Merge remote branch 'origin/remove-dispatcherLock'

This commit is contained in:
Viktor Klang 2011-10-04 14:21:12 +02:00
commit df94449d9b
4 changed files with 80 additions and 28 deletions

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/**
* Copyright (C) 2009-2011 Typesafe Inc. <http://www.typesafe.com>
*/
package akka.dispatch
import java.util.concurrent._
import java.util.concurrent.atomic.AtomicLong
import akka.event.EventHandler
import akka.config.Configuration
import akka.config.Config.TIME_UNIT
import akka.util.{ Duration, Switch, ReentrantGuard }
import java.util.concurrent.ThreadPoolExecutor.{ AbortPolicy, CallerRunsPolicy, DiscardOldestPolicy, DiscardPolicy }
import akka.actor._
/**
* @author <a href="http://jonasboner.com">Jonas Bon&#233;r</a>
*/
final case class Envelope(val receiver: ActorCell, val message: Any, val channel: UntypedChannel) {
if (receiver eq null) throw new IllegalArgumentException("Receiver can't be null")
final def invoke() {
receiver invoke this
}
}
sealed trait SystemMessage extends PossiblyHarmful
case object Create extends SystemMessage
case class Recreate(cause: Throwable) extends SystemMessage
case object Suspend extends SystemMessage
case object Resume extends SystemMessage
case object Terminate extends SystemMessage
case class Supervise(child: ActorRef) extends SystemMessage
case class Link(subject: ActorRef) extends SystemMessage
case class Unlink(subject: ActorRef) extends SystemMessage
final case class SystemEnvelope(val receiver: ActorCell, val message: SystemMessage, val channel: UntypedChannel) {
if (receiver eq null) throw new IllegalArgumentException("Receiver can't be null")
/**
* @return whether to proceed with processing other messages
*/
final def invoke() {
receiver systemInvoke this
}
}
final case class TaskInvocation(function: () Unit, cleanup: () Unit) extends Runnable {
def run() {
try {
function()
} catch {
case e EventHandler.error(e, this, e.getMessage)
} finally {
cleanup()
}
}
}
object MessageDispatcher {
val UNSCHEDULED = 0
val SCHEDULED = 1
val RESCHEDULED = 2
implicit def defaultGlobalDispatcher = Dispatchers.defaultGlobalDispatcher
}
/**
* @author <a href="http://jonasboner.com">Jonas Bon&#233;r</a>
*/
abstract class MessageDispatcher extends Serializable {
import MessageDispatcher._
protected val uuids = new ConcurrentSkipListSet[Uuid]
protected val _tasks = new AtomicLong(0L)
protected val guard = new ReentrantGuard
protected val active = new Switch(false)
private var shutdownSchedule = UNSCHEDULED //This can be non-volatile since it is protected by guard withGuard
/**
* Creates and returns a mailbox for the given actor.
*/
protected[akka] def createMailbox(actor: ActorCell): Mailbox
/**
* Create a blackhole mailbox for the purpose of replacing the real one upon actor termination
*/
protected[akka] val deadLetterMailbox: Mailbox = DeadLetterMailbox
object DeadLetterMailbox extends Mailbox {
become(Mailbox.Closed)
override def dispatcher = null //MessageDispatcher.this
override def enqueue(envelope: Envelope) { envelope.channel sendException new ActorKilledException("Actor has been stopped") }
override def dequeue() = null
override def systemEnqueue(handle: SystemEnvelope): Unit = ()
override def systemDequeue(): SystemEnvelope = null
override def hasMessages = false
override def hasSystemMessages = false
override def numberOfMessages = 0
}
/**
* Name of this dispatcher.
