com.aicas.jamaica.lang
Class MemoryBudget

java.lang.Object
  com.aicas.jamaica.lang.AllocationHandler
      com.aicas.jamaica.lang.MemoryBudget

public abstract class MemoryBudget
extends AllocationHandler

MemoryBudget is a class that provides to equip a thread with a certain memory allocation budget. After the budget is exceeded, the thread will no longer succeed in any allocations that it does.

Constructor Summary

MemoryBudget(Thread t, long budget)
Add a budget for a given thread

Method Summary

boolean	allocationPermitted() Is allocation within thread() still permitted?
void	allowAllocation() Permit allocation for this thread.
long	budget() Get the budget of a given thread
abstract void	budgetEmpty() Handler routine that is called when the budget of a certain thread is exhausted.
void	destroy() Remove this memory budget from thread().
void	forbidAllocation() Forbid allocation for this thread.
Object	handle(Object o) Routine that will be called when a thread allocated an object.
Thread	thread() The thread this budget is assigned to
long	usedBudget() Get the used budget of a given thread

Methods inherited from class com.aicas.jamaica.lang.AllocationHandler

removeAllocationHandler, setAllocationHandler

Methods inherited from class java.lang.Object

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

Constructor Detail

MemoryBudget

public MemoryBudget(Thread t,
                    long budget)

Add a budget for a given thread

Parameters:

t - the thread

budget - the budget in bytes

Method Detail

budget

public long budget()

Get the budget of a given thread

Returns:

the budget in bytes

usedBudget

public long usedBudget()

Get the used budget of a given thread

Returns:

the used budget in bytes

thread

public Thread thread()

The thread this budget is assigned to

Returns:

the thread, never null

allocationPermitted

public boolean allocationPermitted()

Is allocation within thread() still permitted?

Returns:

true if allocation is still permitted, i.e., there was no budget overrun yet.

handle

public final Object handle(Object o)

Routine that will be called when a thread allocated an object.

Specified by:

handle in class AllocationHandler

Parameters:

o - the allocated object

Returns:

the allocated object o or null if the allocation should fail.

forbidAllocation

public void forbidAllocation()

Forbid allocation for this thread. This can be used during a call to budgetEmpty to disallow allocation for thread().

allowAllocation

public void allowAllocation()

Permit allocation for this thread. This undoes the call to forbidAllocation().

budgetEmpty

public abstract void budgetEmpty()

Handler routine that is called when the budget of a certain thread is exhausted.

destroy

public void destroy()

Remove this memory budget from thread(). All MemoryBudget instances must to be destroyed to ensure that the associated resources will be reclaimed.