[jdk17u-dev] RFR: 8338379: Accesses to class init state should be properly synchronized

[Jaroslav Bachorik]

On Tue, 4 Mar 2025 15:17:47 GMT, Matt <duke at openjdk.org> wrote:

> 8338379: Accesses to class init state should be properly synchronized

I have verified that the changes correspond to the ones from the original changeset.

There are two locations, however, where some unrelated changes seem to have been brought in. Please, check and clean up as necessary.

Thanks!

src/hotspot/cpu/x86/templateTable_x86.cpp line 3944:

> 3942:   assert(VM_Version::supports_fast_class_init_checks(), "must support fast class initialization checks");
> 3943:   __ clinit_barrier(rcx, r15_thread, nullptr /*L_fast_path*/, &slow_case);
> 3944: #else

This seems to be unrelated to this backport - this change was added for https://bugs.openjdk.org/browse/JDK-8320276

src/hotspot/share/oops/instanceKlass.hpp line 551:

> 549:   bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }
> 550:   ClassState  init_state() const           { return (ClassState) Atomic::load_acquire(&_init_state); }
> 551:   const char* init_state_name() const;

This line change is not from the original changeset. It was added in https://bugs.openjdk.org/browse/JDK-8275775

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Changes requested by jbachorik (Reviewer).

PR Review: https://git.openjdk.org/jdk17u-dev/pull/3317#pullrequestreview-2749167659
PR Review Comment: https://git.openjdk.org/jdk17u-dev/pull/3317#discussion_r2032691620
PR Review Comment: https://git.openjdk.org/jdk17u-dev/pull/3317#discussion_r2032696505