RFR: 8348960: [leyden] compiler/c1/TestConcurrentPatching.java is stuck

[Aleksey Shipilev]

On Wed, 29 Jan 2025 18:19:15 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> This is seen in GHA, and reproduces well on my machine as well:
> 
> 
> $ CONF=linux-x86_64-server-fastdebug make images test TEST=compiler/c1/TestConcurrentPatching.java
> <stuck, timeout>
> 
> 
> Test runs with `-Xcomp`. gdb "thread apply all bt" shows the compilers are idle. Supplying `-XX:-UseLockFreeCompileQueues` makes the test pass. I believe there is a bug in `UseLockFreeCompileQueues` in leyden repo. 
> 
> The comment hopefully explains what happens here. This is a corner case that seems to reproduce on the test that runs `-Xcomp` with a very few compilations.
> 
> Additional testing:
>  - [x] GHA
>  - [x] Linux x86_64 server fastdebug, `compiler/c1/TestConcurrentPatching.java`, 100x

100x runs of `compiler/c1/TestConcurrentPatching.java` are also done without timeouts. I think this confirms the fix works.

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PR Comment: https://git.openjdk.org/leyden/pull/30#issuecomment-2622837448