1.main方法

  1. public class Sample1_HelloWorld {
  3.     @Benchmark //JMH会自己找到被注解标记的方法进行测试
  4.     public void wellHelloThere() {
  5.         //空方法
  6.     }
  8.     public static void main(String[] args) throws RunnerException {
  9.         Options opt = new OptionsBuilder()
  10.                 .include(Sample1_HelloWorld.class.getSimpleName())
  11.                 .forks(1) //设置总共测几轮
  12.                 .build();
  13.         new Runner(opt).run();
  14.     }
  15. }
  • 直接运行main方法即可

2. 看看执行结果

耐心等待一会儿, 就能看到结果报告了

  1. 17:36:03: Executing task ':Sample1_HelloWorld.main()'...
  3. Starting Gradle Daemon...
  4. Gradle Daemon started in 1 s 433 ms
  5. > Task :compileJava UP-TO-DATE
  6. > Task :processResources NO-SOURCE
  7. > Task :classes UP-TO-DATE
  9. > Task :Sample1_HelloWorld.main()
  10. # JMH version: 1.33
  11. # VM version: JDK 14, OpenJDK 64-Bit Server VM, 14+36-1461
  12. # VM invoker: D:\library\jdks\openjdk-14\bin\java.exe
  13. # VM options: -Dfile.encoding=UTF-8 -Duser.country=CN -Duser.language=zh -Duser.variant
  14. # Blackhole mode: full + dont-inline hint (default, use -Djmh.blackhole.autoDetect=true to auto-detect)
  15. # Warmup: 5 iterations, 10 s each
  16. # Measurement: 5 iterations, 10 s each
  17. # Timeout: 10 min per iteration
  18. # Threads: 1 thread, will synchronize iterations
  19. # Benchmark mode: Throughput, ops/time
  20. # Benchmark: com.zyj.benchmark.Sample1_HelloWorld.wellHelloThere
  22. # Run progress: 0.00% complete, ETA 00:01:40
  23. # Fork: 1 of 1Result
  24. # Warmup Iteration   1: 3929548185.188 ops/s
  25. # Warmup Iteration   2: 3660918456.273 ops/s
  26. # Warmup Iteration   3: 3763137692.570 ops/s
  27. # Warmup Iteration   4: 3987410602.494 ops/s
  28. # Warmup Iteration   5: 3919027111.180 ops/s
  29. Iteration   1: 4018568329.775 ops/s
  30. Iteration   2: 3936715837.231 ops/s
  31. Iteration   3: 3776468903.377 ops/s
  32. Iteration   4: 3760608499.312 ops/s
  33. Iteration   5: 3945780892.039 ops/s
  36. Result "com.zyj.benchmark.Sample1_HelloWorld.wellHelloThere":
  37.   3887628492.347 ±(99.9%) 436615492.380 ops/s [Average]
  38.   (min, avg, max) = (3760608499.312, 3887628492.347, 4018568329.775), stdev = 113387656.839
  39.   CI (99.9%): [3451012999.967, 4324243984.727] (assumes normal distribution)
  42. # Run complete. Total time: 00:01:40
  44. REMEMBER: The numbers below are just data. To gain reusable insights, you need to follow up on
  45. why the numbers are the way they are. Use profilers (see -prof, -lprof), design factorial
  46. experiments, perform baseline and negative tests that provide experimental control, make sure
  47. the benchmarking environment is safe on JVM/OS/HW level, ask for reviews from the domain experts.
  48. Do not assume the numbers tell you what you want them to tell.
  50. Benchmark                           Mode  Cnt           Score           Error  Units
  51. Sample1_HelloWorld.wellHelloThere  thrpt    5  3887628492.347 ± 436615492.380  ops/s
  53. BUILD SUCCESSFUL in 1m 46s
  54. 2 actionable tasks: 1 executed, 1 up-to-date
  55. 17:37:55: Task execution finished ':Sample1_HelloWorld.main()'.

我们来大概看一下执行的结果报告

  1. # Warmup: 5 iterations, 10 s each
  3. # Warmup Iteration   1: 3929548185.188 ops/s
  4. # Warmup Iteration   2: 3660918456.273 ops/s
  5. # Warmup Iteration   3: 3763137692.570 ops/s
  6. # Warmup Iteration   4: 3987410602.494 ops/s
  7. # Warmup Iteration   5: 3919027111.180 ops/s
  • 预热了5轮, 每轮执行10秒
  1. # Measurement: 5 iterations, 10 s each
  3. Iteration   1: 4018568329.775 ops/s
  4. Iteration   2: 3936715837.231 ops/s
  5. Iteration   3: 3776468903.377 ops/s
  6. Iteration   4: 3760608499.312 ops/s
  7. Iteration   5: 3945780892.039 ops/s
  • 测试了5轮, 每轮执行10秒
  1. Result "com.zyj.benchmark.Sample1_HelloWorld.wellHelloThere":
  2.   3887628492.347 ±(99.9%) 436615492.380 ops/s [Average]
  3.   (min, avg, max) = (3760608499.312, 3887628492.347, 4018568329.775), stdev = 113387656.839
  4.   CI (99.9%): [3451012999.967, 4324243984.727] (assumes normal distribution)
  • 这个是被测试方法的执行结果
  • 被测试的方法平均每秒执行次数: 3887628492.347 ±(99.9%) 436615492.380 ops/s
  • (min, avg, max) = (3760608499.312, 3887628492.347, 4018568329.775)
  • 标准差: stdev = 113387656.839
  • 99.9%置信区间: [3451012999.967, 4324243984.727]
  1. Benchmark                           Mode  Cnt           Score           Error  Units
  2. Sample1_HelloWorld.wellHelloThere  thrpt    5  3887628492.347 ± 436615492.380  ops/s
  • 这是此次Benchmark最终的统计报告
  • Mode: thrpt表示测试的指标是吞吐量
  • Cnt: iteration的组数, 我们这里是5, 就表示这个方法被测试了5轮
  • Score: 被统计的指标, 与 Units和Error是对应上的; 此例中是3887628492.347次/秒
  • Error: 统计指标的误差; 此例中是 ± 436615492.380
  • Units: Score与Error的单位; 此例中是 ops/s 每秒执行次数