de.uni_hildesheim.sse.monitoring.runtime.instrumentation

Class MonitoringClassFileTransformer

java.lang.Object

de.uni_hildesheim.sse.monitoring.runtime.instrumentation.AbstractClassTransformer

de.uni_hildesheim.sse.monitoring.runtime.instrumentation.MonitoringClassFileTransformer

All Implemented Interfaces:

ISemanticsCollector, java.lang.instrument.ClassFileTransformer

public class MonitoringClassFileTransformer
extends AbstractClassTransformer
implements java.lang.instrument.ClassFileTransformer

Implements the frontend for dynamic bytecode instrumentation.

Since:

1.00

Version:

1.00

Author:

Holger Eichelberger

Field Summary

Fields inherited from class de.uni_hildesheim.sse.monitoring.runtime.instrumentation.AbstractClassTransformer

DELEGATING_RANDOM_ACCESS_FILE

Constructor Summary

Constructors

Constructor and Description
MonitoringClassFileTransformer() Creates a new monitoring class file transformer.

Method Summary

Modifier and Type	Method and Description
private byte[]	doClass(java.lang.ClassLoader loader, java.lang.String name, byte[] classBytes, boolean isRedefinition) Processes the given class.
private static java.lang.StackTraceElement	getClosest(java.lang.StackTraceElement[] trace, java.lang.String pkg) Returns the first stack trace element in trace which relates to the given package pkg.
private static void	log(java.lang.String text, java.lang.Throwable th, java.util.logging.Level level) Logs the message and attaches the first stack trace element (seen from the top of the stack) which belongs to this package.
protected void	retransformAssigned(java.lang.String[] classNames) Retransforms the specified classes.
byte[]	transform(java.lang.ClassLoader loader, java.lang.String className, java.lang.Class<?> classBeingRedefined, java.security.ProtectionDomain protectionDomain, byte[] classFileBuffer) The implementation of this method may transform the supplied class file and return a new replacement class file.
private byte[]	transform0(java.lang.String name, de.uni_hildesheim.sse.monitoring.runtime.instrumentation.lib.IClass cl, TransformationType type) Top-level call of AbstractClassTransformer.transform(String, IClass, TransformationType).

Methods inherited from class de.uni_hildesheim.sse.monitoring.runtime.instrumentation.AbstractClassTransformer

assignSemantics, deleteSemantics, getAnnotation, getAnnotation, getAnnotation, handleMethodInstrumentationException, internalVmFqnToJavaFqn, javaFqnToInternalVmFqnTo, pruneAnnotation, shouldInstrument, transform

Methods inherited from class java.lang.Object

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

Constructor Detail

MonitoringClassFileTransformer

public MonitoringClassFileTransformer()

Creates a new monitoring class file transformer.

Since:

1.00

Method Detail

transform

public byte[] transform(java.lang.ClassLoader loader,
                        java.lang.String className,
                        java.lang.Class<?> classBeingRedefined,
                        java.security.ProtectionDomain protectionDomain,
                        byte[] classFileBuffer)
                 throws java.lang.instrument.IllegalClassFormatException

The implementation of this method may transform the supplied class file and return a new replacement class file.

Specified by:

transform in interface java.lang.instrument.ClassFileTransformer

Parameters:

loader - - the defining loader of the class to be transformed, may be null if the bootstrap loader

className - - the name of the class in the internal form of fully qualified class and interface names as defined in The Java Virtual Machine Specification. For example, "java/util/List".

classBeingRedefined - - if this is triggered by a redefine or retransform, the class being redefined or retransformed; if this is a class load, null

protectionDomain - - the protection domain of the class being defined or redefined

classFileBuffer - - the input byte buffer in class file format - must not be modified

Returns:

a well-formed class file buffer (the result of the transform), or null if no transform is performed.

Throws:

java.lang.instrument.IllegalClassFormatException - in case that illegal byte code is produced

doClass

private final byte[] doClass(java.lang.ClassLoader loader,
                             java.lang.String name,
                             byte[] classBytes,
                             boolean isRedefinition)

Processes the given class.

Parameters:

loader - the class loader

name - the name of the class given in in the internal form of fully qualified class and interface names as defined in The Java Virtual Machine Specification, i.e. slashes instead of dots.

classBytes - the loaded class as a byte array

isRedefinition - true in case that the class is being redefined / retransformed, false else

Returns:

the new bytecode for the class in case that it was instrumented, null if the class was not modified

Since:

1.00

transform0

private byte[] transform0(java.lang.String name,
                          de.uni_hildesheim.sse.monitoring.runtime.instrumentation.lib.IClass cl,
                          TransformationType type)

Top-level call of AbstractClassTransformer.transform(String, IClass, TransformationType).

Parameters:

name - the name of the class given in the internal form of fully qualified class and interface names as defined in The Java Virtual Machine Specification. For example, "java/util/List".

cl - the class

type - the type of the transformation

Returns:

the new bytecode for the class in case that it was instrumented, null if the class was not modified

Since:

1.00

log

private static final void log(java.lang.String text,
                              java.lang.Throwable th,
                              java.util.logging.Level level)

Logs the message and attaches the first stack trace element (seen from the top of the stack) which belongs to this package.

Parameters:

text - the message to be logged

th - the throwable to be considered

level - the logging level

Since:

1.00

getClosest

private static java.lang.StackTraceElement getClosest(java.lang.StackTraceElement[] trace,
                                                      java.lang.String pkg)

Returns the first stack trace element in trace which relates to the given package pkg.

Parameters:

trace - the trace to be analyzed

pkg - the package

Returns:

the closest (first) stack trace element, null if not found

Since:

1.00

retransformAssigned

protected void retransformAssigned(java.lang.String[] classNames)

Retransforms the specified classes.

Overrides:

retransformAssigned in class AbstractClassTransformer

Parameters:

classNames - the class names, values are ignored

Since:

1.00