C++实现的单例模式代码

#include "singleton_thread.h" Singleton* Singleton::_instance(0); unsigned int Singleton::_used(0); pthread_mutex_t Singleton::_mutex(PTHREAD_MUTEX_INITIALIZER); Singleton* Singleton::getInstance() { pthread_mutex_lock(&_mutex); ++_used; if(_instance == 0) { _instance = new Singleton(); } pthread_mutex_unlock(&_mutex); return _instance; } void Singleton::releaseInstance() { pthread_mutex_lock(&_mutex); --_used; if(_used == 0) { delete _instance; _instance = 0; } pthread_mutex_unlock(&_mutex); }