RFR: 8260301: misc gc/g1/unloading tests fails with "RuntimeException: Method could not be enqueued for compilation at level N"

[Dean Long]

On Tue, 2 Feb 2021 15:44:16 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

> On return WB wait to acquire Compile_lock before checking compilation status
> https://github.com/openjdk/jdk/blob/master/src/hotspot/share/prims/whitebox.cpp#L988 
> 
> This lock is used by ciEnv for compiled code publishing:
> https://github.com/openjdk/jdk/blob/master/src/hotspot/share/ci/ciEnv.cpp#L981
> 
> So while WB waits the lock compiler thread can finish compilation, register nmethod and clear method's queued_for_compilation bit.
> 
> The problem is that WB check `nm` value (compiled code) which it got before the lock and when method compilation is not finished.
> 
> The fix is to check compiled code again similar to check in CompileBroker:
> https://github.com/openjdk/jdk/blob/master/src/hotspot/share/compiler/compileBroker.cpp#L1501 
> 
> Passed hs-tier1-4 testing and 100 x vmTestbase/gc/g1/unloading/tests/unloading_compilation_*.

Looks good.

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Marked as reviewed by dlong (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/2356