sysdeps/unix/sysv/linux/sigwait.c

   1 /* Copyright (C) 1997-2014 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 #include <errno.h>
  19 #include <signal.h>
  20 #define __need_NULL
  21 #include <stddef.h>
  22 #include <string.h>
  23
  24 #include <sysdep-cancel.h>
  25 #include <sys/syscall.h>
  26
  27 #ifdef __NR_rt_sigtimedwait
  28
  29 /* Return any pending signal or wait for one for the given time.  */
  30 static int
  31 do_sigwait (const sigset_t *set, int *sig)
  32 {
  33   int ret;
  34
  35 #ifdef SIGCANCEL
  36   sigset_t tmpset;
  37   if (set != NULL
  38       && (__builtin_expect (__sigismember (set, SIGCANCEL), 0)
  39 # ifdef SIGSETXID
  40           || __builtin_expect (__sigismember (set, SIGSETXID), 0)
  41 # endif
  42           ))
  43     {
  44       /* Create a temporary mask without the bit for SIGCANCEL set.  */
  45       // We are not copying more than we have to.
  46       memcpy (&tmpset, set, _NSIG / 8);
  47       __sigdelset (&tmpset, SIGCANCEL);
  48 # ifdef SIGSETXID
  49       __sigdelset (&tmpset, SIGSETXID);
  50 # endif
  51       set = &tmpset;
  52     }
  53 #endif
  54
  55   /* XXX The size argument hopefully will have to be changed to the
  56      real size of the user-level sigset_t.  */
  57 #ifdef INTERNAL_SYSCALL
  58   INTERNAL_SYSCALL_DECL (err);
  59   do
  60     ret = INTERNAL_SYSCALL (rt_sigtimedwait, err, 4, set,
  61                             NULL, NULL, _NSIG / 8);
  62   while (INTERNAL_SYSCALL_ERROR_P (ret, err)
  63          && INTERNAL_SYSCALL_ERRNO (ret, err) == EINTR);
  64   if (! INTERNAL_SYSCALL_ERROR_P (ret, err))
  65     {
  66       *sig = ret;
  67       ret = 0;
  68     }
  69   else
  70     ret = INTERNAL_SYSCALL_ERRNO (ret, err);
  71 #else
  72   do
  73     ret = INLINE_SYSCALL (rt_sigtimedwait, 4, set, NULL, NULL, _NSIG / 8);
  74   while (ret == -1 && errno == EINTR);
  75   if (ret != -1)
  76     {
  77       *sig = ret;
  78       ret = 0;
  79     }
  80   else
  81     ret = errno;
  82 #endif
  83
  84   return ret;
  85 }
  86
  87 int
  88 __sigwait (set, sig)
  89      const sigset_t *set;
  90      int *sig;
  91 {
  92   if (SINGLE_THREAD_P)
  93     return do_sigwait (set, sig);
  94
  95   int oldtype = LIBC_CANCEL_ASYNC ();
  96
  97   int result = do_sigwait (set, sig);
  98
  99   LIBC_CANCEL_RESET (oldtype);
 100
 101   return result;
 102 }
 103 libc_hidden_def (__sigwait)
 104 weak_alias (__sigwait, sigwait)
 105 #else
 106 # include <sysdeps/posix/sigwait.c>
 107 #endif
 108 strong_alias (__sigwait, __libc_sigwait)