org.apache.activemq.memory
Class UsageManager

java.lang.Object
  org.apache.activemq.memory.UsageManager

public class UsageManager
extends java.lang.Object

Used to keep track of how much of something is being used so that a productive working set usage can be controlled. Main use case is manage memory usage.

Version:

$Revision: 1.3 $

Constructor Summary

UsageManager()

UsageManager(UsageManager parent)
Create the memory manager linked to a parent.

Method Summary

void	addUsageListener(UsageListener listener)
void	decreaseUsage(long value) Decreases the usage by the value amount.
void	enqueueUsage(long value) Tries to increase the usage by value amount but blocks if this object is currently full.
long	getLimit()
int	getPercentUsage()
int	getPercentUsageMinDelta()
long	getUsage()
void	increaseUsage(long value) Increases the usage by the value amount.
boolean	isFull()
boolean	isSendFailIfNoSpace()
boolean	notifyCallbackWhenNotFull(java.lang.Runnable callback)
void	removeUsageListener(UsageListener listener)
void	setLimit(long limit) Sets the memory limit in bytes.
void	setPercentUsageMinDelta(int percentUsageMinDelta) Sets the minimum number of percentage points the usage has to change before a UsageListener event is fired by the manager.
void	setSendFailIfNoSpace(boolean failProducerIfNoSpace) Sets whether or not a send() should fail if there is no space free.
java.lang.String	toString()
void	waitForSpace()
boolean	waitForSpace(long timeout)

Methods inherited from class java.lang.Object

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

Constructor Detail

UsageManager

public UsageManager()

UsageManager

public UsageManager(UsageManager parent)

Create the memory manager linked to a parent. When the memory manager is linked to a parent then when usage increased or decreased, the parent's usage is also increased or decreased.

Parameters:

parent -

Method Detail

enqueueUsage

public void enqueueUsage(long value)
                  throws java.lang.InterruptedException

Tries to increase the usage by value amount but blocks if this object is currently full.

Throws:

java.lang.InterruptedException

waitForSpace

public void waitForSpace()
                  throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

waitForSpace

public boolean waitForSpace(long timeout)
                     throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

notifyCallbackWhenNotFull

public boolean notifyCallbackWhenNotFull(java.lang.Runnable callback)

Parameters:

callback -

Returns:

true if the UsageManager was full. The callback will only be called if this method returns true.

increaseUsage

public void increaseUsage(long value)

Increases the usage by the value amount.

Parameters:

value -

decreaseUsage

public void decreaseUsage(long value)

Decreases the usage by the value amount.

Parameters:

value -

isFull

public boolean isFull()

addUsageListener

public void addUsageListener(UsageListener listener)

removeUsageListener

public void removeUsageListener(UsageListener listener)

getLimit

public long getLimit()

setLimit

public void setLimit(long limit)

Sets the memory limit in bytes. When set using XBean, you can use values such as: "20 mb", "1024 kb", or "1 gb"

getPercentUsage

public int getPercentUsage()

getPercentUsageMinDelta

public int getPercentUsageMinDelta()

setPercentUsageMinDelta

public void setPercentUsageMinDelta(int percentUsageMinDelta)

Sets the minimum number of percentage points the usage has to change before a UsageListener event is fired by the manager.

Parameters:

percentUsageMinDelta -

getUsage

public long getUsage()

setSendFailIfNoSpace

public void setSendFailIfNoSpace(boolean failProducerIfNoSpace)

Sets whether or not a send() should fail if there is no space free. The default value is false which means to block the send() method until space becomes available

isSendFailIfNoSpace

public boolean isSendFailIfNoSpace()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object