();
+  EXPECT_FALSE(mtx.valid());
+}
+
+// Test clear() method
+TEST_F(MutexTest, Clear) {
+  std::string name = generate_unique_mutex_name("clear");
+  
+  mutex mtx(name.c_str());
+  ASSERT_TRUE(mtx.valid());
+  
+  mtx.clear();
+  EXPECT_FALSE(mtx.valid());
+}
+
+// Test clear_storage() static method
+TEST_F(MutexTest, ClearStorage) {
+  std::string name = generate_unique_mutex_name("clear_storage");
+  
+  {
+      mutex mtx(name.c_str());
+      EXPECT_TRUE(mtx.valid());
+  }
+  
+  mutex::clear_storage(name.c_str());
+  
+  // Try to open after clear - should create new or fail gracefully
+  mutex mtx2(name.c_str());
+}
+
+// Test basic lock and unlock
+TEST_F(MutexTest, LockUnlock) {
+  std::string name = generate_unique_mutex_name("lock_unlock");
+  
+  mutex mtx(name.c_str());
+  ASSERT_TRUE(mtx.valid());
+  
+  bool locked = mtx.lock();
+  EXPECT_TRUE(locked);
+  
+  bool unlocked = mtx.unlock();
+  EXPECT_TRUE(unlocked);
+}
+
+// Test try_lock
+TEST_F(MutexTest, TryLock) {
+  std::string name = generate_unique_mutex_name("try_lock");
+  
+  mutex mtx(name.c_str());
+  ASSERT_TRUE(mtx.valid());
+  
+  bool locked = mtx.try_lock();
+  EXPECT_TRUE(locked);
+  
+  if (locked) {
+      mtx.unlock();
+  }
+}
+
+// Test timed lock with infinite timeout
+TEST_F(MutexTest, TimedLockInfinite) {
+  std::string name = generate_unique_mutex_name("timed_lock_inf");
+  
+  mutex mtx(name.c_str());
+  ASSERT_TRUE(mtx.valid());
+  
+  bool locked = mtx.lock(invalid_value);
+  EXPECT_TRUE(locked);
+  
+  if (locked) {
+      mtx.unlock();
+  }
+}
+
+// Test timed lock with timeout
+TEST_F(MutexTest, TimedLockTimeout) {
+  std::string name = generate_unique_mutex_name("timed_lock_timeout");
+  
+  mutex mtx(name.c_str());
+  ASSERT_TRUE(mtx.valid());
+  
+  // Lock with 100ms timeout
+  bool locked = mtx.lock(100);
+  EXPECT_TRUE(locked);
+  
+  if (locked) {
+      mtx.unlock();
+  }
+}
+
+// Test mutex protects critical section
+TEST_F(MutexTest, CriticalSection) {
+  std::string name = generate_unique_mutex_name("critical_section");
+  
+  mutex mtx(name.c_str());
+  ASSERT_TRUE(mtx.valid());
+  
+  int shared_counter = 0;
+  const int iterations = 100;
+  
+  auto increment_task = [&]() {
+      for (int i = 0; i < iterations; ++i) {
+          mtx.lock();
+          ++shared_counter;
+          mtx.unlock();
+      }
+  };
+  
+  std::thread t1(increment_task);
+  std::thread t2(increment_task);
+  
+  t1.join();
+  t2.join();
+  
+  EXPECT_EQ(shared_counter, iterations * 2);
+}
+
+// Test concurrent try_lock
+TEST_F(MutexTest, ConcurrentTryLock) {
+  std::string name = generate_unique_mutex_name("concurrent_try");
+  
+  mutex mtx(name.c_str());
+  ASSERT_TRUE(mtx.valid());
+  
+  std::atomic<int> success_count{0};
+  std::atomic<int> fail_count{0};
+  
+  auto try_lock_task = [&]() {
+      for (int i = 0; i < 10; ++i) {
+          if (mtx.try_lock()) {
+              ++success_count;
+              std::this_thread::sleep_for(std::chrono::milliseconds(1));
+              mtx.unlock();
+          } else {
+              ++fail_count;
+          }
+          std::this_thread::yield();
+      }
+  };
+  
+  std::thread t1(try_lock_task);
+  std::thread t2(try_lock_task);
+  std::thread t3(try_lock_task);
+  
+  t1.join();
+  t2.join();
+  t3.join();
+  
+  EXPECT_GT(success_count.load(), 0);
+  // Some try_locks should succeed
+}
+
+// Test lock contention
+TEST_F(MutexTest, LockContention) {
+  std::string name = generate_unique_mutex_name("contention");
+  
+  mutex mtx(name.c_str());
+  ASSERT_TRUE(mtx.valid());
+  
+  std::atomic<bool> thread1_in_cs{false};
+  std::atomic<bool> thread2_in_cs{false};
+  std::atomic<bool> violation{false};
+  
+  auto contention_task = [&](std::atomic<bool>& my_flag, 
+                              std::atomic<bool>& other_flag) {
+      for (int i = 0; i < 50; ++i) {
+          mtx.lock();
+          
+          my_flag.store(true);
+          if (other_flag.load()) {
+              violation.store(true);
+          }
+          
+          std::this_thread::sleep_for(std::chrono::microseconds(10));
+          
+          my_flag.store(false);
+          mtx.unlock();
+          
+          std::this_thread::yield();
+      }
+  };
+  
+  std::thread t1(contention_task, std::ref(thread1_in_cs), std::ref(thread2_in_cs));
+  std::thread t2(contention_task, std::ref(thread2_in_cs), std::ref(thread1_in_cs));
+  
+  t1.join();
+  t2.join();
+  
+  // Should never have both threads in critical section
+  EXPECT_FALSE(violation.load());
+}
+
+// Test multiple lock/unlock cycles
+TEST_F(MutexTest, MultipleCycles) {
+  std::string name = generate_unique_mutex_name("cycles");
+  
+  mutex mtx(name.c_str());
+  ASSERT_TRUE(mtx.valid());
+  
+  for (int i = 0; i < 100; ++i) {
+      ASSERT_TRUE(mtx.lock());
