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: "[email protected]" <[email protected]>
Date: Tuesday, July 17, 2018 at 1:34 PM
To: Daniil Titov <[email protected]>,
"[email protected] [email protected]"
<[email protected]>
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
