Unblock recvfrom when socket is closed

c sockets select recv
user657178 picture user657178 · Jun 17, 2011 · Viewed 12.5k times · Source

Let's say I start a thread to receive on a port. The socket call will block on recvfrom. Then, somehow in another thread, I close the socket.

On Windows, this will unblock recvfrom and my thread execution will terminate.

On Linux, this does not unblock recvfrom, and as a result, my thread is sitting doing nothing forever, and the thread execution does not terminate.

Can anyone help me with what's happening on Linux? When the socket is closed, I want recvfrom to unblock

I keep reading about using select(), but I don't know how to use it for my specific case.

Answer

ajfabbri picture ajfabbri · Nov 1, 2011

Call shutdown(sock, SHUT_RDWR) on the socket, then wait for the thread to exit. (i.e. pthread_join).

You would think that close() would unblock the recvfrom(), but it doesn't on linux.

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