+      ASSERT_TRUE(mtx.unlock());
+  }
+}
+
+// Test timed lock timeout scenario
+TEST_F(MutexTest, TimedLockTimeoutScenario) {
+  std::string name = generate_unique_mutex_name("timeout_scenario");
+  
+  mutex mtx(name.c_str());
+  ASSERT_TRUE(mtx.valid());
+  
+  // Lock in main thread
+  ASSERT_TRUE(mtx.lock());
+  
+  std::atomic<bool> timeout_occurred{false};
+  
+  std::thread t([&]() {
+      // Try to lock with short timeout - should timeout
+      bool locked = mtx.lock(50); // 50ms timeout
+      if (!locked) {
+          timeout_occurred.store(true);
+      } else {
+          mtx.unlock();
+      }
+  });
+  
+  std::this_thread::sleep_for(std::chrono::milliseconds(100));
+  mtx.unlock();
+  
+  t.join();
+  
+  // Timeout should have occurred since we held the lock
+  EXPECT_TRUE(timeout_occurred.load());
+}
+
+// Test reopen after close
+TEST_F(MutexTest, ReopenAfterClose) {
+  std::string name = generate_unique_mutex_name("reopen");
+  
+  mutex mtx;
+  
+  ASSERT_TRUE(mtx.open(name.c_str()));
+  EXPECT_TRUE(mtx.valid());
+  
+  mtx.close();
+  EXPECT_FALSE(mtx.valid());
+  
+  ASSERT_TRUE(mtx.open(name.c_str()));
+  EXPECT_TRUE(mtx.valid());
+}
+
+// Test named mutex inter-thread synchronization
+TEST_F(MutexTest, NamedMutexInterThread) {
+  std::string name = generate_unique_mutex_name("inter_thread");
+  
+  int shared_data = 0;
+  std::atomic<bool> t1_done{false};
+  std::atomic<bool> t2_done{false};
+  
+  std::thread t1([&]() {
+      mutex mtx(name.c_str());
+      ASSERT_TRUE(mtx.valid());
+      
+      mtx.lock();
+      shared_data = 100;
+      std::this_thread::sleep_for(std::chrono::milliseconds(50));
+      mtx.unlock();
+      
+      t1_done.store(true);
+  });
+  
+  std::thread t2([&]() {
+      // Wait a bit to ensure t1 starts first
+      std::this_thread::sleep_for(std::chrono::milliseconds(10));
+      
+      mutex mtx(name.c_str());
+      ASSERT_TRUE(mtx.valid());
+      
+      mtx.lock();
+      EXPECT_TRUE(t1_done.load() || shared_data == 100);
+      shared_data = 200;
+      mtx.unlock();
+      
+      t2_done.store(true);
+  });
+  
+  t1.join();
+  t2.join();
+  
+  EXPECT_EQ(shared_data, 200);
+}
+
+// Test exception safety of try_lock
+TEST_F(MutexTest, TryLockExceptionSafety) {
+  std::string name = generate_unique_mutex_name("try_lock_exception");
+  
+  mutex mtx(name.c_str());
+  ASSERT_TRUE(mtx.valid());
+  
+  bool exception_thrown = false;
+  try {
+      mtx.try_lock();
+  } catch (const std::system_error&) {
+      exception_thrown = true;
+  } catch (...) {
+      FAIL() << "Unexpected exception type";
+  }
+  
+  // try_lock may throw system_error
+  // Just ensure we can handle it
+}
+
+// Test concurrent open/close operations
+TEST_F(MutexTest, ConcurrentOpenClose) {
+  std::vector<std::thread> threads;
+  std::atomic<int> success_count{0};
+  
+  for (int i = 0; i < 5; ++i) {
+      threads.emplace_back([&, i]() {
+          std::string name = generate_unique_mutex_name("concurrent");
+          name += std::to_string(i);
+          
+          mutex mtx;
+          if (mtx.open(name.c_str())) {
+              ++success_count;
+              mtx.close();
+          }
+      });
+  }
+  
+  for (auto& t : threads) {
+      t.join();
+  }
+  
+  EXPECT_EQ(success_count.load(), 5);
+}
+
+// Test mutex with zero timeout
+TEST_F(MutexTest, ZeroTimeout) {
+  std::string name = generate_unique_mutex_name("zero_timeout");
+  
+  mutex mtx(name.c_str());
+  ASSERT_TRUE(mtx.valid());
+  
+  // Lock with zero timeout (should try once and return)
+  bool locked = mtx.lock(0);
+  
+  if (locked) {
+      mtx.unlock();
+  }
+  // Result may vary, just ensure it doesn't hang
+}
+
+// Test rapid lock/unlock sequence
+TEST_F(MutexTest, RapidLockUnlock) {
+  std::string name = generate_unique_mutex_name("rapid");
+  
+  mutex mtx(name.c_str());
+  ASSERT_TRUE(mtx.valid());
+  
+  auto rapid_task = [&]() {
+      for (int i = 0; i < 1000; ++i) {
+          mtx.lock();
+          mtx.unlock();
+      }
+  };
+  
+  std::thread t1(rapid_task);
+  std::thread t2(rapid_task);
+  
+  t1.join();
+  t2.join();
+  
+  // Should complete without deadlock or crash
+}
+
+// Test lock after clear
+TEST_F(MutexTest, LockAfterClear) {
+  std::string name = generate_unique_mutex_name("lock_after_clear");
+  
+  mutex mtx(name.c_str());
+  ASSERT_TRUE(mtx.valid());
+  
+  mtx.lock();
+  mtx.unlock();
+  
+  mtx.clear();
+  EXPECT_FALSE(mtx.valid());
+  
+  // Attempting to lock after clear should fail gracefully
+  bool locked = mtx.lock();
+  EXPECT_FALSE(locked);
+}

test/test_semaphore.cpp

@@ -0,0 +1,487 @@
+/**
+ * @file test_semaphore.cpp
+ * @brief Comprehensive unit tests for ipc::sync::semaphore class
+ * 
+ * This test suite covers:
+ * - Semaphore construction (default and named with count)
+ * - Wait and post operations
