| /* Implementation of sigwait function from POSIX.1c. |
| Copyright (C) 1996, 1997, 1999, 2000, 2002 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996. |
| |
| The GNU C Library 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. |
| |
| The GNU C Library 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 the GNU C Library; if not, write to the Free |
| Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. */ |
| |
| #include <errno.h> |
| #include <signal.h> |
| #include <stddef.h> /* For NULL. */ |
| #include <sysdep-cancel.h> |
| |
| /* This is our dummy signal handler we use here. */ |
| static void ignore_signal (int sig); |
| |
| /* Place where to remember which signal we got. Please note that this |
| implementation cannot be used for the threaded libc. The |
| libpthread must provide an own version. */ |
| static int was_sig; |
| |
| |
| static int |
| do_sigwait (const sigset_t *set, int *sig) |
| { |
| sigset_t tmp_mask; |
| struct sigaction saved[NSIG]; |
| struct sigaction action; |
| int save_errno; |
| int this; |
| |
| /* Prepare set. */ |
| __sigfillset (&tmp_mask); |
| |
| /* Unblock all signals in the SET and register our nice handler. */ |
| action.sa_handler = ignore_signal; |
| action.sa_flags = 0; |
| __sigfillset (&action.sa_mask); /* Block all signals for handler. */ |
| |
| /* Make sure we recognize error conditions by setting WAS_SIG to a |
| value which does not describe a legal signal number. */ |
| was_sig = -1; |
| |
| for (this = 1; this < NSIG; ++this) |
| if (__sigismember (set, this)) |
| { |
| /* Unblock this signal. */ |
| __sigdelset (&tmp_mask, this); |
| |
| /* Register temporary action handler. */ |
| if (__sigaction (this, &action, &saved[this]) != 0) |
| goto restore_handler; |
| } |
| |
| /* Now we can wait for signals. */ |
| __sigsuspend (&tmp_mask); |
| |
| restore_handler: |
| save_errno = errno; |
| |
| while (--this >= 1) |
| if (__sigismember (set, this)) |
| /* We ignore errors here since we must restore all handlers. */ |
| __sigaction (this, &saved[this], NULL); |
| |
| __set_errno (save_errno); |
| |
| /* Store the result and return. */ |
| *sig = was_sig; |
| return was_sig == -1 ? -1 : 0; |
| } |
| |
| |
| int |
| __sigwait (const sigset_t *set, int *sig) |
| { |
| if (SINGLE_THREAD_P) |
| return do_sigwait (set, sig); |
| |
| int oldtype = LIBC_CANCEL_ASYNC (); |
| |
| int result = do_sigwait (set, sig); |
| |
| LIBC_CANCEL_RESET (oldtype); |
| |
| return result; |
| } |
| libc_hidden_def (__sigwait) |
| weak_alias (__sigwait, sigwait) |
| |
| |
| static void |
| ignore_signal (int sig) |
| { |
| /* Remember the signal. */ |
| was_sig = sig; |
| } |