RFR JDK-8170089: nsk/jdi/EventSet/resume/resume008: ERROR: suspendCounts don't match for : Common-Cleaner

[Gary Adams]

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.
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());
>>>
>>
>