RFR: JDK-8068225: nsk/jdi/EventQueue/remove_l/remove_l005 intermittently times out

[Gary Adams]

So far the only test that has an issue with the change in waitFor order is
nsk/jdi/VirtualMachine/canBeModified, which does not appear to synchronize
with the debuggee.

On 2/6/19, 12:15 PM, Chris Plummer wrote:
> What happens if endDebugee() is called when the caller is not 
> expecting a clean exit of the debugeee? Won't waitFor() wait forever 
> in that case? I think by having the vm.dispose() first, you avoid that 
> issue.
>
> Chris
>
> On 2/6/19 8:04 AM, Gary Adams wrote:
>> Testing an alternate fix that will wait for the debugee process to 
>> terminate after processing the "quit"
>> command before doing the vm tear down.
>>
>>
>> diff --git a/test/hotspot/jtreg/vmTestbase/nsk/share/jdi/Debugee.java 
>> b/test/hotspot/jtreg/vmTestbase/nsk/share/jdi/Debugee.java
>> --- a/test/hotspot/jtreg/vmTestbase/nsk/share/jdi/Debugee.java
>> +++ b/test/hotspot/jtreg/vmTestbase/nsk/share/jdi/Debugee.java
>> @@ -1,5 +1,5 @@
>>  /*
>> - * Copyright (c) 2001, 2018, Oracle and/or its affiliates. All 
>> rights reserved.
>> + * Copyright (c) 2001, 2019, 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
>> @@ -557,6 +557,7 @@
>>       * exit status code.
>>       */
>>      public int endDebugee() {
>> +        int status = waitFor();
>>          if (vm != null) {
>>              try {
>>                  vm.dispose();
>> @@ -564,7 +565,7 @@
>>              }
>>              vm = null;
>>          }
>> -        return waitFor();
>> +        return status;
>>      }
>>
>>
>> On 2/6/19, 8:14 AM, Gary Adams wrote:
>>> Just a quick update on the failure on shutdown ...
>>> I've come across a couple of other tests with a similar failure mode.
>>>
>>> I'm attempting to get some additional diagnostic information from these
>>> tests with "-jdi.trace=all", but the diagnostic output may be 
>>> interfering
>>> with the timing.
>>>
>>> My current investigation is around a possible race condition
>>> in the Debgugee.quit() processing.
>>>    - the "quit" string is sent to the deuggee via the IOpipe
>>>    - the vm.dispose() is handled from the JDWP communication
>>>
>>> If the context switching is not quick enough, the debugee
>>> may not have read and processed the "quit" command before
>>> tear down is handled.
>>>
>>> From earlier comments in the bug report the debuggee was observed
>>> still at the breakpoint, so the resume and the disabling of the 
>>> breakpoint
>>> had not been processed, yet.
>>>
>>> It might be worth having an "ack" returned when the "quit" is
>>> processed in the debugee.
>>>
>>> ...
>>>
>>> On 2/1/19, 2:15 PM, serguei.spitsyn at oracle.com wrote:
>>>> Hi Gary,
>>>>
>>>> The debugee.quit() is to complete the session.
>>>> It makes this call: sendSignal(SGNL_QUIT);
>>>>
>>>> A call to the debugee.quit() is at the end of execTest() method:
>>>>
>>>>             display("");
>>>>         }
>>>>
>>>>         display("");
>>>>         display("=============");
>>>>         display("TEST FINISHES\n");
>>>>
>>>>         brkpReq.disable();
>>>>         debugee.resume();
>>>>         debugee.quit();
>>>>     }
>>>>
>>>> Thanks,
>>>> Serguei
>>>>
>>>>
>>>> On 2/1/19 10:00, Gary Adams wrote:
>>>>> When the remove_l005 runs to completion, it never signals the 
>>>>> debuggee
>>>>> that all iterations have completed.
>>>>>
>>>>>   Issue: https://bugs.openjdk.java.net/browse/JDK-8068225
>>>>>
>>>>> diff --git a/test/hotspot/jtreg/ProblemList.txt 
>>>>> b/test/hotspot/jtreg/ProblemList.txt
>>>>> --- a/test/hotspot/jtreg/ProblemList.txt
>>>>> +++ b/test/hotspot/jtreg/ProblemList.txt
>>>>> @@ -163,7 +163,6 @@
>>>>>  vmTestbase/nsk/jdi/EventRequest/setEnabled/setenabled003/TestDescription.java 
>>>>> 8066993 generic-all
>>>>>  vmTestbase/nsk/jdi/VirtualMachine/redefineClasses/redefineclasses021/TestDescription.java 
>>>>> 8065773 generic-all
>>>>>  vmTestbase/nsk/jdi/VirtualMachine/redefineClasses/redefineclasses023/TestDescription.java 
>>>>> 8065773 generic-all
>>>>> -vmTestbase/nsk/jdi/EventQueue/remove_l/remove_l005/TestDescription.java 
>>>>> 8068225 generic-all
>>>>>
>>>>>  vmTestbase/metaspace/gc/firstGC_10m/TestDescription.java 8208250 
>>>>> generic-all
>>>>>  vmTestbase/metaspace/gc/firstGC_50m/TestDescription.java 8208250 
>>>>> generic-all
>>>>>
>>>>>
>>>>> diff --git 
>>>>> a/test/hotspot/jtreg/vmTestbase/nsk/jdi/EventQueue/remove_l/remove_l005.java 
>>>>> b/test/hotspot/jtreg/vmTestbase/nsk/jdi/EventQueue/remove_l/remove_l005.java 
>>>>>
>>>>> --- 
>>>>> a/test/hotspot/jtreg/vmTestbase/nsk/jdi/EventQueue/remove_l/remove_l005.java
>>>>> +++ 
>>>>> b/test/hotspot/jtreg/vmTestbase/nsk/jdi/EventQueue/remove_l/remove_l005.java
>>>>> @@ -1,5 +1,5 @@
>>>>>  /*
>>>>> - * Copyright (c) 2002, 2018, Oracle and/or its affiliates. All 
>>>>> rights reserved.
>>>>> + * Copyright (c) 2002, 2019, 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
>>>>> @@ -134,6 +134,7 @@
>>>>>              }
>>>>>              display("");
>>>>>          }
>>>>> +        debugee.sendSignal(SGNL_QUIT);
>>>>>
>>>>>          display("");
>>>>>          display("=============");
>>>>
>>>
>>
>
>