title: NSURLConnection and grand central dispatch
body: <p>Is it advisable to wrap up NSUrlConnection in a gcd style blocks and run it on a low_priority queue?</p>
  
  <p>I need to ensure that my connections are not happening on the main thread and the connections need to be asynchronous. I also need several simultaneous requests to go at once.</p>
  
  <p>If I go the gcd route, I'm not sure which thread the NSUrlConnectionDelegate methods get invoked on. </p>
  
  <p>NSURLConnection relies on delegates so once the connection is complete, whatever wrapper class that handles it will need to invoke its caller. I'm not certain how to deal with all of the various callbacks that are invoked when the connection work starts up/finishes:</p>
  
  <pre><code>- (void)connection:(NSURLConnection *)aConnection didReceiveResponse:(NSURLResponse *)response;
  - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)incrementalData;
  - (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error;
  - (void)connectionDidFinishLoading:(NSURLConnection *)connection;
  </code></pre>
  
  <p>Should I just call the synchronous versions but wrapped in gcd blocks? And if I want to cancel a call, use 'dispatch_suspend'?</p>
  
  <pre><code>dispatch_async(queue,^{
        NSString* result = [self mySynchronousHttp:someURLToInvoke];
        });
  
  // If I need to cancel
  dispatch_suspend(queue);
  </code></pre>