/****************************************************class name : MyMutexFunction: support mutex******************************************************/class MyMutex {  pthread_mutex_t a_mutex;  int error;   public:   MyMutex();    ~MyMutex();      int Lock() { error = pthread_mutex_lock(&a_mutex);return error;}   int Trylock() { error = pthread_mutex_trylock(&a_mutex); return error;}   int Unlock() {error = pthread_mutex_unlock(&a_mutex); return error;}   int Error() {return error;}};/****************************************************class name : MyConditionFunction: support MyCondition variable******************************************************/class MyCondition {  pthread_mutex_t a_mutex;     pthread_cond_t got_request;     int error;   public:   MyCondition();    ~MyCondition();      int wait(int second = 0);    // wait until signal by other thread   int wake();           // wake a thread waiting for this condition   int wakeAll();     // wake all threads waiting for this conditoin   int Error() {return error;}};