kill(pid,0) sends a signal or not?
sean at mcneil.com
Mon Jun 21 05:11:20 GMT 2004
I'm trying to trace down an issue with kse threads and firefox. There
is an odd "trick" I haven't seen before:
// kill(pid,0) is a neat trick to check if a
// process exists
if (kill(pid, 0) == 0 || errno != ESRCH)
Does this really work? It is kind of odd that it I appear to get a
signal (if the traceback is accurate) with the signal set to 0:
#10 0x0000000202bc7a80 in thr_resume_wrapper (sig=0, siginfo=0x4,
ucp=0x7fffffffd4c0) at /usr/src/lib/libpthread/thread/thr_kern.c:1112
This later causes a sig 11 and the program core dumps.
Any info on how threads are suppose to behave when a process does a
kill(pid,0) would be greatly appreciated.
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