86 lines
3.4 KiB
C
86 lines
3.4 KiB
C
/* fdwatch.h - header file for fdwatch package
|
|
**
|
|
** This package abstracts the use of the select()/poll()/kqueue()
|
|
** system calls. The basic function of these calls is to watch a set
|
|
** of file descriptors for activity. select() originated in the BSD world,
|
|
** while poll() came from SysV land, and their interfaces are somewhat
|
|
** different. fdwatch lets you write your code to a single interface,
|
|
** with the portability differences hidden inside the package.
|
|
**
|
|
** Usage is fairly simple. Call fdwatch_get_nfiles() to initialize
|
|
** the package and find out how many fine descriptors are available.
|
|
** Then each time through your main loop, call fdwatch_clear(), then
|
|
** fdwatch_add_fd() for each of the descriptors you want to watch,
|
|
** then call fdwatch() to actually perform the watch. After it returns
|
|
** you can check which descriptors are ready via fdwatch_check_fd().
|
|
**
|
|
** If your descriptor set hasn't changed from the last time through
|
|
** the loop, you can skip calling fdwatch_clear() and fdwatch_add_fd()
|
|
** to save a little CPU time.
|
|
**
|
|
**
|
|
** Copyright © 1999 by Jef Poskanzer <jef@mail.acme.com>.
|
|
** All rights reserved.
|
|
**
|
|
** Redistribution and use in source and binary forms, with or without
|
|
** modification, are permitted provided that the following conditions
|
|
** are met:
|
|
** 1. Redistributions of source code must retain the above copyright
|
|
** notice, this list of conditions and the following disclaimer.
|
|
** 2. Redistributions in binary form must reproduce the above copyright
|
|
** notice, this list of conditions and the following disclaimer in the
|
|
** documentation and/or other materials provided with the distribution.
|
|
**
|
|
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
** ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
** SUCH DAMAGE.
|
|
*/
|
|
|
|
#ifndef _FDWATCH_H_
|
|
#define _FDWATCH_H_
|
|
|
|
#define FDW_READ 0
|
|
#define FDW_WRITE 1
|
|
|
|
#ifndef INFTIM
|
|
#define INFTIM -1
|
|
#endif /* INFTIM */
|
|
|
|
/* Figure out how many file descriptors the system allows, and
|
|
** initialize the fdwatch data structures. Returns -1 on failure.
|
|
*/
|
|
int fdwatch_get_nfiles( void );
|
|
|
|
/* Add a descriptor to the watch list. rw is either FDW_READ or FDW_WRITE. */
|
|
void fdwatch_add_fd( int fd, void* client_data, int rw );
|
|
|
|
/* Delete a descriptor from the watch list. */
|
|
void fdwatch_del_fd( int fd );
|
|
|
|
/* Do the watch. Return value is the number of descriptors that are ready,
|
|
** or 0 if the timeout expired, or -1 on errors. A timeout of INFTIM means
|
|
** wait indefinitely.
|
|
*/
|
|
int fdwatch( long timeout_msecs );
|
|
|
|
/* Check if a descriptor was ready. */
|
|
int fdwatch_check_fd( int fd );
|
|
|
|
/* Get the client data for the next returned event. Returns -1 when there
|
|
** are no more events.
|
|
*/
|
|
void* fdwatch_get_next_client_data( void );
|
|
|
|
/* Generate debugging statistics syslog message. */
|
|
void fdwatch_logstats( long secs );
|
|
|
|
#endif /* _FDWATCH_H_ */
|