ios 主队列里使用串行队列 ios异步串行队列

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mob64ca1405a060 2023-11-09 15:37:41

文章标签 ios 主队列里使用串行队列串行队列先进先出 文章分类 iOS 移动开发

首先我们先通过程序来看（串行队列，并行队列），（同步执行，异步执行）的区别，大概就能明白这些名词的意思

1 串行队列+同步执行

//创建串行队列 DISPATCH_QUEUE_SERIAL
dispatch_queue_t queue_serial = dispatch_queue_create("test", DISPATCH_QUEUE_SERIAL);
    //同步执行
dispatch_sync(queue_serial, ^{
sleep(2);
        NSLog(@"1,%@",[NSThread currentThread]);
    });
dispatch_sync(queue_serial, ^{
sleep(2);
        NSLog(@"2,%@",[NSThread currentThread]);
    });
dispatch_sync(queue_serial, ^{
sleep(2);
        NSLog(@"3,%@",[NSThread currentThread]);
    });
dispatch_sync(queue_serial, ^{
sleep(2);
        NSLog(@"4,%@",[NSThread currentThread]);
    });
dispatch_sync(queue_serial, ^{
sleep(2);
        NSLog(@"5,%@",[NSThread currentThread]);
    });
dispatch_sync(queue_serial, ^{
sleep(2);
        NSLog(@"6,%@",[NSThread currentThread]);
    });

ios 主队列里使用串行队列 ios异步串行队列_串行队列

先看懂输出的是什么。前面xxxx-xx-xx （年月日） xx:xx:xx.xxxxxxx(时间) 后面的是nslog 输出的。（currentThread）是打印当前线程的详情

按照我们给的1-6按顺序输出了，也就是先进先出 FIFO 。（好比我们排队打饭，先排进去的先打完饭出来）

大家都是number = 1 ，说明打饭给我们的人肯定是一个人。

2 串行队列 + 异步执行

//串行队列 + 异步执行
dispatch_queue_t queue_serial = dispatch_queue_create("test", DISPATCH_QUEUE_SERIAL);
    //异步执行
dispatch_async(queue_serial, ^{
sleep(2);
        NSLog(@"1,%@",[NSThread currentThread]);
    });
dispatch_async(queue_serial, ^{
sleep(2);
        NSLog(@"2,%@",[NSThread currentThread]);
    });
dispatch_async(queue_serial, ^{
sleep(2);
        NSLog(@"3,%@",[NSThread currentThread]);
    });
dispatch_async(queue_serial, ^{
sleep(2);
        NSLog(@"4,%@",[NSThread currentThread]);
    });
dispatch_async(queue_serial, ^{
sleep(2);
        NSLog(@"5,%@",[NSThread currentThread]);
    });
dispatch_async(queue_serial, ^{
sleep(2);
        NSLog(@"6,%@",[NSThread currentThread]);
    });

ios 主队列里使用串行队列 ios异步串行队列_ios 主队列里使用串行队列_02

同样按照1-6按照2秒间隔输出，大家number = 4，说明也是同一个阿姨给大家打饭。但是为什么是另外一个阿姨了呢。（这就是异步执行的原因，因为食堂开辟了另外一个窗口，异步也就是开辟了另外一个通道，大家也都在这个通道排队打饭）；

3 并行队列 + 同步执行

//并行队列，同步执行
    //并行队列
dispatch_queue_t queue_concurrent = dispatch_queue_create("test", DISPATCH_QUEUE_CONCURRENT);
    //同步执行
dispatch_sync(queue_concurrent, ^{
sleep(2);
        NSLog(@"1,%@",[NSThread currentThread]);
    });
dispatch_sync(queue_concurrent, ^{
sleep(2);
        NSLog(@"2,%@",[NSThread currentThread]);
    });
dispatch_sync(queue_concurrent, ^{
sleep(2);
        NSLog(@"3,%@",[NSThread currentThread]);
    });
dispatch_sync(queue_concurrent, ^{
sleep(2);
        NSLog(@"4,%@",[NSThread currentThread]);
    });
dispatch_sync(queue_concurrent, ^{
sleep(2);
        NSLog(@"5,%@",[NSThread currentThread]);
    });
dispatch_sync(queue_concurrent, ^{
sleep(2);
        NSLog(@"6,%@",[NSThread currentThread]);
    });

ios 主队列里使用串行队列 ios异步串行队列_先进先出_03

number = 1，因为是同步执行，开辟其他通道，也就是食堂没有其他打饭窗口，，大家并行队列的意思是，，，全部人没有排队而是各种插队插队，，可是阿姨一次只能打一个人的饭，所以也还是谁先到窗口谁先打到饭。

4 并行队列 + 异步执行

//并行队列，异步执行
    //并行队列
dispatch_queue_t queue_concurrent = dispatch_queue_create("test", DISPATCH_QUEUE_CONCURRENT);
    //同步执行
dispatch_async(queue_concurrent, ^{
sleep(2);
        NSLog(@"1,%@",[NSThread currentThread]);
    });
dispatch_async(queue_concurrent, ^{
sleep(2);
        NSLog(@"2,%@",[NSThread currentThread]);
    });
dispatch_async(queue_concurrent, ^{
sleep(2);
        NSLog(@"3,%@",[NSThread currentThread]);
    });
dispatch_async(queue_concurrent, ^{
sleep(2);
        NSLog(@"4,%@",[NSThread currentThread]);
    });
dispatch_async(queue_concurrent, ^{
sleep(2);
        NSLog(@"5,%@",[NSThread currentThread]);
    });
dispatch_async(queue_concurrent, ^{
sleep(2);
        NSLog(@"6,%@",[NSThread currentThread]);
    });

ios 主队列里使用串行队列 ios异步串行队列_先进先出_04