java命令行HPROF Profiler

The HPROF Profiler

The Heap and CPU Profiling Agent (HPROF)是JAVA2 SDK自带的一个简单的profiler代理，它通过与Java Virtual Machine Profiler Interface (JVMPI) 交互，将profiling信息通过本地文件或socket输出ASCII或二进制格式的流。

HPROF可以监控CPU使用率，堆分配统计。除此之外，还可以报告JVM所有监视器和线程的完整的堆的dump状态。

HPROF的JVM参数的语法如下：

-Xrunhprof[:help]|[:param=value,param2=value2, ...]

示例:

-Xrunhprof:file=log.txt,thread=y,depth=

The file parameter determines where the stack dump is written.

file参数决定dump的堆栈写入到那个文件。

HPROF的详细参数如下：

Hprof usage: -Xrunhprof[:help]|[:<option>=<value>, ...]

Option Name and Value   Description             Default
---------------------   -----------             -------
heap=dump|sites|all     heap profiling          all
cpu=samples|old         CPU usage               off
format=a|b              ascii or binary output  a
file=<file>             write data to file      java.hprof
                               (.txt for ascii)
net=<host>:<port>       send data over a socket write to file
depth=<size>            stack trace depth
cutoff=<value>          output cutoff point     0.0001
lineno=y|n              line number in traces?  y
thread=y|n              thread in traces?       n
doe=y|n                 dump on exit?           y

一个javac的示例

Command used: javac -J-agentlib:hprof=cpu=samples Hello.java

CPU SAMPLES BEGIN (total = ) Fri Oct  ::
rank   self  accum   count trace method
    53.17% 53.17%        java.util.zip.ZipFile.getEntry
    17.46% 70.63%        java.util.zip.ZipFile.getNextEntry
     5.56% 76.19%         java.lang.ClassLoader.defineClass2
     3.97% 80.16%         java.io.UnixFileSystem.list
     2.38% 82.54%         java.lang.Shutdown.halt0
     1.59% 84.13%         java.util.zip.ZipEntry.initFields
     1.59% 85.71%         java.lang.String.substring
     1.59% 87.30%         java.util.zip.ZipFile.open
     0.79% 88.10%         com.sun.tools.javac.code.Type$ErrorType.<init>
    0.79% 88.89%         java.util.zip.ZipFile.ensureOpen

参考 http://docs.oracle.com/cd/E19798-01/821-1752/beafo/index.html

http://stackoverflow.com/questions/11737013/java-profile-tool-without-gui