+ * - Timed wait with timeout
+ * - Named semaphore for inter-process synchronization
+ * - Resource cleanup (clear, clear_storage)
+ * - Producer-consumer patterns
+ * - Multiple wait/post scenarios
+ */
+
+#include <gtest/gtest.h>
+#include <thread>
+#include <chrono>
+#include <atomic>
+#include <vector>
+#include "libipc/semaphore.h"
+#include "libipc/def.h"
+
+using namespace ipc;
+using namespace ipc::sync;
+
+namespace {
+
+std::string generate_unique_sem_name(const char* prefix) {
+  static int counter = 0;
+  return std::string(prefix) + "_sem_" + std::to_string(++counter);
+}
+
+} // anonymous namespace
+
+class SemaphoreTest : public ::testing::Test {
+protected:
+  void TearDown() override {
+      std::this_thread::sleep_for(std::chrono::milliseconds(10));
+  }
+};
+
+// Test default constructor
+TEST_F(SemaphoreTest, DefaultConstructor) {
+  semaphore sem;
+  // Default constructed semaphore
+}
+
+// Test named constructor with count
+TEST_F(SemaphoreTest, NamedConstructorWithCount) {
+  std::string name = generate_unique_sem_name("named_count");
+  
+  semaphore sem(name.c_str(), 5);
+  EXPECT_TRUE(sem.valid());
+}
+
+// Test named constructor with zero count
+TEST_F(SemaphoreTest, NamedConstructorZeroCount) {
+  std::string name = generate_unique_sem_name("zero_count");
+  
+  semaphore sem(name.c_str(), 0);
+  EXPECT_TRUE(sem.valid());
+}
+
+// Test native() methods
+TEST_F(SemaphoreTest, NativeHandle) {
+  std::string name = generate_unique_sem_name("native");
+  
+  semaphore sem(name.c_str(), 1);
+  ASSERT_TRUE(sem.valid());
+  
+  const void* const_handle = static_cast<const semaphore&>(sem).native();
+  void* handle = sem.native();
+  
+  EXPECT_NE(const_handle, nullptr);
+  EXPECT_NE(handle, nullptr);
+}
+
+// Test valid() method
+TEST_F(SemaphoreTest, Valid) {
+  semaphore sem1;
+  
+  std::string name = generate_unique_sem_name("valid");
+  semaphore sem2(name.c_str(), 1);
+  EXPECT_TRUE(sem2.valid());
+}
+
+// Test open() method
+TEST_F(SemaphoreTest, Open) {
+  std::string name = generate_unique_sem_name("open");
+  
+  semaphore sem;
+  bool result = sem.open(name.c_str(), 3);
+  
+  EXPECT_TRUE(result);
+  EXPECT_TRUE(sem.valid());
+}
+
+// Test close() method
+TEST_F(SemaphoreTest, Close) {
+  std::string name = generate_unique_sem_name("close");
+  
+  semaphore sem(name.c_str(), 1);
+  ASSERT_TRUE(sem.valid());
+  
+  sem.close();
+  EXPECT_FALSE(sem.valid());
+}
+
+// Test clear() method
+TEST_F(SemaphoreTest, Clear) {
+  std::string name = generate_unique_sem_name("clear");
+  
+  semaphore sem(name.c_str(), 1);
+  ASSERT_TRUE(sem.valid());
+  
+  sem.clear();
+  EXPECT_FALSE(sem.valid());
+}
+
+// Test clear_storage() static method
+TEST_F(SemaphoreTest, ClearStorage) {
+  std::string name = generate_unique_sem_name("clear_storage");
+  
+  {
+      semaphore sem(name.c_str(), 1);
+      EXPECT_TRUE(sem.valid());
+  }
+  
+  semaphore::clear_storage(name.c_str());
+}
+
+// Test basic wait and post
+TEST_F(SemaphoreTest, WaitPost) {
+  std::string name = generate_unique_sem_name("wait_post");
+  
+  semaphore sem(name.c_str(), 1);
+  ASSERT_TRUE(sem.valid());
+  
+  bool waited = sem.wait();
+  EXPECT_TRUE(waited);
+  
+  bool posted = sem.post();
+  EXPECT_TRUE(posted);
+}
+
+// Test post with count
+TEST_F(SemaphoreTest, PostWithCount) {
+  std::string name = generate_unique_sem_name("post_count");
+  
+  semaphore sem(name.c_str(), 0);
+  ASSERT_TRUE(sem.valid());
+  
+  bool posted = sem.post(5);
+  EXPECT_TRUE(posted);
+  
+  // Now should be able to wait 5 times
+  for (int i = 0; i < 5; ++i) {
+      EXPECT_TRUE(sem.wait(10)); // 10ms timeout
+  }
+}
+
+// Test timed wait with timeout
+TEST_F(SemaphoreTest, TimedWait) {
+  std::string name = generate_unique_sem_name("timed_wait");
+  
+  semaphore sem(name.c_str(), 1);
+  ASSERT_TRUE(sem.valid());
+  
+  bool waited = sem.wait(100); // 100ms timeout
+  EXPECT_TRUE(waited);
+}
+
+// Test wait timeout scenario
+TEST_F(SemaphoreTest, WaitTimeout) {
+  std::string name = generate_unique_sem_name("wait_timeout");
+  
+  semaphore sem(name.c_str(), 0); // Zero count
+  ASSERT_TRUE(sem.valid());
+  
+  auto start = std::chrono::steady_clock::now();
+  bool waited = sem.wait(50); // 50ms timeout
+  auto end = std::chrono::steady_clock::now();
+  
+  auto elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+  
+  // Should timeout
+  EXPECT_FALSE(waited);
+  EXPECT_GE(elapsed, 40); // Allow some tolerance
+}
+
+// Test infinite wait
+TEST_F(SemaphoreTest, InfiniteWait) {
+  std::string name = generate_unique_sem_name("infinite_wait");
+  
+  semaphore sem(name.c_str(), 0);
+  ASSERT_TRUE(sem.valid());
+  
+  std::atomic<bool> wait_started{false};
+  std::atomic<bool> wait_succeeded{false};
+  
+  std::thread waiter([&]() {
+      wait_started.store(true);
