code.delx.au - pulseaudio/blob - polyp/poll.h

   1 /* $Id$ */
   2
   3 /***
   4    Compatibility definitions for System V `poll' interface.
   5    Copyright (C) 1994,96,97,98,99,2000,2001,2004 Free Software Foundation, Inc.
   6    Copyright (C) 2005, Cendio AB.
   7    This file is part of polypaudio.
   8    Based on work for the GNU C Library.
   9
  10    polypaudio is free software; you can redistribute it and/or modify it
  11    under the terms of the GNU Library General Public License as published
  12    by the Free Software Foundation; either version 2 of the License, or
  13    (at your option) any later version.
  14
  15    polypaudio is distributed in the hope that it will be useful, but
  16    WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18    Library General Public License for more details.
  19
  20    You should have received a copy of the GNU Library General Public
  21    License along with polypaudio; If not, write to the Free Software
  22    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  23    USA.
  24 ***/
  25
  26 /* Event types that can be polled for.  These bits may be set in `events'
  27    to indicate the interesting event types; they will appear in `revents'
  28    to indicate the status of the file descriptor.  */
  29 #define POLLIN          0x001           /* There is data to read.  */
  30 #define POLLPRI         0x002           /* There is urgent data to read.  */
  31 #define POLLOUT         0x004           /* Writing now will not block.  */
  32
  33 /* Event types always implicitly polled for.  These bits need not be set in
  34    `events', but they will appear in `revents' to indicate the status of
  35    the file descriptor.  */
  36 #define POLLERR         0x008           /* Error condition.  */
  37 #define POLLHUP         0x010           /* Hung up.  */
  38 #define POLLNVAL        0x020           /* Invalid polling request.  */
  39
  40
  41 /* Type used for the number of file descriptors.  */
  42 typedef unsigned long int nfds_t;
  43
  44 /* Data structure describing a polling request.  */
  45 struct pollfd
  46   {
  47     int fd;                     /* File descriptor to poll.  */
  48     short int events;           /* Types of events poller cares about.  */
  49     short int revents;          /* Types of events that actually occurred.  */
  50   };
  51
  52 /* Poll the file descriptors described by the NFDS structures starting at
  53    FDS.  If TIMEOUT is nonzero and not -1, allow TIMEOUT milliseconds for
  54    an event to occur; if TIMEOUT is -1, block until an event occurs.
  55    Returns the number of file descriptors with events, zero if timed out,
  56    or -1 for errors.  */
  57 extern int poll (struct pollfd *__fds, nfds_t __nfds, int __timeout);