标签：memory target www 回调 complete cts group imp priority
1.
dispatch_group_enter(group);
dispatch_group_leave(group);
dispatch_group_notify(group1, queue1,block);
在这种组合下，根据任务是同步、异步又分为两种，这两种组合的执行代码与运行结果如下：
第一种：同步任务时
dispatch_queue_t queue2 = dispatch_queue_create("dispatchGroupMethod2.queue2", DISPATCH_QUEUE_CONCURRENT);
dispatch_group_t group2 = dispatch_group_create();
dispatch_group_enter(group2);
dispatch_sync(queue2, ^{
for (NSInteger i =0; i<3; i++) {
sleep(1);
NSLog(@"%@-同步任务执行-:%ld",@"任务1",(long)i);
}
dispatch_group_leave(group2);
});
dispatch_group_enter(group2);
dispatch_sync(queue2, ^{
for (NSInteger i =0; i<3; i++) {
sleep(1);
NSLog(@"%@-同步任务执行-:%ld",@"任务2",(long)i);
}
dispatch_group_leave(group2);
});
// //等待上面的任务全部完成后，会往下继续执行 （会阻塞当前线程）
// dispatch_group_wait(group2, DISPATCH_TIME_FOREVER);
//等待上面的任务全部完成后，会收到通知执行block中的代码 （不会阻塞线程）
dispatch_group_notify(group2, queue2, ^{
NSLog(@"Method2-全部任务执行完成");
});
同步任务执行结果：
第二种：异步任务时
dispatch_queue_t queue2 = dispatch_queue_create("dispatchGroupMethod2.queue2", DISPATCH_QUEUE_CONCURRENT);
dispatch_group_t group2 = dispatch_group_create();
dispatch_group_enter(group2);
dispatch_async(queue2, ^{
for (NSInteger i =0; i<3; i++) {
sleep(1);
NSLog(@"%@-异步任务执行-:%ld",@"任务1",(long)i);
}
dispatch_group_leave(group2);
});
dispatch_group_enter(group2);
dispatch_async(queue2, ^{
for (NSInteger i =0; i<3; i++) {
sleep(1);
NSLog(@"%@-异步任务执行-:%ld",@"任务2",(long)i);
}
dispatch_group_leave(group2);
});
// //等待上面的任务全部完成后，会往下继续执行 （会阻塞当前线程）
// dispatch_group_wait(group2, DISPATCH_TIME_FOREVER);
//等待上面的任务全部完成后，会收到通知执行block中的代码 （不会阻塞线程）
dispatch_group_notify(group2, queue2, ^{
NSLog(@"Method2-全部任务执行完成");
});
异步任务执行结果：
https://www.cnblogs.com/zhou--fei/p/6747938.html
2.
创建一个信号量，作为全局变量。
并初始化，信号量为0
dispatch_semaphore_t semaphore;
semaphore = dispatch_semaphore_create(0);
创建一个dispatch_group_t，开启两个组异步线程（dispatch_group_async），分别执行两个网络请求。
一个组通知线程（dispatch_group_notify），用于接收前面两个线程的结果。
dispatch_group_t group = dispatch_group_create();
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_group_async(group, queue, ^{
[weakSelf loadRelationDetail];//请求1
});
dispatch_group_async(group, queue, ^{
[weakSelf loadRelationReward];//请求2
});
dispatch_group_notify(group, queue, ^{
dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
//合并（此处是数据处理，你可根据具体业务需求进行处理）
NSMutableArray *arr = [NSMutableArray array];
[arr addObjectsFromArray:weakSelf.arr1];
[arr addObjectsFromArray:weakSelf.arr2];
//排序
if (arr.count > 1) {
weakSelf.sumArr = [arr sortedArrayUsingComparator:^NSComparisonResult(ZHShareItem *obj1, ZHShareItem *obj2) {
return [obj1.createTime compare:obj2.createTime];
}];
}else{
weakSelf.sumArr = arr;
}
//有数据刷新
if (weakSelf.sumArr.count > 0) {
//在主线程刷新页面
dispatch_async(dispatch_get_main_queue(), ^{
[weakSelf initTableView];
});
}
});
https://www.jianshu.com/p/4e997f5deda9
3.afnetworking
为每一个NSURLSessionDownloadTask创建AFURLSessionManagerTaskDelegate，把请求的completionHandler也放在delegate。
从统一的回调didCompleteWithError到delegate的didCompleteWithError，再调用completionHandler返回。
- (void)addDelegateForDownloadTask:(NSURLSessionDownloadTask *)downloadTask progress:(void (^)(NSProgress *downloadProgress)) downloadProgressBlock destination:(NSURL * (^)(NSURL *targetPath, NSURLResponse *response))destination completionHandler:(void (^)(NSURLResponse *response, NSURL *filePath, NSError *error))completionHandler { AFURLSessionManagerTaskDelegate *delegate = [[AFURLSessionManagerTaskDelegate alloc] init]; delegate.manager = self; delegate.completionHandler = completionHandler; if (destination) { delegate.downloadTaskDidFinishDownloading = ^NSURL * (NSURLSession * __unused session, NSURLSessionDownloadTask *task, NSURL *location) { return destination(location, task.response); }; } downloadTask.taskDescription = self.taskDescriptionForSessionTasks; [self setDelegate:delegate forTask:downloadTask]; delegate.downloadProgressBlock = downloadProgressBlock; }
