iOS 使用信号量实现多层循环的网络请求

Posted 2023-01-18 夏天然后

- (void)start

		dispatch_async(dispatch_get_global_queue(0, 0), ^

        dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);

        for (int i = 0; i < users.count; i ++) 

            NSString *url = [NSString stringWithFormat:reposListUrl, users[i]];


            // 请求每个用户的所有库
            [XTNetwork requestWithURL:url parameter:nil methods:GET successResult:^(id result) 

                NSArray *data = result;
                NSMutableArray *names = [NSMutableArray array];
                for (int i = 0; i < data.count; i ++) 
                    NSDictionary *dic = data[i];
                    NSString *name = dic[@"name"];
                    [names addObject:name];
                
                NSLog(@"第一层的 i = %d", i);
                dispatch_async(dispatch_get_global_queue(0, 0), ^

                    dispatch_semaphore_t semaphore1 = dispatch_semaphore_create(0);

                    for (int j = 0; j < names.count; j ++) 

                        NSString *detailUrl = [NSString stringWithFormat:reposDetailUrl, users[i], names[j]];

                        [XTNetwork requestWithURL:detailUrl parameter:nil methods:GET successResult:^(id result) 

                            NSLog(@"第二层的 i = %d, j = %d", i, j);
                            dispatch_semaphore_signal(semaphore1);

                        ];
                        dispatch_semaphore_wait(semaphore1, DISPATCH_TIME_FOREVER);

                    
                    dispatch_semaphore_signal(semaphore);
                );
            ];
            dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
        
    );

2023-01-13 20:38:26.257297+0800 XTWeibo[3158:204344] 第一层的 i = 0
2023-01-13 20:38:26.261531+0800 XTWeibo[3158:204344] 第二层的 i = 0, j = 0
2023-01-13 20:38:27.276864+0800 XTWeibo[3158:204344] 第二层的 i = 0, j = 1
2023-01-13 20:38:28.051853+0800 XTWeibo[3158:204344] 第二层的 i = 0, j = 2
2023-01-13 20:38:29.074902+0800 XTWeibo[3158:204344] 第二层的 i = 0, j = 3
2023-01-13 20:38:29.794057+0800 XTWeibo[3158:204344] 第二层的 i = 0, j = 4
2023-01-13 20:38:30.509545+0800 XTWeibo[3158:204344] 第二层的 i = 0, j = 5
2023-01-13 20:38:31.227020+0800 XTWeibo[3158:204344] 第二层的 i = 0, j = 6
2023-01-13 20:38:31.943710+0800 XTWeibo[3158:204344] 第二层的 i = 0, j = 7
2023-01-13 20:38:32.641432+0800 XTWeibo[3158:204344] 第二层的 i = 0, j = 8
2023-01-13 20:38:33.376847+0800 XTWeibo[3158:204344] 第二层的 i = 0, j = 9
2023-01-13 20:38:34.093713+0800 XTWeibo[3158:204344] 第二层的 i = 0, j = 10
2023-01-13 20:38:34.914586+0800 XTWeibo[3158:204344] 第二层的 i = 0, j = 11
2023-01-13 20:38:35.992519+0800 XTWeibo[3158:204344] 第一层的 i = 1
2023-01-13 20:38:37.264356+0800 XTWeibo[3158:204344] 第二层的 i = 1, j = 0
2023-01-13 20:38:37.985781+0800 XTWeibo[3158:204344] 第二层的 i = 1, j = 1
2023-01-13 20:38:39.314381+0800 XTWeibo[3158:204344] 第二层的 i = 1, j = 2
2023-01-13 20:38:40.133719+0800 XTWeibo[3158:204344] 第二层的 i = 1, j = 3
2023-01-13 20:38:41.057140+0800 XTWeibo[3158:204344] 第二层的 i = 1, j = 4
2023-01-13 20:38:42.182486+0800 XTWeibo[3158:204344] 第二层的 i = 1, j = 5
2023-01-13 20:38:43.219709+0800 XTWeibo[3158:204344] 第二层的 i = 1, j = 6
2023-01-13 20:38:44.025821+0800 XTWeibo[3158:204344] 第二层的 i = 1, j = 7
2023-01-13 20:38:44.844844+0800 XTWeibo[3158:204344] 第二层的 i = 1, j = 8