pjproject/pjlib/include/pj/sock_select.h

142 lines
3.9 KiB
C

/* $Header: /pjproject-0.3/pjlib/include/pj/sock_select.h 3 10/14/05 12:26a Bennylp $ */
/* $Log: /pjproject-0.3/pjlib/include/pj/sock_select.h $
*
* 3 10/14/05 12:26a Bennylp
* Finished error code framework, some fixes in ioqueue, etc. Pretty
* major.
*
* 2 9/21/05 1:39p Bennylp
* Periodic checkin for backup.
*
* 1 9/15/05 8:40p Bennylp
* Created.
*/
#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:
*
* - \ref page_pjlib_select_test
*/
/**
* 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[FD_SETSIZE + 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);
/**
* 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);
/**
* Get the number of descriptors in the set.
*
* @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);
/**
* 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__ */