How do I modify global variables from a signal handler?

[Brian Quinlan]

> This behavior isn't very surprising given the nature of signals
> and the fun state they can leave the stack.
> I assume that I have to do something with frame in the signal handler,
> but the use of frame is not documented -- nor is the use of
> Frame Objects as far as I can tell.

You are looking to deep. You just have to declare the use of global
variables:

GLOBAL_SIGCHLD_RECEIVED = 0
def childdied (signum, frame):
+   global GLOBAL_SIGCHLD_RECEIVED
    print 'Signal handler called with signal', signum
    GLOBAL_SIGCHLD_RECEIVED = 1

Cheers,
Brian