Question

I’m doing application for iPhone using C sockets. At some point I’m performing recvfrom on separate NSThread (which is blocking) and I dont know how to force this operation to “unblock” and exit from thread gracefully. Calling shutdown() or close() doesn’t change anything, recvfrom still hangs. Is there any way to keep it as blocking socket and force it to close properly and exit from thread?

As I’m accused of not trying anything this is my piece of code which doesn’t cause recvfrom to “unblock”:

This is what i have right now:

- (void) stopScan
{
    NSLog(@"stopScan !!!");
    [activityIndicator stopAnimating];
    shutdown(broadcastSocket, SHUT_RDWR);
    close(broadcastSocket);
    [discoveryThread cancel];
    [discoveryThread release];
    discoveryThread = nil;
    [scanTimer invalidate];
    broadcastSocket = 0;
    scanTimer = nil;
}

Calling just only shutdown() or close() does not unblock either.

Answer 1

Sounds like you haven’t actually tried anything. Just close it. The recvfrom() will exit with an error.