Evaluation of Barrier Behaviour

This repository contains the configuration files and raw running script result files from my 2022 summer project on 'Evaluating Barrier Behaviour in a Modern JVM' (supervised by Professor Steve Blackburn).

These are the instructions for the refined measurement framework that I used for this project. It requires a full and correct implementation of the barrier that is being measured in MMTk. Here, we will use the object barrier, which is already implemented in the MMTk:

1. Set up running-ng using the instructions on https://anupli.github.io/running-ng/.
2. Set up the OpenJDK binding of MMTk using the tutorial: https://www.mmtk.io/mmtk-core/tutorial/preliminaries/set_up.html. Make sure to set the path to the mmtk-core repo.
3. Navigate to mmtk-core/src/plan/generational/mod.rs.
4. Set FULL_NURSERY_GC to true (L40) and ACTIVE_BARRIER to BarrierSelector::NoBarrier (L38). Produce an MMTk build using the tutorial instructions in step 2 and rename the build to no-bar.
5. Keep FULL_NURSERY_GC as true (L40) and change ACTIVE_BARRIER to BarrierSelector::ObjectBarrier (L38). Produce an MMTk build using the tutorial instructions in step 2 and rename the build to ob-bar.
6. Use the running scripts to take the barrier measurements. A configuration file template is provided at https://github.com/clairexhuang/barrier-behaviour/blob/master/measurement-template.yml.

Note: If the running scripts fail, it may be necessary to change this line https://github.com/mmtk/mmtk-core/blob/master/src/plan/generational/mod.rs#L60 to be 'if true' due to an issue with the side-metadata layout in the master branch.