evmap-internal.h

   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_ */