akka.dispatch
Class NullMessage$

java.lang.Object
  akka.dispatch.NullMessage$

All Implemented Interfaces:

java.io.Serializable, scala.Equals, scala.Product

public class NullMessage$
extends java.lang.Object
implements scala.Product, scala.Serializable

This message is sent directly after the Supervise system message in order to form a barrier wrt. the first real message sent by the child, so that e.g. Failed() cannot overtake Supervise(). Processing this does nothing.

Detailed explanation:

The race happens because Supervise and Failed may be queued between the parent's check for system messages and dequeue(). Thus, if the parent processes the NullMessage first (by way of that tiny race window), it is guaranteed to then find the Supervise system message in its mailbox prior to turning its attention to the next real message.

See Also:

Serialized Form

Field Summary

static NullMessage$

MODULE$ Static reference to the singleton instance of this Scala object.

Constructor Summary

NullMessage$()

Method Summary

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface scala.Product

productArity, productElement, productIterator, productPrefix

Methods inherited from interface scala.Equals

canEqual, equals

Field Detail

MODULE$

public static final NullMessage$ MODULE$

Static reference to the singleton instance of this Scala object.

Constructor Detail

NullMessage$

public NullMessage$()