joeq.Allocator
Class SimpleAllocator

java.lang.Object
  joeq.Allocator.HeapAllocator
      joeq.Allocator.SimpleAllocator

All Implemented Interfaces:

jq_ClassFileConstants

public class SimpleAllocator
extends HeapAllocator

SimpleAllocator is a simple version of a heap allocator. It is basically a bump-pointer allocator with a free list.

Version:

$Id: SimpleAllocator.java,v 1.46 2005/01/21 07:13:15 joewhaley Exp $

Author:

John Whaley

Nested Class Summary

Nested classes/interfaces inherited from class joeq.Allocator.HeapAllocator

HeapAllocator.HeapPointer

Field Summary

static jq_InstanceMethod	_allocateArray
static jq_InstanceMethod	_allocateArrayAlign8
static jq_InstanceMethod	_allocateObject
static jq_InstanceMethod	_allocateObjectAlign8
static jq_Class	_class
static int	BLOCK_SIZE Size of blocks allocated from the OS.
static int	LARGE_THRESHOLD Threshold for direct OS allocation.
static int	MAX_MEMORY Maximum memory, in bytes, to be allocated from the OS.
static int	MIN_SIZE Smallest object size allowed in free list.
static boolean	NO_GC
static boolean	TRACE_ALLOC
static boolean	TRACE_FREELIST
static boolean	TRACE_GC

Fields inherited from class joeq.Allocator.HeapAllocator

_clsinitAndAllocateObject, _data_segment_end, _data_segment_start, data_segment_end, data_segment_start, TRACE

