Added a cleanup interface for the synchronization facilities

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/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/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;
 

src/libipc/platform/linux/mutex.h

@@ -136,7 +136,7 @@ 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;
         auto &info = curr_prog::get();
         IPC_UNUSED_ std::lock_guard<std::mutex> guard {info.lock};
@@ -192,6 +192,23 @@ public:
         ref_   = nullptr;
     }
 
+    void clear() noexcept {
+        if (mutex_ != nullptr) {
+            if (mutex_->name() != nullptr) {
+                release_mutex(mutex_->name(), [] { return true; });
+            }
+            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/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) {

src/libipc/platform/posix/mutex.h

@@ -71,7 +71,7 @@ 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;
         auto &info = curr_prog::get();
         IPC_UNUSED_ std::lock_guard<std::mutex> guard {info.lock};
@@ -169,6 +169,30 @@ public:
         mutex_ = nullptr;
     }
 
+    void clear() noexcept {
+        if ((shm_ != nullptr) && (mutex_ != nullptr)) {
+            if (shm_->name() != nullptr) {
+                release_mutex(shm_->name(), [this] {
+                    int eno;
+                    if ((eno = ::pthread_mutex_destroy(mutex_)) != 0) {
+                        ipc::error("fail pthread_mutex_destroy[%d]\n", eno);
+                    }
+                    return true;
+                });
+            }
+            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 (;;) {

src/libipc/platform/posix/semaphore_impl.h

@@ -62,6 +62,24 @@ public:
         }
     }
 
+    void clear() noexcept {
+        if (valid()) {
+            if (::sem_close(h_) != 0) {
+                ipc::error("fail sem_close[%d]: %s\n", errno);
+            }
+            h_ = SEM_FAILED;
+        }
+        char const *name = shm_.name();
+        if (name == nullptr) return;
+        ::sem_unlink(name);
+        shm_.clear(); // Make sure the storage is cleaned up.
+    }
+
+    static void clear_storage(char const *name) noexcept {
+        ::sem_unlink(name);
+        ipc::shm::handle::clear_storage(name);
+    }
+
     bool wait(std::uint64_t tm) noexcept {
         if (!valid()) return false;
         if (tm == invalid_value) {

src/libipc/platform/posix/shm_posix.cpp

@@ -188,7 +188,7 @@ void remove(id_t id) noexcept {
     }
 }
 
-void remove(char const * name) {
+void remove(char const * name) noexcept {
     if (!is_valid_string(name)) {
         ipc::error("fail remove: name is empty\n");
         return;

src/libipc/platform/win/condition.h

@@ -67,6 +67,16 @@ 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();

src/libipc/platform/win/mutex.h

@@ -47,6 +47,13 @@ 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

@@ -46,6 +46,13 @@ 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

@@ -102,7 +102,7 @@ void * get_mem(id_t id, std::size_t * size) {
     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;
@@ -120,7 +120,7 @@ std::int32_t release(id_t id) {
     return 0;
 }
 
-void remove(id_t id) {
+void remove(id_t id) noexcept {
     if (id == nullptr) {
         ipc::error("fail release: invalid id (null)\n");
         return;
@@ -128,7 +128,7 @@ void remove(id_t id) {
     release(id);
 }
 
-void remove(char const * name) {
+void remove(char const * name) noexcept {
     if (!is_valid_string(name)) {
         ipc::error("fail remove: name is empty\n");
         return;

src/libipc/sync/condition.cpp

@@ -61,6 +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

@@ -61,6 +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

@@ -59,6 +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);
 }