ports/sysdeps/unix/sysv/linux/generic/pause.c

   1 /* Copyright (C) 2011-2014 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library.  If not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <signal.h>
  20 #include <unistd.h>
  21 #include <sysdep-cancel.h>
  22
  23 /* Suspend the process until a signal arrives.
  24    This always returns -1 and sets errno to EINTR.  */
  25
  26 static int
  27 __syscall_pause (void)
  28 {
  29   sigset_t set;
  30
  31   int rc =
  32     INLINE_SYSCALL (rt_sigprocmask, 4, SIG_BLOCK, NULL, &set, _NSIG / 8);
  33   if (rc == 0)
  34     rc = INLINE_SYSCALL (rt_sigsuspend, 2, &set, _NSIG / 8);
  35
  36   return rc;
  37 }
  38
  39 int
  40 __libc_pause (void)
  41 {
  42   if (SINGLE_THREAD_P)
  43     return __syscall_pause ();
  44
  45   int oldtype = LIBC_CANCEL_ASYNC ();
  46
  47   int result = __syscall_pause ();
  48
  49   LIBC_CANCEL_RESET (oldtype);
  50
  51   return result;
  52 }
  53 weak_alias (__libc_pause, pause)
  54
  55 #ifndef NO_CANCELLATION
  56 # include <not-cancel.h>
  57
  58 int
  59 __pause_nocancel (void)
  60 {
  61   return __syscall_pause ();
  62 }
  63 #endif