Fields inherited from interface joeq.Class.jq_ClassFileConstants

ACC_ABSTRACT, ACC_FINAL, ACC_INTERFACE, ACC_NATIVE, ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC, ACC_STATIC, ACC_STRICT, ACC_SUPER, ACC_SYNCHRONIZED, ACC_TRANSIENT, ACC_VOLATILE, CONSTANT_Class, CONSTANT_Double, CONSTANT_FieldRef, CONSTANT_Float, CONSTANT_Integer, CONSTANT_InterfaceMethodRef, CONSTANT_Long, CONSTANT_MethodRef, CONSTANT_NameAndType, CONSTANT_ResolvedClass, CONSTANT_ResolvedIFieldRef, CONSTANT_ResolvedIMethodRef, CONSTANT_ResolvedSFieldRef, CONSTANT_ResolvedSMethodRef, CONSTANT_String, CONSTANT_Utf8, CONSUME_STACK, ILLEGAL_OPCODE, ILLEGAL_TYPE, jbc_AALOAD, jbc_AASTORE, jbc_ACONST_NULL, jbc_ALOAD, jbc_ALOAD_0, jbc_ALOAD_1, jbc_ALOAD_2, jbc_ALOAD_3, jbc_ANEWARRAY, jbc_ARETURN, jbc_ARRAYLENGTH, jbc_ASTORE, jbc_ASTORE_0, jbc_ASTORE_1, jbc_ASTORE_2, jbc_ASTORE_3, jbc_ATHROW, jbc_BALOAD, jbc_BASTORE, jbc_BIPUSH, jbc_BREAKPOINT, jbc_CALOAD, jbc_CASTORE, jbc_CHECKCAST, jbc_D2F, jbc_D2I, jbc_D2L, jbc_DADD, jbc_DALOAD, jbc_DASTORE, jbc_DCMPG, jbc_DCMPL, jbc_DCONST_0, jbc_DCONST_1, jbc_DDIV, jbc_DLOAD, jbc_DLOAD_0, jbc_DLOAD_1, jbc_DLOAD_2, jbc_DLOAD_3, jbc_DMUL, jbc_DNEG, jbc_DREM, jbc_DRETURN, jbc_DSTORE, jbc_DSTORE_0, jbc_DSTORE_1, jbc_DSTORE_2, jbc_DSTORE_3, jbc_DSUB, jbc_DUP, jbc_DUP_X1, jbc_DUP_X2, jbc_DUP2, jbc_DUP2_X1, jbc_DUP2_X2, jbc_F2D, jbc_F2I, jbc_F2L, jbc_FADD, jbc_FALOAD, jbc_FASTORE, jbc_FCMPG, jbc_FCMPL, jbc_FCONST_0, jbc_FCONST_1, jbc_FCONST_2, jbc_FDIV, jbc_FLOAD, jbc_FLOAD_0, jbc_FLOAD_1, jbc_FLOAD_2, jbc_FLOAD_3, jbc_FMUL, jbc_FNEG, jbc_FREM, jbc_FRETURN, jbc_FSTORE, jbc_FSTORE_0, jbc_FSTORE_1, jbc_FSTORE_2, jbc_FSTORE_3, jbc_FSUB, jbc_GETFIELD, jbc_GETSTATIC, jbc_GOTO, jbc_GOTO_W, jbc_I2B, jbc_I2C, jbc_I2D, jbc_I2F, jbc_I2L, jbc_I2S, jbc_IADD, jbc_IALOAD, jbc_IAND, jbc_IASTORE, jbc_ICONST_0, jbc_ICONST_1, jbc_ICONST_2, jbc_ICONST_3, jbc_ICONST_4, jbc_ICONST_5, jbc_ICONST_M1, jbc_IDIV, jbc_IF_ACMPEQ, jbc_IF_ACMPNE, jbc_IF_ICMPEQ, jbc_IF_ICMPGE, jbc_IF_ICMPGT, jbc_IF_ICMPLE, jbc_IF_ICMPLT, jbc_IF_ICMPNE, jbc_IFEQ, jbc_IFGE, jbc_IFGT, jbc_IFLE, jbc_IFLT, jbc_IFNE, jbc_IFNONNULL, jbc_IFNULL, jbc_IINC, jbc_ILOAD, jbc_ILOAD_0, jbc_ILOAD_1, jbc_ILOAD_2, jbc_ILOAD_3, jbc_IMUL, jbc_INEG, jbc_INSTANCEOF, jbc_INT2BYTE, jbc_INT2CHAR, jbc_INT2SHORT, jbc_INVOKEINTERFACE, jbc_INVOKENONVIRTUAL, jbc_INVOKESPECIAL, jbc_INVOKESTATIC, jbc_INVOKEVIRTUAL, jbc_IOR, jbc_IREM, jbc_IRETURN, jbc_ISHL, jbc_ISHR, jbc_ISTORE, jbc_ISTORE_0, jbc_ISTORE_1, jbc_ISTORE_2, jbc_ISTORE_3, jbc_ISUB, jbc_IUSHR, jbc_IXOR, jbc_JSR, jbc_JSR_W, jbc_L2D, jbc_L2F, jbc_L2I, jbc_LADD, jbc_LALOAD, jbc_LAND, jbc_LASTORE, jbc_LCMP, jbc_LCONST_0, jbc_LCONST_1, jbc_LDC, jbc_LDC_W, jbc_LDC2_W, jbc_LDIV, jbc_LLOAD, jbc_LLOAD_0, jbc_LLOAD_1, jbc_LLOAD_2, jbc_LLOAD_3, jbc_LMUL, jbc_LNEG, jbc_LOOKUPSWITCH, jbc_LOR, jbc_LREM, jbc_LRETURN, jbc_LSHL, jbc_LSHR, jbc_LSTORE, jbc_LSTORE_0, jbc_LSTORE_1, jbc_LSTORE_2, jbc_LSTORE_3, jbc_LSUB, jbc_LUSHR, jbc_LXOR, jbc_MONITORENTER, jbc_MONITOREXIT, jbc_MULTIANEWARRAY, jbc_NEW, jbc_NEWARRAY, jbc_NOP, jbc_POP, jbc_POP2, jbc_PUTFIELD, jbc_PUTSTATIC, jbc_RET, jbc_RETURN, jbc_SALOAD, jbc_SASTORE, jbc_SIPUSH, jbc_SWAP, jbc_TABLESWITCH, jbc_WIDE, NO_OF_OPERANDS, OPCODE_NAMES, PRODUCE_STACK, RESERVED, STATE_CLSINITERROR, STATE_CLSINITIALIZED, STATE_CLSINITIALIZING, STATE_CLSINITRUNNING, STATE_COMPILED, STATE_COMPILING, STATE_LOADED, STATE_LOADERROR, STATE_LOADING1, STATE_LOADING2, STATE_LOADING3, STATE_PREPARED, STATE_PREPARING, STATE_SFINITIALIZED, STATE_SFINITIALIZING, STATE_UNLOADED, STATE_VERIFIED, STATE_VERIFYING, T_BOOLEAN, T_BYTE, T_CHAR, T_DOUBLE, T_FLOAT, T_INT, T_LONG, T_SHORT, TC_ARRAY, TC_BOOLEAN, TC_BYTE, TC_CHAR, TC_CLASS, TC_CLASSEND, TC_DOUBLE, TC_FLOAT, TC_INT, TC_LONG, TC_PARAM, TC_PARAMEND, TC_SHORT, TC_VOID, TYPE_OF_OPERANDS, UNDEFINED, UNPREDICTABLE

