gov.nasa.jpf.vm

Class GenericHeap

java.lang.Object

gov.nasa.jpf.vm.GenericHeap

All Implemented Interfaces:

Heap, java.lang.Iterable<ElementInfo>

Direct Known Subclasses:

GenericSGOIDHeap

public abstract class GenericHeap
extends java.lang.Object
implements Heap, java.lang.Iterable<ElementInfo>

this is an abstract root for Heap implementations, providing a standard mark&sweep collector, change attribute management, and generic pinDownList, weakReference and internString handling The concrete Heap implementors have to provide the ElementInfo collection and associated getters, allocators and iterators

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	GenericHeap.ElementInfoMarker

Field Summary

Fields

Modifier and Type	Field and Description
protected int	attributes
protected GenericHeap.ElementInfoMarker	elementInfoMarker
protected java.util.Map<java.lang.Integer,IntTable<java.lang.String>>	internStringsMap
protected boolean	liveBitValue
protected ObjectQueue<ElementInfo>	markQueue
protected int	nLiveObjects
protected IntVector	pinDownList
protected VM	vm
protected java.util.ArrayList<ElementInfo>	weakRefs

Constructor Summary

Constructors

Constructor and Description
GenericHeap(Config config, KernelState ks)

Method Summary

Modifier and Type	Method and Description
protected void	addToInternStrings(java.lang.String str, int objref, int prcId)
protected void	addToPinDownList(int objref)
void	checkConsistency(boolean isStateStore)
void	cleanUpDanglingReferences() clean up reference values that are stored outside of reference fields called from KernelState to process live ElementInfos after GC has finished and only live objects remain in the heap.
protected void	cleanupWeakRefs() reset all weak references that now point to collected objects to 'null' NOTE: this implementation requires our own Reference/WeakReference implementation, to make sure the 'ref' field is the first one
protected ElementInfo	createArray(java.lang.String elementType, int nElements, ClassInfo ci, ThreadInfo ti, int objref)
protected DynamicElementInfo	createElementInfo(int objref, ClassInfo ci, Fields f, Monitor m, ThreadInfo ti)
protected ElementInfo	createObject(ClassInfo ci, ThreadInfo ti, int objref)
void	gc()
abstract ElementInfo	get(int ref) public getter to access but not change ElementInfos
protected ClassInfo	getArrayClassInfo(ThreadInfo ti, java.lang.String elementType)
abstract Memento<Heap>	getMemento()
abstract Memento<Heap>	getMemento(MementoFactory factory)
abstract ElementInfo	getModifiable(int ref) public getter to access modifiable ElementInfos;
protected abstract int	getNewElementInfoIndex(AllocationContext ctx) this is called for newXX(..) allocations that are SUT thread specific, i.e.
protected abstract AllocationContext	getSUTAllocationContext(ClassInfo ci, ThreadInfo ti)
protected abstract AllocationContext	getSystemAllocationContext(ClassInfo ci, ThreadInfo ti, int anchor)
boolean	hasChanged()
protected ElementInfo	initializeStringObject(java.lang.String str, int index, int vref)
boolean	isAlive(ElementInfo ei) check if object is alive.
boolean	isGcEnabled()
boolean	isOutOfMemory()
abstract java.util.Iterator<ElementInfo>	iterator() return Iterator for all non-null ElementInfo entries
abstract java.lang.Iterable<ElementInfo>	liveObjects()
protected void	mark()
void	markChanged(int objref)
protected void	markFinalizableObjects()
void	markStaticRoot(int objref) called during non-recursive phase1 marking of all objects reachable from static fields
void	markThreadRoot(int objref, int tid) called during non-recursive phase1 marking of all objects reachable from Thread roots
ElementInfo	newArray(java.lang.String elementType, int nElements, ThreadInfo ti)
ElementInfo	newInternString(java.lang.String str, ThreadInfo ti)
ElementInfo	newObject(ClassInfo ci, ThreadInfo ti)
protected ElementInfo	newString(ClassInfo ciString, ClassInfo ciChars, java.lang.String str, ThreadInfo ti, AllocationContext ctx)
ElementInfo	newString(java.lang.String str, ThreadInfo ti)
ElementInfo	newSystemArray(java.lang.String elementType, int nElements, ThreadInfo ti, int anchor)
ElementInfo	newSystemObject(ClassInfo ci, ThreadInfo ti, int anchor)
ElementInfo	newSystemString(java.lang.String str, ThreadInfo ti, int anchor)
ElementInfo	newSystemThrowable(ClassInfo ciThrowable, java.lang.String details, int[] stackSnapshot, int causeRef, ThreadInfo ti, int anchor)
void	queueMark(int objref) add a non-null, not yet marked reference to the markQueue called from ElementInfo.markRecursive().
void	registerPinDown(int objref)
void	registerWeakReference(ElementInfo ei)
void	releasePinDown(int objref)
protected abstract void	remove(int ref) internal remover used by generic sweep
protected void	removeFromPinDownList(int objref)
abstract void	resetVolatiles()
abstract void	restoreVolatiles()
protected abstract void	set(int index, ElementInfo ei) internal setter used during allocation
void	setGcEnabled(boolean doGC)
void	setOutOfMemory(boolean isOutOfMemory)
void	setStored()
protected void	sweep() this implementation uses a generic ElementInfo iterator, it can be replaced with a more efficient container specific version
void	unmarkAll()

