On Sat, 23 Feb 2019 05:54:18, Doug Henderson wrote:
> On Fri, 22 Feb 2019 at 17:01, Glyn Gowing <> wrote:
> > I have a program (attached) that works correctly on my mac but does
> > not work with Cygwin on Windows 10. I'm running the latest version of
[snip]
> On further analysis, the call to
> > pthread_mutexattr_setpshared(attr, PTHREAD_PROCESS_SHARED);
> is failing. The error is EINVAL (22) Invalid argument.
>
> This suggests that pthread mutexes cannot be shared between processes
> by using shared memory in cygwin. I have not attempted to determine if
> this is working as expected, or if this is a bug, or a limitation in
> the Windows environment.
For the record, this (i.c. PTHREAD_PROCESS_SHARED) is not yet supported on
Cygwin.
winsup/cygwin/thread.cc
3636 extern "C" int
3637 pthread_mutexattr_setpshared (pthread_mutexattr_t *attr, int pshared)
3638 {
3639 if (!pthread_mutexattr::is_good_object (attr))
3640 return EINVAL;
3641 /* we don't use pshared for anything as yet. We need to test
PROCESS_SHARED
3642 *functionality
3643 */
3644 if (pshared != PTHREAD_PROCESS_PRIVATE)
3645 return EINVAL; <====
3646 (*attr)->pshared = pshared;
3647 return 0;
3648 }
Henri
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