Constructor Summary

SimpleAllocator()

Method Summary

Object	allocateArray(int length, int size, Object vtable) Allocate an array with the default alignment.
Object	allocateArrayAlign8(int length, int size, Object vtable) Allocate an array such that the elements are 8-byte aligned.
Object	allocateObject(int size, Object vtable) Allocate an object with the default alignment.
Object	allocateObjectAlign8(int size, Object vtable) Allocate an object such that the first field is 8-byte aligned.
void	collect() Initiate a garbage collection.
int	freeMemory() Returns an estimate of the amount of free memory available.
static int	getObjectSize(Object o)
void	init() Perform initialization for this allocator.
boolean	isInHeap(Address a) Returns whether the given address falls within the boundaries of this heap.
void	processObjectReference(Address a) Process a reference to a heap object during garbage collection.
void	processPossibleObjectReference(Address a) Process a possible reference to a heap object during garbage collection.
void	sweep()
int	totalMemory() Returns an estimate of the total memory allocated (both used and unused).

Methods inherited from class joeq.Allocator.HeapAllocator

checkObjectReferences, clone, clsinitAndAllocateObject, getGCBit, getScalarObjectReferenceOffsets, initializeDataSegment, isInDataSegment, isObjectAssignableType, isObjectExactType, isValidArray, isValidArray, isValidArrayType, isValidArrayVTable, isValidHeapAddress, isValidObject, isValidObject, isValidReferenceType, isValidVTable, outOfMemory, setGCBit

Methods inherited from class java.lang.Object

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

Field Detail

NO_GC

public static boolean NO_GC

TRACE_ALLOC

public static boolean TRACE_ALLOC

TRACE_FREELIST

public static boolean TRACE_FREELIST

TRACE_GC

public static boolean TRACE_GC

BLOCK_SIZE

public static final int BLOCK_SIZE

Size of blocks allocated from the OS.

See Also:

Constant Field Values

MAX_MEMORY

public static int MAX_MEMORY

Maximum memory, in bytes, to be allocated from the OS.

LARGE_THRESHOLD

public static final int LARGE_THRESHOLD

Threshold for direct OS allocation. When an array overflows the current block and is larger than this size, it is allocated directly from the OS.

See Also:

Constant Field Values

MIN_SIZE

public static final int MIN_SIZE

Smallest object size allowed in free list.

_class

public static final jq_Class _class

_allocateObject

public static final jq_InstanceMethod _allocateObject

_allocateObjectAlign8

public static final jq_InstanceMethod _allocateObjectAlign8

_allocateArray

public static final jq_InstanceMethod _allocateArray

_allocateArrayAlign8

public static final jq_InstanceMethod _allocateArrayAlign8

Constructor Detail

SimpleAllocator

public SimpleAllocator()

Method Detail

init

public void init()
          throws OutOfMemoryError

Perform initialization for this allocator. This will be called before any other methods. This allocates an initial block of memory from the OS and sets up relevant pointers.