+      bool result = sem.wait(invalid_value);
+      wait_succeeded.store(result);
+  });
+  
+  // Wait for thread to start waiting
+  while (!wait_started.load()) {
+      std::this_thread::sleep_for(std::chrono::milliseconds(1));
+  }
+  
+  std::this_thread::sleep_for(std::chrono::milliseconds(50));
+  
+  // Post to release the waiter
+  sem.post();
+  
+  waiter.join();
+  
+  EXPECT_TRUE(wait_succeeded.load());
+}
+
+// Test producer-consumer pattern
+TEST_F(SemaphoreTest, ProducerConsumer) {
+  std::string name = generate_unique_sem_name("prod_cons");
+  
+  semaphore sem(name.c_str(), 0);
+  ASSERT_TRUE(sem.valid());
+  
+  std::atomic<int> produced{0};
+  std::atomic<int> consumed{0};
+  const int count = 10;
+  
+  std::thread producer([&]() {
+      for (int i = 0; i < count; ++i) {
+          ++produced;
+          sem.post();
+          std::this_thread::sleep_for(std::chrono::milliseconds(1));
+      }
+  });
+  
+  std::thread consumer([&]() {
+      for (int i = 0; i < count; ++i) {
+          sem.wait();
+          ++consumed;
+      }
+  });
+  
+  producer.join();
+  consumer.join();
+  
+  EXPECT_EQ(produced.load(), count);
+  EXPECT_EQ(consumed.load(), count);
+}
+
+// Test multiple producers and consumers
+TEST_F(SemaphoreTest, MultipleProducersConsumers) {
+  std::string name = generate_unique_sem_name("multi_prod_cons");
+  
+  semaphore sem(name.c_str(), 0);
+  ASSERT_TRUE(sem.valid());
+  
+  std::atomic<int> total_produced{0};
+  std::atomic<int> total_consumed{0};
+  const int items_per_producer = 5;
+  const int num_producers = 3;
+  const int num_consumers = 3;
+  
+  std::vector<std::thread> producers;
+  for (int i = 0; i < num_producers; ++i) {
+      producers.emplace_back([&]() {
+          for (int j = 0; j < items_per_producer; ++j) {
+              ++total_produced;
+              sem.post();
+              std::this_thread::yield();
+          }
+      });
+  }
+  
+  std::vector<std::thread> consumers;
+  for (int i = 0; i < num_consumers; ++i) {
+      consumers.emplace_back([&]() {
+          for (int j = 0; j < items_per_producer; ++j) {
+              if (sem.wait(1000)) {
+                  ++total_consumed;
+              }
+          }
+      });
+  }
+  
+  for (auto& t : producers) t.join();
+  for (auto& t : consumers) t.join();
+  
+  EXPECT_EQ(total_produced.load(), items_per_producer * num_producers);
+  EXPECT_EQ(total_consumed.load(), items_per_producer * num_producers);
+}
+
+// Test semaphore with initial count
+TEST_F(SemaphoreTest, InitialCount) {
+  std::string name = generate_unique_sem_name("initial_count");
+  const uint32_t initial = 3;
+  
+  semaphore sem(name.c_str(), initial);
+  ASSERT_TRUE(sem.valid());
+  
+  // Should be able to wait 'initial' times without blocking
+  for (uint32_t i = 0; i < initial; ++i) {
+      EXPECT_TRUE(sem.wait(10));
+  }
+  
+  // Next wait should timeout
+  EXPECT_FALSE(sem.wait(10));
+}
+
+// Test rapid post operations
+TEST_F(SemaphoreTest, RapidPost) {
+  std::string name = generate_unique_sem_name("rapid_post");
+  
+  semaphore sem(name.c_str(), 0);
+  ASSERT_TRUE(sem.valid());
+  
+  const int post_count = 100;
+  for (int i = 0; i < post_count; ++i) {
+      EXPECT_TRUE(sem.post());
+  }
+  
+  // Should be able to wait post_count times
+  int wait_count = 0;
+  for (int i = 0; i < post_count; ++i) {
+      if (sem.wait(10)) {
+          ++wait_count;
+      }
+  }
+  
+  EXPECT_EQ(wait_count, post_count);
+}
+
+// Test concurrent post operations
+TEST_F(SemaphoreTest, ConcurrentPost) {
+  std::string name = generate_unique_sem_name("concurrent_post");
+  
+  semaphore sem(name.c_str(), 0);
+  ASSERT_TRUE(sem.valid());
+  
+  std::atomic<int> post_count{0};
+  const int threads = 5;
+  const int posts_per_thread = 10;
+  
+  std::vector<std::thread> posters;
+  for (int i = 0; i < threads; ++i) {
+      posters.emplace_back([&]() {
+          for (int j = 0; j < posts_per_thread; ++j) {
+              if (sem.post()) {
+                  ++post_count;
+              }
+          }
+      });
+  }
+  
+  for (auto& t : posters) t.join();
+  
+  EXPECT_EQ(post_count.load(), threads * posts_per_thread);
+  
+  // Verify by consuming
+  int consumed = 0;
+  for (int i = 0; i < threads * posts_per_thread; ++i) {
+      if (sem.wait(10)) {
+          ++consumed;
+      }
+  }
+  
+  EXPECT_EQ(consumed, threads * posts_per_thread);
+}
+
+// Test reopen after close
+TEST_F(SemaphoreTest, ReopenAfterClose) {
+  std::string name = generate_unique_sem_name("reopen");
+  
+  semaphore sem;
+  
+  ASSERT_TRUE(sem.open(name.c_str(), 2));
+  EXPECT_TRUE(sem.valid());
+  
+  sem.close();
+  EXPECT_FALSE(sem.valid());
+  
+  ASSERT_TRUE(sem.open(name.c_str(), 3));
+  EXPECT_TRUE(sem.valid());
+}
+
+// Test named semaphore sharing between threads
