Class MutableAddressSpace

java.lang.Object

com.ibm.j9ddr.corereaders.tdump.zebedee.dumpreader.AddressSpace

com.ibm.j9ddr.corereaders.tdump.zebedee.dumpreader.MutableAddressSpace

All Implemented Interfaces:

Emulator.ImageSpace, Serializable

public final class MutableAddressSpace
extends AddressSpace
implements Emulator.ImageSpace

Provides the ability to write as well as read to a copy of the address space. This class is provided for use by the Emulator.

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected long	lastMutableBlockAddress	The last mutable block address requested (quick block cache)

Fields declared in class AddressSpace

addressMap, asid, dump, lastBlockAddress, lastButOneBlockAddress, ranges, WILD_POINTER

Modifier and Type	Field	Description
protected IntegerMap	addressMap	Mapping of address to file offsets
protected int	asid	Our address space id
protected Dump	dump	The dump we belong to
protected long	lastBlockAddress	The last block address requested (quick block cache)
protected long	lastButOneBlockAddress	The last but one block address requested (quick block cache)
protected AddressRange[]	ranges	Array of AddressRanges
static final long	WILD_POINTER	Constant used to indicate an uninitialized pointer (for performance reasons we use primitive longs for pointers rather than objects)

Constructor Summary

Constructors

Constructor	Description
MutableAddressSpace(AddressSpace space)	Creates a new MutableAddressSpace from the given AddressSpace.

Method Summary

Modifier and Type	Method	Description
void	allocPage(long address)	Allocate a page of memory at the given address.
void	free(long ptr)	Free the memory that was previously allocated by malloc.
protected byte[]	getBlockFromCacheOrDisk(long address)	Get the block of bytes for the given address.
long	malloc(int size)	Allocate a chunk of unused memory.
long	rmalloc(int size)
void	writeByte(long address, int value)	Write a byte at the specified address.
void	writeBytes(long address, byte[] array)	Write the contents of the byte array to the specified address.
void	writeInt(long address, int value)	Write an int at the specified address.
void	writeLong(long address, long value)	Write a long at the specified address.
void	writeShort(long address, int value)	Write a short at the specified address.
void	writeWord(long address, long value)	Write a word at the specified address.

Methods declared in class AddressSpace

getAddressRanges, getAsid, getBlock, getDump, getImageInputStream, getLowestAddress, getRootAddressSpace, getUnusedAddressRanges, getUserMap, getWordLength, is64bit, isValidAddress, read, read, readAsciiCString, readAsciiString, readAsciiString, readByte, readEbcdicCString, readEbcdicString, readEbcdicString, readInt, readLong, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUtf8String, readWord, readWord, roundToPage, setIs64bit, toString

Modifier and Type	Method	Description
AddressRange[]	getAddressRanges()	Returns an array of all the AddressRanges in this address space.
int	getAsid()	Returns the MVS ASID (Address Space Identifier) for this address space.
final byte[]	getBlock(long address)	Get the block of bytes for the given address.
Dump	getDump()
AddressSpaceImageInputStream	getImageInputStream()	Returns an AddressSpaceImageInputStream for this address space.
long	getLowestAddress()
AddressSpace	getRootAddressSpace()
AddressRange[]	getUnusedAddressRanges()	Returns an array of all the unused address ranges in the address space.
Map	getUserMap()	Returns a general purpose Map object that AddressSpace users can use as they see fit.
int	getWordLength()	Returns the word length in bytes (either 4 or 8 bytes depending on the machine context).
boolean	is64bit()	Returns true if this is a 64-bit machine
boolean	isValidAddress(long address)	Return true if the address is present in this address space
int	read(long address)	Read an unsigned byte at the specified address.
void	read(long address, byte[] b, int off, int len)	Reads len bytes of data from the given address into an array of bytes.
String	readAsciiCString(long address)	Read the ASCII string at the given address.
String	readAsciiString(long address)	Read an ASCII String.
String	readAsciiString(long address, int length)	Read an ASCII String.
byte	readByte(long address)	Read a (signed) byte at the specified address.
String	readEbcdicCString(long address)	Read an EBCDIC String.
String	readEbcdicString(long address)	Read an EBCDIC String.
String	readEbcdicString(long address, int length)	Read an EBCDIC String.
int	readInt(long address)	Read an int at the specified address.
long	readLong(long address)	Read a long at the specified address.
long	readLong(long address, Template template, String field)	Reads the value of a field in a template at the given address.
short	readShort(long address)	Read a (signed) short at the specified address.
int	readUnsignedByte(long address)	Read an unsigned byte at the specified address.
long	readUnsignedInt(long address)	Read an unsigned int at the specified address.
int	readUnsignedShort(long address)	Read an unsigned short at the specified address.
String	readUtf8String(long address)	Read a UTF8 String.
long	readWord(long address)	Read a word at the specified address.
long	readWord(long address, boolean is64bitMode)	Read a word at the specified address.
protected long	roundToPage(long address)	Rounds the address to the base page address.
void	setIs64bit(boolean is64bit)	Sets whether this is a 64-bit machine.
String	toString()	Returns the address space id as a hex string.