Specified by:

init in class HeapAllocator

Throws:

OutOfMemoryError - if there is not enough memory for initialization

freeMemory

public int freeMemory()

Returns an estimate of the amount of free memory available.

Specified by:

freeMemory in class HeapAllocator

Returns:

bytes of free memory

totalMemory

public int totalMemory()

Returns an estimate of the total memory allocated (both used and unused).

Specified by:

totalMemory in class HeapAllocator

Returns:

bytes of memory allocated

allocateObject

public Object allocateObject(int size,
                             Object vtable)
                      throws OutOfMemoryError

Allocate an object with the default alignment. If the object cannot be allocated due to lack of memory, throws OutOfMemoryError.

Specified by:

allocateObject in class HeapAllocator

Parameters:

size - size of object to allocate (including object header), in bytes

vtable - vtable pointer for new object

Returns:

new uninitialized object

Throws:

OutOfMemoryError - if there is insufficient memory to perform the operation

getObjectSize

public static final int getObjectSize(Object o)

allocateObjectAlign8

public Object allocateObjectAlign8(int size,
                                   Object vtable)
                            throws OutOfMemoryError

Allocate an object such that the first field is 8-byte aligned. If the object cannot be allocated due to lack of memory, throws OutOfMemoryError.

Specified by:

allocateObjectAlign8 in class HeapAllocator

Parameters:

size - size of object to allocate (including object header), in bytes

vtable - vtable pointer for new object

Returns:

new uninitialized object

Throws:

OutOfMemoryError - if there is insufficient memory to perform the operation

allocateArray

public Object allocateArray(int length,
                            int size,
                            Object vtable)
                     throws OutOfMemoryError,
                            NegativeArraySizeException

Allocate an array with the default alignment. If length is negative, throws NegativeArraySizeException. If the array cannot be allocated due to lack of memory, throws OutOfMemoryError.

Specified by:

allocateArray in class HeapAllocator

Parameters:

length - length of new array

size - size of array to allocate (including array header), in bytes

vtable - vtable pointer for new array

Returns:

new array

Throws:

NegativeArraySizeException - if length is negative

OutOfMemoryError - if there is insufficient memory to perform the operation

allocateArrayAlign8

public Object allocateArrayAlign8(int length,
                                  int size,
                                  Object vtable)
                           throws OutOfMemoryError,
                                  NegativeArraySizeException

Allocate an array such that the elements are 8-byte aligned. If length is negative, throws NegativeArraySizeException. If the array cannot be allocated due to lack of memory, throws OutOfMemoryError.

Specified by:

allocateArrayAlign8 in class HeapAllocator

Parameters:

length - length of new array

size - size of array to allocate (including array header), in bytes

vtable - vtable pointer for new array

Returns:

new array

Throws:

NegativeArraySizeException - if length is negative

OutOfMemoryError - if there is insufficient memory to perform the operation

collect

public void collect()

Description copied from class: HeapAllocator

Initiate a garbage collection.

Specified by:

collect in class HeapAllocator

sweep

public void sweep()

processObjectReference

public void processObjectReference(Address a)

Description copied from class: HeapAllocator

Process a reference to a heap object during garbage collection.

Specified by:

processObjectReference in class HeapAllocator

processPossibleObjectReference

public void processPossibleObjectReference(Address a)

Description copied from class: HeapAllocator

Process a possible reference to a heap object during garbage collection.

Specified by:

processPossibleObjectReference in class HeapAllocator

isInHeap

public boolean isInHeap(Address a)

Description copied from class: HeapAllocator

Returns whether the given address falls within the boundaries of this heap.

Specified by:

isInHeap in class HeapAllocator