Grand Central Dispatch

[self goDoSomethingLongAndInvolved];
NSLog(@"Done

doing something long and involved");
});

[self goDoSomethingLongAndInvolved];
dispatch_async(dispatch_get_main_queue(),

^{
[textField setStringValue:@"Done doing something long and involved"];
});
});

dispatch_sync(dispatch_get_main_queue(), ^{
stringValue

= [[textField stringValue] copy];
});
[stringValue autorelease];

dispatch_async(dispatch_get_main_queue(), ^{
NSString *stringValue

= [[[textField stringValue] copy] autorelease];
dispatch_async(bgQueue, ^{
// use stringValue in the background now
});
});

[self doSomethingIntensiveWith:obj];
}


Параллельное представление

(при условии потокозащищенности метода doSomethingIntensiveWith:obj):

dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
for(id obj in array) {
dispatch_async(queue, ^{
[self doSomethingIntensiveWith:obj];
});
}

0);
dispatch_group_t group = dispatch_group_create();
for(id obj in

array) {
dispatch_group_async(group, queue, ^{
[self doSomethingIntensiveWith:obj];
});
}
dispatch_group_wait(group, DISPATCH_TIME_FOREVER);
dispatch_release(group);
[self doSomethingWith:array];

0);
dispatch_group_t group = dispatch_group_create();
for(id obj in

array) {
dispatch_group_async(group, queue, ^{
[self doSomethingIntensiveWith:obj];
});
}
dispatch_group_notify(group, queue, ^{
[self doSomethingWith:array];
});
dispatch_release(group);

очереди:
dispatch_queue_t queue = dispatch_get_global_qeueue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_apply([array count], queue,

^(size_t index){
[self doSomethingIntensiveWith:[array objectAtIndex:index]];
});
[self doSomethingWith:array];

Асинхронный вариант выполнения очереди:
dispatch_queue_t queue = dispatch_get_global_qeueue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_async(queue, ^{
dispatch_apply([array count], queue, ^(size_t index){
[self doSomethingIntensiveWith:[array objectAtIndex:index]];
});
[self doSomethingWith:array];
});

работы по сравнению с классическими ООП-подходами распараллеливания
Кроссплатформенность и легкая переносимость

кода
Широкие возможности при простоте использования