Set/restore context class loader around benchmark methods in JMH #421
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This is to make it more obvious that the right benchmark method is called from the given JMH method.
This is what the Benchmark interface actually mandates. The fact that we were using `Level.Iteration` instead of `Level.Invocation` was a result of conceptual mismatch. The duration of the measured operations are in the hundreds of milliseconds or longer, therefore `Level.Invocation` should not really be a problem.
Wraps `Benchmark` interface methods with code that set and restores the context class loader for the current thread when running with JMH. This is because JMH can be asked to create more benchmark runners that invoke the `Benchmark.run()` method concurrently but do not replicate the context class loader of the (initial) main thread. Even though this is not really supported (or intended) use of the `Benchmark` interface, the benchmarks should not crash because they fail to load their classes.
farquet
approved these changes
Oct 11, 2023
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Wraps
Benchmarkinterface methods with code that set and restores the context class loader for the current thread when running with JMH. This is because JMH option-tcauses it to create more benchmark runners that invoke theBenchmark.run()method concurrently on a single benchmark instance, but do not replicate the context class loader of the (initial) main thread.Even though this is not really supported (or intended) use of the
Benchmarkinterface, the benchmarks should not crash because they fail to load their classes.One other change is that the JMH wrappers now call
setupBeforeEach()andtearDownAfterEach()after each measured method invocation as they should. This probably only affects runs with timed JMH iterations, during which JMH would invoke the measured method multiple times without calling the setup/tear-down methods.Fixes #373