xref: /openbsd/usr.bin/dig/lib/isc/include/isc/event.h (revision 1a012e20)
1 /*
2  * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
9  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
10  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
11  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
12  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
13  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
14  * PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #ifndef ISC_EVENT_H
18 #define ISC_EVENT_H 1
19 
20 /*! \file isc/event.h */
21 
22 #include <isc/types.h>
23 
24 /*****
25  ***** Events.
26  *****/
27 
28 typedef void (*isc_eventdestructor_t)(isc_event_t *);
29 
30 #define ISC_EVENT_COMMON(ltype)		\
31 	size_t				ev_size; \
32 	unsigned int			ev_attributes; \
33 	void *				ev_tag; \
34 	isc_eventtype_t			ev_type; \
35 	isc_taskaction_t		ev_action; \
36 	void *				ev_arg; \
37 	void *				ev_sender; \
38 	isc_eventdestructor_t		ev_destroy; \
39 	void *				ev_destroy_arg; \
40 	ISC_LINK(ltype)			ev_link; \
41 	ISC_LINK(ltype)			ev_ratelink
42 
43 /*%
44  * Attributes matching a mask of 0x000000ff are reserved for the task library's
45  * definition.  Attributes of 0xffffff00 may be used by the application
46  * or non-ISC libraries.
47  */
48 #define ISC_EVENTATTR_NOPURGE		0x00000001
49 
50 /*%
51  * The ISC_EVENTATTR_CANCELED attribute is intended to indicate
52  * that an event is delivered as a result of a canceled operation
53  * rather than successful completion, by mutual agreement
54  * between the sender and receiver.  It is not set or used by
55  * the task system.
56  */
57 #define ISC_EVENTATTR_CANCELED		0x00000002
58 
59 #define ISC_EVENT_INIT(event, sz, at, ta, ty, ac, ar, sn, df) \
60 do { \
61 	(event)->ev_size = (sz); \
62 	(event)->ev_attributes = (at); \
63 	(event)->ev_tag = (ta); \
64 	(event)->ev_type = (ty); \
65 	(event)->ev_action = (ac); \
66 	(event)->ev_arg = (ar); \
67 	(event)->ev_sender = (sn); \
68 	(event)->ev_destroy = (df); \
69 	ISC_LINK_INIT((event), ev_link); \
70 	ISC_LINK_INIT((event), ev_ratelink); \
71 } while (0)
72 
73 /*%
74  * This structure is public because "subclassing" it may be useful when
75  * defining new event types.
76  */
77 struct isc_event {
78 	ISC_EVENT_COMMON(struct isc_event);
79 };
80 
81 #define ISC_EVENTTYPE_FIRSTEVENT	0x00000000
82 #define ISC_EVENTTYPE_LASTEVENT		0xffffffff
83 
84 #define ISC_EVENT_PTR(p) ((isc_event_t **)(void *)(p))
85 
86 isc_event_t *
87 isc_event_allocate(void *sender, isc_eventtype_t type,
88 		   isc_taskaction_t action, void *arg, size_t size);
89 /*%<
90  * Allocate an event structure.
91  *
92  * Allocate and initialize in a structure with initial elements
93  * defined by:
94  *
95  * \code
96  *	struct {
97  *		ISC_EVENT_COMMON(struct isc_event);
98  *		...
99  *	};
100  * \endcode
101  *
102  * Requires:
103  *\li	'size' >= sizeof(struct isc_event)
104  *\li	'action' to be non NULL
105  *
106  * Returns:
107  *\li	a pointer to a initialized structure of the requested size.
108  *\li	NULL if unable to allocate memory.
109  */
110 
111 void
112 isc_event_free(isc_event_t **);
113 
114 #endif /* ISC_EVENT_H */
115