Methods inherited from class java.lang.Object

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

Methods inherited from interface gov.nasa.jpf.vm.Heap

size

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

vm

protected VM vm

pinDownList

protected IntVector pinDownList

internStringsMap

protected java.util.Map<java.lang.Integer,IntTable<java.lang.String>> internStringsMap

attributes

protected int attributes

weakRefs

protected java.util.ArrayList<ElementInfo> weakRefs

markQueue

protected ObjectQueue<ElementInfo> markQueue

liveBitValue

protected boolean liveBitValue

elementInfoMarker

protected GenericHeap.ElementInfoMarker elementInfoMarker

nLiveObjects

protected int nLiveObjects

Constructor Detail

GenericHeap

public GenericHeap(Config config,
                   KernelState ks)

Method Detail

createElementInfo

protected DynamicElementInfo createElementInfo(int objref,
                                               ClassInfo ci,
                                               Fields f,
                                               Monitor m,
                                               ThreadInfo ti)

addToPinDownList

protected void addToPinDownList(int objref)

removeFromPinDownList

protected void removeFromPinDownList(int objref)

registerPinDown

public void registerPinDown(int objref)

Specified by:

registerPinDown in interface Heap

releasePinDown

public void releasePinDown(int objref)

Specified by:

releasePinDown in interface Heap

registerWeakReference

public void registerWeakReference(ElementInfo ei)

Specified by:

registerWeakReference in interface Heap

cleanupWeakRefs

protected void cleanupWeakRefs()

reset all weak references that now point to collected objects to 'null' NOTE: this implementation requires our own Reference/WeakReference implementation, to make sure the 'ref' field is the first one

getSUTAllocationContext

protected abstract AllocationContext getSUTAllocationContext(ClassInfo ci,
                                                             ThreadInfo ti)

getSystemAllocationContext

protected abstract AllocationContext getSystemAllocationContext(ClassInfo ci,
                                                                ThreadInfo ti,
                                                                int anchor)

getNewElementInfoIndex

protected abstract int getNewElementInfoIndex(AllocationContext ctx)

this is called for newXX(..) allocations that are SUT thread specific, i.e. in response to a explicit NEW or xNEWARRAY instruction that should take the allocating thread into account

createObject

protected ElementInfo createObject(ClassInfo ci,
                                   ThreadInfo ti,
                                   int objref)

newObject

public ElementInfo newObject(ClassInfo ci,
                             ThreadInfo ti)

Specified by:

newObject in interface Heap

newSystemObject

public ElementInfo newSystemObject(ClassInfo ci,
                                   ThreadInfo ti,
                                   int anchor)

Specified by:

newSystemObject in interface Heap

createArray

protected ElementInfo createArray(java.lang.String elementType,
                                  int nElements,
                                  ClassInfo ci,
                                  ThreadInfo ti,
                                  int objref)

getArrayClassInfo

protected ClassInfo getArrayClassInfo(ThreadInfo ti,
                                      java.lang.String elementType)

newArray

public ElementInfo newArray(java.lang.String elementType,
                            int nElements,
                            ThreadInfo ti)

Specified by:

newArray in interface Heap

newSystemArray

public ElementInfo newSystemArray(java.lang.String elementType,
                                  int nElements,
                                  ThreadInfo ti,
                                  int anchor)

Specified by:

newSystemArray in interface Heap

initializeStringObject

protected ElementInfo initializeStringObject(java.lang.String str,
                                             int index,
                                             int vref)

newString

protected ElementInfo newString(ClassInfo ciString,
                                ClassInfo ciChars,
                                java.lang.String str,
                                ThreadInfo ti,
                                AllocationContext ctx)

newString

public ElementInfo newString(java.lang.String str,
                             ThreadInfo ti)

