做性能分析时可以信任jmc（Java任务控制）吗？

Question

Jave mission control has some great features. For example one can see the "Hot Methods" of the application or there are "Call Tree" section when one can find top consuming functions call hierarchy. But I am wondering can one really rely on profiling results, when you are interested on finding performance bottlenecks(in terms of time)? For example one can put some "sleeps" inside some functions and seems profiler will not point out them.

Answer 1

Hot Methods lists the methods that execute Java code the most. If your application is in native code or sleeping it will not show in that table.

Look at the Latencies tab to see latencies, ie Thread.sleep.

Answer 2

您可以使用事件->“图形”选项卡查看睡眠，锁定...它将帮助您了解线程在这些线程上花费了多长时间