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POdefunct NSURLConnection never executes or times out
 

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    <p>I'm running a LOT of asynchronous (delegate, not block) <code>NSURLConnections</code> simultaneously, and they all come back very quickly as I'm hitting a LAN server.</p> <p>Every so often, one <code>NSURLConnection</code> will go defunct and never return.</p> <p><code>connection:willSendRequest:</code> is called but <code>connection:didReceiveResponse:</code> (and failure) is not.</p> <p>Any ideas? I'm wondering if I should make a simple drop-in replacement using <code>CFNetwork</code> instead.</p> <p>Edit: There's really not much code to show. What I've done is created a wrapper class to download files. I will note that the problem happens <em>less</em> when I run the connection on a separate queue - but still happens.</p> <p>The general gist of what I'm doing is creating a download request for each cell as a tableview scrolls (in <code>cellForRowAtIndexPath</code>) and then asynchronously loading in an image file to the table cell if the cell is still visible.</p> <pre><code>_request = [NSMutableURLRequest requestWithURL:_URL]; _request.cachePolicy = NSURLRequestReloadIgnoringCacheData; _request.timeoutInterval = _timeoutInterval; if(_lastModifiedDate) { [_request setValue:[_lastModifiedDate RFC1123String] forHTTPHeaderField:@"If-Modified-Since"]; } _connection = [[NSURLConnection alloc] initWithRequest:_request delegate:self startImmediately:NO]; [_connection start]; </code></pre> <p>As requested, instance variables:</p> <pre><code>NSMutableURLRequest *_request; NSURLConnection *_connection; </code></pre> <p>And delegate methods:</p> <pre><code>- (NSURLRequest *)connection:(NSURLConnection *)connection willSendRequest:(NSURLRequest *)request redirectResponse:(NSURLResponse *)response { NSLog(@"%@ send", _URL); return request; } - (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response { NSLog(@"%@ response", _URL); _response = (id)response; // create output stream } - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data { _receivedLength += data.length; _estimatedProgress = (Float32)_receivedLength / (Float32)_response.expectedContentLength; [_outputStream write:data.bytes maxLength:data.length]; // notify delegate } - (void)connectionDidFinishLoading:(NSURLConnection *)connection { // close output stream // notify delegate } - (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error { NSLog(@"%@ failure", _URL); // notify delegate } - (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge { if(_credential &amp;&amp; challenge.previousFailureCount == 0) { [[challenge sender] useCredential:_credential forAuthenticationChallenge:challenge]; } } </code></pre>
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    1. COCan you provide more detail of you code please? Btw, I'm having a similar problem with NSURLConnection too. Do you find any common between yours and mine [Here](http://stackoverflow.com/questions/17848290/nsurlconnection-doesnt-receive-data-when-creating-many-downloading-objects-in-i)
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    2. COPlease show declaration for `_request` and `_connection`, and your delegate methods (stripped down). What's `delegate` by the way? Is it the view controller, another object?
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    3. COIt's essentially 'self' for this discussion. I have an option on my wrapper object to use a weak proxy so that NSURLConnection doesn't keep my object alive. That flag is off in this instance.
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