sysdeps/unix/sysv/linux/ppoll.c

   1 /* Copyright (C) 2006, 2007 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 # ifndef __ASSUME_PPOLL
  30 static int __generic_ppoll (struct pollfd *fds, nfds_t nfds,
  31                             const struct timespec *timeout,
  32                             const sigset_t *sigmask);
  33 # endif
  34
  35
  36 int
  37 ppoll (struct pollfd *fds, nfds_t nfds, const struct timespec *timeout,
  38        const sigset_t *sigmask)
  39 {
  40   /* The Linux kernel can in some situations update the timeout value.
  41      We do not want that so use a local variable.  */
  42   struct timespec tval;
  43   if (timeout != NULL)
  44     {
  45       tval = *timeout;
  46       timeout = &tval;
  47     }
  48
  49   int result;
  50
  51   if (SINGLE_THREAD_P)
  52     result = INLINE_SYSCALL (ppoll, 5, fds, nfds, timeout, sigmask, _NSIG / 8);
  53   else
  54     {
  55       int oldtype = LIBC_CANCEL_ASYNC ();
  56
  57       result = INLINE_SYSCALL (ppoll, 5, fds, nfds, timeout, sigmask,
  58                                _NSIG / 8);
  59
  60       LIBC_CANCEL_RESET (oldtype);
  61     }
  62
  63 # ifndef __ASSUME_PPOLL
  64   if (result == -1 && errno == ENOSYS)
  65     result = __generic_ppoll (fds, nfds, timeout, sigmask);
  66 # endif
  67
  68   return result;
  69 }
  70
  71 # ifndef __ASSUME_PPOLL
  72 #  define ppoll static __generic_ppoll
  73 # endif
  74 #endif
  75
  76 #ifndef __ASSUME_PPOLL
  77 # include <io/ppoll.c>
  78 #endif