event.c revision 1.8 
1/*	$NetBSD: event.c,v 1.8 2018/09/29 21:52:31 christos Exp $	*/
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 */
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
37static void
38destroy(isc_event_t *event) {
39	isc_mem_put(event->ev_destroy_arg, event, event->ev_size);
40}
41
42isc_event_t *
43isc_event_allocate(isc_mem_t *mctx, void *sender, isc_eventtype_t type,
44		   isc_taskaction_t action, const void *arg, size_t size)
45{
46	isc_event_t *event;
47	void *deconst_arg;
48
49	REQUIRE(size >= sizeof(struct isc_event));
50	REQUIRE(action != NULL);
51
52	event = isc_mem_get(mctx, size);
53	if (event == NULL)
54		return (NULL);
55
56	/*
57	 * Removing the const attribute from "arg" is the best of two
58	 * evils here.  If the event->ev_arg member is made const, then
59	 * it affects a great many users of the task/event subsystem
60	 * which are not passing in an "arg" which starts its life as
61	 * const.  Changing isc_event_allocate() and isc_task_onshutdown()
62	 * to not have "arg" prototyped as const (which is quite legitimate,
63	 * because neither of those functions modify arg) can cause
64	 * compiler whining anytime someone does want to use a const
65	 * arg that they themselves never modify, such as with
66	 * gcc -Wwrite-strings and using a string "arg".
67	 */
68	DE_CONST(arg, deconst_arg);
69
70	ISC_EVENT_INIT(event, size, 0, NULL, type, action, deconst_arg,
71		       sender, destroy, mctx);
72
73	return (event);
74}
75
76void
77isc_event_free(isc_event_t **eventp) {
78	isc_event_t *event;
79
80	REQUIRE(eventp != NULL);
81	event = *eventp;
82	REQUIRE(event != NULL);
83
84	if (event->ev_destroy != NULL)
85		(event->ev_destroy)(event);
86
87	*eventp = NULL;
88}
89