1.5.9-1: socket() appears NOT to be thread-safe

[Brian Ford]

On Wed, 14 Apr 2004, Enzo Michelangeli wrote:

> While porting to Cygwin the Linux application "sipd"
> (http://www.sxdesign.com/index.php?page=developer&submnu=sipd ), which
> uses pthreads, I noticed that socket() calls issued concurrently by
> several threads often failed, with strerror(errno) saying "operation not
> permitted". Once I protected all the calls with mutex locks, such errors
> went away. Is Cygwin's implementation of socket() known to be
> thread-unsafe?

FWIW, I have seen this symptom as well, primarily on a dual CPU,
Hyperthreaded XP box under 1.5.[8|9]+.  In fact, I just confirmed it
still exists in a current CVS build from this morning.

It seems like a race condition.  Running under strace fixes it, so it has
been difficult to isolate.  If I have time, I'll try to look at it again
soon.  Would you like to work on it together?

-- 
Brian Ford
Senior Realtime Software Engineer
VITAL - Visual Simulation Systems
FlightSafety International
Phone: 314-551-8460
Fax:   314-551-8444

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