RFR: 8340401: DcmdMBeanPermissionsTest.java and SystemDumpMapTest.java fail with assert(_stack_base != nullptr) failed: Sanity check [v2]

[Simon Tooke]

On Fri, 20 Sep 2024 05:37:45 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

>> src/hotspot/share/nmt/memMapPrinter.cpp line 176:
>> 
>>> 174:   // Therefore we go for the simplest way here and check for intersection between VMA and thread stack.
>>> 175:   // If the stack size is zero (i.e. no stack assigned yet), then return false.
>>> 176:   if (t->stack_size() == 0) return false;
>> 
>> I think this should go in the iteration loop:
>> 
>>   for (JavaThreadIteratorWithHandle jtiwh; JavaThread* t = jtiwh.next(); ) {
>>     // We can encounter new threads whose stack has not yet been initialized - so skip them
>>     if (t->stack_size() == 0) continue;
>>     HANDLE_THREAD(t);
>>   }
>> 
>> or even
>> 
>>   for (JavaThreadIteratorWithHandle jtiwh; JavaThread* t = jtiwh.next(); ) {
>>     // We can encounter new threads whose stack has not yet been initialized - so skip them in debug to avoid assertion
>>     DEBUG_ONLY(if (t->stack_size() == 0) continue;)
>>     HANDLE_THREAD(t);
>>   }
>> 
>> this assumes `range_intersects` will correctly handle a zero base and end in a release build.
>
> I would prefer it here, or in HANDLE_THREAD macro, to make sure we do this for all threads printed.

I will put it in HANDLE_THREAD to cover the other tests.

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PR Review Comment: https://git.openjdk.org/jdk/pull/21091#discussion_r1768172985