Hi Serguei,
We could combine both listeners in one but in this case this listener should be
DefaultClassPrepareEventListener that is registered only once at the very
beginning of the whole test. We will also need to add a method to reset
eventReceived counter between invocations of testSourceFilter() since every
call of testSourceFilter() is a separate subtest.
Just wanted to make sure that I correctly understood your proposal.
addListener() is invoked after startListening() just due to specifics of
EventHandler implementation. EventHandler.addListener() adds a listener to the
head of the list, so the last added listener is the first one to be called. And
default listeners (including "unhandled events" one) are created when
EventHandler.startListening() method is called. So to ensure that our listener
is called before the "unhandled events" we have to call addListener() after
startListening() method.
cat -n test/hotspot/jtreg/vmTestbase/nsk/share/jdi/EventHandler.java
222 /**
223 * This is normally called in the main thread of the test debugger.
224 * It starts up an <code>EventHandler</code> thread that gets
events coming in
225 * from the debuggee and distributes them to listeners.
226 */
227 public void startListening() {
228 createDefaultEventRequests();
229 createDefaultListeners();
230 listenThread.start();
231 }
232
250 /**
251 * This method sets up default listeners.
252 */
253 private void createDefaultListeners() {
254 /**
255 * This listener catches up all unexpected events.
256 *
257 */
258 addListener(
259 new EventListener() {
260 public boolean eventReceived(Event event) {
261 log.complain("EventHandler> Unexpected event:
" + event.getClass().getName());
262 unexpectedEventCaught = true;
263 return true;
264 }
265 }
266 );
267
/**
350 * Add at beginning of the list because we want
351 * the LAST added listener to be FIRST to process
352 * current event.
353 */
354 public void addListener(EventListener listener) {
355 display("Adding listener " + listener);
356 synchronized(listeners) {
357 listeners.add(0, listener);
358 }
359 }
Thanks!
Best regards,
Daniil
From: "serguei.spit...@oracle.com" <serguei.spit...@oracle.com>
Date: Tuesday, July 17, 2018 at 4:53 PM
To: Daniil Titov <daniil.x.ti...@oracle.com>,
"serviceability-dev@openjdk.java.net serviceability-dev@openjdk.java.net"
<serviceability-dev@openjdk.java.net>
Subject: Re: RFR 8204695: [Graal]
vmTestbase/nsk/jdi/ClassPrepareRequest/addSourceNameFilter/addSourceNameFilter002/addSourceNameFilter002.java
fails
Hi Daniil,
Thank you for clarification and the webrev update!
I still have a couple of questions though.
I'd suggest more simple approach like below:
154 public boolean eventReceived(Event event) {
155 if (event instanceof ClassPrepareEvent) {
156 ClassPrepareEvent classPrepareEvent = (ClassPrepareEvent)
event;
157 ThreadReference thread = classPrepareEvent.thread();
158 if (thread != null &&
DEBUGGEE_MAIN_THREAD.equals(thread.name())) {
159 eventReceived++;
160
161 log.display("ClassPrepareEventListener: Event
received: " + event +
162 " Class: " +
classPrepareEvent.referenceType().name());
163
164 vm.resume();
165
166 return true;
167 }
168 }
169
170 return false;
171 }
to something like:
public boolean eventReceived(Event event) {
if (event instanceof ClassPrepareEvent) {
ClassPrepareEvent classPrepareEvent = (ClassPrepareEvent)
event;
ThreadReference thread = classPrepareEvent.thread();
if (thread != null &&
DEBUGGEE_MAIN_THREAD.equals(thread.name())) {
eventReceived++;
log.display("ClassPrepareEventListener: Event received: "
+ event +
" Class: " +
classPrepareEvent.referenceType().name());
} else {
log.display("ClassPrepareEventListener: Event filtered
out: " + event +
" Class: " +
classPrepareEvent.referenceType().name() +
" Thread:" + classPrepareEvent.thread().name());
}
vm.resume();
return true;
}
return false;
}
245 eventHandler.startListening();
246 // Add a listener to handle ClassPrepare events fired by other
(e.g. compiler) threads.
247 // The listener should be added after the event listener is
started to ensure that it
248 // called before the default event listener that handles
unexpected events.
249 eventHandler.addListener(new DefaultClassPrepareEventListener());
Still unclear why addListener() is invoked after startListening() but not
before.
