More performant Java Executors.
Tweaks j.u.c.ThreadPoolExecutor in particular.
- make six frequently read volatile fields final
- reduce volatile reads o(e.g.
ctl.get()inaddWorker) - remove volatile reads and writes of
completedTasks(and associated unused methods)
On Ubuntu 16.04 AWS t2.xlarge there is a 10% throughput boost on a single thread:
Benchmark Mode Cnt Score Error Units
Benchmarks.executorDoNothingManyTimesSingleThreadJuc thrpt 10 308.426 ± 2.141 ops/s
Benchmarks.executorDoNothingManyTimesSingleThreadMore thrpt 10 338.532 ± 1.606 ops/s