@interface NSObject (UICaboodle)
- (id) yieldToSelector:(SEL)selector withObject:(id)object;
- (id) yieldToSelector:(SEL)selector;
@end

@implementation NSObject (UICaboodle)

- (void) doNothing {
}

- (void) _yieldToContext:(NSMutableArray *)context { _pooled
    SEL selector(reinterpret_cast<SEL>([[context objectAtIndex:0] pointerValue]));
    id object([[context objectAtIndex:1] nonretainedObjectValue]);
    volatile bool &stopped(*reinterpret_cast<bool *>([[context objectAtIndex:2] pointerValue]));

    /* XXX: deal with exceptions */
    id value([self performSelector:selector withObject:object]);

    NSMethodSignature *signature([self methodSignatureForSelector:selector]);
    [context removeAllObjects];
    if ([signature methodReturnLength] != 0 && value != nil)
        [context addObject:value];

    stopped = true;

    [self
        performSelectorOnMainThread:@selector(doNothing)
        withObject:nil
        waitUntilDone:NO
    ];
}

- (id) yieldToSelector:(SEL)selector withObject:(id)object {
    /*return [self performSelector:selector withObject:object];*/

    volatile bool stopped(false);

    NSMutableArray *context([NSMutableArray arrayWithObjects:
        [NSValue valueWithPointer:selector],
        [NSValue valueWithNonretainedObject:object],
        [NSValue valueWithPointer:const_cast<bool *>(&stopped)],
    nil]);

    NSThread *thread([[[NSThread alloc]
        initWithTarget:self
        selector:@selector(_yieldToContext:)
        object:context
    ] autorelease]);

    [thread start];

    NSRunLoop *loop([NSRunLoop currentRunLoop]);
    NSDate *future([NSDate distantFuture]);

    while (!stopped && [loop runMode:NSDefaultRunLoopMode beforeDate:future]);

    return [context count] == 0 ? nil : [context objectAtIndex:0];
}

- (id) yieldToSelector:(SEL)selector {
    return [self yieldToSelector:selector withObject:nil];
}

@end