Module openj9.dtfj

Package com.ibm.dtfj.java

Interface JavaLocation

All Known Implementing Classes:

DTFJJavaStackFrame, JavaLocation, JCJavaLocation, PHDCorruptJavaLocation, PHDJavaLocation

public interface JavaLocation

Represents a point of execution within a Java method.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object obj)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
ImagePointer	getAddress()	Fetches the absolute address of the code which this location represents.
int	getCompilationLevel()	Get the compilation level for this location.
String	getFilename()	Get the source file name.
int	getLineNumber()	Get the line number.
JavaMethod	getMethod()	Get the method which contains the point of execution.
int	hashCode()	Answers an integer hash code for the receiver.
String	toString()	Answers a string containing a concise, human-readable description of the receiver.

Method Details

getAddress

ImagePointer getAddress()
                 throws CorruptDataException

Fetches the absolute address of the code which this location represents. This pointer will be contained within one of the segments returned by getBytecodeSections() or getCompiledSections() of the method returned by getMethod().

null may be returned, particularly for methods with no bytecode or compiled sections (e.g. some native methods)

Although an offset into the method may be calculated using this pointer, caution should be exercised in attempting to map this offset to an offset within the original class file. Various transformations may have been applied to the bytecodes by the VM or other agents which may make the offset difficult to interpret.

For native methods, the address may be meaningless.

Returns:

the address in memory of the managed code

Throws:

CorruptDataException

getLineNumber

int getLineNumber()
           throws DataUnavailable,
CorruptDataException

Get the line number.

Returns:

the line number, if available, or throws DataUnavailable if it is not available Line numbers are counted from 1

Throws:

DataUnavailable - if the line number data is not available for this location

CorruptDataException

getFilename

String getFilename()
            throws DataUnavailable,
CorruptDataException

Get the source file name.

Returns:

the name of the source file, if available, or throws DataUnavailable if it is not available

Throws:

DataUnavailable - if the source file name is unavailable in the core

CorruptDataException

getCompilationLevel

int getCompilationLevel()
                 throws CorruptDataException

Get the compilation level for this location. This is an implementation defined number indicating the level at which the current location was compiled. 0 indicates interpreted. Any positive number indicates some level of JIT compilation. Typically, higher numbers indicate more aggressive compilation strategies

For native methods, a non-zero compilation level indicates that some level of JIT compilation has been applied to the native call (e.g. a custom native call stub). To determine if the method is native, use getMethod().getModifiers().

Returns:

the compilation level

Throws:

CorruptDataException

getMethod

JavaMethod getMethod()
              throws CorruptDataException

Get the method which contains the point of execution.

Returns:

the method which contains the point of execution

Throws:

CorruptDataException

toString

String toString()

Description copied from class: java.lang.Object

Answers a string containing a concise, human-readable description of the receiver.

Overrides:

toString in class Object

Returns:

A string representing the location as it would be seen in a Java stack trace

equals

boolean equals(Object obj)

Description copied from class: java.lang.Object

Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison. The implementation in Object answers true only if the argument is the exact same object as the receiver (==).

Overrides:

equals in class Object

Parameters:

obj -

Returns:

True if the given object refers to the same Java Location in the image

See Also:

• Object.hashCode()

hashCode

int hashCode()

Description copied from class: java.lang.Object

Answers an integer hash code for the receiver. Any two objects which answer true when passed to .equals must answer the same value for this method.

Overrides:

hashCode in class Object

Returns:

the receiver's hash.

See Also:

• Object.equals(java.lang.Object)