It can be that a place add this listener is not right and have to be moved
into testSourceFilter().
But I hope this fragment is not needed with the simplified approach.
Otherwise, it looks good.
Thanks,
Serguei
On 7/17/18 14:55, Daniil Titov wrote:
Hi Serguei,
The test starts the event handler (nsk.share.jdi.EventHandler) and then
iterates several times calling testSourceFilter() method passing there
different parameters. The testSourceFilter() method does the following:
1. creates a ClassPrepareRequest object
2. registers new ClassPrepareEventListener
3. sends a command to debuggee to a load test class
4. waits till the debuggee performed the command
5. removes ClassPrepareEventListener
6. checks if a ClassPrepareEvent was received
Upon its start the EventHandler creates a default list of events listeners. The
last listener in this list handles unexpected events (that are events not
processed by the previous listeners)
cat -n test/hotspot/jtreg/vmTestbase/nsk/share/jdi/EventHandler.java
/**
251 * This method sets up default listeners.
252 */
253 private void createDefaultListeners() {
254 /**
255 * This listener catches up all unexpected events.
256 *
257 */
258 addListener(
259 new EventListener() {
260 public boolean eventReceived(Event event) {
261 log.complain("EventHandler> Unexpected event:
" + event.getClass().getName());
262 unexpectedEventCaught = true;
263 return true;
264 }
265 }
266 );
267
On step 2 above the ClassPrepareEventListener is added at the head of the list
of the listeners. It handles ClassPrepareEvents and prevents the next listeners
from being invoked by returning "true" from its eventReceived(Event) method.
With Graal turned on after step 1 the JVMTI compiler thread starts sending
class prepare events for classes it compiles. If any of such event is
dispatched after step 5 (when ClassPrepareEventListener is removed) there is
no any registered listeners to handle it and this event is handled by the
"unexpected events listener" (see above) that marks the test as failed.
That is why DefaultClassPrepareEventListener is needed: to process ClassPrepare
events dispatched after ClassPrepareEventListener is unregistered inside
testSourceFilter() method.
Please see below the new webrev with the changes you suggested.
Webrev: http://cr.openjdk.java.net/~dtitov/8204695/webrev.02/
Thanks!
Best regards,
Daniil
From: mailto:serguei.spit...@oracle.com mailto:serguei.spit...@oracle.com
Date: Tuesday, July 17, 2018 at 1:34 PM
To: Daniil Titov mailto:daniil.x.ti...@oracle.com,
mailto:serviceability-...@openjdk.java.netserviceability-...@openjdk.java.net
mailto:serviceability-dev@openjdk.java.net
Subject: Re: RFR 8204695: [Graal]
vmTestbase/nsk/jdi/ClassPrepareRequest/addSourceNameFilter/addSourceNameFilter002/addSourceNameFilter002.java
fails
Hi Daniil,
Not sure, I fully understand the fix.
So, let's start from some questions.
Why the DefaultClassPrepareEventListener is needed?
Is it not enough to filter out the other threads in the
ClassPrepareEventListener.eventReceived() method ?
243 eventHandler.startListening();
244 // Add a listener to handle class prepared events fired by other (
e.g. compiler) threads.
245 // The listener should be added after the event listener is
started to ensure that it called before
246 // the default event listener that handles unexpected events.
247 eventHandler.addListener(new DefaultClassPrepareEventListener());
It is still not clear why the default listener is added
after the listening is started but not before.
If the default listener is really needed then could you, please,
split the lines above and L129, L160 to make a little bit shorter?
I'd also suggest to replace "class prepared events" at L244
with "ClassPrepare event" or "class prepare event".
There is also an unneeded space in the "( e.g. compiler)".
Thanks,
Serguei
On 7/17/18 01:20, Daniil Titov wrote:
Please review the change that fix the JDI test when running with Graal.
The problem here is that the test verifies that a class prepare event is
generated when the target VM loads a specific test class, but with Graal turned
on additional class prepare events are generated by the compiler threads. The
test doesn't expect them and fails. The fix ensures that additional class
prepare events are ignored by the test and properly handled.
Bug: https://bugs.openjdk.java.net/browse/JDK-8204695
Webrev: http://cr.openjdk.java.net/~dtitov/8204695/webrev.01/
Thanks!
--Daniil
