RFR JDK-8170089: nsk/jdi/EventSet/resume/resume008: ERROR: suspendCounts don't match for : Common-Cleaner
Gary Adams
gary.adams at oracle.com
Fri Aug 24 12:32:46 UTC 2018
Here's an updated webrev with the isDisconnected checks removed
in the setValue handling.
http://cr.openjdk.java.net/~gadams/8170089/webrev.02/index.html
Testing is in progress, but no failed tests have shown up so far
with the extra check removed.
On 8/22/18, 1:05 PM, Gary Adams wrote:
> On 8/6/18, 3:16 PM, Chris Plummer wrote:
>> On 8/6/18 11:41 AM, Gary Adams wrote:
>>> On 8/6/18, 1:56 PM, Chris Plummer wrote:
>>>> On 8/6/18 4:16 AM, Gary Adams wrote:
>>>>> On 8/3/18, 6:38 PM, Chris Plummer wrote:
>>>>>> Hi Gary,
>>>>>>
>>>>>> Overall it looks good.
>>>>>>
>>>>>> Is the EventHandler.isDisconnected() check needed?
>>>>> This just follows the pattern used in other calls to setValue.
>>>> I'm not seeing any other examples of this. Can you point me to
>>>> them? Isn't it expected that you will always be connected, and it
>>>> will only be disconnected if there is something very wrong with the
>>>> execution of the test? Not producing an error in that case could
>>>> actually be misleading, causing the test to fail with some sort of
>>>> state related error rather than some sort of exception indicating
>>>> it was disconnected.
>>> The best examples of checking EventHandler.isDisconnected()
>>> can be seen in the implementation of shouldRunAfterBreakPoint()
>>> See test/hotspot/jtreg/vmTestbase/nsk/share/jdi/TestDebuggerType1.java
>>>
>>> It's used in the loop waiting for the breakpoint event to be observed,
>>> and in the getValue() fetching of the next "instruction" indicating
>>> testing is completed.
>> Well, that's just 2 uses of isDisconnected() out of the 200+
>> get/setValue() calls. I can see its use in the loop, since it is used
>> to force the exit of the loop when disconnected (rather than waiting
>> for timeout). The one before the getValue() call is more like your
>> use, and I don't see the need in this case either. What's to prevent
>> becoming disconnected between the isDisconnected() and the
>> get/setValue() call?
>
> Just following up on this loose end after vacation ...
>
> I agree that there is nothing preventing the connection being terminated
> between the time isDisconnected() is checked and the call to setValue()
> being made. I also don't see any harm in including the isDisconnected()
> check here. If you think the test is improved by removing the check,
> I'll make those changes, post a fresh webrev and repeat the testing.
>>
>> Chris
>>>>
>>>> Chris
>>>>> No point in attempting the operation, if you know the
>>>>> connection was lost. An exception at this point could
>>>>> be misleading, if some other error has already occurred.
>>>>>>
>>>>>> In resume008a.java you removed a lot of empty lines. In some
>>>>>> places it's fine, but the lines at 132 and 134 should have
>>>>>> remained. Also, for the ones that were ok to remove, I don't see
>>>>>> you doing the same thing in the other files. I think probably
>>>>>> it's best to be consistent, and for this webrev probably best not
>>>>>> to do them since it distracts too much from the important changes.
>>>>> The original bug was reported against resume008, so more time was
>>>>> spent in that
>>>>> particular test, including some line wrapping changes. I will
>>>>> restore the blank lines
>>>>> you mentioned before producing a final patch. The other tests had
>>>>> observed failures
>>>>> also during testing. Applying the same change fixed those failures
>>>>> as well.
>>>>>>
>>>>>> Seems like there is a lot of abstraction that could have been
>>>>>> done with these tests to share a lot of code, but since so far
>>>>>> that hasn't been done, probably not a good idea to start doing
>>>>>> that with this fix. Do you think it's worth filing an enhancement
>>>>>> request for?
>>>>> Reformatting or refactoring these older tests would be at best a P5.
>>>>> I don't think it's worth filing a bug, but as we fix bugs in these
>>>>> test it's
>>>>> worth some minimal amount of cleanup while we are in the code.
>>>>>>
>>>>>> thanks,
>>>>>>
>>>>>> Chris
>>>>>>
>>>>>> On 8/3/18 11:04 AM, Gary Adams wrote:
>>>>>>> Here is an updated webrev with the alternate solution
>>>>>>> implemented for
>>>>>>> resume 1 to 10. The debugger sets testCase variable in the debuggee
>>>>>>> when each test case completes in the debugger. By having the
>>>>>>> debuggee
>>>>>>> wait for the debugger to complete with test case 0, it avoids
>>>>>>> the interference
>>>>>>> that occurs by proceeding to the breakpoint set in
>>>>>>> MethodForCommunication
>>>>>>> before the debugger has compared expected suspend counts.
>>>>>>>
>>>>>>> Webrev:
>>>>>>> http://cr.openjdk.java.net/~gadams/8170089/webrev.01/index.html
>>>>>>>
>>>>>>> On 7/17/18, 11:33 AM, Gary Adams wrote:
>>>>>>>> A race condition exists between the debugger and the debuggee.
