Using AsyncSocket with secondary threads on the iPhone

I use AsyncSocket on the iPhone to communicate with a server. AsyncSocket is based on run loops but my app is based on threads. That means, I start a new thread to write data and wait until a response is received on the same thread. But I can't call an AsyncSocket's method directly from another thread, I have to use:

[self performSelectorOnMainThread:@selector(writeSomeData:) withObject:dataToWrite waitUntilDone:YES];

It does work, but I cannot get the response from my method "writeSomeData:" called this way, because performSelectorOnMainThread returns nothing.

The method writeSomeDat开发者_JAVA技巧a: does something like this:

-(NSData *)writeData:(NSData *)dataToWrite {
    dataReceived = nil; // AsyncSocket writes data to this variable
    [asyncSocket writeData:dataToWrite withTimeout:-1 tag:0];
    [asyncSocket readDataToData:[@"<EOF" dataUsingEncoding:NSUTF8StringEncoding] withTimeout:-1 tag:0];
    int counter = 0;
    while (dataReceived == nil && counter < 5) {
        // runLoop is [NSRunLoop currentRunloop]
        [runLoop runMode:NSDefaultRunLoopMode beforeDate:[NSDate dateWithTimeIntervalSinceNow:0.3]];
        ++counter;
    }

    return [dataReceived copy];
}

I could get the response by accessing the class variable "dataReceived", but it's content is changed at this time.

Can anybody tell me how to use AsyncSocket (or generally, how to deal with run loop based classes) on separate threads, so that if I call a method of that class it blocks until the method is executed and a response is received?

Thank you.

Try using GCD(Grand Central Dispatch) to write your data on a separate thread and than come back to the main thread the moment that the data was written. You could do it like this:

// call this on the main thread
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
    NSData *data = [self writeData:dataToWrite];
    dispatch_async(dispatch_get_main_queue(), ^{
        // do something with the data on the main thread.
    });
});

I hope something like this can help you...