granicus.if.org Git - libevent/blob - watch.c

   1 /*
   2  * Redistribution and use in source and binary forms, with or without
   3  * modification, are permitted provided that the following conditions
   4  * are met:
   5  * 1. Redistributions of source code must retain the above copyright
   6  *    notice, this list of conditions and the following disclaimer.
   7  * 2. Redistributions in binary form must reproduce the above copyright
   8  *    notice, this list of conditions and the following disclaimer in the
   9  *    documentation and/or other materials provided with the distribution.
  10  * 3. The name of the author may not be used to endorse or promote products
  11  *    derived from this software without specific prior written permission.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  14  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  15  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  16  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  17  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  18  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  19  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  20  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  22  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  23  */
  24
  25 #include "event2/watch.h"
  26 #include "event-internal.h"
  27 #include "evthread-internal.h"
  28
  29 static inline struct evwatch *
  30 evwatch_new(struct event_base *base, union evwatch_cb callback, void *arg, unsigned type)
  31 {
  32         struct evwatch *watcher = mm_malloc(sizeof(struct evwatch));
  33         if (!watcher)
  34                 return NULL;
  35         watcher->base = base;
  36         watcher->type = type;
  37         watcher->callback = callback;
  38         watcher->arg = arg;
  39         EVBASE_ACQUIRE_LOCK(base, th_base_lock);
  40         TAILQ_INSERT_TAIL(&base->watchers[type], watcher, next);
  41         EVBASE_RELEASE_LOCK(base, th_base_lock);
  42         return watcher;
  43 }
  44
  45 struct evwatch *
  46 evwatch_prepare_new(struct event_base *base, evwatch_prepare_cb callback, void *arg)
  47 {
  48         union evwatch_cb cb = { .prepare = callback };
  49         return evwatch_new(base, cb, arg, EVWATCH_PREPARE);
  50 }
  51
  52 struct evwatch *
  53 evwatch_check_new(struct event_base *base, evwatch_check_cb callback, void *arg)
  54 {
  55         union evwatch_cb cb = { .check = callback };
  56         return evwatch_new(base, cb, arg, EVWATCH_CHECK);
  57 }
  58
  59 struct event_base *
  60 evwatch_base(struct evwatch *watcher)
  61 {
  62         return watcher->base;
  63 }
  64
  65 void
  66 evwatch_free(struct evwatch *watcher)
  67 {
  68         EVBASE_ACQUIRE_LOCK(watcher->base, th_base_lock);
  69         TAILQ_REMOVE(&watcher->base->watchers[watcher->type], watcher, next);
  70         EVBASE_RELEASE_LOCK(watcher->base, th_base_lock);
  71         mm_free(watcher);
  72 }
  73
  74 int
  75 evwatch_prepare_get_timeout(const struct evwatch_prepare_cb_info *info, struct timeval *timeout)
  76 {
  77         if (info->timeout) {
  78                 *timeout = *(info->timeout);
  79                 return 1;
  80         }
  81         return 0;
  82 }