bits/poll.h

   1 /* Copyright (C) 1997, 2000, 2001 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 Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the 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    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    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          01              /* There is data to read.  */
  27 #define POLLPRI         02              /* There is urgent data to read.  */
  28 #define POLLOUT         04              /* Writing now will not block.  */
  29
  30 /* Some aliases.  */
  31 #define POLLWRNORM      POLLOUT
  32 #define POLLRDNORM      POLLIN
  33 #define POLLRDBAND      POLLPRI
  34
  35 /* Event types always implicitly polled for.  These bits need not be set in
  36    `events', but they will appear in `revents' to indicate the status of
  37    the file descriptor.  */
  38 #define POLLERR         010             /* Error condition.  */
  39 #define POLLHUP         020             /* Hung up.  */
  40 #define POLLNVAL        040             /* Invalid polling request.  */
  41
  42 #ifdef __USE_MISC
  43 /* Canonical number of polling requests to read in at a time in poll.  */
  44 # define NPOLLFILE      30
  45 #endif