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author | Ivan Topolnjak <ivantopo@gmail.com> | 2017-04-24 13:54:40 +0200 |
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committer | Ivan Topolnjak <ivantopo@gmail.com> | 2017-04-24 13:54:40 +0200 |
commit | 4d828e1a3195e55365c865aa3a78af9668742643 (patch) | |
tree | 07fff2683933c96297a8ba577bbdc89888da16e1 /kamon-core/src/legacy-main/scala/kamon/util/LazyActorRef.scala | |
parent | 469c11dc1ddb140f407a33f48033e533bf60611c (diff) | |
download | Kamon-4d828e1a3195e55365c865aa3a78af9668742643.tar.gz Kamon-4d828e1a3195e55365c865aa3a78af9668742643.tar.bz2 Kamon-4d828e1a3195e55365c865aa3a78af9668742643.zip |
Prepare for the major cleanup
Moved all the original files from src/main to src/legacy-main, same with test files. Also
removed the autoweave module, examples and bench as I'm planning to have them in separate
repositories.
Diffstat (limited to 'kamon-core/src/legacy-main/scala/kamon/util/LazyActorRef.scala')
-rw-r--r-- | kamon-core/src/legacy-main/scala/kamon/util/LazyActorRef.scala | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/kamon-core/src/legacy-main/scala/kamon/util/LazyActorRef.scala b/kamon-core/src/legacy-main/scala/kamon/util/LazyActorRef.scala new file mode 100644 index 00000000..a07abea6 --- /dev/null +++ b/kamon-core/src/legacy-main/scala/kamon/util/LazyActorRef.scala @@ -0,0 +1,69 @@ +/* + * ========================================================================================= + * Copyright © 2013-2015 the kamon project <http://kamon.io/> + * + * Licensed 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. + * ========================================================================================= + */ + +package kamon.util + +import java.util +import java.util.concurrent.ConcurrentLinkedQueue + +import akka.actor.{Actor, ActorRef} +import org.HdrHistogram.WriterReaderPhaser + +import scala.annotation.tailrec + +/** + * A LazyActorRef accumulates messages sent to an actor that doesn't exist yet. Once the actor is created and + * the LazyActorRef is pointed to it, all the accumulated messages are flushed and any new message sent to the + * LazyActorRef will immediately be sent to the pointed ActorRef. + * + * This is intended to be used during Kamon's initialization where some components need to use ActorRefs to work + * (like subscriptions and the trace incubator) but our internal ActorSystem is not yet ready to create the + * required actors. + */ +class LazyActorRef { + private val _refPhaser = new WriterReaderPhaser + private val _backlog = new ConcurrentLinkedQueue[(Any, ActorRef)]() + @volatile private var _target: Option[ActorRef] = None + + def tell(message: Any)(implicit sender: ActorRef = Actor.noSender): Unit = { + val criticalEnter = _refPhaser.writerCriticalSectionEnter() + try { + _target.map(_.tell(message, sender)) getOrElse { + _backlog.add((message, sender)) + } + + } finally { _refPhaser.writerCriticalSectionExit(criticalEnter) } + } + + def point(target: ActorRef): Unit = { + @tailrec def drain(q: util.Queue[(Any, ActorRef)]): Unit = if (!q.isEmpty) { + val (msg, sender) = q.poll() + target.tell(msg, sender) + drain(q) + } + + try { + _refPhaser.readerLock() + + if (_target.isEmpty) { + _target = Some(target) + _refPhaser.flipPhase(1000L) + drain(_backlog) + + } else sys.error("A LazyActorRef cannot be pointed more than once.") + } finally { _refPhaser.readerUnlock() } + } +} |