3. Implementation/Windows API

Using Timer Queues

SSKK 2008. 10. 24. 21:53

The following example creates a timer routine that will be executed by a timer-queue thread after a 10 second delay. First, the code uses the CreateEvent function to create an event object that is signaled when the timer-queue thread completes. Then it creates a timer queue and a timer-queue timer, using the CreateTimerQueue and CreateTimerQueueTimer functions, respectively. The code uses the WaitForSingleObject function to determine when the timer routine has completed. Finally, the code calls DeleteTimerQueue to clean up.

For more information on the timer routine, see WaitOrTimerCallback.

 

#include <windows.h>

#include <stdio.h>

 

HANDLE gDoneEvent;

 

VOID CALLBACK TimerRoutine(PVOID lpParam, BOOL 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);

    }

 

    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 (!gDoneEvent)

    {

        printf("CreateEvent failed (%d)\n", GetLastError());

        return 1;

    }

 

    // Create the timer queue.

    hTimerQueue = CreateTimerQueue();

    if (!hTimerQueue)

    {

        printf("CreateTimerQueue failed (%d)\n", GetLastError());

        return 2;

    }

 

    // Set a timer to call the timer routine in 10 seconds.

    if (!CreateTimerQueueTimer(

        &hTimer, hTimerQueue, 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());

 

    // Delete all timers in the timer queue.

    if (!DeleteTimerQueue(hTimerQueue))

        printf("DeleteTimerQueue failed (%d)\n", GetLastError());

 

    return 0;

}

 

FROM : MSDN