1*795d594fSAndroid Build Coastguard Worker# chainagent 2*795d594fSAndroid Build Coastguard Worker 3*795d594fSAndroid Build Coastguard WorkerThe chainagents agent is a JVMTI agent that chain loads other agents from a file found at a 4*795d594fSAndroid Build Coastguard Workerlocation relative to a passed in path. It can be used in combination with android startup_agents 5*795d594fSAndroid Build Coastguard Workerin order to implement more complicated agent-loading rules. 6*795d594fSAndroid Build Coastguard Worker 7*795d594fSAndroid Build Coastguard WorkerIt will open the file `chain_agents.txt` from the directory passed in as an argument and read it 8*795d594fSAndroid Build Coastguard Workerline-by-line loading the agents (with the arguments) listed in the file. 9*795d594fSAndroid Build Coastguard Worker 10*795d594fSAndroid Build Coastguard WorkerErrors in loading are logged then ignored. 11*795d594fSAndroid Build Coastguard Worker 12*795d594fSAndroid Build Coastguard Worker# Usage 13*795d594fSAndroid Build Coastguard Worker### Build 14*795d594fSAndroid Build Coastguard Worker> `m libchainagents` 15*795d594fSAndroid Build Coastguard Worker 16*795d594fSAndroid Build Coastguard WorkerThe libraries will be built for 32-bit, 64-bit, host and target. Below examples 17*795d594fSAndroid Build Coastguard Workerassume you want to use the 64-bit version. 18*795d594fSAndroid Build Coastguard Worker 19*795d594fSAndroid Build Coastguard Worker### Command Line 20*795d594fSAndroid Build Coastguard Worker#### ART 21*795d594fSAndroid Build Coastguard Worker> `art -Xplugin:$ANDROID_HOST_OUT/lib64/libopenjdkjvmti.so -agentpath:$ANDROID_HOST_OUT/lib64/libchainagents.so=/some/path/here -Xint helloworld` 22*795d594fSAndroid Build Coastguard Worker 23*795d594fSAndroid Build Coastguard Worker* `-Xplugin` and `-agentpath` need to be used, otherwise libtitrace agent will fail during init. 24*795d594fSAndroid Build Coastguard Worker* If using `libartd.so`, make sure to use the debug version of jvmti. 25*795d594fSAndroid Build Coastguard Worker 26*795d594fSAndroid Build Coastguard Worker### chain_agents.txt file format. 27*795d594fSAndroid Build Coastguard Worker 28*795d594fSAndroid Build Coastguard WorkerThe chain-agents file is a list of agent files and arguments to load in the same format as the 29*795d594fSAndroid Build Coastguard Worker`-agentpath` argument. 30*795d594fSAndroid Build Coastguard Worker 31*795d594fSAndroid Build Coastguard Worker#### Example chain_agents.txt file 32*795d594fSAndroid Build Coastguard Worker 33*795d594fSAndroid Build Coastguard Worker``` 34*795d594fSAndroid Build Coastguard Worker/data/data/com.android.launcher3/code_cache/libtifast32.so=ClassLoad 35*795d594fSAndroid Build Coastguard Worker/data/data/com.android.launcher3/code_cache/libtifast64.so=ClassLoad 36*795d594fSAndroid Build Coastguard Worker``` 37