RFR: 8291555: Replace stack-locking with fast-locking

[Roman Kennke]

On Thu, 11 Aug 2022 11:39:01 GMT, Robbin Ehn <rehn at openjdk.org> wrote:

> > > > Thanks for giving this PR a spin. I pushed a fix for the aarch64 build problem (seems weird that GHA did not catch it).
> > > 
> > > 
> > > NP, thanks. I notice some other user of owning_thread_from_monitor_owner() such as DeadlockCycle::print_on_with() which asserts on "assert(adr != reinterpret_cast<void*>(1)) failed: must convert to lock object".
> > 
> > 
> > Do you know by any chance which tests trigger this?
> 
> Yes, there is a couple of to choose from, I think the jstack cmd may be easiest: jstack/DeadlockDetectionTest.java

I pushed a refactoring and fixes to the relevant code, and all users should now work correctly. It's passing test tiers1-3 and tier4 is running while I write this.

@robehn or @dholmes-ora I believe one of you mentioned somewhere (can't find the comment, though) that we might need to support the bytecode sequence monitorenter A; monitorenter B; monitorexit A; monitorexit B; properly. I have now made a testcase that checks this, and it does indeed fail with this PR, while passing with upstream. Also, the JVM spec doesn't mention anywhere that it is required that monitorenter/exit are properly nested. I'll have to fix this in the interpreter (JIT compilers refuse to compile not-properly-nested monitorenter/exit anyway).

See https://github.com/rkennke/jdk/blob/fast-locking/test/hotspot/jtreg/runtime/locking/TestUnstructuredLocking.jasm

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PR: https://git.openjdk.org/jdk/pull/9680