[C++] Add C++ interface for RT-Thread kernel.

components/cplusplus/Mutex.cpp

@@ -0,0 +1,35 @@
+#include "Mutex.h"
+
+using namespace rtthread;
+
+Mutex::Mutex(const char *name)
+{
+    rt_mutex_init(&mID, name, RT_IPC_FLAG_FIFO);
+}
+
+bool Mutex::lock(int32_t millisec)
+{
+    rt_int32_t tick;
+
+    if (millisec < 0)
+        tick = -1;
+    else
+        tick = rt_tick_from_millisecond(millisec);
+
+    return rt_mutex_take(&mID, tick) == RT_EOK;
+}
+
+bool Mutex::trylock()
+{
+    return lock(0);
+}
+
+void Mutex::unlock()
+{
+    rt_mutex_release(&mID);
+}
+
+Mutex::~Mutex()
+{
+    rt_mutex_detach(&mID);
+}