8382616: Create GCArguments::set_heap_size interface

[xmas92]

Move the static Arguments::set_heap_size() to be a virtual interface on GCArguments via GCArguments::set_heap_size() with a a base implementation which is the same as the current Arguments::set_heap_size().

The main motivation is to allow the GCs to modify the behaviour of heap selection. This is something we rely on for the automatic heap sizing implementation in ZGC (JDK-8380289).

To keep the code motion minimal here Arguments friends GCArguments so it can use shared code without expanding its public interface. There is probably room for improvement here. But unless someone has a strong objections, or a trivial solution here, I would prefer keeping that to separate RFE.

Testing:

• GHA
• Tier 1-3 Oracle supported platforms

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Progress

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Issue

• JDK-8382616: Create GCArguments::set_heap_size interface (Enhancement - P4)

Reviewers

• Joel Sikström (@jsikstro - Reviewer)

Reviewing

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[openjdk]

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[mlbridge]

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• 02: Full (d170896b)
• 01: Full - Incremental (6e48d498)
• 00: Full (02fb1e97)

[jsikstro]

We should update the comment here to reflect that the function has moved from Arguments to GCArguments:

jdk/src/hotspot/share/gc/shared/jvmFlagConstraintsGC.cpp

Line 286 in d9c2268

// If an overflow happened in Arguments::set_heap_size(), MaxHeapSize will have too large a value.

[jsikstro]

Looks good.

When #30768 is integrated we can move limit_heap_by_allocatable_memory to GCArguments.

[albertnetymk]

/cc hotspot-gc

[openjdk]

@albertnetymk
The hotspot-gc label was successfully added.

[xmas92]

Merged in JDK-8381829 / #30768 and moved limit_heap_by_allocatable_memory to GCArguments and removed the friend class declaration.