external/bsd/ntp/dist/lib/isc/event.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
   5  * Copyright (C) 1998-2001  Internet Software Consortium.
   6  *
   7  * Permission to use, copy, modify, and/or distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  12  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  13  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  14  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  15  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  16  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  17  * PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 /* Id: event.c,v 1.21 2007/06/19 23:47:17 tbox Exp */
  21
  22 /*!
  23  * \file
  24  * \author Principal Author: Bob Halley
  25  */
  26
  27 #include <config.h>
  28
  29 #include <isc/event.h>
  30 #include <isc/mem.h>
  31 #include <isc/util.h>
  32
  33 /***
  34  *** Events.
  35  ***/
  36
  37 static void
  38 destroy(isc_event_t *event) {
  39         isc_mem_t *mctx = event->ev_destroy_arg;
  40
  41         isc_mem_put(mctx, event, event->ev_size);
  42 }
  43
  44 isc_event_t *
  45 isc_event_allocate(isc_mem_t *mctx, void *sender, isc_eventtype_t type,
  46                    isc_taskaction_t action, const void *arg, size_t size)
  47 {
  48         isc_event_t *event;
  49         void *deconst_arg;
  50
  51         REQUIRE(size >= sizeof(struct isc_event));
  52         REQUIRE(action != NULL);
  53
  54         event = isc_mem_get(mctx, size);
  55         if (event == NULL)
  56                 return (NULL);
  57
  58         /*
  59          * Removing the const attribute from "arg" is the best of two
  60          * evils here.  If the event->ev_arg member is made const, then
  61          * it affects a great many users of the task/event subsystem
  62          * which are not passing in an "arg" which starts its life as
  63          * const.  Changing isc_event_allocate() and isc_task_onshutdown()
  64          * to not have "arg" prototyped as const (which is quite legitimate,
  65          * because neither of those functions modify arg) can cause
  66          * compiler whining anytime someone does want to use a const
  67          * arg that they themselves never modify, such as with
  68          * gcc -Wwrite-strings and using a string "arg".
  69          */
  70         DE_CONST(arg, deconst_arg);
  71
  72         ISC_EVENT_INIT(event, size, 0, NULL, type, action, deconst_arg,
  73                        sender, destroy, mctx);
  74
  75         return (event);
  76 }
  77
  78 void
  79 isc_event_free(isc_event_t **eventp) {
  80         isc_event_t *event;
  81
  82         REQUIRE(eventp != NULL);
  83         event = *eventp;
  84         REQUIRE(event != NULL);
  85
  86         if (event->ev_destroy != NULL)
  87                 (event->ev_destroy)(event);
  88
  89         *eventp = NULL;
  90 }