c++多线程安全同步释放示例

#include <stdio.h>
#include <thread>
#include <map>
#include <mutex>

typedef struct VnoSInfo_
{
	void* p = NULL;

	int fun()
	{
		printf("fun ........ \n");
		std::this_thread::sleep_for(std::chrono::milliseconds(10));
		return 0;
	}


}VnoSInfo;


int64_t getCurrentTicket()
{
	return  std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::steady_clock::now().time_since_epoch()).count();
}

std::mutex g_mutex;
std::map<long, std::shared_ptr<VnoSInfo>> g_map;
long g_handle = 0;


bool g_isExit = false;


std::shared_ptr<VnoSInfo> GetSharePtr(long handle, bool isErase)
{
	std::shared_ptr<VnoSInfo> p;
	{
		std::unique_lock<std::mutex> lock(g_mutex);
		std::map<long, std::shared_ptr<VnoSInfo>>::iterator it = g_map.find(handle);
		if (it != g_map.end())
		{
			p = it->second;
			if (isErase)
			{
				g_map.erase(it);
			}
		}
	}
	return p;
}
long Create()
{
	std::shared_ptr<VnoSInfo> p = std::make_shared<VnoSInfo>();
	std::unique_lock<std::mutex> lock(g_mutex);
	g_handle++;
	g_map[g_handle] = p;
	return g_handle;
}

int Destroy(long handle)
{
	int ret = 0;
	std::shared_ptr<VnoSInfo> p = GetSharePtr(handle, true);
	if (p)
	{
		while (1)
		{
			printf("Destroy 222  p.use_count:%d time:%lld \n", p.use_count(), getCurrentTicket());
			if (p.use_count() == 1)
			{
				p.reset();
				printf("Destroy 333  p.use_count:%d time:%lld \n", p.use_count(), getCurrentTicket());
				ret = 0;
				break;
			}
			std::this_thread::sleep_for(std::chrono::milliseconds(1));
		}
	}
	else
	{
		ret = -1;
	}
	return ret;
}

int Incoming(long handle, char* data, int len)
{
	std::shared_ptr<VnoSInfo> p = GetSharePtr(handle, false);
	if (!p)
	{
		printf("Incoming error \n");
		return -1;
	}

	return p->fun();
}

void ThreadRun(long t_handle)
{
	while (!g_isExit)
	{
		if (t_handle > 0)
		{
			Incoming(t_handle, NULL, 10);
		}
	}

}



int main(int argc, char* argv[])
{

	long t_handle = Create();

	std::thread *m_Thread = new std::thread(ThreadRun, t_handle);

	getchar();

	int ret = Destroy(t_handle);

	printf("Destroy ret:%d \n", ret);


	std::this_thread::sleep_for(std::chrono::milliseconds(100));
	ret = Destroy(t_handle);

	printf("Destroy 111  ret:%d \n", ret);


	g_isExit = true;
	m_Thread->join();
	delete m_Thread;
	m_Thread = 0;


	return 0;
}