sysdeps/unix/sysv/linux/bits/poll.h

   1 /* Copyright (C) 1997 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 Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    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    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #ifndef _SYS_POLL_H
  20 # error "Never use <bits/poll.h> directly; include <sys/poll.h> instead."
  21 #endif
  22
  23 /* Event types that can be polled for.  These bits may be set in `events'
  24    to indicate the interesting event types; they will appear in `revents'
  25    to indicate the status of the file descriptor.  */
  26 #define POLLIN          0x001           /* There is data to read.  */
  27 #define POLLPRI         0x002           /* There is urgent data to read.  */
  28 #define POLLOUT         0x004           /* Writing now will not block.  */
  29
  30 #ifdef __USE_XOPEN
  31 /* These values are defined in XPG4.2.  */
  32 # define POLLRDNORM     0x040           /* Normal data may be read.  */
  33 # define POLLRDBAND     0x080           /* Priority data may be read.  */
  34 # define POLLWRNORM     0x100           /* Writing now will not block.  */
  35 # define POLLWRBAND     0x200           /* Priority data may be written.  */
  36 #endif
  37
  38 #ifdef __USE_GNU
  39 /* This is an extension for Linux.  */
  40 # define POLLMSG        0x400
  41 #endif
  42
  43 /* Event types always implicitly polled for.  These bits need not be set in
  44    `events', but they will appear in `revents' to indicate the status of
  45    the file descriptor.  */
  46 #define POLLERR         0x008           /* Error condition.  */
  47 #define POLLHUP         0x010           /* Hung up.  */
  48 #define POLLNVAL        0x020           /* Invalid polling request.  */
  49
  50 /* Canonical number of polling requests to read in at a time in poll.  */
  51 #define NPOLLFILE       30