event.c revision 290001 
1/*
2 * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1998-2001  Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/* $Id: event.c,v 1.21 2007/06/19 23:47:17 tbox Exp $ */
19
20/*!
21 * \file
22 * \author Principal Author: Bob Halley
23 */
24
25#include <config.h>
26
27#include <isc/event.h>
28#include <isc/mem.h>
29#include <isc/util.h>
30
31/***
32 *** Events.
33 ***/
34
35static void
36destroy(isc_event_t *event) {
37	isc_mem_put(event->ev_destroy_arg, event, event->ev_size);
38}
39
40isc_event_t *
41isc_event_allocate(isc_mem_t *mctx, void *sender, isc_eventtype_t type,
42		   isc_taskaction_t action, const void *arg, size_t size)
43{
44	isc_event_t *event;
45	void *deconst_arg;
46
47	REQUIRE(size >= sizeof(struct isc_event));
48	REQUIRE(action != NULL);
49
50	event = isc_mem_get(mctx, size);
51	if (event == NULL)
52		return (NULL);
53
54	/*
55	 * Removing the const attribute from "arg" is the best of two
56	 * evils here.  If the event->ev_arg member is made const, then
57	 * it affects a great many users of the task/event subsystem
58	 * which are not passing in an "arg" which starts its life as
59	 * const.  Changing isc_event_allocate() and isc_task_onshutdown()
60	 * to not have "arg" prototyped as const (which is quite legitimate,
61	 * because neither of those functions modify arg) can cause
62	 * compiler whining anytime someone does want to use a const
63	 * arg that they themselves never modify, such as with
64	 * gcc -Wwrite-strings and using a string "arg".
65	 */
66	DE_CONST(arg, deconst_arg);
67
68	ISC_EVENT_INIT(event, size, 0, NULL, type, action, deconst_arg,
69		       sender, destroy, mctx);
70
71	return (event);
72}
73
74void
75isc_event_free(isc_event_t **eventp) {
76	isc_event_t *event;
77
78	REQUIRE(eventp != NULL);
79	event = *eventp;
80	REQUIRE(event != NULL);
81
82	if (event->ev_destroy != NULL)
83		(event->ev_destroy)(event);
84
85	*eventp = NULL;
86}
87