DelayedPerform.m

#include <Foundation/Foundation.h>

@interface BusyWaiter : NSObject
{
    BOOL _done;
}

- (void)markDone;
- (BOOL)isDone;
@end

@implementation BusyWaiter

- (void)markDone; {
    NSLog(@"Marked done.");
    _done = YES;
}

- (BOOL)isDone; {
    return _done;
}
@end

int main(int argc, char **argv) {
    NSAutoreleasePool *p = [NSAutoreleasePool new];
    NSRunLoop *currentRunLoop = [NSRunLoop currentRunLoop];
    BusyWaiter *b = [BusyWaiter new];
    [b performSelector:@selector(markDone) withObject:nil afterDelay:1.0f];
    while (![b isDone]) {
        if(![[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]])
            break;
        NSLog(@"Ran.");
    }
    [p drain];
    return 0;
}