com.newrelic.agent.instrumentation

Class AgentWrapper

java.lang.Object

com.newrelic.agent.instrumentation.AgentWrapper

All Implemented Interfaces:

java.lang.reflect.InvocationHandler

public class AgentWrapper
extends java.lang.Object
implements java.lang.reflect.InvocationHandler

This class helps us instrument bootstrap classloader classes. Normally our instrumentation fetches a handle to the agent through AgentBridge.getAgent(), but this won't work since the bootstrap classloader has no visibility to our classes. Also, because the bootstrap classloader has no visibility to our classes it cannot directly invoke any methods on our interfaces and classes even if it has an object reference. This wrapper is also necessary because some classloader implementations impose rules that strict classloading visibility. OSGi classloaders are a good example. We work around this problem by sticking a reference to our agent in Proxy. We use this class as a wrapper so that the object implement InvocationHandler, which is visible to the bootstrap classloader. The instrumentation code then makes calls to get a tracer and to finish the tracer through this reflection interface.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	CLASSLOADER_KEY
static java.lang.String	SUCCESSFUL_METHOD_INVOCATION
static java.lang.String	UNSUCCESSFUL_METHOD_INVOCATION

Method Summary

Modifier and Type	Method and Description
static AgentWrapper	getAgentWrapper(PointCutClassTransformer classTransformer)
java.lang.Object	invoke(java.lang.Object proxy, java.lang.reflect.Method method, java.lang.Object[] args)
static com.newrelic.agent.bridge.ExitTracer	invoke(PointCutInvocationHandler invocationHandler, java.lang.String className, java.lang.String methodName, java.lang.String methodDesc, java.lang.Object invocationTarget, java.lang.Object[] args)

Methods inherited from class java.lang.Object

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

Field Detail

CLASSLOADER_KEY

public static final java.lang.String CLASSLOADER_KEY

See Also:

Constant Field Values

SUCCESSFUL_METHOD_INVOCATION

public static final java.lang.String SUCCESSFUL_METHOD_INVOCATION

See Also:

Constant Field Values

UNSUCCESSFUL_METHOD_INVOCATION

public static final java.lang.String UNSUCCESSFUL_METHOD_INVOCATION

See Also:

Constant Field Values

Method Detail

getAgentWrapper

public static AgentWrapper getAgentWrapper(PointCutClassTransformer classTransformer)

invoke

public java.lang.Object invoke(java.lang.Object proxy,
                               java.lang.reflect.Method method,
                               java.lang.Object[] args)

Specified by:

invoke in interface java.lang.reflect.InvocationHandler

See Also:

InvocationHandlerTracingMethodAdapter, ReflectionStyleClassMethodAdapter

invoke

public static com.newrelic.agent.bridge.ExitTracer invoke(PointCutInvocationHandler invocationHandler,
                                                          java.lang.String className,
                                                          java.lang.String methodName,
                                                          java.lang.String methodDesc,
                                                          java.lang.Object invocationTarget,
                                                          java.lang.Object[] args)

See Also:

ReflectionStyleClassMethodAdapter