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SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Object groovyx.gpars.agent.AgentCore groovyx.gpars.agent.AgentBase groovyx.gpars.agent.Agent
@SuppressWarnings({"MethodNamesDifferingOnlyByCase"}) public class Agent extends AgentBase
A special-purpose thread-safe non-blocking reference implementation inspired by Agents in Clojure. Agents safe-guard mutable values by allowing only a single agent-managed thread to make modifications to them. The mutable values are not directly accessible from outside, but instead requests have to be sent to the agent and the agent guarantees to process the requests sequentially on behalf of the callers. Agents guarantee sequential execution of all requests and so consistency of the values. An agent wraps a reference to mutable state, held inside a single field, and accepts code (closures / commands) as messages, which can be sent to the Agent just like to any other actor using the '<<' operator or any of the send() methods. After reception of a closure / command, the closure is invoked against the internal mutable field. The closure is guaranteed to be run without intervention from other threads and so may freely alter the internal state of the Agent held in the internal data field. The return value of the submitted closure is sent in reply to the sender of the closure. If the message sent to an agent is not a closure, it is considered to be a new value for the internal reference field. The internal reference can also be changed using the updateValue() method from within the received closures. The 'val' property of an agent will safely return the current value of the Agent, while the valAsync() method will do the same without blocking the caller. The 'instantVal' property will retrieve the current value of the Agent without having to wait in the queue of tasks. The initial internal value can be passed to the constructor. The two-parameter constructor allows to alter the way the internal value is returned from val/valAsync. By default the original reference is returned, but in many scenarios a copy or a clone might be more appropriate.
Field Summary |
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Fields inherited from class AgentBase | |
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awaitClosure, copy, data, listeners, lock, validators |
Fields inherited from class AgentCore | |
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core, errors |
Constructor Summary | |
Agent()
Creates a new Agent with the internal state set to null |
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Agent(T data)
Creates a new Agent around the supplied modifiable object |
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Agent(T data, groovy.lang.Closure copy)
Creates a new Agent around the supplied modifiable object |
Method Summary | |
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static Agent
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agent(T state)
Creates an agent instance initialized with the given state. |
static Agent
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agent(T state, groovy.lang.Closure copy)
Creates an agent instance initialized with the given state. |
static Agent
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fairAgent(T state)
Creates an agent instance initialized with the given state, which will cooperate in thread sharing with other Agent instances in a fair manner. |
static Agent
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fairAgent(T state, groovy.lang.Closure copy)
Creates an agent instance initialized with the given state, which will cooperate in thread sharing with other agents and actors in a fair manner. |
void
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handleMessage(java.lang.Object message)
Dynamically dispatches the method call |
Methods inherited from class AgentBase | |
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addListener, addValidator, await, checkClosure, getInstantVal, getVal, onMessage, onMessage, onMessage, sendAndWait, updateValue, valAsync |
Methods inherited from class AgentCore | |
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attachToThreadPool, call, getErrors, handleMessage, hasErrors, isFair, leftShift, makeFair, registerError, send, setPGroup |
Methods inherited from class java.lang.Object | |
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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() |
Constructor Detail |
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public Agent()
public Agent(T data)
data
- The object to use for storing the internal state of the variable
public Agent(T data, groovy.lang.Closure copy)
data
- The object to use for storing the internal state of the variablecopy
- A closure to use to create a copy of the internal state when sending the internal state out
Method Detail |
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@SuppressWarnings({"unchecked"}) public static Agent agent(T state)
state
- The initial internal state of the new Agent instance
@SuppressWarnings({"unchecked"}) public static Agent agent(T state, groovy.lang.Closure copy)
state
- The initial internal state of the new Agent instancecopy
- A closure to use to create a copy of the internal state when sending the internal state out
@SuppressWarnings({"unchecked"}) public static Agent fairAgent(T state)
state
- The initial internal state of the new Agent instance
@SuppressWarnings({"unchecked"}) public static Agent fairAgent(T state, groovy.lang.Closure copy)
state
- The initial internal state of the new Agent instancecopy
- A closure to use to create a copy of the internal state when sending the internal state out
@SuppressWarnings({"unchecked", "ChainOfInstanceofChecks"}) @Override public void handleMessage(java.lang.Object message)
Copyright © 2008–2010 Václav Pech. All Rights Reserved.