The following function is expected to be added to the JVMTI for JDK 9:
void JNICALL MonitorContendedExit(JvmtiEnv* env, JNIEnv* jni_env, jhread thread, jobject monitor);

It is needed to associate the MonitorContended{Enter/Entered} events with the thread
that was holding the ObjectMonitor and so, causing the contention.
It seems reasonable to have a matching event in the JDI/JDWP.

The package com.sun.jdi.event must be extended with the new interface:

 public interface MonitorContendedExitEvent extends LocatableEvent

The interface should define the following two methods:

ThreadReference thread()

Returns the thread in which this event has occurred.

Specified by:
    thread in interface LocatableEvent
Returns:
    a ThreadReference which mirrors the event's thread in the target VM.


ObjectReference monitor()

Returns the monitor that was entered.

Returns:
    an ObjectReference for the monitor.