1 /*
2  * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  * 3. The name of the author may not be used to endorse or promote products
13  *    derived from this software without specific prior written permission.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 #ifndef EVMAP_INTERNAL_H_INCLUDED_
27 #define EVMAP_INTERNAL_H_INCLUDED_
28 
29 /** @file evmap-internal.h
30  *
31  * An event_map is a utility structure to map each fd or signal to zero or
32  * more events.  Functions to manipulate event_maps should only be used from
33  * inside libevent.  They generally need to hold the lock on the corresponding
34  * event_base.
35  **/
36 
37 struct event_base;
38 struct event;
39 
40 /** Initialize an event_map for use.
41  */
42 void evmap_io_initmap_(struct event_io_map* ctx);
43 void evmap_signal_initmap_(struct event_signal_map* ctx);
44 
45 /** Remove all entries from an event_map.
46 
47 	@param ctx the map to clear.
48  */
49 void evmap_io_clear_(struct event_io_map* ctx);
50 void evmap_signal_clear_(struct event_signal_map* ctx);
51 
52 /** Add an IO event (some combination of EV_READ or EV_WRITE) to an
53     event_base's list of events on a given file descriptor, and tell the
54     underlying eventops about the fd if its state has changed.
55 
56     Requires that ev is not already added.
57 
58     @param base the event_base to operate on.
59     @param fd the file descriptor corresponding to ev.
60     @param ev the event to add.
61 */
62 int evmap_io_add_(struct event_base *base, evutil_socket_t fd, struct event *ev);
63 /** Remove an IO event (some combination of EV_READ or EV_WRITE) to an
64     event_base's list of events on a given file descriptor, and tell the
65     underlying eventops about the fd if its state has changed.
66 
67     @param base the event_base to operate on.
68     @param fd the file descriptor corresponding to ev.
69     @param ev the event to remove.
70  */
71 int evmap_io_del_(struct event_base *base, evutil_socket_t fd, struct event *ev);
72 /** Active the set of events waiting on an event_base for a given fd.
73 
74     @param base the event_base to operate on.
75     @param fd the file descriptor that has become active.
76     @param events a bitmask of EV_READ|EV_WRITE|EV_ET.
77 */
78 void evmap_io_active_(struct event_base *base, evutil_socket_t fd, short events);
79 
80 
81 /* These functions behave in the same way as evmap_io_*, except they work on
82  * signals rather than fds.  signals use a linear map everywhere; fds use
83  * either a linear map or a hashtable. */
84 int evmap_signal_add_(struct event_base *base, int signum, struct event *ev);
85 int evmap_signal_del_(struct event_base *base, int signum, struct event *ev);
86 void evmap_signal_active_(struct event_base *base, evutil_socket_t signum, int ncalls);
87 
88 /* Return the fdinfo object associated with a given fd.  If the fd has no
89  * events associated with it, the result may be NULL.
90  */
91 void *evmap_io_get_fdinfo_(struct event_io_map *ctx, evutil_socket_t fd);
92 
93 /* Helper for event_reinit(): Tell the backend to re-add every fd and signal
94  * for which we have a pending event.
95  */
96 int evmap_reinit_(struct event_base *base);
97 
98 /* Helper for event_base_free(): Call event_del() on every pending fd and
99  * signal event.
100  */
101 void evmap_delete_all_(struct event_base *base);
102 
103 /* Helper for event_base_assert_ok_(): Check referential integrity of the
104  * evmaps.
105  */
106 void evmap_check_integrity_(struct event_base *base);
107 
108 /* Helper: Call fn on every fd or signal event, passing as its arguments the
109  * provided event_base, the event, and arg.  If fn returns 0, process the next
110  * event.  If it returns any other value, return that value and process no
111  * more events.
112  */
113 int evmap_foreach_event_(struct event_base *base,
114     event_base_foreach_event_cb fn,
115     void *arg);
116 
117 #endif /* EVMAP_INTERNAL_H_INCLUDED_ */
118