Proposal: jtreg tests with native components

[Staffan Larsen]

The change in jtreg that I would like to see is the addition of a flag to specify the path of the test binaries. I’m thinking something like “-natives:<path>”. This would do two things:

- Set the java.library.path when invoking tests. This is needed for System.loadLibrary() to work.
- Set a test.natives property. This is needed in the cases where the test binary is not a library, but a program. In this case the test will want to launch that program and needs the path to the program.

Both of these would be set to <path> above. Jtreg should check that the path exists.

Does that sound like a reasonable change?

Thanks,
/Staffan


On 25 apr 2014, at 14:02, Staffan Larsen <staffan.larsen at oracle.com> wrote:

> There are a couple of jtreg tests today that depend on native components (either JNI libraries or executables). These are handled in one of two ways:
> 
> 1) The binaries are pre-compiled and checked into the repository (often inside jar files).
> 2) The test will try to invoke a compiler (gcc, cl, …) when the test is being run.
> 
> Neither of these are very good solutions. #1 makes it hard to run the setup the test for all platforms and requires binaries in the source control system. #2 is hit-and-miss: the correct compiler may or may not be installed on the test machine, and the approach requires platform specific logic to be maintained.
> 
> I would like to propose that these native components are instead compiled when the product is built by the same makefile logic as the product. At product build time we know we have access to the (correct) compilers and we have excellent support in the makefiles for building on all platforms.
> 
> If we build the native test components together with the product, we also have to take care of distributing the result together with the product when we do testing across a larger number of machines. We will also need a way to tell the jtreg tests where these pre-built binaries are located.
> 
> I suggest that at the end of a distributed build run, the pre-built test binaries are packaged in a zip or tar file (just like the product bits) and stored next to the product bundles. When we run distributed tests, we need to pick up the product bundle and the test bundle before the testing is started.
> 
> To tell the tests where the native code is, I would like to add a flag to jtreg to point out the path to the binaries. This should cause jtreg to set java.library.path before invoking a test and also set a test.* property which can be used by test to find it’s native components.
> 
> This kind of setup would make it easier to add and maintain tests that have a native component. I think this will be especially important as more tests are written using jtreg in the hotspot repository.
> 
> Thoughts on this? Is the general approach ok? There are lots of details to be figured out, but at this stage I would like to hear feedback on the idea as such.
> 
> Thanks,
> /Staffan
>