GCD之同步函数、异步函数和串行队列、并发队列

来源：互联网发布：安全炒股软件编辑：程序博客网时间：2024/06/06 12:45

// ViewController.m

// 1124GCD多线程同步异步函数和并发串行队列

// Created by weibiao on 15/11/24.

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {

[superviewDidLoad];

[selfsyncGlobalQueue];

// [self asyncGlobalQueue];

// [self asyncSerialQueue];

// [self syncSerialQueue];

}

// 异步函数，执行串行队列，只会创建一条线程

/**

* 会创建1条线程

- (void)asyncSerialQueue {

dispatch_queue_t queue =dispatch_queue_create("WBO",NULL);

dispatch_async(queue, ^{

NSLog(@"下载图片A----%@",[NSThreadcurrentThread]);

});

dispatch_async(queue, ^{

NSLog(@"下载图片B----%@",[NSThreadcurrentThread]);

});

dispatch_async(queue, ^{

NSLog(@"下载图片C----%@",[NSThreadcurrentThread]);

});

}

// 异步函数，执行并发队列，会创建多条队列

/**

* 会创建3条线程

- (void)asyncGlobalQueue {

dispatch_queue_t queue =dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT,0);

dispatch_async(queue, ^{

NSLog(@"下载图片A----%@",[NSThreadcurrentThread]);

});

dispatch_async(queue, ^{

NSLog(@"下载图片B----%@",[NSThreadcurrentThread]);

});

dispatch_async(queue, ^{

NSLog(@"下载图片C----%@",[NSThreadcurrentThread]);

});

}

// 同步函数，执行串行队列，不会创建线程，在主线程中执行操作

/**

* 不会创建新的线程

- (void)syncSerialQueue {

dispatch_queue_t queue =dispatch_queue_create("WB",NULL);

dispatch_sync(queue, ^{

NSLog(@"下载图片A----%@",[NSThreadcurrentThread]);

});

dispatch_sync(queue, ^{

NSLog(@"下载图片B----%@",[NSThreadcurrentThread]);

});

dispatch_sync(queue, ^{

NSLog(@"下载图片C----%@",[NSThreadcurrentThread]);

});

}

// 同步函数，执行并发队列，不会创建队列

/**

* 不会创建新的线程

- (void)syncGlobalQueue {

dispatch_queue_t queue =dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT,0);

dispatch_sync(queue, ^{

NSLog(@"下载图片A----%@",[NSThreadcurrentThread]);

});

dispatch_sync(queue, ^{

NSLog(@"下载图片B----%@",[NSThreadcurrentThread]);

});

dispatch_sync(queue, ^{

NSLog(@"下载图片C----%@",[NSThreadcurrentThread]);

});

}

/**

* 同步函数没有开线程的能力

@end

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