sysdeps/unix/sysv/linux/ppoll.c

   1 /* Copyright (C) 2006, 2007, 2012 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <signal.h>
  21 #include <time.h>
  22 #include <sys/poll.h>
  23 #include <kernel-features.h>
  24 #include <sysdep-cancel.h>
  25
  26
  27 #ifdef __NR_ppoll
  28 # ifndef __ASSUME_PPOLL
  29 static int __generic_ppoll (struct pollfd *fds, nfds_t nfds,
  30                             const struct timespec *timeout,
  31                             const sigset_t *sigmask);
  32 # endif
  33
  34
  35 int
  36 ppoll (struct pollfd *fds, nfds_t nfds, const struct timespec *timeout,
  37        const sigset_t *sigmask)
  38 {
  39   /* The Linux kernel can in some situations update the timeout value.
  40      We do not want that so use a local variable.  */
  41   struct timespec tval;
  42   if (timeout != NULL)
  43     {
  44       tval = *timeout;
  45       timeout = &tval;
  46     }
  47
  48   int result;
  49
  50   if (SINGLE_THREAD_P)
  51     result = INLINE_SYSCALL (ppoll, 5, fds, nfds, timeout, sigmask, _NSIG / 8);
  52   else
  53     {
  54       int oldtype = LIBC_CANCEL_ASYNC ();
  55
  56       result = INLINE_SYSCALL (ppoll, 5, fds, nfds, timeout, sigmask,
  57                                _NSIG / 8);
  58
  59       LIBC_CANCEL_RESET (oldtype);
  60     }
  61
  62 # ifndef __ASSUME_PPOLL
  63   if (result == -1 && errno == ENOSYS)
  64     result = __generic_ppoll (fds, nfds, timeout, sigmask);
  65 # endif
  66
  67   return result;
  68 }
  69 libc_hidden_def (ppoll)
  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