+TEST_F(SemaphoreTest, NamedSemaphoreSharing) {
+  std::string name = generate_unique_sem_name("sharing");
+  
+  std::atomic<int> value{0};
+  
+  std::thread t1([&]() {
+      semaphore sem(name.c_str(), 0);
+      ASSERT_TRUE(sem.valid());
+      
+      sem.wait(); // Wait for signal
+      value.store(100);
+  });
+  
+  std::thread t2([&]() {
+      std::this_thread::sleep_for(std::chrono::milliseconds(50));
+      
+      semaphore sem(name.c_str(), 0);
+      ASSERT_TRUE(sem.valid());
+      
+      sem.post(); // Signal t1
+  });
+  
+  t1.join();
+  t2.join();
+  
+  EXPECT_EQ(value.load(), 100);
+}
+
+// Test post multiple count at once
+TEST_F(SemaphoreTest, PostMultiple) {
+  std::string name = generate_unique_sem_name("post_multiple");
+  
+  semaphore sem(name.c_str(), 0);
+  ASSERT_TRUE(sem.valid());
+  
+  const uint32_t count = 10;
+  bool posted = sem.post(count);
+  EXPECT_TRUE(posted);
+  
+  // Consume all
+  for (uint32_t i = 0; i < count; ++i) {
+      EXPECT_TRUE(sem.wait(10));
+  }
+  
+  // Should be empty now
+  EXPECT_FALSE(sem.wait(10));
+}
+
+// Test semaphore after clear
+TEST_F(SemaphoreTest, AfterClear) {
+  std::string name = generate_unique_sem_name("after_clear");
+  
+  semaphore sem(name.c_str(), 5);
+  ASSERT_TRUE(sem.valid());
+  
+  sem.wait();
+  sem.clear();
+  EXPECT_FALSE(sem.valid());
+  
+  // Operations after clear should fail gracefully
+  EXPECT_FALSE(sem.wait(10));
+  EXPECT_FALSE(sem.post());
+}
+
+// Test zero timeout
+TEST_F(SemaphoreTest, ZeroTimeout) {
+  std::string name = generate_unique_sem_name("zero_timeout");
+  
+  semaphore sem(name.c_str(), 0);
+  ASSERT_TRUE(sem.valid());
+  
+  bool waited = sem.wait(0);
+  // Should return immediately (either success or timeout)
+}
+
+// Test high-frequency wait/post
+TEST_F(SemaphoreTest, HighFrequency) {
+  std::string name = generate_unique_sem_name("high_freq");
+  
+  semaphore sem(name.c_str(), 0);
+  ASSERT_TRUE(sem.valid());
+  
+  std::thread poster([&]() {
+      for (int i = 0; i < 1000; ++i) {
+          sem.post();
+      }
+  });
+  
+  std::thread waiter([&]() {
+      for (int i = 0; i < 1000; ++i) {
+          sem.wait(100);
+      }
+  });
+  
+  poster.join();
+  waiter.join();
+}

test/test_shm.cpp

@@ -1,102 +1,521 @@
+/**
+ * @file test_shm.cpp
+ * @brief Comprehensive unit tests for ipc::shm (shared memory) functionality
+ * 
+ * This test suite covers:
+ * - Low-level shared memory functions (acquire, get_mem, release, remove)
+ * - Reference counting (get_ref, sub_ref)
+ * - High-level handle class interface
+ * - Create and open modes
+ * - Resource cleanup and error handling
+ */
+
+#include <gtest/gtest.h>
 #include <cstring>
-#include <cstdint>
-#include <thread>
-
+#include <memory>
+#include <string>
 #include "libipc/shm.h"
-#include "test.h"
 
-using namespace ipc::shm;
+using namespace ipc;
 
 namespace {
 
-TEST(SHM, acquire) {
-    handle shm_hd;
-    EXPECT_FALSE(shm_hd.valid());
-
-    EXPECT_TRUE(shm_hd.acquire("my-test-1", 1024));
-    EXPECT_TRUE(shm_hd.valid());
-    EXPECT_STREQ(shm_hd.name(), "my-test-1");
-
-    EXPECT_TRUE(shm_hd.acquire("my-test-2", 2048));
-    EXPECT_TRUE(shm_hd.valid());
-    EXPECT_STREQ(shm_hd.name(), "my-test-2");
-
-    EXPECT_TRUE(shm_hd.acquire("my-test-3", 4096));
-    EXPECT_TRUE(shm_hd.valid());
-    EXPECT_STREQ(shm_hd.name(), "my-test-3");
+// Generate unique shared memory names for tests
+std::string generate_unique_name(const char* prefix) {
+  static int counter = 0;
+  return std::string(prefix) + "_test_" + std::to_string(++counter);
 }
 
-TEST(SHM, release) {
-    handle shm_hd;
-    EXPECT_FALSE(shm_hd.valid());
-    shm_hd.release();
-    EXPECT_FALSE(shm_hd.valid());
-    EXPECT_TRUE(shm_hd.acquire("release-test-1", 512));
-    EXPECT_TRUE(shm_hd.valid());
-    shm_hd.release();
-    EXPECT_FALSE(shm_hd.valid());
-}
+} // anonymous namespace
 
-TEST(SHM, get) {
-    handle shm_hd;
-    EXPECT_TRUE(shm_hd.get() == nullptr);
-    EXPECT_TRUE(shm_hd.acquire("get-test", 2048));
-
-    auto mem = shm_hd.get();
-    EXPECT_TRUE(mem != nullptr);
-    EXPECT_TRUE(mem == shm_hd.get());
-
-    std::uint8_t buf[1024] = {};
-    EXPECT_TRUE(memcmp(mem, buf, sizeof(buf)) == 0);
-
-    handle shm_other(shm_hd.name(), shm_hd.size());
-    EXPECT_TRUE(shm_other.get() != shm_hd.get());
-}
-
-TEST(SHM, hello) {
-    handle shm_hd;
-    EXPECT_TRUE(shm_hd.acquire("hello-test", 128));
-    auto mem = shm_hd.get();
-    EXPECT_TRUE(mem != nullptr);
-
-    constexpr char hello[] = "hello!";
-    std::memcpy(mem, hello, sizeof(hello));
-    EXPECT_STREQ((char const *)shm_hd.get(), hello);
-
-    shm_hd.release();
-    EXPECT_TRUE(shm_hd.get() == nullptr);
-    EXPECT_TRUE(shm_hd.acquire("hello-test", 1024));
-
-    mem = shm_hd.get();
-    EXPECT_TRUE(mem != nullptr);
-    std::uint8_t buf[1024] = {};
