Function Tk_CreateTimerHandler

micropolis-activity/src/tk/tkevent.c:925–979

(milliseconds, proc, clientData)

 * Results:
 *	The return value is a token for the timer event, which
 *	may be used to delete the event before it fires.
 *
 * Side effects:
 *	When milliseconds have elapsed, proc will be invoked
 *	exactly once.
 *
 *--------------------------------------------------------------
 */

Tk_TimerToken
Tk_CreateTimerHandler(milliseconds, proc, clientData)
    int milliseconds;		/* How many milliseconds to wait
				 * before invoking proc. */
    Tk_TimerProc *proc;		/* Procedure to invoke. */
    ClientData clientData;	/* Arbitrary data to pass to proc. */
{
    register TimerEvent *timerPtr, *tPtr2, *prevPtr;
    static int id = 0;

    timerPtr = NewTimerEvent();

    /*
     * Compute when the event should fire.
     */

    (void) gettimeofday(&timerPtr->time, (struct timezone *) NULL);
    timerPtr->time.tv_sec += milliseconds/1000;
    timerPtr->time.tv_usec += (milliseconds%1000)*1000;
    if (timerPtr->time.tv_usec > 1000000) {
	timerPtr->time.tv_usec -= 1000000;
	timerPtr->time.tv_sec += 1;
    }

    /*
     * Fill in other fields for the event.
     */

    timerPtr->proc = proc;
    timerPtr->clientData = clientData;
    id++;
    timerPtr->token = (Tk_TimerToken) id;

    /*
     * Add the event to the queue in the correct position
     * (ordered by event firing time).
     */

    for (tPtr2 = timerQueue, prevPtr = NULL; tPtr2 != NULL;
	    prevPtr = tPtr2, tPtr2 = tPtr2->nextPtr) {
	if ((tPtr2->time.tv_sec > timerPtr->time.tv_sec)
		|| ((tPtr2->time.tv_sec == timerPtr->time.tv_sec)
		&& (tPtr2->time.tv_usec > timerPtr->time.tv_usec))) {
	    break;
	}
    }
    if (prevPtr == NULL) {
	timerPtr->nextPtr = timerQueue;
	timerQueue = timerPtr;