ios 异步线程 NSLock 小结

oc
1

    dispatch_queue_t q =dispatch_queue_create("thread-one",DISPATCH_QUEUE_SERIAL) ;
    dispatch_async(q, ^{
     //to  do
    });
     // 获取 名字的方法 
    // NSLog(@"%s", dispatch_queue_get_label(DISPATCH_CURRENT_QUEUE_LABEL));

2

   NSThread *thread = [[NSThread alloc]initWithTarget:self selector:@selector(display) object:nil];
    thread.name = @"thread-three";
    [thread start];

swfit
1

     let queue1 = DispatchQueue(label: "thread-one")
        queue1.async {
        // to do ;
        }

2

      let thread1 = Thread(target: self, selector: #selector(ViewController.display), object: nil)
        thread1.name = "thread1"
        thread1.start()

Nslock使用

 let thread1 = Thread(target: self, selector: #selector(ViewController.display), object: nil)
        thread1.name = "thread1"
        thread1.start()
        let thread2 = Thread(target: self, selector: #selector(ViewController.display), object: nil)
        thread2.name = "thread2"
        thread2.start()
        let thread3 = Thread(target: self, selector: #selector(ViewController.display), object: nil)
        thread3.name = "thread3"
        thread3.start()

    func display(){

       // lock.lock() //打开
            //耗时操作
            self.name =  Thread.current.name! ;
            //
            Thread.sleep(forTimeInterval: TimeInterval(5))

                    print("\(self.name) -- \(Thread.current.name!) ")
       // lock.unlock()//打开

    }

输出

thread2 -- thread3 
thread2 -- thread1 
thread2 -- thread2 

混乱了，修改display方法 注释打开 输出

thread3 -- thread3 
thread1 -- thread1 
thread2 -- thread2 

正常了

   func display(){
       lock.lock()
            self.name =  Thread.current.name!
        let timer:Timer = Timer(timeInterval: 5.0,
                                target: self,
                                selector: #selector(ViewController.log),
                                userInfo: nil,
                                repeats: false)

        // 将定时器添加到运行循环
        RunLoop.current.add(timer, forMode: RunLoopMode.defaultRunLoopMode)
        RunLoop.current.run()
       lock.unlock()

    }
    func log(){

      print("\(self.name) -- \(Thread.current.name!) ")
        Thread.sleep(forTimeInterval: 10);
    }

如果 lock 的内容 有异步执行的 会等异步执行完 再解锁 上面 一共过了 15s 才解锁