lib/if-notifier-manual.c

   1 /*
   2  * Copyright (c) 2019 Ilya Maximets <i.maximets@ovn.org>.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include <config.h>
  18 #include "openvswitch/compiler.h"
  19 #include "openvswitch/thread.h"
  20 #include "openvswitch/util.h"
  21 #include "if-notifier.h"
  22
  23 /* Implementation of a manual interface notifier.
  24  *
  25  * Intended for catching interface events that could not be tracked by
  26  * OS specific interface notifiers, e.g. iface updates in netdev-dpdk.
  27  * For that purpose 'if_notifier_manual_report()' should be called directly
  28  * by the code that aware of interface changes.
  29  *
  30  * Thread-safety
  31  * =============
  32  * This notifier is thread-safe in terms of calling its functions from
  33  * different thread contexts,  however if the callback passed to
  34  * 'if_notifier_manual_set_cb' is used by some other code (i.e. by OS
  35  * specific notifiers) it must be thread-safe itself.
  36  */
  37
  38 static struct ovs_mutex manual_notifier_mutex = OVS_MUTEX_INITIALIZER;
  39 static if_notify_func *notify OVS_GUARDED_BY(manual_notifier_mutex) = NULL;
  40
  41 void
  42 if_notifier_manual_set_cb(if_notify_func *cb)
  43 {
  44     ovs_mutex_lock(&manual_notifier_mutex);
  45     notify = cb;
  46     ovs_mutex_unlock(&manual_notifier_mutex);
  47 }
  48
  49 void
  50 if_notifier_manual_report(void)
  51 {
  52     ovs_mutex_lock(&manual_notifier_mutex);
  53     if (notify) {
  54         notify(NULL);
  55     }
  56     ovs_mutex_unlock(&manual_notifier_mutex);
  57 }