ios线程

dispatch_queue_t queue = dispatch_queue_create("me.tutuge.test.gcd", DISPATCH_QUEUE_SERIAL);
//提交第一个block，延时5秒打印。
dispatch_async(queue, ^{
    [NSThread sleepForTimeInterval:5];
    NSLog(@"After 5 seconds...");
});
//提交第二个block，也是延时5秒打印
dispatch_async(queue, ^{
    [NSThread sleepForTimeInterval:5];
    NSLog(@"After 5 seconds again...");
});
//延时一秒
NSLog(@"sleep 1 second...");
[NSThread sleepForTimeInterval:1];
//挂起队列                        
NSLog(@"suspend...");
dispatch_suspend(queue);
//延时10秒                
NSLog(@"sleep 10 second...");
[NSThread sleepForTimeInterval:10];
//恢复队列            
NSLog(@"resume...");
dispatch_resume(queue);