使用計時器佇列

下列範例會建立計時器常式,此常式將在 10 秒延遲後由 計時器佇列 中的執行緒執行。 首先,程式碼會使用 CreateEvent 函式來建立計時器佇列執行緒完成時發出訊號的事件物件。 然後,它會分別使用 CreateTimerQueueCreateTimerQueueTimer 函式來建立計時器佇列和計時器佇列計時器。 程式碼會使用 WaitForSingleObject 函式來判斷計時器常式何時完成。 最後,程式碼會呼叫 DeleteTimerQueue 來清除。

如需計時器常式的詳細資訊,請參閱 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;
}