-    EXPECT_TRUE(memcmp(mem, buf, sizeof(buf)) == 0);
-
-    std::memcpy(mem, hello, sizeof(hello));
-    EXPECT_STREQ((char const *)shm_hd.get(), hello);
-}
-
-TEST(SHM, mt) {
-    handle shm_hd;
-    EXPECT_TRUE(shm_hd.acquire("mt-test", 256));
-    constexpr char hello[] = "hello!";
-    std::memcpy(shm_hd.get(), hello, sizeof(hello));
-
-    std::thread {
-        [&shm_hd] {
-            handle shm_mt(shm_hd.name(), shm_hd.size());
-            shm_hd.release();
-            constexpr char hello[] = "hello!";
-            EXPECT_STREQ((char const *)shm_mt.get(), hello);
+class ShmTest : public ::testing::Test {
+protected:
+  void TearDown() override {
+      // Clean up any leftover shared memory segments
   }
-    }.join();
+};
 
-    EXPECT_TRUE(shm_hd.get() == nullptr);
-    EXPECT_FALSE(shm_hd.valid());
+// ========== Low-level API Tests ==========
 
-    EXPECT_TRUE(shm_hd.acquire("mt-test", 1024));
-    std::uint8_t buf[1024] = {};
-    EXPECT_TRUE(memcmp(shm_hd.get(), buf, sizeof(buf)) == 0);
+// Test acquire with create mode
+TEST_F(ShmTest, AcquireCreate) {
+  std::string name = generate_unique_name("acquire_create");
+  const std::size_t size = 1024;
+  
+  shm::id_t id = shm::acquire(name.c_str(), size, shm::create);
+  ASSERT_NE(id, nullptr);
+  
+  std::size_t actual_size = 0;
+  void* mem = shm::get_mem(id, &actual_size);
+  EXPECT_NE(mem, nullptr);
+  EXPECT_GE(actual_size, size);
+  
+  // Use remove(id) to clean up - it internally calls release()
+  shm::remove(id);
 }
 
-} // internal-linkage
+// Test acquire with open mode (should fail if not exists)
+TEST_F(ShmTest, AcquireOpenNonExistent) {
+  std::string name = generate_unique_name("acquire_open_fail");
+  
+  shm::id_t id = shm::acquire(name.c_str(), 1024, shm::open);
+  // Opening non-existent shared memory should return nullptr or handle failure gracefully
+  if (id != nullptr) {
+      shm::release(id);
+  }
+}
+
+// Test acquire with both create and open modes
+TEST_F(ShmTest, AcquireCreateOrOpen) {
+  std::string name = generate_unique_name("acquire_both");
+  const std::size_t size = 2048;
+  
+  shm::id_t id = shm::acquire(name.c_str(), size, shm::create | shm::open);
+  ASSERT_NE(id, nullptr);
+  
+  std::size_t actual_size = 0;
+  void* mem = shm::get_mem(id, &actual_size);
+  EXPECT_NE(mem, nullptr);
+  EXPECT_GE(actual_size, size);
+  
+  // Use remove(id) to clean up - it internally calls release()
+  shm::remove(id);
+}
+
+// Test get_mem function
+TEST_F(ShmTest, GetMemory) {
+  std::string name = generate_unique_name("get_mem");
+  const std::size_t size = 512;
+  
+  shm::id_t id = shm::acquire(name.c_str(), size, shm::create);
+  ASSERT_NE(id, nullptr);
+  
+  std::size_t returned_size = 0;
+  void* mem = shm::get_mem(id, &returned_size);
+  
+  EXPECT_NE(mem, nullptr);
+  EXPECT_GE(returned_size, size);
+  
+  // Write and read test data
+  const char* test_data = "Shared memory test data";
+  std::strcpy(static_cast<char*>(mem), test_data);
+  EXPECT_STREQ(static_cast<char*>(mem), test_data);
+  
+  // Use remove(id) to clean up - it internally calls release()
+  shm::remove(id);
+}
+
+// Test get_mem without size parameter
+TEST_F(ShmTest, GetMemoryNoSize) {
+  std::string name = generate_unique_name("get_mem_no_size");
+  
+  shm::id_t id = shm::acquire(name.c_str(), 256, shm::create);
+  ASSERT_NE(id, nullptr);
+  
+  void* mem = shm::get_mem(id, nullptr);
+  EXPECT_NE(mem, nullptr);
+  
+  // Use remove(id) to clean up - it internally calls release()
+  shm::remove(id);
+}
+
+// Test release function
+TEST_F(ShmTest, ReleaseMemory) {
+  std::string name = generate_unique_name("release");
+  
+  shm::id_t id = shm::acquire(name.c_str(), 128, shm::create);
+  ASSERT_NE(id, nullptr);
+  
+  // Must call get_mem to map memory and set reference count
+  void* mem = shm::get_mem(id, nullptr);
+  ASSERT_NE(mem, nullptr);
+  
+  // release returns the reference count before decrement, or -1 on error
+  std::int32_t ref_count = shm::release(id);
+  EXPECT_EQ(ref_count, 1);  // Should be 1 (set by get_mem, before decrement)
+  
+  shm::remove(name.c_str());
+}
+
+// Test remove by id
+TEST_F(ShmTest, RemoveById) {
+  std::string name = generate_unique_name("remove_by_id");
+  
+  shm::id_t id = shm::acquire(name.c_str(), 256, shm::create);
+  ASSERT_NE(id, nullptr);
+  
+  // remove(id) internally calls release(id), so we don't need to call release first
+  shm::remove(id); // Should succeed
+}
+
+// Test remove by name
+TEST_F(ShmTest, RemoveByName) {
+  std::string name = generate_unique_name("remove_by_name");
+  
+  shm::id_t id = shm::acquire(name.c_str(), 256, shm::create);
+  ASSERT_NE(id, nullptr);
+  
+  shm::release(id);
+  shm::remove(name.c_str()); // Should succeed
+}
+
+// Test reference counting
+TEST_F(ShmTest, ReferenceCount) {
