mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-04 08:47:11 +00:00
93 lines
2.7 KiB
C
93 lines
2.7 KiB
C
/* POSIX compatible signal blocking for threads.
|
|
Copyright (C) 2011-2023 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
|
|
}
|