poll-compat.h

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 */
 
/*---------------------------------------------------------------------------*\
  $Id$
 
  NAME
 
    poll - select(2)-based poll() emulation function for BSD systems.
 
  SYNOPSIS
    #include "poll.h"
 
    struct pollfd
    {
        int     fd;
        short   events;
        short   revents;
    }
 
    int poll (struct pollfd *pArray, unsigned long n_fds, int timeout)
 
  DESCRIPTION
 
    This file, and the accompanying "poll.c", implement the System V
    poll(2) system call for BSD systems (which typically do not provide
    poll()).  Poll() provides a method for multiplexing input and output
    on multiple open file descriptors; in traditional BSD systems, that
    capability is provided by select().  While the semantics of select()
    differ from those of poll(), poll() can be readily emulated in terms
    of select() -- which is how this function is implemented.
 
  REFERENCES
    Stevens, W. Richard. Unix Network Programming.  Prentice-Hall, 1990.
 
  NOTES
    1. This software requires an ANSI C compiler.
 
  LICENSE
 
    This software is released under the following license:
 
        Copyright (c) 1995-2002 Brian M. Clapper
        All rights reserved.
 
        Redistribution and use in source and binary forms are
        permitted provided that: (1) source distributions retain
        this entire copyright notice and comment; (2) modifications
        made to the software are prominently mentioned, and a copy
        of the original software (or a pointer to its location) are
        included; and (3) distributions including binaries display
        the following acknowledgement: "This product includes
        software developed by Brian M. Clapper <bmc@clapper.org>"
        in the documentation or other materials provided with the
        distribution. The name of the author may not be used to
        endorse or promote products derived from this software
        without specific prior written permission.
 
        THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS
        OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE
        IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
        PARTICULAR PURPOSE.
 
    Effectively, this means you can do what you want with the software
    except remove this notice or take advantage of the author's name.
    If you modify the software and redistribute your modified version,
    you must indicate that your version is a modification of the
    original, and you must provide either a pointer to or a copy of the
    original.
\*---------------------------------------------------------------------------*/
 
#ifndef __AST_POLL_COMPAT_H
#define __AST_POLL_COMPAT_H
 
#include "asterisk/select.h"
 
#ifndef AST_POLL_COMPAT
 
#include <poll.h>
 
#define ast_poll(a, b, c) poll(a, b, c)
 
#else /* AST_POLL_COMPAT */
 
#define POLLIN      0x01
#define POLLPRI     0x02
#define POLLOUT     0x04
#define POLLERR     0x08
#define POLLHUP     0x10
#define POLLNVAL    0x20
 
struct pollfd {
    int     fd;
    short   events;
    short   revents;
};
 
#ifdef __cplusplus
extern "C" {
#endif
 
#define ast_poll(a, b, c) ast_internal_poll(a, b, c)
 
int ast_internal_poll(struct pollfd *pArray, unsigned long n_fds, int timeout);
 
#ifdef __cplusplus
}
#endif
 
#endif /* AST_POLL_COMPAT */
 
/*!
 * \brief Same as poll(2), except the time is specified in microseconds and
 * the tv argument is modified to indicate the time remaining.
 */
int ast_poll2(struct pollfd *pArray, unsigned long n_fds, struct timeval *tv);
 
/*!
 * \brief Shortcut for conversion of FD_ISSET to poll(2)-based
 */
static inline int ast_poll_fd_index(struct pollfd *haystack, int nfds, int needle)
{
    int i;
    for (i = 0; i < nfds; i++) {
        if (haystack[i].fd == needle) {
            return i;
        }
    }
    return -1;
}
 
#endif /* __AST_POLL_COMPAT_H */