Question

I’m just getting started with using threads in obj-c/cocoa and I’m running into some trouble.. I get this error in the console:

2010-02-15 09:18:41.467 Timer[1007:4503] *** __NSAutoreleaseNoPool(): Object 0x10012adc0 of class __NSCFDate autoreleased with no pool in place - just leaking
2010-02-15 09:18:41.478 Timer[1007:4503] *** __NSAutoreleaseNoPool(): Object 0x1003362b0 of class NSCFTimer autoreleased with no pool in place - just leaking

here is the code that creates the new thread:

    // Timer
JHTimer *timer = [[JHTimer alloc] init];
[timer setMinTextLabel:minTextLabel];
[timer setSecTextLabel:secTextLabel];
[timer setHrTextLabel:hrTextLabel];
timerTimeInt = 30;
[timer setTimerInterval:timerTimeInt];
[NSThread detachNewThreadSelector:@selector(start) toTarget:timer withObject:nil];

and the code that creates the autorelease pool (and the start method that creates the timer):

- (void)main {
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
}

- (void)start {
    timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(timerDidUpdate:) userInfo:nil repeats:YES];
    NSLog(@"Test");
}

and I can’t figure out that’s wrong

Answer 1

Where is your JHTimer‘s main being invoked from? You need to create the autorelease pool in the method for the selector you provide to detachNewThreadSelector:toTarget:withObject: as it says in the documentation.

For non garbage-collected applications, the method aSelector is responsible for setting up an autorelease pool for the newly detached thread and freeing that pool before it exits. Garbage-collected applications do not need to create an autorelease pool.