mpm/simple/simple_event.c

	simple_event.c revision f997d134bcee6bfa4cd87b69acee96e80c5a358b
/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define APR_RING_DEBUG 1

#include "simple_types.h"
#include "simple_event.h"

void
simple_register_timer(simple_core_t *sc,
                      simple_timer_cb cb,
                      void *baton,
                      apr_time_t relative_time)
{
  simple_timer_t *elem = NULL;
  simple_timer_t *ep = NULL;
  int inserted  = 0;
  apr_time_t t = apr_time_now() + relative_time;

  apr_thread_mutex_lock(sc->mtx);

  APR_RING_CHECK_CONSISTENCY(&sc->timer_ring, simple_timer_t, link);
  APR_RING_CHECK_CONSISTENCY(&sc->dead_timer_ring, simple_timer_t, link);

  if (!APR_RING_EMPTY(&sc->dead_timer_ring, simple_timer_t, link)) {
    elem = APR_RING_FIRST(&sc->dead_timer_ring);
    APR_RING_REMOVE(elem, link);
    APR_RING_CHECK_CONSISTENCY(&sc->dead_timer_ring, simple_timer_t, link);
  }
  else {
    elem = (simple_timer_t *) apr_pcalloc(sc->pool, sizeof(simple_timer_t));
  }

  APR_RING_ELEM_INIT(elem, link);
  elem->expires = t;
  elem->cb = cb;
  elem->baton = baton;

  APR_RING_CHECK_CONSISTENCY(&sc->timer_ring, simple_timer_t, link);

  /* pqXXXXXX: skiplist would be a nice optimization here. */
  if (!APR_RING_EMPTY(&sc->timer_ring, simple_timer_t, link)) {
    ep = APR_RING_FIRST(&sc->timer_ring);
    while (inserted == 0 &&
           ep != APR_RING_SENTINEL(&sc->timer_ring, simple_timer_t, link))
    {
      if (ep->expires < elem->expires) {
        APR_RING_CHECK_CONSISTENCY(&sc->timer_ring, simple_timer_t, link);
        APR_RING_INSERT_BEFORE(ep, elem, link);
        inserted = 1;
        APR_RING_CHECK_CONSISTENCY(&sc->timer_ring, simple_timer_t, link);
      }
      ep = APR_RING_NEXT(ep, link);
    }
  }

  APR_RING_CHECK_CONSISTENCY(&sc->timer_ring, simple_timer_t, link);

  if (!inserted) {
    APR_RING_INSERT_TAIL(&sc->timer_ring,
                         elem, simple_timer_t, link);
  }

  APR_RING_CHECK_CONSISTENCY(&sc->timer_ring, simple_timer_t, link);

  apr_thread_mutex_unlock(sc->mtx);
}