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Annotation of embedaddon/thttpd/fdwatch.h, revision 1.1

1.1     ! misho       1: /* fdwatch.h - header file for fdwatch package
        !             2: **
        !             3: ** This package abstracts the use of the select()/poll()/kqueue()
        !             4: ** system calls.  The basic function of these calls is to watch a set
        !             5: ** of file descriptors for activity.  select() originated in the BSD world,
        !             6: ** while poll() came from SysV land, and their interfaces are somewhat
        !             7: ** different.  fdwatch lets you write your code to a single interface,
        !             8: ** with the portability differences hidden inside the package.
        !             9: **
        !            10: ** Usage is fairly simple.  Call fdwatch_get_nfiles() to initialize
        !            11: ** the package and find out how many fine descriptors are available.
        !            12: ** Then each time through your main loop, call fdwatch_clear(), then
        !            13: ** fdwatch_add_fd() for each of the descriptors you want to watch,
        !            14: ** then call fdwatch() to actually perform the watch.  After it returns
        !            15: ** you can check which descriptors are ready via fdwatch_check_fd().
        !            16: **
        !            17: ** If your descriptor set hasn't changed from the last time through
        !            18: ** the loop, you can skip calling fdwatch_clear() and fdwatch_add_fd()
        !            19: ** to save a little CPU time.
        !            20: **
        !            21: **
        !            22: ** Copyright © 1999 by Jef Poskanzer <jef@mail.acme.com>.
        !            23: ** All rights reserved.
        !            24: **
        !            25: ** Redistribution and use in source and binary forms, with or without
        !            26: ** modification, are permitted provided that the following conditions
        !            27: ** are met:
        !            28: ** 1. Redistributions of source code must retain the above copyright
        !            29: **    notice, this list of conditions and the following disclaimer.
        !            30: ** 2. Redistributions in binary form must reproduce the above copyright
        !            31: **    notice, this list of conditions and the following disclaimer in the
        !            32: **    documentation and/or other materials provided with the distribution.
        !            33: **
        !            34: ** THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
        !            35: ** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
        !            36: ** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
        !            37: ** ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
        !            38: ** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
        !            39: ** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
        !            40: ** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
        !            41: ** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
        !            42: ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
        !            43: ** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
        !            44: ** SUCH DAMAGE.
        !            45: */
        !            46: 
        !            47: #ifndef _FDWATCH_H_
        !            48: #define _FDWATCH_H_
        !            49: 
        !            50: #define FDW_READ 0
        !            51: #define FDW_WRITE 1
        !            52: 
        !            53: #ifndef INFTIM
        !            54: #define INFTIM -1
        !            55: #endif /* INFTIM */
        !            56: 
        !            57: /* Figure out how many file descriptors the system allows, and
        !            58: ** initialize the fdwatch data structures.  Returns -1 on failure.
        !            59: */
        !            60: extern int fdwatch_get_nfiles( void );
        !            61: 
        !            62: /* Add a descriptor to the watch list.  rw is either FDW_READ or FDW_WRITE.  */
        !            63: extern void fdwatch_add_fd( int fd, void* client_data, int rw );
        !            64: 
        !            65: /* Delete a descriptor from the watch list. */
        !            66: extern void fdwatch_del_fd( int fd );
        !            67: 
        !            68: /* Do the watch.  Return value is the number of descriptors that are ready,
        !            69: ** or 0 if the timeout expired, or -1 on errors.  A timeout of INFTIM means
        !            70: ** wait indefinitely.
        !            71: */
        !            72: extern int fdwatch( long timeout_msecs );
        !            73: 
        !            74: /* Check if a descriptor was ready. */
        !            75: extern int fdwatch_check_fd( int fd );
        !            76: 
        !            77: /* Get the client data for the next returned event.  Returns -1 when there
        !            78: ** are no more events.
        !            79: */
        !            80: extern void* fdwatch_get_next_client_data( void );
        !            81: 
        !            82: /* Generate debugging statistics syslog message. */
        !            83: extern void fdwatch_logstats( long secs );
        !            84: 
        !            85: #endif /* _FDWATCH_H_ */