- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
// GCD 开几条线程并不是我们可以控制的，而是系统来决定的，
// [self asyncConcurrent];
// [self asyncSerial];
// [self syncConcurrent];
// [self syncSerial];
// [self test_get_global_queue];
// [self syncMain];//主线程操作直接死锁
[NSThread detachNewThreadSelector:@selector(syncMain) toTarget:self withObject:nil];//在子线程地调用，会直接执行，不会死锁
}
/**
异步函数 + 并发队列 ：会开启多条线程，队列中的任务是异步执行的（并发执行）(无序执行的)
*/
- (void)asyncConcurrent{
//1.创建任务
/*
参数1：const char * _Nullable label ， C语言参数 字符串 ，标识符，为了区分队列的 推荐写法：反着写
参数2：dispatch_queue_attr_t _Nullable attr，队列类型
DISPATCH_QUEUE_CONCURRENT 并发，
DISPATCH_QUEUE_SERIAL 串行
*/
dispatch_queue_t queue = dispatch_queue_create("com.520it.www", DISPATCH_QUEUE_CONCURRENT);
//2 2.1封装任务 2.2添加到任务队列中
/**
dispatch_async(<#dispatch_queue_t _Nonnull queue#>, <#^(void)block#>)
参数1：dispatch_queue_t _Nonnull queue 队列
参数2：<#^(void)block#> 要执行的任务
*/
dispatch_async(queue, ^{
NSLog(@"打印一下111 --- %@", [NSThread currentThread]);
});
dispatch_async(queue, ^{
NSLog(@"打印一下222 --- %@", [NSThread currentThread]);
});
dispatch_async(queue, ^{
NSLog(@"打印一下333 --- %@", [NSThread currentThread]);
});
}
/**
异步函数 + 串行队列：可以开启线程，但是串行队列只会在同一个子线程执行
*/
- (void)asyncSerial{
dispatch_queue_t queue = dispatch_queue_create("asyncSerial", DISPATCH_QUEUE_SERIAL);
dispatch_async(queue, ^{
NSLog(@"打印一下111 --- %@", [NSThread currentThread]);
});
dispatch_async(queue, ^{
NSLog(@"打印一下222 --- %@", [NSThread currentThread]);
});
dispatch_async(queue, ^{
NSLog(@"打印一下333 --- %@", [NSThread currentThread]);
});
}
/**
同步函数 + 并发队列 ：不会会开启多条线程，不管后面是并发还是串行，任务是串行执行的
*/
- (void)syncConcurrent{
//1.创建任务
dispatch_queue_t queue = dispatch_queue_create("com.520it.www", DISPATCH_QUEUE_CONCURRENT);
dispatch_sync(queue, ^{
NSLog(@"打印一下111 --- %@", [NSThread currentThread]);
});
dispatch_sync(queue, ^{
NSLog(@"打印一下222 --- %@", [NSThread currentThread]);
});
dispatch_sync(queue, ^{
NSLog(@"打印一下333 --- %@", [NSThread currentThread]);
});
}
/**
同步函数 + 串行队列 ：不会会开启多条线程，不管后面是并发还是串行，任务是串行执行的
*/
- (void)syncSerial{
dispatch_queue_t queue = dispatch_queue_create("syncSerial", DISPATCH_QUEUE_SERIAL);
dispatch_sync(queue, ^{
NSLog(@"打印一下111 --- %@", [NSThread currentThread]);
});
dispatch_sync(queue, ^{
NSLog(@"打印一下222 --- %@", [NSThread currentThread]);
});
dispatch_sync(queue, ^{
NSLog(@"打印一下333 --- %@", [NSThread currentThread]);
});
}
/**
获得全局队列
*/
-(void)test_get_global_queue{
/**
获得全局并发队列 ： 这个队列已经存在的， 我们只是获得
参数1 ： long identifier 优先级，
DISPATCH_QUEUE_PRIORITY_HIGH 2
DISPATCH_QUEUE_PRIORITY_DEFAULT 0
DISPATCH_QUEUE_PRIORITY_LOW (-2)
DISPATCH_QUEUE_PRIORITY_BACKGROUND INT16_MIN 这是最低的优先级
参数2 ： unsigned long flags 给未来使用， 总是给个0
*/
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_async(queue, ^{
NSLog(@"打印一下111 --- %@", [NSThread currentThread]);
});
dispatch_async(queue, ^{
NSLog(@"打印一下222 --- %@", [NSThread currentThread]);
});
dispatch_async(queue, ^{
NSLog(@"打印一下333 --- %@", [NSThread currentThread]);
});
}
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