Application not getting suspended

I am observing a strange behavior. I am executing this method:

- (void) aLongRunningMethod: (NSString*) input {
    for (int i = 0; i < 100; ++i) {
        //Sleep for 1 second
        [NSThread sleepForTimeInterval: 1];
        NSLog(@"Progress: %d", i);
    }
}

In the iOS simulator, I hit the home button. I expect the thread to be suspended right away. But, that does not happen. The method keeps going. I am pretty sure that that is not the designed behavior. Is this a defect in the simulator or am I mi开发者_运维百科sunderstood about application's state transition.

Anything running on the current/main runloop with have a chance to finish. But the operating system reserved the rights to kill anything taking too long.

If you execute that method on a background thread it will suspend right away when you press the Home button.

Try it:

[self performSelectorInBackground:@selector(aLongRunningMethod:) withObject:@"Running in background"];