response
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error { AFURLSessionManagerTaskDelegate *delegate = [self delegateForTask:task]; // delegate may be nil when completing a task in the background if (delegate) { [delegate URLSession:session task:task didCompleteWithError:error]; ... //需要加锁 - (AFURLSessionManagerTaskDelegate *)delegateForTask:(NSURLSessionTask *)task { NSParameterAssert(task); AFURLSessionManagerTaskDelegate *delegate = nil; [self.lock lock]; delegate = self.mutableTaskDelegatesKeyedByTaskIdentifier[@(task.taskIdentifier)]; [self.lock unlock]; return delegate; } ... //每一个delegate #pragma mark - NSURLSessionTaskDelegate - (void)URLSession:(__unused NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error { #pragma clang diagnostic push #pragma clang diagnostic ignored "-Wgnu" __strong AFURLSessionManager *manager = self.manager; __block id responseObject = nil; __block NSMutableDictionary *userInfo = [NSMutableDictionary dictionary]; userInfo[AFNetworkingTaskDidCompleteResponseSerializerKey] = manager.responseSerializer; //Performance Improvement from #2672 NSData *data = nil; if (self.mutableData) { data = [self.mutableData copy]; //We no longer need the reference, so nil it out to gain back some memory. self.mutableData = nil; } if (self.downloadFileURL) { userInfo[AFNetworkingTaskDidCompleteAssetPathKey] = self.downloadFileURL; } else if (data) { userInfo[AFNetworkingTaskDidCompleteResponseDataKey] = data; } if (error) { userInfo[AFNetworkingTaskDidCompleteErrorKey] = error; dispatch_group_async(manager.completionGroup ?: url_session_manager_completion_group(), manager.completionQueue ?: dispatch_get_main_queue(), ^{ if (self.completionHandler) { self.completionHandler(task.response, responseObject, error); } dispatch_async(dispatch_get_main_queue(), ^{ [[NSNotificationCenter defaultCenter] postNotificationName:AFNetworkingTaskDidCompleteNotification object:task userInfo:userInfo]; }); }); } else { dispatch_async(url_session_manager_processing_queue(), ^{ NSError *serializationError = nil; responseObject = [manager.responseSerializer responseObjectForResponse:task.response data:data error:&serializationError]; if (self.downloadFileURL) { responseObject = self.downloadFileURL; } if (responseObject) { userInfo[AFNetworkingTaskDidCompleteSerializedResponseKey] = responseObject; } if (serializationError) { userInfo[AFNetworkingTaskDidCompleteErrorKey] = serializationError; } dispatch_group_async(manager.completionGroup ?: url_session_manager_completion_group(), manager.completionQueue ?: dispatch_get_main_queue(), ^{ if (self.completionHandler) { self.completionHandler(task.response, responseObject, serializationError); } dispatch_async(dispatch_get_main_queue(), ^{ [[NSNotificationCenter defaultCenter] postNotificationName:AFNetworkingTaskDidCompleteNotification object:task userInfo:userInfo]; }); }); }); } #pragma clang diagnostic pop }
标签：memory target www 回调 complete cts group imp priority
原文地址：https://www.cnblogs.com/javastart/p/9855825.html