Methods declared in class Object

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

Methods declared in interface Emulator.ImageSpace

is64bit, readInt, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort

Modifier and Type	Method	Description
boolean	is64bit()	Return true if this dump is from a 64-bit machine
int	readInt(long address)	Read an int at the specified address.
long	readLong(long address)	Read a long at the specified address.
short	readShort(long address)	Read a short at the specified address.
int	readUnsignedByte(long address)	Read a byte at the specified address.
long	readUnsignedInt(long address)	Read an unsigned int at the specified address.
int	readUnsignedShort(long address)	Read an unsigned short at the specified address.

Field Details

lastMutableBlockAddress

protected long lastMutableBlockAddress

The last mutable block address requested (quick block cache)

Constructor Details

MutableAddressSpace

public MutableAddressSpace(AddressSpace space)

Creates a new MutableAddressSpace from the given AddressSpace. Updates to this "forked" copy will not be reflected in the parent AddressSpace.

Parameters:

AddressSpace - the address space we read from

Method Details

getBlockFromCacheOrDisk

protected byte[] getBlockFromCacheOrDisk(long address)
                                  throws IOException

Get the block of bytes for the given address. We look first in our own cache and if its not there call the superclass method.

Overrides:

getBlockFromCacheOrDisk in class AddressSpace

Throws:

IOException

writeBytes

public void writeBytes(long address,
 byte[] array)
                throws IOException

Write the contents of the byte array to the specified address.

Throws:

IOException - if the given address (of offset from there) is not present in this address space

writeWord

public void writeWord(long address,
 long value)
               throws IOException

Write a word at the specified address. A word is either 32 or 64 bits depending on the machine context.

Throws:

IOException

writeByte

public void writeByte(long address,
 int value)
               throws IOException

Write a byte at the specified address.

Specified by:

writeByte in interface Emulator.ImageSpace

Throws:

IOException - if the given address is not present in this address space

writeShort

public void writeShort(long address,
 int value)
                throws IOException

Write a short at the specified address.

Specified by:

writeShort in interface Emulator.ImageSpace

Throws:

IOException - if the given address is not present in this address space

writeInt

public void writeInt(long address,
 int value)
              throws IOException

Write an int at the specified address.

Specified by:

writeInt in interface Emulator.ImageSpace

Throws:

IOException - if the given address is not present in this address space

writeLong

public void writeLong(long address,
 long value)
               throws IOException

Write a long at the specified address.

Specified by:

writeLong in interface Emulator.ImageSpace

Throws:

IOException - if the given address is not present in this address space

malloc

public long malloc(int size)
            throws IOException

Allocate a chunk of unused memory. This searches the known address ranges and tries to find an unallocated area of the given size. If successful, this area effectively becomes part of this ImageSpace and may be read and written to as normal. This method is used by users of the Emulator for things like allocating stack, arguments etc.

Specified by:

malloc in interface Emulator.ImageSpace

Returns:

the address of the allocated memory

Throws:

IOException

rmalloc

public long rmalloc(int size)
             throws IOException

Throws:

IOException

free

public void free(long ptr)
          throws IOException

Free the memory that was previously allocated by malloc.

Throws:

IOException

allocPage

public void allocPage(long address)
               throws IOException

Allocate a page of memory at the given address. The address must not already be in use. A page is 4096 bytes in length. Address must be on a page boundary.

Throws:

IOException