com.google.testing.threadtester
Class TestInstrumenter

java.lang.Object
  com.google.testing.threadtester.TestInstrumenter

All Implemented Interfaces:

Instrumenter, ClassFileTransformer

public class TestInstrumenter
extends Object
implements Instrumenter, ClassFileTransformer

An Instrumenter that transforms a class' bytecode in order to add tracing calls to a CallLogger. The tracing can be used to create Breakpoints that allow the execution of this class to be suspended.

A TestInstrumenter is normally invoked via an InstrumentedClassLoader. If tesst are run using a BaseThreadedTestRunner, this is handled automatically. In addition, a TestInstrumenter implements the ClassFileTransformer interface, so that it can be used to instrument classes as they are loaded by the system classloader.

Author:

alasdair.mackintosh@gmail.com (Alasdair Mackintosh)

Field Summary

protected static String	GET_METHOD
protected static String	LOGGER
protected static String	METHOD_TABLE

Constructor Summary

TestInstrumenter(List<String> classes)
Creates a new TestInstrumenter that will instrumented the given list of named classes.

Method Summary

byte[]	instrument(String className, byte[] bytes) Transforms an array of bytes that defines a class.
static void	premain(String agentArgument, Instrumentation instrumentation) The premain method that will be invoked if the TestInstrumenter is used in conjunction with the -javaagent command-line option.
byte[]	transform(ClassLoader loader, String className, Class clss, ProtectionDomain domain, byte[] bytes)

Methods inherited from class java.lang.Object

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

Field Detail

GET_METHOD

protected static final String GET_METHOD

See Also:

Constant Field Values

METHOD_TABLE

protected static final String METHOD_TABLE

See Also:

Constant Field Values

LOGGER

protected static final String LOGGER

See Also:

Constant Field Values

Constructor Detail

TestInstrumenter

public TestInstrumenter(List<String> classes)

Creates a new TestInstrumenter that will instrumented the given list of named classes. These names should be in the format returned by Class.getName().

Method Detail

premain

public static void premain(String agentArgument,
                           Instrumentation instrumentation)

The premain method that will be invoked if the TestInstrumenter is used in conjunction with the -javaagent command-line option. See the package documentation for java.lang.instrument.

Parameters:

agentArgument - a comma-separated list of classnames to instrument

instrumentation - the JVM's instrumentation service.

transform

public byte[] transform(ClassLoader loader,
                        String className,
                        Class clss,
                        ProtectionDomain domain,
                        byte[] bytes)

Specified by:

transform in interface ClassFileTransformer

instrument

public byte[] instrument(String className,
                         byte[] bytes)

Description copied from interface: Instrumenter

Transforms an array of bytes that defines a class.

Specified by:

instrument in interface Instrumenter

Parameters:

className - the name of the class being defined.

bytes - the bytes that make up the class data.

Returns:

the transformed bytecode. A given Instrumenter may chose not to transform all classes, in which case it may just return the given classData.