subr_callback.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10

    1 /*      $NetBSD: subr_callback.c,v 1.7 2009/11/24 20:11:50 rmind Exp $  */
    2 
    3 /*-
    4  * Copyright (c)2006 YAMAMOTO Takashi,
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   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 
   29 #include <sys/cdefs.h>
   30 __KERNEL_RCSID(0, "$NetBSD: subr_callback.c,v 1.7 2009/11/24 20:11:50 rmind Exp $");
   31 
   32 #include <sys/param.h>
   33 #include <sys/systm.h>
   34 #include <sys/proc.h>
   35 #include <sys/callback.h>
   36 
   37 void
   38 callback_head_init(struct callback_head *ch, int ipl)
   39 {
   40 
   41         memset(ch, 0, sizeof(struct callback_head));
   42         mutex_init(&ch->ch_lock, MUTEX_DEFAULT, ipl);
   43         cv_init(&ch->ch_cv, "callback");
   44         TAILQ_INIT(&ch->ch_q);
   45 #if 0 /* already zero-initialized */
   46         ch->ch_next = NULL;
   47         ch->ch_nentries = 0;
   48         ch->ch_running = 0;
   49         ch->ch_flags = 0;
   50 #endif
   51 }
   52 
   53 void
   54 callback_head_destroy(struct callback_head *ch)
   55 {
   56 
   57         mutex_destroy(&ch->ch_lock);
   58         cv_destroy(&ch->ch_cv);
   59 }
   60 
   61 void
   62 callback_register(struct callback_head *ch, struct callback_entry *ce,
   63     void *obj, int (*fn)(struct callback_entry *, void *, void *))
   64 {
   65 
   66         KASSERT(fn != NULL);
   67         ce->ce_func = fn;
   68         ce->ce_obj = obj;
   69         mutex_enter(&ch->ch_lock);
   70         TAILQ_INSERT_TAIL(&ch->ch_q, ce, ce_q);
   71         ch->ch_nentries++;
   72         mutex_exit(&ch->ch_lock);
   73 }
   74 
   75 void
   76 callback_unregister(struct callback_head *ch, struct callback_entry *ce)
   77 {
   78 
   79         mutex_enter(&ch->ch_lock);
   80         while (ch->ch_running > 0)
   81                 cv_wait(&ch->ch_cv, &ch->ch_lock);
   82         if (__predict_false(ch->ch_next == ce)) {
   83                 ch->ch_next = TAILQ_NEXT(ce, ce_q);
   84         }
   85         TAILQ_REMOVE(&ch->ch_q, ce, ce_q);
   86         ch->ch_nentries--;
   87         mutex_exit(&ch->ch_lock);
   88 }
   89 
   90 static int
   91 callback_runone(struct callback_head *ch, void *arg)
   92 {
   93         struct callback_entry *ce;
   94         int result;
   95 
   96         KASSERT(ch->ch_nentries > 0);
   97         KASSERT(ch->ch_running > 0);
   98 
   99         ce = ch->ch_next;
  100         if (ce == NULL) {
  101                 ce = TAILQ_FIRST(&ch->ch_q);
  102         }
  103         KASSERT(ce != NULL);
  104         KASSERT(ce->ce_func != NULL);
  105         result = (*ce->ce_func)(ce, ce->ce_obj, arg);
  106         ch->ch_next = TAILQ_NEXT(ce, ce_q);
  107         return result;
  108 }
  109 
  110 static void
  111 callback_run_enter(struct callback_head *ch)
  112 {
  113 
  114         mutex_enter(&ch->ch_lock);
  115         ch->ch_running++;
  116         mutex_exit(&ch->ch_lock);
  117 }
  118 
  119 static void
  120 callback_run_leave(struct callback_head *ch)
  121 {
  122 
  123         mutex_enter(&ch->ch_lock);
  124         KASSERT(ch->ch_running > 0);
  125         ch->ch_running--;
  126         if (ch->ch_running == 0)
  127                 cv_broadcast(&ch->ch_cv);
  128         mutex_exit(&ch->ch_lock);
  129 }
  130 
  131 int
  132 callback_run_roundrobin(struct callback_head *ch, void *arg)
  133 {
  134         int i;
  135         int n;
  136         int result = 0;
  137 
  138         callback_run_enter(ch);
  139         n = ch->ch_nentries;
  140         for (i = 0; i < n; i++) {
  141                 result = callback_runone(ch, arg);
  142                 if (result != CALLBACK_CHAIN_CONTINUE) {
  143                         break;
  144                 }
  145         }
  146         callback_run_leave(ch);
  147 
  148         return result;
  149 }

Cache object: 91328566eb57ea11e3eaf8f997a4593a

[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.

FreeBSD/Linux Kernel Cross Reference sys/kern/subr_callback.c

FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_callback.c