diff options
Diffstat (limited to 'tests/pthread_sigmask.c')
-rw-r--r-- | tests/pthread_sigmask.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/tests/pthread_sigmask.c b/tests/pthread_sigmask.c new file mode 100644 index 0000000..9ccf89b --- /dev/null +++ b/tests/pthread_sigmask.c @@ -0,0 +1,92 @@ +/* POSIX compatible signal blocking for threads. + Copyright (C) 2011-2017 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU 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 +} |