多线程中的CFReadStream:回调从未被调用

Question

一个多线程函数:

[NSThread detachNewThreadSelector:@selecter(download:) toTarget:..... withObject:....];

在内部调用回调函数。在多线程之前，回调机制工作得很好，但是现在回调函数永远不会被调用。

我已经检查了线程函数是否工作。

代码如下，非常感谢。

+(void) download:(id) param{
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];  
    while(true){
        NSLog(@"Thread going ");
        NSArray* ary = [Data_Center sharedData_Center]->data;
        for(int i = 0; i < [ary count]; i++) {
            NSLog(@"code = %@", code);
            ..........            
            NSURL* url1 = [NSURL URLWithString:str_code];
            [str_code length];

            CFStreamClientContext dataStreamContext = {0, self, NULL, NULL, NULL};
            CFHTTPMessageRef message = CFHTTPMessageCreateRequest(kCFAllocatorDefault, CFSTR("GET"), (CFURLRef)url1, kCFHTTPVersion1_1);
            CFHTTPMessageSetBody(message, (CFDataRef)(CFSTR("")));
            CFReadStreamRef readStream = CFReadStreamCreateForHTTPRequest(kCFAllocatorDefault, message);
            CFOptionFlags events = kCFStreamEventHasBytesAvailable | kCFStreamEventErrorOccurred | kCFStreamEventEndEncountered;
            // print "client = 1" here                    
            //NSLog(@"client = %d" , CFReadStreamSetClient(readStream, events, readStreamEventCallBack, & dataStreamContext));

            if(CFReadStreamSetClient(readStream, events, readStreamEventCallBack, & dataStreamContext)) {
                CFReadStreamScheduleWithRunLoop(readStream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
            }

            CFReadStreamOpen(readStream);
        }

        [NSThread sleepForTimeInterval:10];
    }
    [pool release];
}

Answer 1

重要编辑:我下面的答案是不正确的，它实际上并没有在另一个线程中创建和运行读流!它似乎只是将读流安排在主线程中的运行循环上运行。

1. 调用CFRunLoopGetCurrent ()

2. 在获得新线程上的循环后调用CFRunLoopRun()

   if(CFReadStreamSetClient(readStream, events, readStreamEventCallBack, & dataStreamContext)) {
    CFReadStreamScheduleWithRunLoop(readStream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
    CFRunLoopRun();
   }
   

   是正确的代码!如果您希望在主线程的循环中运行代码，则只执行以下操作:

我发现你需要调用CFRunLoopGetMain()而不是CFRunLoopGetCurrent()

 if(CFReadStreamSetClient(readStream, events, readStreamEventCallBack, & dataStreamContext)) {
     CFReadStreamScheduleWithRunLoop(readStream, CFRunLoopGetMain(), kCFRunLoopCommonModes);}

在这种情况下，

应该是正确的代码

Answer 2

请检查readStream是否打开

if (CFReadStreamOpen((CFReadStreamRef)readStream)) {
    NSLog(@"CFReadStreamOpen Sucessfully");
}
else {
    NSLog(@"Unable to start HTTP connection");
}

如果打开，试着评论NSAutoReleasePool我认为一些请求值在ReadStream打开之前被自动释放。

谢谢,

Answer 3

现在可以运行了

这很奇怪。回调永远不会被触发。相反，我可以在ReadStream打开后从原始函数读取数据。