vc++信号量同步机制例子

HANDLE hSemaphore;
cout<<1<<endl;

hSemaphore = CreateSemaphore( NULL, 0, 10000, NULL); 

ReleaseSemaphore(hSemaphore, 1, NULL);
ReleaseSemaphore(hSemaphore, 1, NULL);

DWORD dwWaitResult = WaitForSingleObject(hSemaphore, INFINITE);
	cout<<2<<endl;
 WaitForSingleObject(hSemaphore, INFINITE);
	cout<<3<<endl;

WaitForSingleObject(hSemaphore, INFINITE);
	cout<<4<<endl;

输出

1

2

3

_

//CreateSemaphore( NULL, 0, 100, NULL); 初始信号为0

//ReleaseSemaphore(hSemaphore, 1, NULL);信号加1

//WaitForSingleObject(hSemaphore, INFINITE);阻塞式等待，返回时，信号减1

线程间的通知：

如果线程B需要线程A的数据。

当线程A的数据增加时，可以ReleaseSemaphore(hSemaphore, 1, NULL);

线程B使用WaitForSingleObject(hSemaphore, INFINITE);来判断线程A有无数据