ovsdb/trigger.c

   1 /* Copyright (c) 2009, 2010, 2011, 2012 Nicira, Inc.
   2  *
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 #include <config.h>
  17
  18 #include "trigger.h"
  19
  20 #include <limits.h>
  21
  22 #include "json.h"
  23 #include "jsonrpc.h"
  24 #include "ovsdb.h"
  25 #include "poll-loop.h"
  26 #include "server.h"
  27
  28 static bool ovsdb_trigger_try(struct ovsdb_trigger *, long long int now);
  29 static void ovsdb_trigger_complete(struct ovsdb_trigger *);
  30
  31 void
  32 ovsdb_trigger_init(struct ovsdb_session *session, struct ovsdb *db,
  33                    struct ovsdb_trigger *trigger,
  34                    struct json *request, long long int now)
  35 {
  36     trigger->session = session;
  37     trigger->db = db;
  38     ovs_list_push_back(&trigger->db->triggers, &trigger->node);
  39     trigger->request = request;
  40     trigger->result = NULL;
  41     trigger->created = now;
  42     trigger->timeout_msec = LLONG_MAX;
  43     ovsdb_trigger_try(trigger, now);
  44 }
  45
  46 void
  47 ovsdb_trigger_destroy(struct ovsdb_trigger *trigger)
  48 {
  49     ovs_list_remove(&trigger->node);
  50     json_destroy(trigger->request);
  51     json_destroy(trigger->result);
  52 }
  53
  54 bool
  55 ovsdb_trigger_is_complete(const struct ovsdb_trigger *trigger)
  56 {
  57     return trigger->result != NULL;
  58 }
  59
  60 struct json *
  61 ovsdb_trigger_steal_result(struct ovsdb_trigger *trigger)
  62 {
  63     struct json *result = trigger->result;
  64     trigger->result = NULL;
  65     return result;
  66 }
  67
  68 void
  69 ovsdb_trigger_run(struct ovsdb *db, long long int now)
  70 {
  71     struct ovsdb_trigger *t, *next;
  72     bool run_triggers;
  73
  74     run_triggers = db->run_triggers;
  75     db->run_triggers = false;
  76     LIST_FOR_EACH_SAFE (t, next, node, &db->triggers) {
  77         if (run_triggers || now - t->created >= t->timeout_msec) {
  78             ovsdb_trigger_try(t, now);
  79         }
  80     }
  81 }
  82
  83 void
  84 ovsdb_trigger_wait(struct ovsdb *db, long long int now)
  85 {
  86     if (db->run_triggers) {
  87         poll_immediate_wake();
  88     } else {
  89         long long int deadline = LLONG_MAX;
  90         struct ovsdb_trigger *t;
  91
  92         LIST_FOR_EACH (t, node, &db->triggers) {
  93             if (t->created < LLONG_MAX - t->timeout_msec) {
  94                 long long int t_deadline = t->created + t->timeout_msec;
  95                 if (deadline > t_deadline) {
  96                     deadline = t_deadline;
  97                     if (now >= deadline) {
  98                         break;
  99                     }
 100                 }
 101             }
 102         }
 103
 104         if (deadline < LLONG_MAX) {
 105             poll_timer_wait_until(deadline);
 106         }
 107     }
 108 }
 109
 110 static bool
 111 ovsdb_trigger_try(struct ovsdb_trigger *t, long long int now)
 112 {
 113     t->result = ovsdb_execute(t->db, t->session,
 114                               t->request, now - t->created, &t->timeout_msec);
 115     if (t->result) {
 116         ovsdb_trigger_complete(t);
 117         return true;
 118     } else {
 119         return false;
 120     }
 121 }
 122
 123 static void
 124 ovsdb_trigger_complete(struct ovsdb_trigger *t)
 125 {
 126     ovs_assert(t->result != NULL);
 127     ovs_list_remove(&t->node);
 128     ovs_list_push_back(&t->session->completions, &t->node);
 129 }