pulseaudio/polyp/poll.h

/* $Id$ */

/***
   Compatibility definitions for System V `poll' interface.
   Copyright (C) 1994,96,97,98,99,2000,2001,2004 Free Software Foundation, Inc.
   Copyright (C) 2005, Cendio AB.
   This file is part of polypaudio.
   Based on work for the GNU C Library.

   polypaudio is free software; you can redistribute it and/or modify it
   under the terms of the GNU Library General Public License as published
   by the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   polypaudio is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with polypaudio; If not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
   USA.
***/

/* Event types that can be polled for.  These bits may be set in `events'
   to indicate the interesting event types; they will appear in `revents'
   to indicate the status of the file descriptor.  */
#define POLLIN          0x001           /* There is data to read.  */
#define POLLPRI         0x002           /* There is urgent data to read.  */
#define POLLOUT         0x004           /* Writing now will not block.  */

/* Event types always implicitly polled for.  These bits need not be set in
   `events', but they will appear in `revents' to indicate the status of
   the file descriptor.  */
#define POLLERR         0x008           /* Error condition.  */
#define POLLHUP         0x010           /* Hung up.  */
#define POLLNVAL        0x020           /* Invalid polling request.  */


/* Type used for the number of file descriptors.  */
typedef unsigned long int nfds_t;

/* Data structure describing a polling request.  */
struct pollfd
  {
    int fd;                     /* File descriptor to poll.  */
    short int events;           /* Types of events poller cares about.  */
    short int revents;          /* Types of events that actually occurred.  */
  };

/* Poll the file descriptors described by the NFDS structures starting at
   FDS.  If TIMEOUT is nonzero and not -1, allow TIMEOUT milliseconds for
   an event to occur; if TIMEOUT is -1, block until an event occurs.
   Returns the number of file descriptors with events, zero if timed out,
   or -1 for errors.  */
extern int poll (struct pollfd *__fds, nfds_t __nfds, int __timeout);