sysdeps/posix/sigpause.c

   1 /* Copyright (C) 1991,92,94-98,2000,2002,2003,2004
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   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 #define sigpause __rename_sigpause
  20 #include <errno.h>
  21 #include <signal.h>
  22 #include <stddef.h>             /* For NULL.  */
  23 #include <sysdep-cancel.h>
  24 #undef sigpause
  25
  26 #include <sigset-cvt-mask.h>
  27
  28 /* Set the mask of blocked signals to MASK,
  29    wait for a signal to arrive, and then restore the mask.  */
  30 static int
  31 do_sigpause (int sig_or_mask, int is_sig)
  32 {
  33   sigset_t set;
  34
  35   if (is_sig != 0)
  36     {
  37       /* The modern X/Open implementation is requested.  */
  38       if (__sigprocmask (0, NULL, &set) < 0
  39           || sigdelset (&set, sig_or_mask) < 0)
  40         return -1;
  41     }
  42   else if (sigset_set_old_mask (&set, sig_or_mask) < 0)
  43     return -1;
  44
  45   /* Note the sigpause() is a cancellation point.  But since we call
  46      sigsuspend() which itself is a cancellation point we do not have
  47      to do anything here.  */
  48   return __sigsuspend (&set);
  49 }
  50
  51 int
  52 __sigpause (int sig_or_mask, int is_sig)
  53 {
  54   if (SINGLE_THREAD_P)
  55     return do_sigpause (sig_or_mask, is_sig);
  56
  57   int oldtype = LIBC_CANCEL_ASYNC ();
  58
  59   int result = do_sigpause (sig_or_mask, is_sig);
  60
  61   LIBC_CANCEL_RESET (oldtype);
  62
  63   return result;
  64 }
  65 libc_hidden_def (__sigpause)
  66
  67 /* We have to provide a default version of this function since the
  68    standards demand it.  The version which is a bit more reasonable is
  69    the BSD version.  So make this the default.  */
  70 int
  71 __attribute__ ((weak))
  72 __default_sigpause (int mask)
  73 {
  74   return __sigpause (mask, 0);
  75 }
  76 #undef sigpause
  77 weak_alias (__default_sigpause, sigpause)
  78 strong_alias (__default_sigpause, __libc_sigpause)
  79
  80
  81 /* We have to provide a default version of this function since the
  82    standards demand it.  The version which is a bit more reasonable is
  83    the BSD version.  So make this the default.  */
  84 int
  85 __attribute__ ((weak))
  86 __xpg_sigpause (int sig)
  87 {
  88   return __sigpause (sig, 1);
  89 }
  90 strong_alias (__xpg_sigpause, __libc___xpg_sigpause)