sys/sys/poll.h

   1 /*-
   2  * Copyright (c) 1997 Peter Wemm <peter@freebsd.org>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  *
  28  * $FreeBSD: src/sys/sys/poll.h,v 1.6.2.1 2000/08/21 12:25:58 sheldonh Exp $
  29  * $DragonFly: src/sys/sys/poll.h,v 1.7 2008/01/12 06:01:27 nant Exp $
  30  */
  31
  32 #ifndef _SYS_POLL_H_
  33 #define _SYS_POLL_H_
  34
  35 /*
  36  * This file is intended to be compatible with the traditional poll.h.
  37  */
  38
  39 typedef unsigned int    nfds_t;
  40
  41 /*
  42  * This structure is passed as an array to poll(2).
  43  */
  44 struct pollfd {
  45         int     fd;             /* which file descriptor to poll */
  46         short   events;         /* events we are interested in */
  47         short   revents;        /* events found on return */
  48 };
  49
  50 /*
  51  * Requestable events.  If poll(2) finds any of these set, they are
  52  * copied to revents on return.
  53  * XXX Note that FreeBSD doesn't make much distinction between POLLPRI
  54  * and POLLRDBAND since none of the file types have distinct priority
  55  * bands - and only some have an urgent "mode".
  56  * XXX Note POLLIN isn't really supported in true SVSV terms.  Under SYSV
  57  * POLLIN includes all of normal, band and urgent data.  Most poll handlers
  58  * on FreeBSD only treat it as "normal" data.
  59  */
  60 #define POLLIN          0x0001          /* any readable data available */
  61 #define POLLPRI         0x0002          /* OOB/Urgent readable data */
  62 #define POLLOUT         0x0004          /* file descriptor is writeable */
  63 #define POLLRDNORM      0x0040          /* non-OOB/URG data available */
  64 #define POLLWRNORM      POLLOUT         /* no write type differentiation */
  65 #define POLLRDBAND      0x0080          /* OOB/Urgent readable data */
  66 #define POLLWRBAND      0x0100          /* OOB/Urgent data can be written */
  67
  68 /*
  69  * FreeBSD extension.
  70  */
  71 #define POLLINIGNEOF    0x2000          /* POLLIN, except ignore EOF */
  72
  73 /*
  74  * FreeBSD extensions: polling on a regular file might return one
  75  * of these events (currently only supported on UFS).
  76  */
  77 #define POLLEXTEND      0x0200          /* file may have been extended */
  78 #define POLLATTRIB      0x0400          /* file attributes may have changed */
  79 #define POLLNLINK       0x0800          /* (un)link/rename may have happened */
  80 #define POLLWRITE       0x1000          /* file's contents may have changed */
  81
  82 /*
  83  * These events are set if they occur regardless of whether they were
  84  * requested.
  85  */
  86 #define POLLERR         0x0008          /* some poll error occurred */
  87 #define POLLHUP         0x0010          /* file descriptor was "hung up" */
  88 #define POLLNVAL        0x0020          /* requested events "invalid" */
  89
  90 #define POLLSTANDARD    (POLLIN|POLLPRI|POLLOUT|POLLRDNORM|POLLRDBAND|\
  91                          POLLWRBAND|POLLERR|POLLHUP|POLLNVAL)
  92
  93 /*
  94  * Request that poll() wait forever.
  95  * XXX in SYSV, this is defined in stropts.h, which is not included
  96  * by poll.h.
  97  */
  98 #define INFTIM          (-1)
  99
 100 #ifndef _KERNEL
 101
 102 #include <sys/cdefs.h>
 103
 104 __BEGIN_DECLS
 105 /*
 106  * XXX logically, poll() should be declared in <poll.h>, but SVR4 at
 107  * least has it here in <sys/poll.h>.
 108  */
 109 int     poll (struct pollfd *, nfds_t, int);
 110 __END_DECLS
 111
 112 #endif /* !_KERNEL */
 113
 114 #endif /* !_SYS_POLL_H_ */