*/
def name: String
/**
* Attaches the specified actor instance to this dispatcher
*/
final def attach(actor: ActorCell) {
guard.lock.lock()
try {
startIfUnstarted()
register(actor)
} finally {
guard.lock.unlock()
}
}
/**
* Detaches the specified actor instance from this dispatcher
*/
final def detach(actor: ActorCell) {
guard withGuard {
unregister(actor)
if (uuids.isEmpty && _tasks.get == 0) {
shutdownSchedule match {
case UNSCHEDULED
shutdownSchedule = SCHEDULED
Scheduler.scheduleOnce(shutdownAction, timeoutMs, TimeUnit.MILLISECONDS)
case SCHEDULED
shutdownSchedule = RESCHEDULED
case RESCHEDULED //Already marked for reschedule
}
}
}
}
protected final def startIfUnstarted() {
if (active.isOff) guard withGuard { active.switchOn { start() } }
}
protected[akka] final def dispatchTask(block: () Unit) {
_tasks.getAndIncrement()
try {
startIfUnstarted()
executeTask(TaskInvocation(block, taskCleanup))
} catch {
case e
_tasks.decrementAndGet
throw e
}
}
private val taskCleanup: () Unit =
() if (_tasks.decrementAndGet() == 0) {
guard withGuard {
if (_tasks.get == 0 && uuids.isEmpty) {
shutdownSchedule match {
case UNSCHEDULED
shutdownSchedule = SCHEDULED
Scheduler.scheduleOnce(shutdownAction, timeoutMs, TimeUnit.MILLISECONDS)
case SCHEDULED
shutdownSchedule = RESCHEDULED
case RESCHEDULED //Already marked for reschedule
}
}
}
}
/**
* Only "private[akka] for the sake of intercepting calls, DO NOT CALL THIS OUTSIDE OF THE DISPATCHER,
* and only call it under the dispatcher-guard, see "attach" for the only invocation
*/
protected[akka] def register(actor: ActorCell) {
if (uuids add actor.uuid) {
systemDispatch(SystemEnvelope(actor, Create, NullChannel)) //FIXME should this be here or moved into ActorCell.start perhaps?
} else System.err.println("Couldn't register: " + actor)
}
/**
* Only "private[akka] for the sake of intercepting calls, DO NOT CALL THIS OUTSIDE OF THE DISPATCHER,
* and only call it under the dispatcher-guard, see "detach" for the only invocation
*/
protected[akka] def unregister(actor: ActorCell) {
if (uuids remove actor.uuid) {
val mailBox = actor.mailbox
mailBox.become(Mailbox.Closed)
actor.mailbox = deadLetterMailbox //FIXME getAndSet would be preferrable here
cleanUpMailboxFor(actor, mailBox)
} else System.err.println("Couldn't unregister: " + actor)
}
/**
* Overridable callback to clean up the mailbox for a given actor,
* called when an actor is unregistered.
*/
protected def cleanUpMailboxFor(actor: ActorCell, mailBox: Mailbox) {
if (mailBox.hasSystemMessages) {
var envelope = mailBox.systemDequeue()
while (envelope ne null) {
deadLetterMailbox.systemEnqueue(envelope)
envelope = mailBox.systemDequeue()
}
}
if (mailBox.hasMessages) {
var envelope = mailBox.dequeue
while (envelope ne null) {
deadLetterMailbox.enqueue(envelope)
envelope = mailBox.dequeue
}
}
}
private val shutdownAction = new Runnable {
def run() {
guard withGuard {
shutdownSchedule match {
case RESCHEDULED
shutdownSchedule = SCHEDULED
Scheduler.scheduleOnce(this, timeoutMs, TimeUnit.MILLISECONDS)
case SCHEDULED
if (uuids.isEmpty && _tasks.get == 0) {
active switchOff {
shutdown() // shut down in the dispatcher's references is zero
}
}
shutdownSchedule = UNSCHEDULED
case UNSCHEDULED //Do nothing
}
}
}
}
/**
* When the dispatcher no longer has any actors registered, how long will it wait until it shuts itself down, in Ms
* defaulting to your akka configs "akka.actor.dispatcher-shutdown-timeout" or otherwise, 1 Second
*/
protected[akka] def timeoutMs: Long = Dispatchers.DEFAULT_SHUTDOWN_TIMEOUT.toMillis
/**
* After the call to this method, the dispatcher mustn't begin any new message processing for the specified reference
*/
def suspend(actor: ActorCell): Unit =
if (uuids.contains(actor.uuid)) actor.mailbox.become(Mailbox.Suspended)
/*
