/*
* Copyright (c) 1998, 2016, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
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*/
/*
* This source code is provided to illustrate the usage of a given feature
* or technique and has been deliberately simplified. Additional steps
* required for a production-quality application, such as security checks,
* input validation and proper error handling, might not be present in
* this sample code.
*/
package com.sun.tools.example.debug.tty;
import com.sun.jdi.*;
import com.sun.jdi.event.*;
import com.sun.jdi.request.EventRequest;
public class EventHandler implements Runnable {
EventNotifier notifier;
Thread thread;
volatile boolean connected = true;
boolean completed = false;
String shutdownMessageKey;
boolean stopOnVMStart;
EventHandler(EventNotifier notifier, boolean stopOnVMStart) {
this.notifier = notifier;
this.stopOnVMStart = stopOnVMStart;
this.thread = new Thread(this, "event-handler");
this.thread.start();
}
synchronized void shutdown() {
connected = false; // force run() loop termination
thread.interrupt();
while (!completed) {
try {wait();} catch (InterruptedException exc) {}
}
}
@Override
public void run() {
EventQueue queue = Env.vm().eventQueue();
while (connected) {
try {
EventSet eventSet = queue.remove();
boolean resumeStoppedApp = false;
EventIterator it = eventSet.eventIterator();
while (it.hasNext()) {
resumeStoppedApp |= !handleEvent(it.nextEvent());
}
if (resumeStoppedApp) {
eventSet.resume();
} else if (eventSet.suspendPolicy() == EventRequest.SUSPEND_ALL) {
setCurrentThread(eventSet);
notifier.vmInterrupted();
}
} catch (InterruptedException exc) {
// Do nothing. Any changes will be seen at top of loop.
} catch (VMDisconnectedException discExc) {
handleDisconnectedException();
break;
}
}
synchronized (this) {
completed = true;
notifyAll();
}
}
private boolean handleEvent(Event event) {
notifier.receivedEvent(event);
if (event instanceof ExceptionEvent) {
return exceptionEvent(event);
} else if (event instanceof BreakpointEvent) {
return breakpointEvent(event);
} else if (event instanceof WatchpointEvent) {
return fieldWatchEvent(event);
} else if (event instanceof StepEvent) {
return stepEvent(event);
} else if (event instanceof MethodEntryEvent) {
return methodEntryEvent(event);
} else if (event instanceof MethodExitEvent) {
return methodExitEvent(event);
} else if (event instanceof ClassPrepareEvent) {
return classPrepareEvent(event);
} else if (event instanceof ClassUnloadEvent) {
return classUnloadEvent(event);
} else if (event instanceof ThreadStartEvent) {
return threadStartEvent(event);
} else if (event instanceof ThreadDeathEvent) {
return threadDeathEvent(event);
} else if (event instanceof VMStartEvent) {
return vmStartEvent(event);
} else {
return handleExitEvent(event);
}
}
private boolean vmDied = false;
private boolean handleExitEvent(Event event) {
if (event instanceof VMDeathEvent) {
vmDied = true;
return vmDeathEvent(event);
} else if (event instanceof VMDisconnectEvent) {
connected = false;
if (!vmDied) {
vmDisconnectEvent(event);
}
/*
* Inform jdb command line processor that jdb is being shutdown. JDK-8154144.
*/
((TTY)notifier).setShuttingDown(true);
Env.shutdown(shutdownMessageKey);
return false;
} else {
throw new InternalError(MessageOutput.format("Unexpected event type",
new Object[] {event.getClass()}));
}
}
synchronized void handleDisconnectedException() {
/*
* A VMDisconnectedException has happened while dealing with
* another event. We need to flush the event queue, dealing only
* with exit events (VMDeath, VMDisconnect) so that we terminate
* correctly.
*/
EventQueue queue = Env.vm().eventQueue();
while (connected) {
try {
EventSet eventSet = queue.remove();
EventIterator iter = eventSet.eventIterator();
while (iter.hasNext()) {
handleExitEvent(iter.next());
}
} catch (InterruptedException exc) {
// ignore
} catch (InternalError exc) {
// ignore
}
}
}
private ThreadReference eventThread(Event event) {
if (event instanceof ClassPrepareEvent) {
return ((ClassPrepareEvent)event).thread();
} else if (event instanceof LocatableEvent) {
return ((LocatableEvent)event).thread();
} else if (event instanceof ThreadStartEvent) {
return ((ThreadStartEvent)event).thread();
} else if (event instanceof ThreadDeathEvent) {
return ((ThreadDeathEvent)event).thread();
} else if (event instanceof VMStartEvent) {
return ((VMStartEvent)event).thread();
} else {
return null;
}
}
private void setCurrentThread(EventSet set) {
ThreadReference thread;
if (set.size() > 0) {
/*
* If any event in the set has a thread associated with it,
* they all will, so just grab the first one.
*/
Event event = set.iterator().next(); // Is there a better way?
thread = eventThread(event);
} else {
thread = null;
}
setCurrentThread(thread);
}
private void setCurrentThread(ThreadReference thread) {
ThreadInfo.invalidateAll();
ThreadInfo.setCurrentThread(thread);
}
private boolean vmStartEvent(Event event) {
VMStartEvent se = (VMStartEvent)event;
notifier.vmStartEvent(se);
return stopOnVMStart;
}
private boolean breakpointEvent(Event event) {
BreakpointEvent be = (BreakpointEvent)event;
notifier.breakpointEvent(be);
return true;
}
private boolean methodEntryEvent(Event event) {
MethodEntryEvent me = (MethodEntryEvent)event;
notifier.methodEntryEvent(me);
return true;
}
private boolean methodExitEvent(Event event) {
MethodExitEvent me = (MethodExitEvent)event;
return notifier.methodExitEvent(me);
}
private boolean fieldWatchEvent(Event event) {
WatchpointEvent fwe = (WatchpointEvent)event;
notifier.fieldWatchEvent(fwe);
return true;
}
private boolean stepEvent(Event event) {
StepEvent se = (StepEvent)event;
notifier.stepEvent(se);
return true;
}
private boolean classPrepareEvent(Event event) {
ClassPrepareEvent cle = (ClassPrepareEvent)event;
notifier.classPrepareEvent(cle);
if (!Env.specList.resolve(cle)) {
MessageOutput.lnprint("Stopping due to deferred breakpoint errors.");
return true;
} else {
return false;
}
}
private boolean classUnloadEvent(Event event) {
ClassUnloadEvent cue = (ClassUnloadEvent)event;
notifier.classUnloadEvent(cue);
return false;
}
private boolean exceptionEvent(Event event) {
ExceptionEvent ee = (ExceptionEvent)event;
notifier.exceptionEvent(ee);
return true;
}
private boolean threadDeathEvent(Event event) {
ThreadDeathEvent tee = (ThreadDeathEvent)event;
ThreadInfo.removeThread(tee.thread());
return false;
}
private boolean threadStartEvent(Event event) {
ThreadStartEvent tse = (ThreadStartEvent)event;
ThreadInfo.addThread(tse.thread());
notifier.threadStartEvent(tse);
return false;
}
public boolean vmDeathEvent(Event event) {
shutdownMessageKey = "The application exited";
notifier.vmDeathEvent((VMDeathEvent)event);
return false;
}
public boolean vmDisconnectEvent(Event event) {
shutdownMessageKey = "The application has been disconnected";
notifier.vmDisconnectEvent((VMDisconnectEvent)event);
return false;
}
}