sysdeps/unix/sysv/linux/sigwait.c

   1 /* Copyright (C) 1997,1998,2000,2002-2004,2005 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   do
  62     ret = INTERNAL_SYSCALL (rt_sigtimedwait, err, 4, CHECK_SIGSET (set),
  63                             NULL, NULL, _NSIG / 8);
  64   while (INTERNAL_SYSCALL_ERROR_P (ret, err)
  65          && INTERNAL_SYSCALL_ERRNO (ret, err) == EINTR);
  66   if (! INTERNAL_SYSCALL_ERROR_P (ret, err))
  67     {
  68       *sig = ret;
  69       ret = 0;
  70     }
  71   else
  72     ret = INTERNAL_SYSCALL_ERRNO (ret, err);
  73 #else
  74   do
  75     ret = INLINE_SYSCALL (rt_sigtimedwait, 4, CHECK_SIGSET (set),
  76                           NULL, NULL, _NSIG / 8);
  77   while (ret == -1 && errno == EINTR);
  78   if (ret != -1)
  79     {
  80       *sig = ret;
  81       ret = 0;
  82     }
  83   else
  84     ret = errno;
  85 #endif
  86
  87   return ret;
  88 }
  89
  90 int
  91 __sigwait (set, sig)
  92      const sigset_t *set;
  93      int *sig;
  94 {
  95   if (SINGLE_THREAD_P)
  96     return do_sigwait (set, sig);
  97
  98   int oldtype = LIBC_CANCEL_ASYNC ();
  99
 100   int result = do_sigwait (set, sig);
 101
 102   LIBC_CANCEL_RESET (oldtype);
 103
 104   return result;
 105 }
 106 libc_hidden_def (__sigwait)
 107 weak_alias (__sigwait, sigwait)
 108 #else
 109 # include <sysdeps/posix/sigwait.c>
 110 #endif
 111 strong_alias (__sigwait, __libc_sigwait)