ASIHTTP: addOperation when other threads are running
<p>I have a project using ASIHTTP to multi download files from a site</p>

<p>when I add a new request:</p>

<pre><code>[networkQueue cancelAllOperations];
[networkQueue  setDownloadProgressDelegate:a];
[networkQueue  setDelegate:self];
[networkQueue   setRequestDidFinishSelector:@selector(requestDone:)];

NSURL *url = [NSURL URLWithString:@"http://www.google.com"];
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[request setDelegate:self];
[request startAsynchronous];
[networkQueue  addOperation:request];

[networkQueue  go];
</code></pre>

<p>it reported:</p>

<p><strong>* Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*</strong> -[ASINetworkQueue addOperation:]: operation is executing and cannot be enqueued'</p>

<p>It looks like I can not add a new request when others are running.</p>

<p>Welcome any comment</p>

<p>Thanks</p>

<p>interdev</p>
