sysdeps/unix/sysv/linux/sigwait.c

   1 /* Copyright (C) 1997,1998,2000,2002,2003,2004 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 #include <string.h>
  24
  25 #include <sysdep-cancel.h>
  26 #include <sys/syscall.h>
  27 #include <bp-checks.h>
  28
  29 #ifdef __NR_rt_sigtimedwait
  30
  31 /* Return any pending signal or wait for one for the given time.  */
  32 static int
  33 do_sigwait (const sigset_t *set, int *sig)
  34 {
  35   int ret;
  36
  37 #ifdef SIGCANCEL
  38   sigset_t tmpset;
  39   if (set != NULL
  40       && (__builtin_expect (__sigismember (set, SIGCANCEL), 0)
  41 # ifdef SIGSETXID
  42           || __builtin_expect (__sigismember (set, SIGSETXID), 0)
  43 # endif
  44           ))
  45     {
  46       /* Create a temporary mask without the bit for SIGCANCEL set.  */
  47       // We are not copying more than we have to.
  48       memcpy (&tmpset, set, _NSIG / 8);
  49       __sigdelset (&tmpset, SIGCANCEL);
  50 # ifdef SIGSETXID
  51       __sigdelset (&tmpset, SIGSETXID);
  52 # endif
  53       set = &tmpset;
  54     }
  55 #endif
  56
  57   /* XXX The size argument hopefully will have to be changed to the
  58      real size of the user-level sigset_t.  */
  59 #ifdef INTERNAL_SYSCALL
  60   INTERNAL_SYSCALL_DECL (err);
  61   ret = INTERNAL_SYSCALL (rt_sigtimedwait, err, 4, CHECK_SIGSET (set),
  62                           NULL, NULL, _NSIG / 8);
  63   if (! INTERNAL_SYSCALL_ERROR_P (ret, err))
  64     {
  65       *sig = ret;
  66       ret = 0;
  67     }
  68   else
  69     ret = INTERNAL_SYSCALL_ERRNO (ret, err);
  70 #else
  71   ret = INLINE_SYSCALL (rt_sigtimedwait, 4, CHECK_SIGSET (set),
  72                         NULL, NULL, _NSIG / 8);
  73   if (ret != -1)
  74     {
  75       *sig = ret;
  76       ret = 0;
  77     }
  78   else
  79     ret = errno;
  80 #endif
  81
  82   return ret;
  83 }
  84
  85 int
  86 __sigwait (set, sig)
  87      const sigset_t *set;
  88      int *sig;
  89 {
  90   if (SINGLE_THREAD_P)
  91     return do_sigwait (set, sig);
  92
  93   int oldtype = LIBC_CANCEL_ASYNC ();
  94
  95   int result = do_sigwait (set, sig);
  96
  97   LIBC_CANCEL_RESET (oldtype);
  98
  99   return result;
 100 }
 101 libc_hidden_def (__sigwait)
 102 weak_alias (__sigwait, sigwait)
 103 #else
 104 # include <sysdeps/posix/sigwait.c>
 105 #endif
 106 strong_alias (__sigwait, __libc_sigwait)