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groovyx.gpars.agent
[Java] Class AgentBase

java.lang.Object
  groovyx.gpars.agent.AgentCore
      groovyx.gpars.agent.AgentBase

abstract class AgentBase
extends AgentCore

Implements most of Agent's public method in Java

Authors:
Vaclav Pech

Nested Class Summary
private static class AgentBase.AwaitClosure

Returns the current value of the Agent's state
 
Field Summary
private static groovy.lang.Closure awaitClosure

private groovy.lang.Closure copy

Function converting the internal state during read to prevent internal state escape from the protected boundary of the agent
protected T data

Holds the internal mutable state
private java.util.Collection listeners

Holds all listeners interested in state updates A listener should be a closure accepting the old and the new value in this order.
protected java.util.concurrent.locks.ReadWriteLock lock

Allows reads not to wait in the message queue.

private java.util.Collection validators

Holds all validators checking the agent's state A validator should be a closure accepting the old and the new value in this order.
 
Fields inherited from class AgentCore
core, errors
 
Constructor Summary
AgentBase(T data)

AgentBase(T data, groovy.lang.Closure copy)

Creates a new Agent around the supplied modifiable object
 
Method Summary
void addListener(groovy.lang.Closure listener)

Adds a listener interested in state updates A listener should be a closure accepting the old and the new value in this order plus optionally the agent reference as the first argument.
void addValidator(groovy.lang.Closure validator)

Adds a validator checking the agent's state A listener should be a closure accepting the old and the new value in this order plus optionally the agent reference as the first argument.
void await()

Blocks until all messages in the queue prior to call to await() complete.

private groovy.lang.Closure checkClosure(groovy.lang.Closure code)

Only two-argument closures are allowed
T getInstantVal()

A shorthand method for safe message-based retrieval of the internal state.

T getVal()

A shorthand method for safe message-based retrieval of the internal state.

void onMessage(org.codehaus.groovy.runtime.NullObject obj)

Accepts a NullObject instance and sets the internal state to null
void onMessage(groovy.lang.Closure code)

Accepts and invokes the closure
void onMessage(T message)

Other messages than closures are accepted as new values for the internal state
T sendAndWait(groovy.lang.Closure message)

Submits the closure waiting for the result
void updateValue(T newValue)

Allows closures to set the new internal state as a whole Do not call this method directly from the outside.

void valAsync(groovy.lang.Closure callback)

A shorthand method for safe asynchronous message-based retrieval of the internal state.

 
Methods inherited from class AgentCore
attachToThreadPool, call, getErrors, handleMessage, hasErrors, isFair, leftShift, makeFair, registerError, send, setPGroup
 
Methods inherited from class java.lang.Object
java.lang.Object#wait(long), java.lang.Object#wait(), java.lang.Object#wait(long, int), java.lang.Object#equals(java.lang.Object), java.lang.Object#toString(), java.lang.Object#hashCode(), java.lang.Object#getClass(), java.lang.Object#notify(), java.lang.Object#notifyAll()
 

Field Detail

awaitClosure

private static final groovy.lang.Closure awaitClosure

copy

private final groovy.lang.Closure copy
Function converting the internal state during read to prevent internal state escape from the protected boundary of the agent

data

protected T data
Holds the internal mutable state

listeners

private final java.util.Collection listeners
Holds all listeners interested in state updates A listener should be a closure accepting the old and the new value in this order.

lock

protected java.util.concurrent.locks.ReadWriteLock lock
Allows reads not to wait in the message queue. Writes and reads are mutually separated by using write or read locks respectively.

validators

private final java.util.Collection validators
Holds all validators checking the agent's state A validator should be a closure accepting the old and the new value in this order.

 
Constructor Detail

AgentBase

AgentBase(T data)

AgentBase

AgentBase(T data, groovy.lang.Closure copy)
Creates a new Agent around the supplied modifiable object
Parameters:
data - The object to use for storing the internal state of the variable
copy - A closure to use to create a copy of the internal state when sending the internal state out

 
Method Detail

addListener

public void addListener(groovy.lang.Closure listener)
Adds a listener interested in state updates A listener should be a closure accepting the old and the new value in this order plus optionally the agent reference as the first argument.
Parameters:
listener - The closure with two or three arguments

addValidator

public void addValidator(groovy.lang.Closure validator)
Adds a validator checking the agent's state A listener should be a closure accepting the old and the new value in this order plus optionally the agent reference as the first argument.
Parameters:
validator - The closure with two or three arguments

await

public final void await()
Blocks until all messages in the queue prior to call to await() complete. Provides a means to synchronize with the Agent
throws:
InterruptedException If the thread gets interrupted while waiting for a value to be bound

checkClosure

private groovy.lang.Closure checkClosure(groovy.lang.Closure code)
Only two-argument closures are allowed
Parameters:
code - The passed-in closure
Returns:
Either the original closure or a two-argument closure after currying the first argument of the passed-in closure to self

getInstantVal

@SuppressWarnings({"unchecked"})
public final T getInstantVal()
A shorthand method for safe message-based retrieval of the internal state. Retrieves the internal state immediately by-passing the queue of tasks waiting to be processed.
Returns:
The current value of the actor's state

getVal

public final T getVal()
A shorthand method for safe message-based retrieval of the internal state. The request to retrieve a value is put into the message queue, so will wait for all messages delivered earlier to complete.
throws:
InterruptedException If the thread gets interrupted while waiting for a value to be bound
Returns:
The value of the actor's state once all previously sent messages in the queue get processed

onMessage

final void onMessage(org.codehaus.groovy.runtime.NullObject obj)
Accepts a NullObject instance and sets the internal state to null
Parameters:
obj - The received message

onMessage

final void onMessage(groovy.lang.Closure code)
Accepts and invokes the closure
Parameters:
code - The received message

onMessage

final void onMessage(T message)
Other messages than closures are accepted as new values for the internal state
Parameters:
message - The received message

sendAndWait

@SuppressWarnings({"unchecked"})
final T sendAndWait(groovy.lang.Closure message)
Submits the closure waiting for the result
throws:
InterruptedException If the thread gets interrupted while waiting for a value to be bound
Parameters:
message - The message/closure to send
Returns:
The return value of the closure

updateValue

@SuppressWarnings({"unchecked", "CatchGenericClass"})
public final void updateValue(T newValue)
Allows closures to set the new internal state as a whole Do not call this method directly from the outside. It is designed to be used from within the submitted closures.
Parameters:
newValue - The value to set the internal state to

valAsync

public final void valAsync(groovy.lang.Closure callback)
A shorthand method for safe asynchronous message-based retrieval of the internal state. The request to retrieve a value is put into the message queue, so will wait for all messages delivered earlier to complete.
Parameters:
callback - A closure to invoke with the internal state as a parameter

 

Copyright © 2008–2010 Václav Pech. All Rights Reserved.