+  std::string name = generate_unique_name("ref_count");
+  
+  shm::id_t id1 = shm::acquire(name.c_str(), 512, shm::create);
+  ASSERT_NE(id1, nullptr);
+  
+  // Reference count is 0 after acquire (memory not mapped yet)
+  std::int32_t ref_before_get_mem = shm::get_ref(id1);
+  EXPECT_EQ(ref_before_get_mem, 0);
+  
+  // get_mem maps memory and sets reference count to 1
+  void* mem1 = shm::get_mem(id1, nullptr);
+  ASSERT_NE(mem1, nullptr);
+  
+  std::int32_t ref1 = shm::get_ref(id1);
+  EXPECT_EQ(ref1, 1);
+  
+  // Acquire again and get_mem (should increase reference count)
+  shm::id_t id2 = shm::acquire(name.c_str(), 512, shm::open);
+  if (id2 != nullptr) {
+      void* mem2 = shm::get_mem(id2, nullptr);
+      ASSERT_NE(mem2, nullptr);
+      
+      std::int32_t ref2 = shm::get_ref(id2);
+      EXPECT_EQ(ref2, 2);  // Should be 2 now
+      
+      shm::release(id2);
+  }
+  
+  shm::release(id1);
+  shm::remove(name.c_str());
+}
+
+// Test sub_ref function
+TEST_F(ShmTest, SubtractReference) {
+  std::string name = generate_unique_name("sub_ref");
+  
+  shm::id_t id = shm::acquire(name.c_str(), 256, shm::create);
+  ASSERT_NE(id, nullptr);
+  
+  // Must call get_mem first to map memory and initialize reference count
+  void* mem = shm::get_mem(id, nullptr);
+  ASSERT_NE(mem, nullptr);
+  
+  std::int32_t ref_before = shm::get_ref(id);
+  EXPECT_EQ(ref_before, 1);  // Should be 1 after get_mem
+  
+  shm::sub_ref(id);
+  
+  std::int32_t ref_after = shm::get_ref(id);
+  EXPECT_EQ(ref_after, 0);  // Should be 0 after sub_ref
+  
+  // Use remove(id) to clean up - it internally calls release()
+  shm::remove(id);
+}
+
+// ========== High-level handle class Tests ==========
+
+// Test default handle constructor
+TEST_F(ShmTest, HandleDefaultConstructor) {
+  shm::handle h;
+  EXPECT_FALSE(h.valid());
+  EXPECT_EQ(h.size(), 0u);
+  EXPECT_EQ(h.get(), nullptr);
+}
+
+// Test handle constructor with name and size
+TEST_F(ShmTest, HandleConstructorWithParams) {
+  std::string name = generate_unique_name("handle_ctor");
+  const std::size_t size = 1024;
+  
+  shm::handle h(name.c_str(), size);
+  
+  EXPECT_TRUE(h.valid());
+  EXPECT_GE(h.size(), size);
+  EXPECT_NE(h.get(), nullptr);
+  EXPECT_STREQ(h.name(), name.c_str());
+}
+
+// Test handle move constructor
+TEST_F(ShmTest, HandleMoveConstructor) {
+  std::string name = generate_unique_name("handle_move");
+  
+  shm::handle h1(name.c_str(), 512);
+  ASSERT_TRUE(h1.valid());
+  
+  void* ptr1 = h1.get();
+  std::size_t size1 = h1.size();
+  
+  shm::handle h2(std::move(h1));
+  
+  EXPECT_TRUE(h2.valid());
+  EXPECT_EQ(h2.get(), ptr1);
+  EXPECT_EQ(h2.size(), size1);
+  
+  // h1 should be invalid after move
+  EXPECT_FALSE(h1.valid());
+}
+
+// Test handle swap
+TEST_F(ShmTest, HandleSwap) {
+  std::string name1 = generate_unique_name("handle_swap1");
+  std::string name2 = generate_unique_name("handle_swap2");
+  
+  shm::handle h1(name1.c_str(), 256);
+  shm::handle h2(name2.c_str(), 512);
+  
+  void* ptr1 = h1.get();
+  void* ptr2 = h2.get();
+  std::size_t size1 = h1.size();
+  std::size_t size2 = h2.size();
+  
+  h1.swap(h2);
+  
+  EXPECT_EQ(h1.get(), ptr2);
+  EXPECT_EQ(h1.size(), size2);
+  EXPECT_EQ(h2.get(), ptr1);
+  EXPECT_EQ(h2.size(), size1);
+}
+
+// Test handle assignment operator
+TEST_F(ShmTest, HandleAssignment) {
+  std::string name = generate_unique_name("handle_assign");
+  
+  shm::handle h1(name.c_str(), 768);
+  void* ptr1 = h1.get();
+  
+  shm::handle h2;
+  h2 = std::move(h1);
+  
+  EXPECT_TRUE(h2.valid());
+  EXPECT_EQ(h2.get(), ptr1);
+  EXPECT_FALSE(h1.valid());
+}
+
+// Test handle valid() method
+TEST_F(ShmTest, HandleValid) {
+  shm::handle h1;
+  EXPECT_FALSE(h1.valid());
+  
+  std::string name = generate_unique_name("handle_valid");
+  shm::handle h2(name.c_str(), 128);
+  EXPECT_TRUE(h2.valid());
+}
+
+// Test handle size() method
+TEST_F(ShmTest, HandleSize) {
+  std::string name = generate_unique_name("handle_size");
+  const std::size_t requested_size = 2048;
+  
+  shm::handle h(name.c_str(), requested_size);
+  
+  EXPECT_GE(h.size(), requested_size);
+}
+
+// Test handle name() method
+TEST_F(ShmTest, HandleName) {
+  std::string name = generate_unique_name("handle_name");
+  
+  shm::handle h(name.c_str(), 256);
+  
+  EXPECT_STREQ(h.name(), name.c_str());
+}
+
+// Test handle ref() method
+TEST_F(ShmTest, HandleRef) {
+  std::string name = generate_unique_name("handle_ref");
+  
+  shm::handle h(name.c_str(), 256);
+  
+  std::int32_t ref = h.ref();
+  EXPECT_GT(ref, 0);
+}
+
+// Test handle sub_ref() method
+TEST_F(ShmTest, HandleSubRef) {
+  std::string name = generate_unique_name("handle_sub_ref");
+  
+  shm::handle h(name.c_str(), 256);
+  
+  std::int32_t ref_before = h.ref();
+  h.sub_ref();
+  std::int32_t ref_after = h.ref();
