GCDAsyncsocket 使用异步串行子线程中for循环执行一半就不执行了，代码如下，过程是点击发送按钮返回到主页面，然后异步执行下面的代码上传图片；

    
    - (void)sendAction{
      dispatch_queue_t queue = dispatch_queue_create("uploadImage", DISPATCH_QUEUE_SERIAL);
         dispatch_async(queue, ^{
       for (int i =0; i < 10; i++) {
              
         NSLog(@"async ------------ %@", [NSThread currentThread]);
        
        //第一张图的资源
        PHAsset *asset = self.sendImageArray[i];
        NSString *fileType;
        NSString *fileName;
      
        if (asset.mediaType == PHAssetMediaTypeImage) {
            fileType = @"jpg";
            NSData *data = [NSData dataWithContentsOfFile:filePath[i]];

            [self upLoadImageData:data type:@"jpg" name:fileName];
        } else if(asset.mediaType == PHAssetMediaTypeVideo) {
            fileType = @"mp4";
              NSData *data = [NSData dataWithContentsOfFile:filePath[i]];
            [self uploadMp4Data:data type:fileType name:fileName];
            
        }       
  }
  });
  }
  
  - (void)upLoadImageData:(NSData*)data  type:(NSString *)fileType name:(NSString *)fileName{
     dataNameMutStr = [NSMutableString stringWithFormat:@"ios_%@_%@.jpg\n", @"图片",fileName];
   NSData *dataName = [dataNameMutStr dataUsingEncoding:NSUTF8StringEncoding];
   [self sendSocket:dataName data:data];
   }
   
   
   - (void)sendSocket:(NSData *)dataName data:(NSData *)datas{
     [self createClientTcpSocket];//发图片
     [_asyncsocket writeData:datas withTimeout:-1 tag:0];

   }