gnu.cajo.utils.extra

Class Nice

java.lang.Object

gnu.cajo.utils.extra.Nice

All Implemented Interfaces:

Invoke, Serializable

public final class Nice
extends Object
implements Invoke

This class wraps an object, and dynamically alters the priority of the invocation thread at runtime. Normally, the thread is moved to lowest priority, to reduce the burden on the serving JVM for methods requiring a lot of processing resources. However the wrapper can also be used escalate the invocation thread to maximum priority, for time critical tasks.

Version:

1.0, 07-Mar-09

Author:

John Catherino

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
boolean	fast A flag to indicate if this wrapper is maximising or minimising the priority of the invocation thread.
Object	item The presumably local object reference, for which invocation thread priority will be managed.

Constructor Summary

Constructors

Constructor and Description
Nice(Object item, boolean fast) The constuctor wraps an object reference, and allows invocations to execute at either minumum or maximum priority.

Method Summary

Methods

Modifier and Type	Method and Description
Object	invoke(String method, Object args) This method intercepts the remote invocation thread, and alters its priority from normal.

Methods inherited from class java.lang.Object

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

Field Detail

item

public final Object item

The presumably local object reference, for which invocation thread priority will be managed.

fast

public final boolean fast

A flag to indicate if this wrapper is maximising or minimising the priority of the invocation thread.

Constructor Detail

Nice

public Nice(Object item,
    boolean fast)

The constuctor wraps an object reference, and allows invocations to execute at either minumum or maximum priority.

Parameters:

item - The object reference to be invoked

fast - True to execute invocations at maximum priority, false to invoke at minimum priorty.

Method Detail

invoke

public Object invoke(String method,
            Object args)
              throws Exception

This method intercepts the remote invocation thread, and alters its priority from normal. Typically the invocation thread is set to minimum priority, but can also be used to evelate the thread to maximum priority, if desired. When the invocation is complete, the thread will be restored to its original priority, to prevent potential side affects if an invocation is local.

Specified by:

invoke in interface Invoke

Parameters:

method - The name of the method to invoke on the wrapped object

args - The data relevant to the invocation. It can be a single object, an array, or null

Returns:

The method result defined by a wrapped object's implementation, if any

Throws:

Exception - As needed by the object, also, a java.rmi.RemoteException can be thrown for network related reasons, also a SecurityException can be thrown, if the codebase does not have permission from the SecurityManager to alter thread priority.