java - 如何在 JMH 中查看调用树分析？

Question

我想分析 JMH 测试并查看 VisualVM 中的调用树。但是当我使用 StackProfiler 时，它会为我提供类似的本地方法，这对我来说完全没用。

....[Thread state distributions]....................................................................
 59,9%         TIMED_WAITING
 23,0%         WAITING
 17,0%         RUNNABLE

....[Thread state: TIMED_WAITING]...................................................................
 47,3%  78,9% sun.misc.Unsafe.park
  8,3%  13,8% java.lang.Thread.sleep
  4,4%   7,3% java.lang.Object.wait

....[Thread state: WAITING].........................................................................
 21,9%  95,1% sun.misc.Unsafe.park
  1,1%   4,9% java.lang.Object.wait

....[Thread state: RUNNABLE]........................................................................
 13,5%  79,0% sun.nio.ch.EPollArrayWrapper.epollWait
  2,0%  11,5% java.net.SocketInputStream.socketRead0
  1,0%   5,7% java.net.PlainSocketImpl.socketAccept

Answer 1

JMH 的堆栈分析器是一个相当简单的实现。为什么不使用成熟的分析器——例如您提到的 VisualVM——如果您需要更多？或者，参见 -prof stack:help:

$ java -jar jmh-samples/target/benchmarks.jar -prof stack:help
Usage: -prof <profiler-name>:opt1=value1,value2;opt2=value3

Options accepted by org.openjdk.jmh.profile.StackProfiler:

  lines=<int>     Number of stack lines to save in each stack trace.
                  Larger values provide more insight into who is calling
                  the top stack method, as the expense of more stack
                  trace shapes to collect. (default: [1])