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  1. Android.bp
  2. chainagents.cc
  3. README.md
tools/jvmti-agents/chain-agents/README.md

chainagent

The chainagents agent is a JVMTI agent that chain loads other agents from a file found at a location relative to a passed in path. It can be used in combination with android startup_agents in order to implement more complicated agent-loading rules.

It will open the file chain_agents.txt from the directory passed in as an argument and read it line-by-line loading the agents (with the arguments) listed in the file.

Errors in loading are logged then ignored.

Usage

Build

m libchainagents

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

Command Line

ART

art -Xplugin:$ANDROID_HOST_OUT/lib64/libopenjdkjvmti.so -agentpath:$ANDROID_HOST_OUT/lib64/libchainagents.so=/some/path/here -Xint helloworld

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

chain_agents.txt file format.

The chain-agents file is a list of agent files and arguments to load in the same format as the -agentpath argument.

Example chain_agents.txt file

/data/data/com.android.launcher3/code_cache/libtifast32.so=ClassLoad
/data/data/com.android.launcher3/code_cache/libtifast64.so=ClassLoad