如何暂停多个线程？
我在main函数中创建了多个线程，每个线程都有个while(1)循环，并且这些线程要访问一些全局变量，我用互斥对象做了线程同步，在线程运行了一段时间后（在主线程中用Sleep()计时），我想暂停这些线程，输出这些全局变量的值，应该如何使多个线程暂停（只是暂停，因为我想输出全局变量值后再使这些线程继续运行），能不能给些方法？
[解决办法]
http://msdn.microsoft.com/en-us/library/windows/desktop/ms682396%28v=vs.85%29.aspx
HANDLE WINAPI CreateEvent(
__in_opt LPSECURITY_ATTRIBUTES lpEventAttributes,
__in BOOL bManualReset,
__in BOOL bInitialState,
__in_opt LPCTSTR lpName
);
The following example uses event objects to prevent several threads from reading from a shared memory buffer while a master thread is writing to that buffer. First, the master thread uses the CreateEvent function to create a manual-reset event object whose initial state is nonsignaled. Then it creates several reader threads. The master thread performs a write operation and then sets the event object to the signaled state when it has finished writing.
#include <windows.h>#include <stdio.h>#define THREADCOUNT 4 HANDLE ghWriteEvent; HANDLE ghThreads[THREADCOUNT];DWORD WINAPI ThreadProc(LPVOID);void CreateEventsAndThreads(void) { int i; DWORD dwThreadID; // Create a manual-reset event object. The write thread sets this // object to the nonsignaled state when it finishes writing to a // shared buffer. ghWriteEvent = CreateEvent( NULL, // default security attributes TRUE, // manual-reset event FALSE, // initial state is nonsignaled TEXT("WriteEvent") // object name ); if (ghWriteEvent == NULL) { printf("CreateEvent failed (%d)\n", GetLastError()); return; } // Create multiple threads to read from the buffer. for(i = 0; i < THREADCOUNT; i++) { // TODO: More complex scenarios may require use of a parameter // to the thread procedure, such as an event per thread to // be used for synchronization. ghThreads[i] = CreateThread( NULL, // default security 0, // default stack size ThreadProc, // name of the thread function NULL, // no thread parameters 0, // default startup flags &dwThreadID); if (ghThreads[i] == NULL) { printf("CreateThread failed (%d)\n", GetLastError()); return; } }}void WriteToBuffer(VOID) { // TODO: Write to the shared buffer. printf("Main thread writing to the shared buffer...\n"); // Set ghWriteEvent to signaled if (! SetEvent(ghWriteEvent) ) { printf("SetEvent failed (%d)\n", GetLastError()); return; }}void CloseEvents(){ // Close all event handles (currently, only one global handle). CloseHandle(ghWriteEvent);}int main( void ){ DWORD dwWaitResult; // TODO: Create the shared buffer // Create events and THREADCOUNT threads to read from the buffer CreateEventsAndThreads(); // At this point, the reader threads have started and are most // likely waiting for the global event to be signaled. However, // it is safe to write to the buffer because the event is a // manual-reset event. WriteToBuffer(); printf("Main thread waiting for threads to exit...\n"); // The handle for each thread is signaled when the thread is // terminated. dwWaitResult = WaitForMultipleObjects( THREADCOUNT, // number of handles in array ghThreads, // array of thread handles TRUE, // wait until all are signaled INFINITE); switch (dwWaitResult) { // All thread objects were signaled case WAIT_OBJECT_0: printf("All threads ended, cleaning up for application exit...\n"); break; // An error occurred default: printf("WaitForMultipleObjects failed (%d)\n", GetLastError()); return 1; } // Close the events to clean up CloseEvents(); return 0;}DWORD WINAPI ThreadProc(LPVOID lpParam) { // lpParam not used in this example. UNREFERENCED_PARAMETER(lpParam); DWORD dwWaitResult; printf("Thread %d waiting for write event...\n", GetCurrentThreadId()); dwWaitResult = WaitForSingleObject( ghWriteEvent, // event handle INFINITE); // indefinite wait switch (dwWaitResult) { // Event object was signaled case WAIT_OBJECT_0: // // TODO: Read from the shared buffer // printf("Thread %d reading from buffer\n", GetCurrentThreadId()); break; // An error occurred default: printf("Wait error (%d)\n", GetLastError()); return 0; } // Now that we are done reading the buffer, we could use another // event to signal that this thread is no longer reading. This // example simply uses the thread handle for synchronization (the // handle is signaled when the thread terminates.) printf("Thread %d exiting\n", GetCurrentThreadId()); return 1;}
[解决办法]
创建线程时，保留线程的句柄，暂停时调用SuspendThread，再次运行调用 ResumeThread
[解决办法]
使用事件Event,要暂停时调用ResetEvent设成无信号，线程while里面使用WaritForSingleObject让线程阻塞，输完变量后，再SetEvent让线程运行