Ubuntu18.0.4.1编译openjdk8

诣极

2018-10-26

Ubuntu18.0.4.1 编译openjdk 8

之前写过在mac os中编译openjdk 8,但是因为使用不是官网的代码，编译过中遇到错误也会修改源代码，可能会导致jvm莫名其妙的crash非常痛苦。实践证明，要研究jvm最好还是在linux中编译和实践。

这里要非常感谢Debian系统开发者(John Paul Adrian Glaubitz)提供的帮助。

概述

这次安装采用最新的Ubuntu18.0.4.1LTS版本，直接百度下载对应的操作系统，然后在虚拟机安装即可，我采用的是VMware Fusion作为虚拟机，比Virtualbox稳定一些。

在上面虚拟机安装完成的基础上，先更新国内源(用于加速ubuntu软件下载速度)。

在替换操作系统默认源前，建议先备份：

sudo mv  /etc/apt/sources.list  /etc/apt/sources.list.bak

# 如果没有安装vim, 执行`sudo apt-get install vim`
sudo vim /etc/apt/sources.list

在新创建的文件sources.list加入下面地址：

# 中科大
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse

# 阿里
deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse

最后在终端执行更新：

1	sudo apt-get update

根据Debian系统开发者(John Paul Adrian Glaubitz)的建议，使用如下命令安装jdk环境所有依赖：

1	sudo apt build-dep openjdk-8

这个会自动下载需要的依赖，也会安装openjdk。

安装准备

源码下载

这次采用官方源码安装，官网地址：http://openjdk.java.net/projects/jdk8u/:

1
2
3

hg clone http://hg.openjdk.java.net/jdk8u/jdk8u
cd jdk8u
bash get_source.sh

可以反复执行bash get_source.sh知道下载所有子模块的源代码。

安装依赖

boot 启动jdk

我在线尝试各种安装openjdk7作为引导都失败，所以执行手动安装，可以下载这里面的附件：

上面4个文件下载后，在包含这个目录下面执行：

1	sudo dpkg -i openjdk-7-* libjpeg62-turbo*

如果报错如下：

Errors were encountered while processing:
openjdk-7-jre:amd64
openjdk-7-jre-headless:amd64
openjdk-7-jdk:amd64

再执行下面命令安装缺少的依赖即可：

1	sudo apt install -f

这个时候可以切换到jdk7的版本：

1	sudo update-java-alternatives -s java-1.7.0-openjdk-amd64

我手动安装openjdk7的执行结果如下：

yiji@ubuntu:~$ java -version
java version "1.7.0_161"
OpenJDK Runtime Environment (IcedTea 2.6.12) (7u161-2.6.12-1)
OpenJDK 64-Bit Server VM (build 24.161-b01, mixed mode)

ubuntu中可以使用如下指令快速切换不同版本的jdk:

 yiji@ubuntu:~$ sudo update-alternatives --config java
[sudo] password for yiji: 
There are 3 choices for the alternative java (providing /usr/bin/java).

  Selection    Path                                            Priority   Status
------------------------------------------------------------
  0            /usr/lib/jvm/java-11-openjdk-amd64/bin/java      1101      auto mode
  1            /usr/lib/jvm/java-11-openjdk-amd64/bin/java      1101      manual mode
* 2            /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java   1071      manual mode
  3            /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java   1081      manual mode

Press <enter> to keep the current choice[*], or type selection number:

设置环境变量

在~/.bashrc文件最后一行添加export LANG=C，然后执行source ~/.bashrc生效。

开始编译

因为在linux环境中编译，唯一改动的文件（~/jdk8u/hotsport/make/linux/makefiles/gcc.make）：

1 2	# Compiler warnings are treated as errors # WARNINGS_ARE_ERRORS = -Werror

注释了这个脚本，主要处理忽略警告，否则警告会当做错误处理导致无法编译。

注意，我代码迁出在自己的home目录, 改动文件要进入自己clone代码的位置。

生成配置

为了方便调试jvm，我开启了--enable-debug会生成fastdebug版本的jdk:

MAKE_VERBOSE=y QUIETLY= LOG=debug sh ./configure --enable-debug --with-jvm-variants=server --with-boot-jdk=/usr/lib/jvm/java-7-openjdk-amd64/ --disable-precompiled-headers --with-freetype-include=/usr/include/freetype2/ --with-freetype-lib=/usr/lib/x86_64-linux-gnu

执行命令后我电脑输出：

====================================================
A new configuration has been successfully created in
/home/yiji/jdk8u/build/linux-x86_64-normal-server-fastdebug
using configure arguments '--enable-debug --with-jvm-variants=server --with-boot-jdk=/usr/lib/jvm/java-7-openjdk-amd64/ --disable-precompiled-headers --with-freetype-include=/usr/include/freetype2/ --with-freetype-lib=/usr/lib/x86_64-linux-gnu'.

Configuration summary:
* Debug level:    fastdebug
* JDK variant:    normal
* JVM variants:   server
* OpenJDK target: OS: linux, CPU architecture: x86, address length: 64

Tools summary:
* Boot JDK:       java version "1.7.0_161" OpenJDK Runtime Environment (IcedTea 2.6.12) (7u161-2.6.12-1) OpenJDK 64-Bit Server VM (build 24.161-b01, mixed mode)  (at /usr/lib/jvm/java-7-openjdk-amd64)
* Toolchain:      gcc (GNU Compiler Collection)
* C Compiler:     Version 7.3.0 (at /usr/bin/gcc)
* C++ Compiler:   Version 7.3.0 (at /usr/bin/g++)

Build performance summary:
* Cores to use:   3
* Memory limit:   3921 MB

WARNING: The result of this configuration has overridden an older
configuration. You *should* run 'make clean' to make sure you get a
proper build. Failure to do so might result in strange build problems.

生成jdk8

执行下面命令进行构建jdk:

1	make JOBS=8 MAKE_VERBOSE=y QUIETLY= LOG=debug all

生成openjdk8成功会输出耗时信息：

## Finished docs (build time 00:02:17)

----- Build times -------
Start 2018-10-26 13:36:24
End   2018-10-26 13:51:32
00:00:24 corba
00:00:19 demos
00:02:17 docs
00:07:56 hotspot
00:00:23 images
00:00:14 jaxp
00:00:20 jaxws
00:02:32 jdk
00:00:29 langtools
00:00:14 nashorn
00:15:08 TOTAL
-------------------------
Finished building OpenJDK for target 'all'

使用openjdk8

生成的jdk Home 在源码目录build ：

1	~/jdk8u/build/linux-x86_64-normal-server-fastdebug/images/j2sdk-image

直接在intellij idea 或者 eclipse 中指定上面的Home即可。

验证jdk版本

yiji@ubuntu:~/jdk8u/build/linux-x86_64-normal-server-fastdebug/jdk/bin$ ./java -version
openjdk version "1.8.0-internal-fastdebug"
OpenJDK Runtime Environment (build 1.8.0-internal-fastdebug-yiji_2018_10_26_13_36-b00)
OpenJDK 64-Bit Server VM (build 25.71-b00-fastdebug, mixed mode)

为什么要编译JDK源码

已发布jdk版本去除了调试信息和运行时信息，降低内存占用提升运行速度，但是不适合开发者调试jdk代码
深入jvm细节，自己动手编译为深入学习打基础

参考

理解arthas原理

记一次对mosn中dubbo、hessian-go的性能优化