1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 1999 Michael Smith <msmith@freebsd.org> 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 * $FreeBSD$ 29 */ 30 31 #ifndef _SYS__EVENTHANDLER_H_ 32 #define _SYS__EVENTHANDLER_H_ 33 34 #include <sys/queue.h> 35 36 struct eventhandler_entry { 37 TAILQ_ENTRY(eventhandler_entry) ee_link; 38 int ee_priority; 39 #define EHE_DEAD_PRIORITY (-1) 40 void *ee_arg; 41 }; 42 43 typedef struct eventhandler_entry *eventhandler_tag; 44 45 /* 46 * You can optionally use the EVENTHANDLER_LIST and EVENTHANDLER_DIRECT macros 47 * to pre-define a symbol for the eventhandler list. This symbol can be used by 48 * EVENTHANDLER_DIRECT_INVOKE, which has the advantage of not needing to do a 49 * locked search of the global list of eventhandler lists. At least 50 * EVENTHANDLER_LIST_DEFINE must be used for EVENTHANDLER_DIRECT_INVOKE to 51 * work. EVENTHANDLER_LIST_DECLARE is only needed if the call to 52 * EVENTHANDLER_DIRECT_INVOKE is in a different compilation unit from 53 * EVENTHANDLER_LIST_DEFINE. If the events are even relatively high frequency 54 * it is suggested that you directly define a list for them. 55 */ 56 struct eventhandler_list; 57 #define EVENTHANDLER_LIST_DECLARE(name) \ 58 extern struct eventhandler_list *_eventhandler_list_ ## name \ 59 60 /* 61 * Event handlers need to be declared, but do not need to be defined. The 62 * declaration must be in scope wherever the handler is to be invoked. 63 */ 64 #define EVENTHANDLER_DECLARE(name, type) \ 65 struct eventhandler_entry_ ## name \ 66 { \ 67 struct eventhandler_entry ee; \ 68 type eh_func; \ 69 }; \ 70 struct __hack 71 72 #endif 73