Android7.0 JACK编译器不支持多用户同时编译的问题的解决

 Android7.0（也就是Android N）上默认使用JACK编译器而不再使用openjdk了，但发现JACK不是很好用，比如最大的一个问题就是，同一台linux服务器上不允许不同用户同时进行andorid7.0的编译，原因就是后面开始编译的用户无法正常启动jack server，而jack server居然不能关闭，虽然JACK文档中有说提供一些宏，只要设置宏为对应的值就可以关闭，但实测发现无效，关闭不了，这个蛋痛的问题，搞了2天，不过总算有方法可以搞定，下面是我对多用户无法同时编译的问题的解决过程（最下面有解决方案，如果你有更好的方法，欢迎告知，谢谢）：

 1，尝试关闭JACK，但发现失败：

1），当在板型目录中的BoardConfig.mk中添加ANDROID_COMPILE_WITH_JACK:=false时，编译会出错：

ninja: error: 'out/target/common/obj/APPS/ActSensorCalib_intermediates/with-local/classes.dex', needed by 'out/target/common/obj/APPS/ActSensorCalib_intermediates/classes.dex', missing and no known rule to make it

make[1]: *** [ninja_wrapper] Error 1

2），当在板型目录中的BoardConfig.mk中添加DEFAULT_JACK_ENABLED := disabled时，仍然不能关闭JACK，都会报错：

[ 34% 13188/37803] Ensure Jack server is installed and started

FAILED: /bin/bash -c "(prebuilts/sdk/tools/jack-admin install-server prebuilts/sdk/tools/jack-launcher.jar prebuilts/sdk/tools/jack-server-4.8.ALPHA.jar  2>&1 || (exit 0) ) &&

(JACK_SERVER_VM_ARGUMENTS=\"-Dfile.encoding=UTF-8 -XX:+TieredCompilation\" prebuilts/sdk/tools/jack-admin start-server 2>&1 || exit 0 ) &&

(prebuilts/sdk/tools/jack-admin update server prebuilts/sdk/tools/jack-server-4.8.ALPHA.jar 4.8.ALPHA 2>&1 || exit 0 ) &&

(prebuilts/sdk/tools/jack-admin update jackprebuilts/sdk/tools/jacks/jack-2.28.RELEASE.jar 2.28.RELEASE || exit 47;

prebuilts/sdk/tools/jack-admin update jack prebuilts/sdk/tools/jacks/jack-3.36.CANDIDATE.jar 3.36.CANDIDATE || exit 47;

prebuilts/sdk/tools/jack-admin update jack prebuilts/sdk/tools/jacks/jack-4.7.BETA.jar 4.7.BETA || exit 47 )"

Writing client settings in /home/test/.jack-settings

Installing jack server in "/home/test/.jack-server"

Communication error with Jack server (58), try 'jack-diagnose' or see Jack server log

Failed to contact Jack server: Problem reading /home/test/.jack-server/client.pem. Try 'jack-diagnose'

Failed to contact Jack server: Problem reading /home/test/.jack-server/client.pem. Try 'jack-diagnose'

[ 34% 13188/37803] Compiling SDK Stubs...tubs_current_intermediates/classes.jar

Note: Some input files use or override a deprecated API.

Note: Recompile with -Xlint:deprecation for details.

Note: Some input files use unchecked or unsafe operations.

Note: Recompile with -Xlint:unchecked for details.

[ 34% 13188/37803] target SharedLib: l...bLLVM_intermediates/LINKED/libLLVM.so)

ninja: build stopped: subcommand failed.

make[1]: *** [ninja_wrapper] Error 1

make[1]: Leaving directory `/home/test/700E/android/android'

3），尝试通过设置ANDROID_FORCE_JACK_ENABLED := disabled来进行关闭JACK ，编译也报错，跟1）一样的错误：

ninja: warning: multiple rules generate out/target/product/s900_RY_VR/system/xbin/su. builds involving this target will not be correct; continuing anyway [-w dupbuild=warn]

ninja: error: 'out/target/common/obj/APPS/ActSensorCalib_intermediates/with-local/classes.dex', needed by 'out/target/common/obj/APPS/ActSensorCalib_intermediates/classes.dex', missing and no known rule to make it

make[1]: *** [ninja_wrapper] Error 1

 

2，尝试解决，网上有很多人反映这个问题，https://code.google.com/p/android/issues/detail?id=194027，但是目前没有有效的解决方案，最可能的办法是从2个方面尝试：

1），这个issue有人说是需要增加RAM：I was on VitualMachine when I had the error. And the fix was to increase the RAM，不过他是在虚拟机上，我们的应该跟RAM无关；

2），通过修改配置文件$HOME/.jack-settings，设置不同的端口号：

# Server settings

SERVER_HOST=127.0.0.1

SERVER_PORT_SERVICE=8076

SERVER_PORT_ADMIN=8077

# Internal, do not touch

SETTING_VERSION=4

通过实验发现，单独修改配置文件$HOME/.jack-settings中的端口号没有效果，jack server一直启动失败，提示端口被占用：

com.android.jack.server.api.v01.ServerException: Problem while opening service port

        at com.android.jack.server.JackHttpServer.start(JackHttpServer.java:611)

        at com.android.jack.server.JackServerImpl.run(JackServerImpl.java:62)

        at com.android.jack.launcher.ServerLauncher$3.run(ServerLauncher.java:391)

        at java.lang.Thread.run(Thread.java:745)

Caused by: java.net.BindException: Address already in use

        at sun.nio.ch.Net.bind0(Native Method)

        at sun.nio.ch.Net.bind(Net.java:433)

        at sun.nio.ch.Net.bind(Net.java:425)

        at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)

        at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)

        at com.android.jack.server.ServerParameters.openSocket(ServerParameters.java:88)

        at com.android.jack.server.ServerParameters.getServiceSocket(ServerParameters.java:67)

        at com.android.jack.server.JackHttpServer.start(JackHttpServer.java:605)

 3），需要同时修改 $HOME/.jack-server/config.properties 中的端口号，方才有效，可以在别的用户启动了jack server的情况再启动另一个jack server，这样就可以实现多用户同时编译，亲测有效：

#Tue Sep 13 17:44:41 CST 2016

jack.server.max-jars-size=104857600

jack.server.max-service=4

jack.server.service.port=8076 

jack.server.max-service.by-mem=1\=2147483648\:2\=3221225472\:3\=4294967296

jack.server.admin.port=8077

jack.server.config.version=2

jack.server.time-out=7200      (修改上面红色这2行，比如改为8086，8087等)