Module openj9.dtfj

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

Class AddressSpace

java.lang.Object

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

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

MutableAddressSpace

public class AddressSpace
extends Object
implements Serializable

This class represents an address space in an svcdump. It provides the ability to read the contents of an address amongst other things. Note that in Zebedee as a whole, addresses are always represented by a long (Java primitive) to avoid the overhead of continually creating address objects.

See Also:

• Serialized Form

Field Summary

Fields

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
AddressSpace(Dump dump, int asid)	Creates a new AddressSpace belonging to the given Dump and having the given id.

Method Summary

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.
protected byte[]	getBlockFromCacheOrDisk(long address)	Get the block either from the cache or from disk.
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 java.lang.Object

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

Field Details

dump

protected Dump dump

The dump we belong to

asid

protected int asid

Our address space id

addressMap

protected IntegerMap addressMap

Mapping of address to file offsets

lastBlockAddress

protected long lastBlockAddress

The last block address requested (quick block cache)

lastButOneBlockAddress

protected long lastButOneBlockAddress

The last but one block address requested (quick block cache)

ranges

protected AddressRange[] ranges

Array of AddressRanges

WILD_POINTER

public static final long WILD_POINTER

Constant used to indicate an uninitialized pointer (for performance reasons we use primitive longs for pointers rather than objects)

See Also:

• Constant Field Values

Constructor Details

AddressSpace

public AddressSpace(Dump dump,
 int asid)

Creates a new AddressSpace belonging to the given Dump and having the given id.

Parameters:

dump - the Dump this space belongs to

asid - the address space id

Method Details

getDump

public Dump getDump()

Returns:

the Dump we belong to

getRootAddressSpace

public AddressSpace getRootAddressSpace()

Returns:

the root address space

getLowestAddress

public long getLowestAddress()

Returns:

the lowest address in this address space

getUserMap

public Map getUserMap()

Returns a general purpose Map object that AddressSpace users can use as they see fit. This map is provided as a convenience since users of AddressSpace often want to store related info somewhere. Care should be taken that nobody else has used the same key - one way to achieve this would be to use a class object as a key.

getAsid

public int getAsid()

Returns the MVS ASID (Address Space Identifier) for this address space.

getAddressRanges

public AddressRange[] getAddressRanges()

Returns an array of all the AddressRanges in this address space. An address range is simply a pair of [low, high] addresses for which memory is available in the dump.

getUnusedAddressRanges

public AddressRange[] getUnusedAddressRanges()

Returns an array of all the unused address ranges in the address space. This is the inverse of getAddressRanges().

getImageInputStream

public AddressSpaceImageInputStream getImageInputStream()

Returns an AddressSpaceImageInputStream for this address space. The ImageInputStream interface provides a wealth of read methods.

roundToPage

protected long roundToPage(long address)

Rounds the address to the base page address.

isValidAddress

public boolean isValidAddress(long address)

Return true if the address is present in this address space

getBlock

public final byte[] getBlock(long address)
                      throws IOException

Get the block of bytes for the given address. Usually we find this in the cache. A block is 4096 bytes in length.

Throws:

IOException

getBlockFromCacheOrDisk

protected byte[] getBlockFromCacheOrDisk(long address)
                                  throws IOException

Get the block either from the cache or from disk. This protected method is provided so that MutableAddressSpace has the chance to look in its own cache first.

Throws:

IOException

read

public int read(long address)
         throws IOException

Read an unsigned byte at the specified address.

Throws:

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

readInt

public int readInt(long address)
            throws IOException

Read an int at the specified address.

Throws:

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

readUnsignedByte

public int readUnsignedByte(long address)
                     throws IOException

Read an unsigned byte at the specified address.

Throws:

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

readByte

public byte readByte(long address)
              throws IOException

Read a (signed) byte at the specified address.

Throws:

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

readUnsignedShort

public int readUnsignedShort(long address)
                      throws IOException

Read an unsigned short at the specified address.

Throws:

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

readShort

public short readShort(long address)
                throws IOException

Read a (signed) short at the specified address.

Throws:

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

readUnsignedInt

public long readUnsignedInt(long address)
                     throws IOException

Read an unsigned int at the specified address.

Throws:

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

readLong

public long readLong(long address)
              throws IOException

Read a long at the specified address.

Throws:

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

readWord

public long readWord(long address)
              throws IOException

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

Throws:

IOException

readWord

public long readWord(long address,
 boolean is64bitMode)
              throws IOException

Read a word at the specified address. A word is either 32 or 64 bits depending on the flag passed.

Throws:

IOException

getWordLength

public int getWordLength()

Returns the word length in bytes (either 4 or 8 bytes depending on the machine context).

read

public void read(long address,
 byte[] b,
 int off,
 int len)
          throws IOException

Reads len bytes of data from the given address into an array of bytes.

Parameters:

address - the address to read from

b - - the buffer into which the data is read

off - - the start offset in array b at which the data is written

len - - the number of bytes to read

Throws:

IOException

readEbcdicString

public String readEbcdicString(long address,
 int length)
                        throws IOException

Read an EBCDIC String. This method expects to find a sequence of EBCDIC bytes at the given address.

Parameters:

address - the start address of the EBCDIC bytes

length - the number of bytes to be read

Throws:

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

readEbcdicString

public String readEbcdicString(long address)
                        throws IOException

Read an EBCDIC String. Assumes that address points to the halfword length immediately followed by the EBCDIC bytes.

Parameters:

address - the start address of the EBCDIC bytes

Throws:

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

readEbcdicCString

public String readEbcdicCString(long address)
                         throws IOException

Read an EBCDIC String. Assumes that address points to a null-terminated EBCDIC string.

Parameters:

address - the start address of the EBCDIC bytes

Throws:

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

readAsciiString

public String readAsciiString(long address,
 int length)
                       throws IOException

Read an ASCII String. This method expects to find a sequence of ASCII bytes at the given address.

Parameters:

address - the start address of the ASCII bytes

length - the number of bytes to be read

Throws:

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

readAsciiCString

public String readAsciiCString(long address)
                        throws IOException

Read the ASCII string at the given address. Assumes that address points to a null-terminated ASCII C string.

Parameters:

address - the start address of the ASCII bytes

Throws:

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

readAsciiString

public String readAsciiString(long address)
                       throws IOException

Read an ASCII String. Assumes that address points to the halfword length immediately followed by the ASCII bytes.

Parameters:

address - the start address of the ASCII bytes

Throws:

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

readUtf8String

public String readUtf8String(long address)
                      throws IOException

Read a UTF8 String. Assumes that address points to the halfword length immediately followed by the utf8 bytes. XXX Despite the name no UTF8 conversion is done yet! (i.e. assumes ASCII)

Parameters:

address - the start address of the structure

Throws:

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

readLong

public long readLong(long address,
 Template template,
 String field)
              throws NoSuchFieldException,
IOException

Reads the value of a field in a template at the given address. Provided as a convenience.

Parameters:

address - the address of the base of the template

template - the template that describes the structure at that address

field - the name of the field

Throws:

NoSuchFieldException - if there is no such field in that type

IOException - if any errors occurred on reading from the stream

is64bit

public boolean is64bit()

Returns true if this is a 64-bit machine

setIs64bit

public void setIs64bit(boolean is64bit)

Sets whether this is a 64-bit machine. Unfortunately there is no way of knowing at the beginning if we are running in 64-bit mode, this is only discovered in le/Caa. So perhaps this knowledge should only be in the le layer?

toString

public String toString()

Returns the address space id as a hex string.

Overrides:

toString in class Object

Returns:

String a printable representation for the receiver.