Common JMH benchmark

ref:

• http://openjdk.java.net/projects/code-tools/jmh
• http://java-performance.info/jmh/
• http://java-performance.info/introduction-jmh-profilers/
• http://hg.openjdk.java.net/code-tools/jmh/file/tip/jmh-samples/src/main/java/org/openjdk/jmh/samples/

build jar

mvn clean package

get help from cmd java -jar target/benchmarks.jar -h

• List matching benchmarks -- java -jar target/benchmarks.jar -l
• List profilers -- java -jar target/benchmarks.jar -lprof

test case

• ThreadLocalGetXTimeBenchmark:

java -jar target/benchmarks.jar  ThreadLocalGetXTimeBenchmark

Benchmark                                             Mode  Cnt       Score      Error   Units  Score/min
ThreadLocalGetXTimeBenchmark.getThreadLocalFourTime  thrpt   50   70274.092 ±  140.994  ops/ms      1.000
ThreadLocalGetXTimeBenchmark.getThreadLocalOnce1     thrpt   50  232928.024 ±  308.397  ops/ms      3.315
ThreadLocalGetXTimeBenchmark.getThreadLocalTwice     thrpt   50  159792.399 ± 4924.628  ops/ms      2.274

ThreadLocal get once vs twice fast over 40% ( 3.315/ 2.274 )