android13/art/tools/jvmti-agents/enable-vlog

enablevlog

enablevlog is a JVMTI agent designed for changing the VLOG options of a running process. Currently it only allows one to turn vlog options 'on'.

Usage

Build

m libenablevlog

The libraries will be built for 32-bit, 64-bit, host and target. Below examples assume you want to use the 64-bit version.

Use libenablevlogs if you wish to build a version without non-NDK dynamic dependencies.

Command Line

The agent is loaded using -agentpath like normal. It takes arguments in the following format:

[vlog1[,vlog2[,...]]]

It will cause the runtime to act as though you had passed these after the -verbose:[...] argument to dalvikvm.

Supported events

At the time of writing, the following events may be listened for with this agent

• class

• collector

• compiler

• deopt

• gc

• heap

• interpreter

• jdwp

• jit

• jni

• monitor

• oat

• profiler

• signals

• simulator

• startup

• third-party-jni

• threads

• verifier

• verifier-debug

• image

• systrace-locks

• plugin

• agents

• dex

These are not particularly stable and new options might get added. Examine the LogVerbosity struct definition and the parser for a up-to-date list.

ART

art -Xplugin:$ANDROID_HOST_OUT/lib64/libopenjdkjvmti.so '-agentpath:libenablevlog.so=class,profiler' -cp tmp/java/helloworld.dex -Xint helloworld

• -Xplugin and -agentpath need to be used, otherwise the agent will fail during init.
• If using libartd.so, make sure to use the debug version of jvmti.

adb shell setenforce 0

adb push $ANDROID_PRODUCT_OUT/system/lib64/libenablevlog.so /data/local/tmp/

adb shell am start-activity --attach-agent /data/local/tmp/libenablevlog.so=class,jit some.debuggable.apps/.the.app.MainActivity