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emacs/lib/pthread_sigmask.c
Paul Eggert 68a256c892 Update from Gnulib
Make the following changes by hand, and run 'admin/merge-gnulib'.
* .gitignore: Add lib/malloc/*.gl.h.
* admin/merge-gnulib: Copy lib/af_alg.h and lib/save-cwd.h
directly from Gnulib, without worrying about Gnulib modules,
as these files are special cases.
(AVOIDED_MODULES): Remove malloc-posix.
* lib/malloc.c, lib/realloc.c, m4/malloc.m4, m4/realloc.m4:
* m4/year2038.m4: New files, copied from Gnulib.
* lib/malloca.c, lib/malloca.h:
* m4/close-stream.m4, m4/glibc21.m4, m4/malloca.m4:
Remove.  These are either no longer present in Gnulib, or are no
longer needed by modules that Emacs uses.
* oldXMenu/AddPane.c, oldXmenu/Addsel.c: Include XmenuInt.h first;
needed for new Gnulib.
* src/xmenu.c: Call emacs_abort, not abort.
2021-10-04 15:21:31 -07:00

93 lines
2.7 KiB
C

/* POSIX compatible signal blocking for threads.
Copyright (C) 2011-2021 Free Software Foundation, Inc.
This file is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
This file is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
#include <config.h>
/* Specification. */
#include <signal.h>
#include <errno.h>
#include <stddef.h>
#if PTHREAD_SIGMASK_INEFFECTIVE
# include <string.h>
#endif
#if PTHREAD_SIGMASK_UNBLOCK_BUG
# include <unistd.h>
#endif
int
pthread_sigmask (int how, const sigset_t *new_mask, sigset_t *old_mask)
#undef pthread_sigmask
{
#if HAVE_PTHREAD_SIGMASK
int ret;
# if PTHREAD_SIGMASK_INEFFECTIVE
sigset_t omask, omask_copy;
sigset_t *old_mask_ptr = &omask;
sigemptyset (&omask);
/* Add a signal unlikely to be blocked, so that OMASK_COPY
is unlikely to match the actual mask. */
sigaddset (&omask, SIGILL);
memcpy (&omask_copy, &omask, sizeof omask);
# else
sigset_t *old_mask_ptr = old_mask;
# endif
ret = pthread_sigmask (how, new_mask, old_mask_ptr);
# if PTHREAD_SIGMASK_INEFFECTIVE
if (ret == 0)
{
/* Detect whether pthread_sigmask is currently ineffective.
Don't cache the information: libpthread.so could be dynamically
loaded after the program started and after pthread_sigmask was
called for the first time. */
if (memcmp (&omask_copy, &omask, sizeof omask) == 0
&& pthread_sigmask (1729, &omask_copy, NULL) == 0)
{
/* pthread_sigmask is currently ineffective. The program is not
linked to -lpthread. So use sigprocmask instead. */
return (sigprocmask (how, new_mask, old_mask) < 0 ? errno : 0);
}
if (old_mask)
memcpy (old_mask, &omask, sizeof omask);
}
# endif
# if PTHREAD_SIGMASK_FAILS_WITH_ERRNO
if (ret == -1)
return errno;
# endif
# if PTHREAD_SIGMASK_UNBLOCK_BUG
if (ret == 0
&& new_mask != NULL
&& (how == SIG_UNBLOCK || how == SIG_SETMASK))
{
/* Give the OS the opportunity to raise signals that were pending before
the pthread_sigmask call and have now been unblocked. */
usleep (1);
}
# endif
return ret;
#else
int ret = sigprocmask (how, new_mask, old_mask);
return (ret < 0 ? errno : 0);
#endif
}