@Group和@GroupThreads在jmh中引用了什么?

时间:2015-05-08 07:20:09

标签: java jmh

我一直在研究jmh实现“多线程”基准测试的方式。根据我的理解,注释@Group("Identifier")@GroupThreads(thread_number)可以并行运行同一组内的基准。

@Benchmark
@Group("parallel")
@GroupThreads(1)
public void benchmark_1() {
    while(true) {}
}

@Benchmark
@Group("parallel")
@GroupThreads(1)
public void benchmark_2() {
    while(true) {}
}

使用CPU监视器,我完全使用了两个CPU。 我想知道跑步者如何解释这些注释。

1 个答案:

答案 0 :(得分:3)

您是否尝试过阅读Javadocs?那些没有回答这个问题的人吗?

E.g。 @Group说:

 * <p>Multiple {@link Benchmark} methods can be bound in the execution group
 * to produce the asymmetric benchmark. Each execution group contains of one
 * or more threads. Each thread within a particular execution group executes
 * one of {@link Group}-annotated {@link Benchmark} methods. The number of
 * threads executing a particular {@link Benchmark} defaults to a single thread,
 * and can be overridden by {@link GroupThreads}.</p>
 *
 * <p>Multiple copies of an execution group may participate in the run, and
 * the number of groups depends on the number of worker threads requested.
 * JMH will take the requested number of worker threads, round it up to execution
 * group size, and then distribute the threads among the (multiple) groups.
 * Among other things, this guarantees fully-populated execution groups.</p>

 * <p>For example, running {@link Group} with two {@link Benchmark} methods,
 * each having {@link GroupThreads}(4), will run 8*N threads, where N is an
 * integer.</p>

因此,@Group生成非对称基准,@GroupThreads控制组内线程的分布(CLI中的-tg ...对其进行配音)。 @Threads表示总共需要运行多少个线程(CLI中为-t ...配音)。