RFR: 8312132: Add tracking of multiple address spaces in NMT [v105]

[Thomas Stuefe]

On Thu, 23 May 2024 04:40:31 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

>> Johan Sjölen has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Lower number of pages
>
> test/hotspot/gtest/nmt/test_vmatree.cpp line 71:
> 
>> 69:   NativeCallStackStorage::StackIndex si1 = ncs.push(stack1);
>> 70:   NativeCallStackStorage::StackIndex si2 = ncs.push(stack2);
>> 71: 
> 
> Please make these auto functions normal conventional functions. I really dislike that style.
> 
> It has real disadvantages. For example, no IDE I know can resolve a call graph across them, or even into them. E.g., in CDT, one of the most capable C++ IDEs, the call graph for VMATreeTest::in_type_of gives me .... nothing. I need to do a dumb full text search to find the call sites. And if the term to search for is very generic, I am out of luck. I know several developers that rely heavily on call graph search in CDT, I certainly do.
> 
> New techniques should serve a purpose. Lambdas as replacement for our old Closures makes sense, since they bring benefit (avoiding runtime polymorphy). But here I don't see the point.

Also, please split all of these scopes up into individual TESTs. A finer granularity allows you to reproduce individual TESTS without having to sit through 20+ irrelevant ones. It also makes for cleaner code.

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PR Review Comment: https://git.openjdk.org/jdk/pull/18289#discussion_r1610969221