>>>>>>>>
>>>>>>>> The first test thread is started with SUSPEND_NONE policy set.
>>>>>>>> While processing the thread start event the debugger captures
>>>>>>>> an initial set of thread suspend counts and resumes the
>>>>>>>> debuggee vm. If the debuggee advances quickly it reaches
>>>>>>>> the breakpoint set for methodForCommunication. Since the
>>>>>>>> breakpoint
>>>>>>>> carries with it SUSPEND_ALL policy, when the debugger captures
>>>>>>>> a second
>>>>>>>> set of suspend counts, it will not match the expected counts for
>>>>>>>> a SUSPEND_NONE scenario.
>>>>>>>>
>>>>>>>> The proposed fix introduces a yield in the debuggee test thread
>>>>>>>> run method
>>>>>>>> to allow the debugger to get the expected sampled values.
>>>>>>>>
>>>>>>>> Issue: https://bugs.openjdk.java.net/browse/JDK-8170089
>>>>>>>> Webrev: http://cr.openjdk.java.net/~gadams/8170089/webrev.00/
>>>>>>>>
>>>>>>>>
>>>>>>>> test/hotspot/jtreg/vmTestbase/nsk/share/jdi/TestDebuggerType1.java:
>>>>>>>>
>>>>>>>> ...
>>>>>>>> 186 private void
>>>>>>>> setCommunicationBreakpoint(ReferenceType refType, String
>>>>>>>> methodName) {
>>>>>>>> 187 Method method =
>>>>>>>> debuggee.methodByName(refType, methodName);
>>>>>>>> 188 Location location = null;
>>>>>>>> 189 try {
>>>>>>>> 190 location = method.allLineLocations().get(0);
>>>>>>>> 191 } catch (AbsentInformationException e) {
>>>>>>>> 192 throw new Failure(e);
>>>>>>>> 193 }
>>>>>>>> 194 bpRequest = debuggee.makeBreakpoint(location);
>>>>>>>> 195
>>>>>>>>
>>>>>>>> 196 bpRequest.setSuspendPolicy(EventRequest.SUSPEND_ALL);
>>>>>>>>
>>>>>>>> 197 bpRequest.putProperty("number", "zero");
>>>>>>>> 198 bpRequest.enable();
>>>>>>>> 199
>>>>>>>> 200 eventHandler.addListener(
>>>>>>>> 201 new EventHandler.EventListener() {
>>>>>>>> 202 public boolean eventReceived(Event
>>>>>>>> event) {
>>>>>>>> 203 if (event instanceof
>>>>>>>> BreakpointEvent && bpRequest.equals(event.request())) {
>>>>>>>> 204 synchronized(eventHandler) {
>>>>>>>> 205 display("Received
>>>>>>>> communication breakpoint event.");
>>>>>>>> 206 bpCount++;
>>>>>>>> 207 eventHandler.notifyAll();
>>>>>>>> 208 }
>>>>>>>> 209 return true;
>>>>>>>> 210 }
>>>>>>>> 211 return false;
>>>>>>>> 212 }
>>>>>>>> 213 }
>>>>>>>> 214 );
>>>>>>>> 215 }
>>>>>>>>
>>>>>>>>
>>>>>>>> test/hotspot/jtreg/vmTestbase/nsk/jdi/EventSet/resume/resume008.java:
>>>>>>>>
>>>>>>>> ...
>>>>>>>> 140 display("......--> vm.suspend();");
>>>>>>>> 141 vm.suspend();
>>>>>>>> 142
>>>>>>>> 143 display(" getting :
>>>>>>>> Map<String, Integer> suspendsCounts1");
>>>>>>>> 144
>>>>>>>> 145 Map<String, Integer> suspendsCounts1
>>>>>>>> = new HashMap<String, Integer>();
>>>>>>>> 146 for (ThreadReference threadReference
>>>>>>>> : vm.allThreads()) {
>>>>>>>> 147 suspendsCounts1.put(threadReference.name(),
>>>>>>>> threadReference.suspendCount());
>>>>>>>> 148 }
>>>>>>>> 149 display(suspendsCounts1.toString());
>>>>>>>> 150
>>>>>>>> 151 display(" eventSet.resume;");
>>>>>>>> 152 eventSet.resume();
>>>>>>>> 153
>>>>>>>> 154 display(" getting :
>>>>>>>> Map<String, Integer> suspendsCounts2");
>>>>>>>>
>>>>>>>> This is where the breakpoint is encountered before the second
>>>>>>>> set of suspend counts is acquired.
>>>>>>>>
>>>>>>>> 155 Map<String, Integer> suspendsCounts2
>>>>>>>> = new HashMap<String, Integer>();
>>>>>>>> 156 for (ThreadReference threadReference
>>>>>>>> : vm.allThreads()) {
>>>>>>>> 157 suspendsCounts2.put(threadReference.name(),
>>>>>>>> threadReference.suspendCount());
>>>>>>>> 158 }
>>>>>>>> 159 display(suspendsCounts2.toString());
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>
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