pjsip-pjproject/pjlib/include/pj/sock_select.h

152 lines
4.8 KiB
C

/*
* Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
* Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef __PJ_SELECT_H__
#define __PJ_SELECT_H__
/**
* @file sock_select.h
* @brief Socket select().
*/
#include <pj/types.h>
PJ_BEGIN_DECL
/**
* @defgroup PJ_SOCK_SELECT Socket select() API.
* @ingroup PJ_IO
* @{
* This module provides portable abstraction for \a select() like API.
* The abstraction is needed so that it can utilize various event
* dispatching mechanisms that are available across platforms.
*
* The API is very similar to normal \a select() usage.
*
* \section pj_sock_select_examples_sec Examples
*
* For some examples on how to use the select API, please see:
*
* - Socket Select() test: \src{pjlib/src/pjlib-test/select.c}
*/
/**
* Portable structure declarations for pj_fd_set.
* The implementation of pj_sock_select() does not use this structure
* per-se, but instead it will use the native fd_set structure. However,
* we must make sure that the size of pj_fd_set_t can accomodate the
* native fd_set structure.
*/
typedef struct pj_fd_set_t
{
pj_sock_t data[PJ_IOQUEUE_MAX_HANDLES+ 4]; /**< Opaque buffer for fd_set */
} pj_fd_set_t;
/**
* Initialize the descriptor set pointed to by fdsetp to the null set.
*
* @param fdsetp The descriptor set.
*/
PJ_DECL(void) PJ_FD_ZERO(pj_fd_set_t *fdsetp);
/**
* This is an internal function, application shouldn't use this.
*
* Get the number of descriptors in the set. This is defined in sock_select.c
* This function will only return the number of sockets set from PJ_FD_SET
* operation. When the set is modified by other means (such as by select()),
* the count will not be reflected here.
*
* @param fdsetp The descriptor set.
*
* @return Number of descriptors in the set.
*/
PJ_DECL(pj_size_t) PJ_FD_COUNT(const pj_fd_set_t *fdsetp);
/**
* Add the file descriptor fd to the set pointed to by fdsetp.
* If the file descriptor fd is already in this set, there shall be no effect
* on the set, nor will an error be returned.
*
* @param fd The socket descriptor.
* @param fdsetp The descriptor set.
*/
PJ_DECL(void) PJ_FD_SET(pj_sock_t fd, pj_fd_set_t *fdsetp);
/**
* Remove the file descriptor fd from the set pointed to by fdsetp.
* If fd is not a member of this set, there shall be no effect on the set,
* nor will an error be returned.
*
* @param fd The socket descriptor.
* @param fdsetp The descriptor set.
*/
PJ_DECL(void) PJ_FD_CLR(pj_sock_t fd, pj_fd_set_t *fdsetp);
/**
* Evaluate to non-zero if the file descriptor fd is a member of the set
* pointed to by fdsetp, and shall evaluate to zero otherwise.
*
* @param fd The socket descriptor.
* @param fdsetp The descriptor set.
*
* @return Nonzero if fd is member of the descriptor set.
*/
PJ_DECL(pj_bool_t) PJ_FD_ISSET(pj_sock_t fd, const pj_fd_set_t *fdsetp);
/**
* This function wait for a number of file descriptors to change status.
* The behaviour is the same as select() function call which appear in
* standard BSD socket libraries.
*
* @param n On Unices, this specifies the highest-numbered
* descriptor in any of the three set, plus 1. On Windows,
* the value is ignored.
* @param readfds Optional pointer to a set of sockets to be checked for
* readability.
* @param writefds Optional pointer to a set of sockets to be checked for
* writability.
* @param exceptfds Optional pointer to a set of sockets to be checked for
* errors.
* @param timeout Maximum time for select to wait, or null for blocking
* operations.
*
* @return The total number of socket handles that are ready, or
* zero if the time limit expired, or -1 if an error occurred.
*/
PJ_DECL(int) pj_sock_select( int n,
pj_fd_set_t *readfds,
pj_fd_set_t *writefds,
pj_fd_set_t *exceptfds,
const pj_time_val *timeout);
/**
* @}
*/
PJ_END_DECL
#endif /* __PJ_SELECT_H__ */