sysdeps/posix/sigpause.c

   1 /* Copyright (C) 1991-2015 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #define sigpause __rename_sigpause
  19 #include <errno.h>
  20 #include <signal.h>
  21 #include <stddef.h>             /* For NULL.  */
  22 #include <sysdep-cancel.h>
  23 #undef sigpause
  24
  25 #include <sigset-cvt-mask.h>
  26
  27 /* Set the mask of blocked signals to MASK,
  28    wait for a signal to arrive, and then restore the mask.  */
  29 static int
  30 do_sigpause (int sig_or_mask, int is_sig)
  31 {
  32   sigset_t set;
  33
  34   if (is_sig != 0)
  35     {
  36       /* The modern X/Open implementation is requested.  */
  37       if (__sigprocmask (0, NULL, &set) < 0
  38           || sigdelset (&set, sig_or_mask) < 0)
  39         return -1;
  40     }
  41   else if (sigset_set_old_mask (&set, sig_or_mask) < 0)
  42     return -1;
  43
  44   /* Note the sigpause() is a cancellation point.  But since we call
  45      sigsuspend() which itself is a cancellation point we do not have
  46      to do anything here.  */
  47   return __sigsuspend (&set);
  48 }
  49
  50 int
  51 __sigpause (int sig_or_mask, int is_sig)
  52 {
  53   if (SINGLE_THREAD_P)
  54     return do_sigpause (sig_or_mask, is_sig);
  55
  56   int oldtype = LIBC_CANCEL_ASYNC ();
  57
  58   int result = do_sigpause (sig_or_mask, is_sig);
  59
  60   LIBC_CANCEL_RESET (oldtype);
  61
  62   return result;
  63 }
  64 libc_hidden_def (__sigpause)
  65
  66 /* We have to provide a default version of this function since the
  67    standards demand it.  The version which is a bit more reasonable is
  68    the BSD version.  So make this the default.  */
  69 int
  70 __attribute__ ((weak))
  71 __default_sigpause (int mask)
  72 {
  73   return __sigpause (mask, 0);
  74 }
  75 #undef sigpause
  76 weak_alias (__default_sigpause, sigpause)
  77 strong_alias (__default_sigpause, __libc_sigpause)
  78
  79
  80 /* We have to provide a default version of this function since the
  81    standards demand it.  The version which is a bit more reasonable is
  82    the BSD version.  So make this the default.  */
  83 int
  84 __attribute__ ((weak))
  85 __xpg_sigpause (int sig)
  86 {
  87   return __sigpause (sig, 1);
  88 }
  89 strong_alias (__xpg_sigpause, __libc___xpg_sigpause)