Regression Test Harness for the OpenJDK platform: jtreg

This page is primarily for developers working on the implementation of jtreg. For help on using jtreg to run OpenJDK tests, see here.

Building and testing jtreg

The primary way to build and test jtreg is using make and the Makefiles in the make directory. You can also use Ant to build jtreg and run a subset of the tests using make/build.xml, but this is not recommended for production builds.

Currently, the makefiles are just set up for use on Unix-like systems. On Windows, you can use Cygwin to provide a suitable environment for building jtreg.

For more information, see the README file in the source repository.

So you want to change jtreg ...

jtreg is not a general purpose testing harness, and primarily exists to serve the overall needs of the OpenJDK community to test the OpenJDK platform.

Many requests to change the way that jtreg runs tests can be addressed by writing library code to be executed by jtreg, as a "wrapper" or "envelope" for the test. This technique is already used for many specialized testing frameworks within the various OpenJDK test suites. It can be used to reduce the boilerplate code in a test, to exec java with custom options, or even exec other commands on the host system, maybe after verifying that such commands are available.

Originally, the recommendation for writing "non-standard" tests was to use a shell script. Now, that practice is deprecated, because of the difficulty of ensuring that such tests run on all supported platforms. Instead, it is recommended to write the equivalent code in Java. Note that if the test suite is being run in agentvm or samevm mode, there is negligible overhead in compiling and executing the Java code – i.e., no extra JVMs will be started.

As a rough guideline, if you can find a way to do what you want without changing jtreg, that is generally preferable to changing jtreg.

The sort of enhancements may be considered are those that need to be handled within the jtreg infrastructure. Recent enhancements have been:


Issues are tracked in the JDK Bug System, in the CODETOOLS project, tools component, jtreg subcomponent.

Other Resources

Further information