Threads, signals and sockets (on UNIX)

[geoffbache]

Hi all,

I have a Python program (on UNIX) whose main job is to listen on a
socket, for which I use the SocketServer module. However, I would also
like it to be sensitive to signals received, which it isn't if it's
listening on the socket. ("signals can only be received between atomic
actions of the python interpreter", presumably - and control will not
return to Python unless something appears on the socket). Does anyone
have a tip of a good way to do this?

I can of course put the SocketServer in a thread and call
signal.pause() in the main thread, but this falls down when the
SocketServer terminates normally, as the signal.pause() cannot be
interrupted except via signals. So I tried sending a "dummy" signal
(SIGCHLD) from the thread when the SocketServer terminates, which
seems to work on Linux but not Solaris. And which in any case feels a
bit hackish - surely there has to be a better way?

Regards,
Geoff Bache