Question

I am trying to run a timer in the background of my application, i am using the timer heavily in my application and i’d rather running it in the background, However i am getting memory leaks when trying to release the NSAoutreleasePool. My Timer class is singleton, so if i start new timer the old timer get dealloc it .

+ (void)timerThread{

    timerThread = [[NSThread alloc] initWithTarget:self selector:@selector(startTimerThread) object:nil]; //Create a new thread
    [timerThread start]; //start the thread
}

//the thread starts by sending this message
+ (void) startTimerThread
{
    timerNSPool = [[NSAutoreleasePool alloc] init];
    NSRunLoop* runLoop = [NSRunLoop currentRunLoop];
    timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(startTime:) userInfo:nil repeats:YES];
    //timer = [NSTimer timerWithTimeInterval:1.0 target:self selector:@selector(startTime:) userInfo:nil repeats:YES];
    //[[NSRunLoop currentRunLoop] addTimer:timer forMode:NSRunLoopCommonModes];
    [runLoop run];
    [timerNSPool release];
}

+ (void)startTime:(NSTimer *)theTimer{

    if(timeDuration > 1)
        timeLabel.text = [NSString stringWithFormat:@"%d",--timeDuration];
    else{
        [self stopTimer];
        [delegate timeIsUp];
    }

}
+ (void) stopTimer{

    if(timer != nil)
    {       
        [timerThread release]; 
        [timeLabel release];
        [timer invalidate];
        timer = nil;
    }

}

I never had a problem running the NSTimer on the main thread runLoop with application autoreleasepool.
I am getting leak at [timerNSPool release];
GeneralBlock-16 Malloc WebCore WKSetCurrentGraphicsContext

What causing the Leak is updating UI from a secondary thread :

timeLabel.text = [NSString stringWithFormat:@"%d",--timeDuration];

However i added another method updateTextLbl, then i am calling it using this

[self performSelectorOnMainThread:@selector(updateTextLbl) withObject:nil waitUntilDone:YES];

on the main thread. I did not have leaks at all , but this will defeats the purpose of having a second threads.

This my first post , and i appreciate any help Thanks… in advance….

Answer 1

You’re updating your UI in +startTime:, but that method does not run in the main thread. That may be the source of the WebCore warning you’re seeing.