[Objective-C] GCDについての備忘録 ref: http://qiita.com/edo_m18/items/2f8c6bde4492ef116ed0

file0.m

dispatch_queue_t queue = dispatch_queue_create("com.hoge.queue", [attribute]);

file1.m

// 3秒後に処理を実行
dispatch_time_t time = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(3 * NSEC_PER_SEC));

dispatch_after(time, dispatch_get_main_queue(), ^{
    // do something.
});

file2.m

size_t iterations = 10;
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITIY_DEFAULT, 0);
dispatch_apply(iterations, queue, ^(size_t i) {
    NSLog(@"Current i: %lu", i);
});