使用计时器队列
以下示例创建一个计时器例程,该例程将在 10 秒延迟后由 计时器队列 中的线程执行。 首先,代码使用 CreateEvent 函数创建一个事件对象,该对象在计时器队列线程完成时发出信号。 然后,它分别使用 CreateTimerQueue 和 CreateTimerQueueTimer 函数创建计时器队列和 计时器 队列计时器。 该代码使用 WaitForSingleObject 函数来确定计时器例程何时完成。 最后,代码调用 DeleteTimerQueue 进行清理。
有关计时器例程的详细信息,请参阅 WaitOrTimerCallback。
#include <windows.h>
#include <stdio.h>
HANDLE gDoneEvent;
VOID CALLBACK TimerRoutine(PVOID lpParam, BOOLEAN TimerOrWaitFired)
{
if (lpParam == NULL)
{
printf("TimerRoutine lpParam is NULL\n");
}
else
{
// lpParam points to the argument; in this case it is an int
printf("Timer routine called. Parameter is %d.\n",
*(int*)lpParam);
if(TimerOrWaitFired)
{
printf("The wait timed out.\n");
}
else
{
printf("The wait event was signaled.\n");
}
}
SetEvent(gDoneEvent);
}
int main()
{
HANDLE hTimer = NULL;
HANDLE hTimerQueue = NULL;
int arg = 123;
// Use an event object to track the TimerRoutine execution
gDoneEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (NULL == gDoneEvent)
{
printf("CreateEvent failed (%d)\n", GetLastError());
return 1;
}
// Create the timer queue.
hTimerQueue = CreateTimerQueue();
if (NULL == hTimerQueue)
{
printf("CreateTimerQueue failed (%d)\n", GetLastError());
return 2;
}
// Set a timer to call the timer routine in 10 seconds.
if (!CreateTimerQueueTimer( &hTimer, hTimerQueue,
(WAITORTIMERCALLBACK)TimerRoutine, &arg , 10000, 0, 0))
{
printf("CreateTimerQueueTimer failed (%d)\n", GetLastError());
return 3;
}
// TODO: Do other useful work here
printf("Call timer routine in 10 seconds...\n");
// Wait for the timer-queue thread to complete using an event
// object. The thread will signal the event at that time.
if (WaitForSingleObject(gDoneEvent, INFINITE) != WAIT_OBJECT_0)
printf("WaitForSingleObject failed (%d)\n", GetLastError());
CloseHandle(gDoneEvent);
// Delete all timers in the timer queue.
if (!DeleteTimerQueue(hTimerQueue))
printf("DeleteTimerQueue failed (%d)\n", GetLastError());
return 0;
}