* After the call to this method, the dispatcher must begin any new message processing for the specified reference
*/
def resume(actor: ActorCell): Unit = if (uuids.contains(actor.uuid)) {
val mbox = actor.mailbox
mbox.become(Mailbox.Idle)
registerForExecution(mbox, false, false)
}
/**
* Will be called when the dispatcher is to queue an invocation for execution
*/
protected[akka] def systemDispatch(invocation: SystemEnvelope)
/**
* Will be called when the dispatcher is to queue an invocation for execution
*/
protected[akka] def dispatch(invocation: Envelope)
/**
* Suggest to register the provided mailbox for execution
*/
protected[akka] def registerForExecution(mbox: Mailbox, hasMessageHint: Boolean, hasSystemMessageHint: Boolean): Boolean
// TODO check whether this should not actually be a property of the mailbox
protected[akka] def throughput: Int
protected[akka] def throughputDeadlineTime: Int
protected[akka] def executeTask(invocation: TaskInvocation)
/**
* Called one time every time an actor is attached to this dispatcher and this dispatcher was previously shutdown
*/
protected[akka] def start(): Unit
/**
* Called one time every time an actor is detached from this dispatcher and this dispatcher has no actors left attached
*/
protected[akka] def shutdown(): Unit
/**
* Returns the size of the mailbox for the specified actor
*/
def mailboxSize(actor: ActorCell): Int = actor.mailbox.numberOfMessages
/**
* Returns the "current" emptiness status of the mailbox for the specified actor
*/
def mailboxIsEmpty(actor: ActorCell): Boolean = !actor.mailbox.hasMessages
/**
* Returns the amount of tasks queued for execution
*/
def tasks: Long = _tasks.get
}
/**
* Trait to be used for hooking in new dispatchers into Dispatchers.fromConfig
*/
abstract class MessageDispatcherConfigurator {
/**
* Returns an instance of MessageDispatcher given a Configuration
*/
def configure(config: Configuration): MessageDispatcher
def mailboxType(config: Configuration): MailboxType = {
val capacity = config.getInt("mailbox-capacity", Dispatchers.MAILBOX_CAPACITY)
if (capacity < 1) UnboundedMailbox()
else {
val duration = Duration(
config.getInt("mailbox-push-timeout-time", Dispatchers.MAILBOX_PUSH_TIME_OUT.toMillis.toInt),
TIME_UNIT)
BoundedMailbox(capacity, duration)
}
}
def configureThreadPool(config: Configuration, createDispatcher: (ThreadPoolConfig) MessageDispatcher): ThreadPoolConfigDispatcherBuilder = {
import ThreadPoolConfigDispatcherBuilder.conf_?
//Apply the following options to the config if they are present in the config
ThreadPoolConfigDispatcherBuilder(createDispatcher, ThreadPoolConfig()).configure(
conf_?(config getInt "keep-alive-time")(time _.setKeepAliveTime(Duration(time, TIME_UNIT))),
conf_?(config getDouble "core-pool-size-factor")(factor _.setCorePoolSizeFromFactor(factor)),
conf_?(config getDouble "max-pool-size-factor")(factor _.setMaxPoolSizeFromFactor(factor)),
conf_?(config getInt "executor-bounds")(bounds _.setExecutorBounds(bounds)),
conf_?(config getBool "allow-core-timeout")(allow _.setAllowCoreThreadTimeout(allow)),
conf_?(config getInt "task-queue-size" flatMap {
case size if size > 0
config getString "task-queue-type" map {
case "array" ThreadPoolConfig.arrayBlockingQueue(size, false) //TODO config fairness?
case "" | "linked" ThreadPoolConfig.linkedBlockingQueue(size)
case x throw new IllegalArgumentException("[%s] is not a valid task-queue-type [array|linked]!" format x)
}
case _ None
})(queueFactory _.setQueueFactory(queueFactory)),
conf_?(config getString "rejection-policy" map {
case "abort" new AbortPolicy()
case "caller-runs" new CallerRunsPolicy()
case "discard-oldest" new DiscardOldestPolicy()
case "discard" new DiscardPolicy()
case x throw new IllegalArgumentException("[%s] is not a valid rejectionPolicy [abort|caller-runs|discard-oldest|discard]!" format x)
})(policy _.setRejectionPolicy(policy)))
}
}