sysdeps/unix/sysv/linux/sigwait.c

   1 /* Copyright (C) 1997, 1998, 2000, 2002, 2003 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <signal.h>
  21 #define __need_NULL
  22 #include <stddef.h>
  23
  24 #include <sysdep-cancel.h>
  25 #include <sys/syscall.h>
  26 #include <bp-checks.h>
  27
  28 #ifdef __NR_rt_sigtimedwait
  29 extern int __syscall_rt_sigtimedwait (const sigset_t *__unbounded, siginfo_t *__unbounded,
  30                                       const struct timespec *__unbounded, size_t);
  31
  32
  33 /* Return any pending signal or wait for one for the given time.  */
  34 static int
  35 do_sigwait (const sigset_t *set, int *sig)
  36 {
  37   int ret;
  38
  39 #ifdef SIGCANCEL
  40   sigset_t tmpset;
  41   if (set != NULL && __sigismember (set, SIGCANCEL))
  42     {
  43       /* Create a temporary mask without the bit for SIGCANCEL set.  */
  44       // We are not copying more than we have to.
  45       memcpy (&tmpset, set, _NSIG / 8);
  46       __sigdelset (&tmpset, SIGCANCEL);
  47       set = &tmpset;
  48     }
  49 #endif
  50
  51   /* XXX The size argument hopefully will have to be changed to the
  52      real size of the user-level sigset_t.  */
  53 #ifdef INTERNAL_SYSCALL
  54   INTERNAL_SYSCALL_DECL (err);
  55   ret = INTERNAL_SYSCALL (rt_sigtimedwait, err, 4, CHECK_SIGSET (set),
  56                           NULL, NULL, _NSIG / 8);
  57   if (! INTERNAL_SYSCALL_ERROR_P (ret, err))
  58     {
  59       *sig = ret;
  60       ret = 0;
  61     }
  62   else
  63     ret = INTERNAL_SYSCALL_ERRNO (ret, err);
  64 #else
  65   ret = INLINE_SYSCALL (rt_sigtimedwait, 4, CHECK_SIGSET (set),
  66                         NULL, NULL, _NSIG / 8);
  67   if (ret != -1)
  68     {
  69       *sig = ret;
  70       ret = 0;
  71     }
  72   else
  73     ret = errno;
  74 #endif
  75
  76   return ret;
  77 }
  78
  79 int
  80 __sigwait (set, sig)
  81      const sigset_t *set;
  82      int *sig;
  83 {
  84   if (SINGLE_THREAD_P)
  85     return do_sigwait (set, sig);
  86
  87   int oldtype = LIBC_CANCEL_ASYNC ();
  88
  89   int result = do_sigwait (set, sig);
  90
  91   LIBC_CANCEL_RESET (oldtype);
  92
  93   return result;
  94 }
  95 libc_hidden_def (__sigwait)
  96 weak_alias (__sigwait, sigwait)
  97 #else
  98 # include <sysdeps/posix/sigwait.c>
  99 #endif
 100 strong_alias (__sigwait, __libc_sigwait)