Module com.yasuenag.ffmasm

Package com.yasuenag.ffmasm

Class CodeSegment

java.lang.Object

com.yasuenag.ffmasm.CodeSegment

All Implemented Interfaces:

AutoCloseable

public class CodeSegment
extends Object
implements AutoCloseable

Memory segment for executables.

Author:

Yasumasa Suenaga

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	CodeSegment.CleanerAction	Class to register calling close() as Cleaner action.
static final record	CodeSegment.MethodInfo	Holder for method information.

Field Summary

Fields

Modifier and Type	Field	Description
static final long	DEFAULT_CODE_SEGMENT_SIZE	Default size of code segment.

Constructor Summary

Constructors

Constructor	Description
CodeSegment()	Allocate memory for this code segment with default size (4096 bytes).
CodeSegment(long size)	Allocate memory for this code segment.

Method Summary

Modifier and Type	Method	Description
CodeSegment.MethodInfo	addMethodInfo(String name, long address, int size)	Add method info.
void	alignTo16Bytes()	Align the tail to 16 bytes
void	close()	Release memory for this code segment.
void	disablePerfMapDumper()	Disable perf map dumper
void	enablePerfMapDumper(Path path)	Enable perf map dumper at shutdown hook for dumping all of functions in this CodeSegment.
MemorySegment	getAddr()	Get MemorySegment which relates to this segment.
long	getTail()	Get the tail of this segment.
MemorySegment	getTailOfMemorySegment()	Get slice of this segment from the tail.
void	incTail(long size)	Increment the tail with given size.

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_CODE_SEGMENT_SIZE

public static final long DEFAULT_CODE_SEGMENT_SIZE

Default size of code segment.

See Also:

• Constant Field Values

Constructor Details

CodeSegment

public CodeSegment()
            throws PlatformException,
UnsupportedPlatformException

Allocate memory for this code segment with default size (4096 bytes).

Throws:

PlatformException - thrown when native function call failed.

UnsupportedPlatformException - thrown when the platform is not supported.

CodeSegment

public CodeSegment(long size)
            throws PlatformException,
UnsupportedPlatformException

Allocate memory for this code segment.

Parameters:

size - size of code segment.

Throws:

PlatformException - thrown when native function call failed.

UnsupportedPlatformException - thrown when the platform is not supported.

Method Details

close

public void close()
           throws Exception

Release memory for this code segment.

Specified by:

close in interface AutoCloseable

Throws:

Exception

getTailOfMemorySegment

public MemorySegment getTailOfMemorySegment()

Get slice of this segment from the tail.

Returns:

Slice of this segment from the tail.

alignTo16Bytes

public void alignTo16Bytes()

Align the tail to 16 bytes

getTail

public long getTail()

Get the tail of this segment.

Returns:

the tail of this segment.

incTail

public void incTail(long size)

Increment the tail with given size.

Parameters:

size - value to increment

getAddr

public MemorySegment getAddr()

Get MemorySegment which relates to this segment.

Returns:

MemorySegment of this segment.

addMethodInfo

public CodeSegment.MethodInfo addMethodInfo(String name,
 long address,
 int size)

Add method info. It will be dumped to perf map as related method of this CodeSegment.

Parameters:

name - Method name

address - Address of the method

size - Size of the method (machine code)

Returns:

MethodInfo of the method info.

Throws:

IllegalArgumentException - if the address is out of range from this CodeSegment.

enablePerfMapDumper

public void enablePerfMapDumper(Path path)

Enable perf map dumper at shutdown hook for dumping all of functions in this CodeSegment.

Parameters:

path - Path to dumpfile

disablePerfMapDumper

public void disablePerfMapDumper()

Disable perf map dumper

Throws:

IllegalStateException - if enablePerfMapDumper() is not called before.