+  
+  EXPECT_EQ(ref_after, ref_before - 1);
+}
+
+// Test handle acquire() method
+TEST_F(ShmTest, HandleAcquire) {
+  shm::handle h;
+  EXPECT_FALSE(h.valid());
+  
+  std::string name = generate_unique_name("handle_acquire");
+  bool result = h.acquire(name.c_str(), 512);
+  
+  EXPECT_TRUE(result);
+  EXPECT_TRUE(h.valid());
+  EXPECT_GE(h.size(), 512u);
+}
+
+// Test handle release() method
+TEST_F(ShmTest, HandleRelease) {
+  std::string name = generate_unique_name("handle_release");
+  
+  shm::handle h(name.c_str(), 256);
+  ASSERT_TRUE(h.valid());
+  
+  std::int32_t ref_count = h.release();
+  EXPECT_GE(ref_count, 0);
+}
+
+// Test handle clear() method
+TEST_F(ShmTest, HandleClear) {
+  std::string name = generate_unique_name("handle_clear");
+  
+  shm::handle h(name.c_str(), 256);
+  ASSERT_TRUE(h.valid());
+  
+  h.clear();
+  EXPECT_FALSE(h.valid());
+}
+
+// Test handle clear_storage() static method
+TEST_F(ShmTest, HandleClearStorage) {
+  std::string name = generate_unique_name("handle_clear_storage");
+  
+  {
+      shm::handle h(name.c_str(), 256);
+      EXPECT_TRUE(h.valid());
+  }
+  
+  shm::handle::clear_storage(name.c_str());
+  
+  // Try to open - should fail or create new
+  shm::handle h2(name.c_str(), 256, shm::open);
+  // Behavior depends on implementation
+}
+
+// Test handle get() method
+TEST_F(ShmTest, HandleGet) {
+  std::string name = generate_unique_name("handle_get");
+  
+  shm::handle h(name.c_str(), 512);
+  
+  void* mem = h.get();
+  EXPECT_NE(mem, nullptr);
+  
+  // Write and read test
+  const char* test_str = "Handle get test";
+  std::strcpy(static_cast<char*>(mem), test_str);
+  EXPECT_STREQ(static_cast<char*>(mem), test_str);
+}
+
+// Test handle detach() and attach() methods
+TEST_F(ShmTest, HandleDetachAttach) {
+  std::string name = generate_unique_name("handle_detach_attach");
+  
+  shm::handle h1(name.c_str(), 256);
+  ASSERT_TRUE(h1.valid());
+  
+  shm::id_t id = h1.detach();
+  EXPECT_NE(id, nullptr);
+  EXPECT_FALSE(h1.valid()); // Should be invalid after detach
+  
+  shm::handle h2;
+  h2.attach(id);
+  EXPECT_TRUE(h2.valid());
+  
+  // Clean up - use h2.clear() or shm::remove(id) alone, not both
+  // Option 1: Use handle's clear() which calls shm::remove(id) internally
+  id = h2.detach(); // Detach first to get the id without releasing
+  shm::remove(id);  // Then remove to clean up both memory and disk file
+}
+
+// Test writing and reading data through shared memory
+TEST_F(ShmTest, WriteReadData) {
+  std::string name = generate_unique_name("write_read");
+  const std::size_t size = 1024;
+  
+  shm::handle h1(name.c_str(), size);
+  ASSERT_TRUE(h1.valid());
+  
+  // Write test data
+  struct TestData {
+      int value;
+      char text[64];
+  };
+  
+  TestData* data1 = static_cast<TestData*>(h1.get());
+  data1->value = 42;
+  std::strcpy(data1->text, "Shared memory data");
+  
+  // Open in another "shm::handle" (simulating different process)
+  shm::handle h2(name.c_str(), size, shm::open);
+  if (h2.valid()) {
+      TestData* data2 = static_cast<TestData*>(h2.get());
+      EXPECT_EQ(data2->value, 42);
+      EXPECT_STREQ(data2->text, "Shared memory data");
+  }
+}
+
+// Test handle with different modes
+TEST_F(ShmTest, HandleModes) {
+  std::string name = generate_unique_name("handle_modes");
+  
+  // Create only
+  shm::handle h1(name.c_str(), 256, shm::create);
+  EXPECT_TRUE(h1.valid());
+  
+  // Open existing
+  shm::handle h2(name.c_str(), 256, shm::open);
+  EXPECT_TRUE(h2.valid());
+  
+  // Both modes
+  shm::handle h3(name.c_str(), 256, shm::create | shm::open);
+  EXPECT_TRUE(h3.valid());
+}
+
+// Test multiple handles to same shared memory
+TEST_F(ShmTest, MultipleHandles) {
+  std::string name = generate_unique_name("multiple_handles");
+  const std::size_t size = 512;
+  
+  shm::handle h1(name.c_str(), size);
+  shm::handle h2(name.c_str(), size, shm::open);
+  
+  ASSERT_TRUE(h1.valid());
+  ASSERT_TRUE(h2.valid());
+  
+  // Should point to same memory
+  int* data1 = static_cast<int*>(h1.get());
+  int* data2 = static_cast<int*>(h2.get());
+  
+  *data1 = 12345;
+  EXPECT_EQ(*data2, 12345);
+}
+
+// Test large shared memory segment
+TEST_F(ShmTest, LargeSegment) {
+  std::string name = generate_unique_name("large_segment");
+  const std::size_t size = 10 * 1024 * 1024; // 10 MB
+  
+  shm::handle h(name.c_str(), size);
+  
+  if (h.valid()) {
+      EXPECT_GE(h.size(), size);
+      
+      // Write pattern to a portion of memory
+      char* mem = static_cast<char*>(h.get());
+      for (std::size_t i = 0; i < 1024; ++i) {
+          mem[i] = static_cast<char>(i % 256);
+      }
+      
+      // Verify pattern
+      for (std::size_t i = 0; i < 1024; ++i) {
+          EXPECT_EQ(mem[i], static_cast<char>(i % 256));
+      }
+  }
+}