多线程 队列的简单操作

 

 NSOperationQueue *queue = [[NSOperationQueuealloc]init];

 

     queue.maxConcurrentOperationCount = 2;

//线程池中的线程数，也就是并发操作数。默认情况下是-1，-1表示没有限制，这样会同时运行队列中的全部的操作。

 

    for (NSInteger i = 0 ; i <1000000;i ++ ) {

        NSBlockOperation *operation = [NSBlockOperation blockOperationWithBlock:^{

            sleep(1);

            NSLog(@"%ld%@",i,[NSThread currentThread]);

        }];

        [queue addOperation:operation];

 

    }

 NSBlockOperation *operation = [NSBlockOperation blockOperationWithBlock:^{

        sleep(1);

        NSLog(@"外加0%@",[NSThreadcurrentThread]);

    }];

    NSBlockOperation *operation1 = [NSBlockOperation blockOperationWithBlock:^{

        sleep(1);

        NSLog(@"外加1%@",[NSThreadcurrentThread]);

    }];

    NSBlockOperation *operation2 = [NSBlockOperation blockOperationWithBlock:^{

        sleep(1);

        NSLog(@"外加2%@",[NSThreadcurrentThread]);

    }];

    [operation addDependency:operation2];//添加依赖关系改变执行顺序

    [operation2  setQueuePriority:NSOperationQueuePriorityHigh];//设置operation2为高优先级先执行

    [queue addOperation:operation];

    [queue addOperation:operation1];

    [queue addOperation:operation2];

 

    

    [queue addOperationWithBlock:^{

        NSLog(@"执行一个新的操作，线程：%@", [NSThreadcurrentThread]);

    }];

    // 阻塞当前线程，等待queue的所有操作执行完毕

    [queue waitUntilAllOperationsAreFinished];

    [queue setSuspended:YES];//暂停

    [queue setSuspended:NO];//恢复

    [queue cancelAllOperations];//取消所有操作