sysdeps/unix/sysv/linux/ppoll.c

   1 /* Copyright (C) 2006 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2006.
   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 <errno.h>
  21 #include <signal.h>
  22 #include <time.h>
  23 #include <sys/poll.h>
  24 #include <kernel-features.h>
  25 #include <sysdep-cancel.h>
  26
  27
  28 #ifdef __NR_ppoll
  29 static int __generic_ppoll (struct pollfd *fds, nfds_t nfds,
  30                             const struct timespec *timeout,
  31                             const sigset_t *sigmask);
  32
  33
  34 int
  35 ppoll (struct pollfd *fds, nfds_t nfds, const struct timespec *timeout,
  36        const sigset_t *sigmask)
  37 {
  38   /* The Linux kernel can in some situations update the timeout value.
  39      We do not want that so use a local variable.  */
  40   struct timespec tval;
  41   if (timeout != NULL)
  42     {
  43       tval = *timeout;
  44       timeout = &tval;
  45     }
  46
  47   int result;
  48
  49   if (SINGLE_THREAD_P)
  50     result = INLINE_SYSCALL (ppoll, 5, fds, nfds, timeout, sigmask, _NSIG / 8);
  51   else
  52     {
  53       int oldtype = LIBC_CANCEL_ASYNC ();
  54
  55       result = INLINE_SYSCALL (ppoll, 5, fds, nfds, timeout, sigmask,
  56                                _NSIG / 8);
  57
  58       LIBC_CANCEL_RESET (oldtype);
  59     }
  60
  61 # ifndef __ASSUME_PPOLL
  62   if (result == -1 && errno == ENOSYS)
  63     result = __generic_ppoll (fds, nfds, timeout, sigmask);
  64 # endif
  65
  66   return result;
  67 }
  68
  69 # ifndef __ASSUME_PPOLL
  70 #  define ppoll static __generic_ppoll
  71 # endif
  72 #endif
  73
  74 #ifndef __ASSUME_PPOLL
  75 # include <io/ppoll.c>
  76 #endif