Specified by:

newString in interface Heap

newSystemString

public ElementInfo newSystemString(java.lang.String str,
                                   ThreadInfo ti,
                                   int anchor)

Specified by:

newSystemString in interface Heap

newInternString

public ElementInfo newInternString(java.lang.String str,
                                   ThreadInfo ti)

Specified by:

newInternString in interface Heap

addToInternStrings

protected void addToInternStrings(java.lang.String str,
                                  int objref,
                                  int prcId)

newSystemThrowable

public ElementInfo newSystemThrowable(ClassInfo ciThrowable,
                                      java.lang.String details,
                                      int[] stackSnapshot,
                                      int causeRef,
                                      ThreadInfo ti,
                                      int anchor)

Specified by:

newSystemThrowable in interface Heap

set

protected abstract void set(int index,
                            ElementInfo ei)

internal setter used during allocation

Parameters:

index -

ei -

get

public abstract ElementInfo get(int ref)

public getter to access but not change ElementInfos

Specified by:

get in interface Heap

getModifiable

public abstract ElementInfo getModifiable(int ref)

public getter to access modifiable ElementInfos;

Specified by:

getModifiable in interface Heap

remove

protected abstract void remove(int ref)

internal remover used by generic sweep

iterator

public abstract java.util.Iterator<ElementInfo> iterator()

return Iterator for all non-null ElementInfo entries

Specified by:

iterator in interface java.lang.Iterable<ElementInfo>

liveObjects

public abstract java.lang.Iterable<ElementInfo> liveObjects()

Specified by:

liveObjects in interface Heap

isGcEnabled

public boolean isGcEnabled()

setGcEnabled

public void setGcEnabled(boolean doGC)

unmarkAll

public void unmarkAll()

Specified by:

unmarkAll in interface Heap

queueMark

public void queueMark(int objref)

add a non-null, not yet marked reference to the markQueue called from ElementInfo.markRecursive(). We don't want to expose the markQueue since a copying collector might not have it

Specified by:

queueMark in interface Heap

markStaticRoot

public void markStaticRoot(int objref)

called during non-recursive phase1 marking of all objects reachable from static fields

Specified by:

markStaticRoot in interface Heap

markThreadRoot

public void markThreadRoot(int objref,
                           int tid)

called during non-recursive phase1 marking of all objects reachable from Thread roots

Specified by:

markThreadRoot in interface Heap

sweep

protected void sweep()

this implementation uses a generic ElementInfo iterator, it can be replaced with a more efficient container specific version

markFinalizableObjects

protected void markFinalizableObjects()

mark

protected void mark()

gc

public void gc()

Specified by:

gc in interface Heap

cleanUpDanglingReferences

public void cleanUpDanglingReferences()

clean up reference values that are stored outside of reference fields called from KernelState to process live ElementInfos after GC has finished and only live objects remain in the heap. <2do> full heap enumeration is BAD - check if this can be moved into the sweep loop

Specified by:

cleanUpDanglingReferences in interface Heap

isAlive

public boolean isAlive(ElementInfo ei)

check if object is alive. This is here and not in ElementInfo because we might own the liveness bit. In fact, the generic implementation uses bit-toggle to avoid iteration over all live objects at the end of GC

Specified by:

isAlive in interface Heap

resetVolatiles

public abstract void resetVolatiles()

Specified by:

resetVolatiles in interface Heap

restoreVolatiles

public abstract void restoreVolatiles()

Specified by:

restoreVolatiles in interface Heap

hasChanged

public boolean hasChanged()

Specified by:

hasChanged in interface Heap

markChanged

public void markChanged(int objref)

Specified by:

markChanged in interface Heap

setStored

public void setStored()

getMemento

public abstract Memento<Heap> getMemento(MementoFactory factory)

Specified by:

getMemento in interface Heap

getMemento

public abstract Memento<Heap> getMemento()

Specified by:

getMemento in interface Heap

isOutOfMemory

public boolean isOutOfMemory()

Specified by:

isOutOfMemory in interface Heap

setOutOfMemory

public void setOutOfMemory(boolean isOutOfMemory)

Specified by:

setOutOfMemory in interface Heap

checkConsistency

public void checkConsistency(boolean isStateStore)

Specified by:

checkConsistency in interface Heap