harpoon.Analysis
Class ChainedAllocationProperties

java.lang.Object
  harpoon.Analysis.ChainedAllocationProperties

All Implemented Interfaces:

AllocationInformation.AllocationProperties

public class ChainedAllocationProperties
extends Object
implements AllocationInformation.AllocationProperties

ChainedAllocationProperties allows us to change several properties of an already existing AllocationProperties. By default, it forwards each request to the original AllocationProperties that it's chained with (that object is passed to the ChainedAllocationProperties constructor). By overriding some of its methods, we can change only several allocation properties attached with a specific allocation site.

Version:

$Id: ChainedAllocationProperties.java,v 1.2 2003/03/03 23:41:27 salcianu Exp $

Author:

Alexandru Salcianu <salcianu@MIT.edu>

Constructor Summary

ChainedAllocationProperties(AllocationInformation.AllocationProperties oap)
Createsv a new ChainedAllocationProperties object

Method Summary

HClass	actualClass()
Temp	allocationHeap()
boolean	canBeStackAllocated()
boolean	canBeThreadAllocated()
Label	getLabelOfPtrToMemoryChunk()
int	getUniqueID()
boolean	hasInteriorPointers()
boolean	makeHeap()
boolean	noSync()
boolean	setDynamicWBFlag()

Methods inherited from class java.lang.Object

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

Constructor Detail

ChainedAllocationProperties

public ChainedAllocationProperties(AllocationInformation.AllocationProperties oap)

Createsv a new ChainedAllocationProperties object

Parameters:

oap - original AllocationProperties; the created ChainedAllocationProperties is chained with oap. By default, all method calls are forwarded toward oap.

Method Detail

hasInteriorPointers

public boolean hasInteriorPointers()

Specified by:

hasInteriorPointers in interface AllocationInformation.AllocationProperties

Returns:

true if the object allocated at this site has interior pointers; that is, it is not a primitive array, and some field in the allocated object is not primitive.

canBeStackAllocated

public boolean canBeStackAllocated()

Specified by:

canBeStackAllocated in interface AllocationInformation.AllocationProperties

Returns:

true if the object can be allocated on the stack; that is, the lifetime of the object does not exceed the execution of the method containing the allocation.

canBeThreadAllocated

public boolean canBeThreadAllocated()

Specified by:

canBeThreadAllocated in interface AllocationInformation.AllocationProperties

Returns:

true if the object can be allocated on a thread-local heap; that is, the lifetime of the object does not exceed the lifetime of the thread object specified by the allocationHeap method.

makeHeap

public boolean makeHeap()

Specified by:

makeHeap in interface AllocationInformation.AllocationProperties

Returns:

true if a thread-local heap should be associated with this object --- typically this means that the allocation site is a thread creation. If this is true and canBeThreadAllocated() is also true, then the new object will be itself allocated on the created heap; otherwise the new object will be globally allocated.

allocationHeap

public Temp allocationHeap()

Specified by:

allocationHeap in interface AllocationInformation.AllocationProperties

Returns:

a Temp which at the allocation site contains a reference to either the thread object of a thread-local allocation, or to another object whose lifetime is correlated with that of the (not-yet-created) thread object. Returns null if the allocation should use the heap associated with the "current" thread. If this returns non-null, then makeHeap() should return false and canBeThreadAllocated() should return true.

actualClass

public HClass actualClass()

Specified by:

actualClass in interface AllocationInformation.AllocationProperties

Returns:

the HClass representing the "actual" or instantiated class of the object for which memory is being allocated (as opposed to the declared class).

noSync

public boolean noSync()

Specified by:

noSync in interface AllocationInformation.AllocationProperties

setDynamicWBFlag

public boolean setDynamicWBFlag()

Specified by:

setDynamicWBFlag in interface AllocationInformation.AllocationProperties

Returns:

true if the dynamic write barrier flag needs to be set when the object is allocated--this typically means that one or more write barriers associated with stores into the object created at this allocation site have been optimistically removed.

getLabelOfPtrToMemoryChunk

public Label getLabelOfPtrToMemoryChunk()

Specified by:

getLabelOfPtrToMemoryChunk in interface AllocationInformation.AllocationProperties

Returns:

a Label for a pointer that points (at runtime) to a preallocated memory chunk to be used for this allocation site. Returns null if we cannot preallocate this allocation site.

getUniqueID

public int getUniqueID()

Specified by:

getUniqueID in interface AllocationInformation.AllocationProperties

Returns:

an unique integer ID for the allocation site. Useful for instrumentation purposes.