sysdeps/unix/sysv/linux/waitid.c

   1 /* Linux implementation of waitid.
   2    Copyright (C) 2004 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <stddef.h>
  21 #include <errno.h>
  22 #include <sys/wait.h>
  23 #include <kernel-features.h>
  24 #include <sysdep.h>
  25
  26
  27 #ifdef __NR_waitid
  28
  29 # if __ASSUME_WAITID_SYSCALL > 0
  30
  31 static inline int
  32 do_waitid (idtype_t idtype, id_t id, siginfo_t *infop, int options)
  33 {
  34   /* The unused fifth argument is a `struct rusage *' that we could
  35      pass if we were using waitid to simulate wait3/wait4.  */
  36   return INLINE_SYSCALL (waitid, 5, idtype, id, infop, options, NULL);
  37 }
  38 # define NO_DO_WAITID
  39
  40 # else
  41
  42 static int do_compat_waitid (idtype_t idtype, id_t id,
  43                              siginfo_t *infop, int options);
  44 # define DO_WAITID do_compat_waitid
  45
  46 static int
  47 do_waitid (idtype_t idtype, id_t id, siginfo_t *infop, int options)
  48 {
  49   static int waitid_works;
  50   if (waitid_works > 0)
  51     return INLINE_SYSCALL (waitid, 5, idtype, id, infop, options, NULL);
  52   if (waitid_works == 0)
  53     {
  54       int result = INLINE_SYSCALL (waitid, 5,
  55                                    idtype, id, infop, options, NULL);
  56       if (result < 0 && errno == ENOSYS)
  57         waitid_works = -1;
  58       else
  59         {
  60           waitid_works = 1;
  61           return result;
  62         }
  63     }
  64   return do_compat_waitid (idtype, id, infop, options);
  65 }
  66
  67 # endif
  68
  69 #endif
  70
  71 #include "sysdeps/posix/waitid.c"