java - 发送10个网络请求，然后再接收到所有回应之后执行后续操作，如何实现？

Question

我想到的

for iOS
1.用dispatch_group实现
2.用RunLoop实现   

还有没有其他的比较好的实现方式,求关于并发编程的文章.

Answer 1

Someone said NSOperation, but I won’t say it.
But I prefer GCD. This problem can be solved using barrier:

    dispatch_queue_t queue = dispatch_queue_create("JOHNSHAW", DISPATCH_QUEUE_CONCURRENT);
    
    dispatch_async(queue, ^{
        NSLog(@"task 1");
        sleep(1);
    });
    dispatch_async(queue, ^{
        NSLog(@"task 2");
        sleep(1);
    });
    
    dispatch_barrier_async(queue, ^{
        NSLog(@"after task 1 and task 2");
        sleep(1);
    });
    
    dispatch_async(queue, ^{
        NSLog(@"do someting else");
    });

Actually, I prefer RAC, but RAC is a heavy-duty framework after all, and not many companies use it

    RACSignal *task1 = ...;
    RACSignal *task2 = ...;
    
    [[RACSignal combineLatest:@[task1,task2]] subscribeNext:^(id x) {
        NSLog(@"after task1 and task2 ");
    }];

Answer 2

Use RxAndroid. A .zip method is all it takes. .

Answer 3

A better way to use NSOperation is because of the addDependecy method~

Answer 4

For javascript:

1. https://github.com/caolan/async
   It’s very convenient to handle asynchronous parallelism and serialization

2. Use jQuery’s Promise, or other libraries’ Promise implementation :)

Answer 5

Learn from the map reduce method, which is similar to the idea of ​​merge sort

Answer 6

Just use dispatch_group_wait and dispatch_group_notify normally.

You can also use dispatch_barrier_sync / dispatch_barrier_async to use the operation after receiving all responses as a barrier block. Then this block will wait for all network requests to complete before executing.

Answer 7

I don’t know whether you are asking about Android or iOS. If it is Android, use CountDownLatch to control threads

Answer 8

In Java, you can use the future api of the concurrent package to implement separate requests from multiple threads, and then process the results after all responses.

Answer 9

for iOS
Create a serial queue for processing. Does not affect external concurrent requests.

Answer 10

How to implement it in JS?