diff --git a/build/CMakeLists.txt b/build/CMakeLists.txt
index 586c563..b69eed3 100644
--- a/build/CMakeLists.txt
+++ b/build/CMakeLists.txt
@@ -6,4 +6,5 @@ if(NOT MSVC)
   set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O2")
 endif()
 
-add_subdirectory(test)
\ No newline at end of file
+add_subdirectory(test)
+add_subdirectory(chat)
\ No newline at end of file
diff --git a/build/chat/CMakeLists.txt b/build/chat/CMakeLists.txt
new file mode 100644
index 0000000..686c633
--- /dev/null
+++ b/build/chat/CMakeLists.txt
@@ -0,0 +1,14 @@
+project(chat)
+
+include_directories(../../include)
+file(GLOB SRC_FILES ../../demo/chat/*.cpp)
+file(GLOB HEAD_FILES ../../demo/chat/*.h)
+set(EXECUTABLE_OUTPUT_PATH ${CMAKE_SOURCE_DIR}/../output)
+
+link_directories(${EXECUTABLE_OUTPUT_PATH})
+add_executable(${PROJECT_NAME} ${SRC_FILES} ${HEAD_FILES})
+
+target_link_libraries(${PROJECT_NAME} ipc)
+if(NOT MSVC)
+  target_link_libraries(${PROJECT_NAME} pthread rt)
+endif()
diff --git a/include/def.h b/include/def.h
index 3845e37..3f99855 100644
--- a/include/def.h
+++ b/include/def.h
@@ -27,10 +27,10 @@ using uint_t = typename uint<N>::type;
 // constants
 
 enum : std::size_t {
-    invalid_value = (std::numeric_limits<std::size_t>::max)(),
-    data_length   = 64,
-    name_length   = 64,
-    send_wait     = 100 // ms
+    invalid_value  = (std::numeric_limits<std::size_t>::max)(),
+    data_length    = 64,
+    name_length    = 64,
+    default_timeut = 100 // ms
 };
 
 enum class relat { // multiplicity of the relationship
diff --git a/src/ipc.cpp b/src/ipc.cpp
index 29bf9cb..d19e978 100644
--- a/src/ipc.cpp
+++ b/src/ipc.cpp
@@ -230,7 +230,7 @@ static bool send(ipc::handle_t h, void const * data, std::size_t size) {
         return [info, que, msg_id](int remain, void const * data, std::size_t size) {
             if (!wait_for(info->wt_waiter_, [&] {
                     return !que->push(que, msg_id, remain, data, size);
-                }, send_wait)) {
+                }, default_timeut)) {
                 if (!que->force_push(que, msg_id, remain, data, size)) {
                     return false;
                 }
diff --git a/src/platform/waiter_linux.h b/src/platform/waiter_linux.h
index 42216d5..8d01163 100644
--- a/src/platform/waiter_linux.h
+++ b/src/platform/waiter_linux.h
@@ -113,8 +113,10 @@ public:
             calc_wait_time(ts, tm);
             int eno;
             if ((eno = ::pthread_cond_timedwait(&cond_, &mtx.native(), &ts)) != 0) {
-                ipc::error("fail pthread_cond_timedwait[%d]: tm = %zd, tv_sec = %ld, tv_nsec = %ld\n",
-                           eno, tm, ts.tv_sec, ts.tv_nsec);
+                if (eno != ETIMEDOUT) {
+                    ipc::error("fail pthread_cond_timedwait[%d]: tm = %zd, tv_sec = %ld, tv_nsec = %ld\n",
+                               eno, tm, ts.tv_sec, ts.tv_nsec);
+                }
                 return false;
             }
             return true;
@@ -181,8 +183,10 @@ public:
             timespec ts;
             calc_wait_time(ts, tm);
             if (::sem_timedwait(h, &ts) != 0) {
-                ipc::error("fail sem_timedwait[%d]: tm = %zd, tv_sec = %ld, tv_nsec = %ld\n",
-                           errno, tm, ts.tv_sec, ts.tv_nsec);
+                if (errno != ETIMEDOUT) {
+                    ipc::error("fail sem_timedwait[%d]: tm = %zd, tv_sec = %ld, tv_nsec = %ld\n",
+                               errno, tm, ts.tv_sec, ts.tv_nsec);
+                }
                 return false;
             }
             return true;
@@ -260,7 +264,7 @@ public:
         if (counter_ > 0) {
             ret = sem_helper::post(std::get<1>(h));
             -- counter_;
-            ret = ret && sem_helper::wait(std::get<2>(h));
+            ret = ret && sem_helper::wait(std::get<2>(h), default_timeut);
         }
         return ret;
     }
@@ -278,7 +282,7 @@ public:
             }
             do {
                 -- counter_;
-                ret = ret && sem_helper::wait(std::get<2>(h));
+                ret = ret && sem_helper::wait(std::get<2>(h), default_timeut);
             } while (counter_ > 0);
         }
         return ret;
diff --git a/src/platform/waiter_win.h b/src/platform/waiter_win.h
index bcee368..db0daf6 100644
--- a/src/platform/waiter_win.h
+++ b/src/platform/waiter_win.h
@@ -39,7 +39,6 @@ public:
             return true;
         }
         if (ret == WAIT_TIMEOUT) {
-            ipc::log("WaitForSingleObject is timeout.\n");
             return false;
         }
         ipc::error("fail WaitForSingleObject[%lu]: 0x%08X\n", ::GetLastError(), ret);
@@ -127,7 +126,7 @@ public:
         if (*counter_ > 0) {
             ret = sema_.post();
             -- *counter_;
-            ret = ret && handshake_.wait();
+            ret = ret && handshake_.wait(default_timeut);
         }
         return ret;
     }
@@ -143,7 +142,7 @@ public:
             ret = sema_.post(*counter_);
             do {
                 -- *counter_;
-                ret = ret && handshake_.wait();
+                ret = ret && handshake_.wait(default_timeut);
             } while (*counter_ > 0);
         }
         return ret;