jitload

Jitload is an art-specific agent allowing one to count the number of classes loaded on the jit-thread or verify that none were.

Usage

Build

m libjitload # or 'm libjitloadd' with debugging checks enabled

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 -Xplugin:$ANDROID_HOST_OUT/lib64/libopenjdkjvmti.so -agentpath:$ANDROID_HOST_OUT/lib64/libjitload.so -cp tmp/java/helloworld.dex -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 and agent.
  • Pass the '=fatal' option to the agent to cause it to abort if any classes are loaded on a jit thread. Otherwise a warning will be printed.

art -d -Xplugin:$ANDROID_HOST_OUT/lib64/libopenjdkjvmtid.so -agentpath:$ANDROID_HOST_OUT/lib64/libjitloadd.so=fatal -cp tmp/java/helloworld.dex -Xint helloworld

  • To use with run-test or testrunner.py use the --with-agent argument.

./test/run-test --host --with-agent libtitraced.so=fatal 001-HelloWorld

Printing the Results

All statistics gathered during the trace are printed automatically when the program normally exits. In the case of Android applications, they are always killed, so we need to manually print the results.

kill -SIGQUIT $(pid com.example.android.displayingbitmaps)

Will initiate a dump of the counts (to logcat).