操作 NSOperation
操作队列 NSOperationQueues
主队列
NSOperationQueue *mainQueue = [NSOperationQueue mainQueue];
自定义队列
NSOperationQueue *queue = [[NSOperationQueue alloc]init];

将操作加入到队列中

- (void)addOperationToQueue {
    NSOperationQueue *queue = [[NSOperationQueue alloc]init];
    NSInvocationOperation *op1 = [[NSInvocationOperation alloc]initWithTarget:self selector:@selector(task1) object:nil];
    NSInvocationOperation *op2 = [[NSInvocationOperation alloc]initWithTarget:self selector:@selector(task2) object:nil];
    NSBlockOperation *op3 = [NSBlockOperation blockOperationWithBlock:^{
        for (int i = 0; i < 2; i++) {
            [NSThread sleepForTimeInterval:2];
            NSLog(@"3---%@",[NSThread currentThread]);
        }
    }];
    [op3 addExecutionBlock:^{
        for (int i = 0; i < 2; i++) {
            [NSThread sleepForTimeInterval:2];
            NSLog(@"4---%@",[NSThread currentThread]);
        }
    }];
   
    [queue addOperation:op1];
    [queue addOperation:op2];
    [queue addOperation:op3];
}

或者

- (void)addOperationWithBlockToQueue {
    NSOperationQueue *queue = [[NSOperationQueue alloc]init];
    [queue addOperationWithBlock:^{
        for (int i = 0; i < 2; i++) {
            [NSThread sleepForTimeInterval:2];
            NSLog(@"1---%@",[NSThread currentThread]);
        }
    }];
    [queue addOperationWithBlock:^{
        for (int i = 0; i < 2; i++) {
            [NSThread sleepForTimeInterval:2];
            NSLog(@"2---%@",[NSThread currentThread]);
        }
    }];
    [queue addOperationWithBlock:^{
        for (int i = 0; i < 2; i++) {
            [NSThread sleepForTimeInterval:2];
            NSLog(@"3---%@",[NSThread currentThread]);
        }
    }];
}

控制串行执行,并发执行(最大并发数)

- (void)setMaxConcurrentOperationCount {
    NSOperationQueue *queue = [[NSOperationQueue alloc]init];
//    queue.maxConcurrentOperationCount = 1; //串行队列
//    queue.maxConcurrentOperationCount = 2; //并发队列
    queue.maxConcurrentOperationCount = 8; //并发队列
    [queue addOperationWithBlock:^{
        for (int i = 0; i < 2; i++) {
            [NSThread sleepForTimeInterval:2];
            NSLog(@"1---%@",[NSThread currentThread]);
        }
    }];
    [queue addOperationWithBlock:^{
        for (int i = 0; i < 2; i++) {
            [NSThread sleepForTimeInterval:2];
            NSLog(@"2---%@",[NSThread currentThread]);
        }
    }];
    [queue addOperationWithBlock:^{
        for (int i = 0; i < 2; i++) {
            [NSThread sleepForTimeInterval:2];
            NSLog(@"3---%@",[NSThread currentThread]);
        }
    }];
}

操作依赖

- (void)addDependency {
    NSOperationQueue *queue = [[NSOperationQueue alloc]init];
    NSBlockOperation *op1 = [NSBlockOperation blockOperationWithBlock:^{
        for (int i = 0; i < 2; i++) {
            [NSThread sleepForTimeInterval:2];
            NSLog(@"1---%@",[NSThread currentThread]);
        }
    }];
    NSBlockOperation *op2 = [NSBlockOperation blockOperationWithBlock:^{
        for (int i = 0; i < 2; i++) {
            [NSThread sleepForTimeInterval:2];
            NSLog(@"2---%@",[NSThread currentThread]);
        }
    }];
    NSBlockOperation *op3 = [NSBlockOperation blockOperationWithBlock:^{
        for (int i = 0; i < 2; i++) {
            [NSThread sleepForTimeInterval:2];
            NSLog(@"3---%@",[NSThread currentThread]);
        }
    }];
    [op2 addDependency:op1]; //op2依赖于op1
    [queue addOperation:op1];
    [queue addOperation:op2];
    [queue addOperation:op3];
}

线程间的通信

- (void)communication {
    NSOperationQueue *queue = [[NSOperationQueue alloc]init];
    [queue addOperationWithBlock:^{
        for (int i = 0; i < 2; i++) {
            [NSThread sleepForTimeInterval:2];
            NSLog(@"1---%@",[NSThread currentThread]);
        }
        [[NSOperationQueue mainQueue] addOperationWithBlock:^{
            for (int i = 0; i < 2; i++) {
                [NSThread sleepForTimeInterval:2];
                NSLog(@"2---%@",[NSThread currentThread]);
            }
        }];
    }];
}