App files

• .dex : Java to java bytecode through javac, android converts java bytecode to dalvik through dx or D8. This bytecode is wrapped into dex format. https://source.android.com/devices/tech/dalvik/dex-format.
• .odex :
• .vdex :
• .art :
• .oat :

Tools:

• dex2oat :
• dalvikvm :
• app_process :

Zygote startup

• https://elinux.org/Android_Zygote_Startup

Init runs /system/bin/app_process (a c++ program), and name this process as zygote.
As in init.rc:

service zygote /system/bin/app_process -Xzygote /system/bin --zygote --start-system-server

Usage of app_process is:

Usage: app_process [java-options] cmd-dir start-class-name [options]

app_process does runtime.start("com.android.internal.os.ZygoteInit", startSystemServer)

JNI API signature

• https://developer.android.com/training/articles/perf-jni
• JNI Heap view in memory profile

JavaVM and JNIEnv

https://developer.android.com/training/articles/perf-jni

• JavaVM
• JNIEnv: JNI Apis/functions as first argument. Used for thread local storage. Can't be shared b/w threads.

Thread pool in Java and C++