evmap-internal.h revision 290001 
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
37struct event_base;
38struct event;
39
40/** Initialize an event_map for use.
41 */
42void evmap_io_initmap_(struct event_io_map* ctx);
43void 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 */
49void evmap_io_clear_(struct event_io_map* ctx);
50void 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*/
62int 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 */
71int 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*/
78void 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. */
84int evmap_signal_add_(struct event_base *base, int signum, struct event *ev);
85int evmap_signal_del_(struct event_base *base, int signum, struct event *ev);
86void 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 */
91void *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 */
96int 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 */
101void evmap_delete_all_(struct event_base *base);
102
103/* Helper for event_base_assert_ok_(): Check referential integrity of the
104 * evmaps.
105 */
106void 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 */
113int 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