[boost] [build] Running 1 per N tests

Subject: [boost] [build] Running 1 per N tests
From: Adam Wulkiewicz (adam.wulkiewicz_at_[hidden])
Date: 2016-06-29 06:34:15

Hi,

At Boost.Geometry we're using CircleCI for testing. They allow to run 
the tests concurently on N virtual machines. I'd like to alter my script 
to automatically redistribute the tests evenly across all of the 
machines, i.e. to run 1/N of the tests on each machine. The problem is 
that at Boost.Geometry we have a lot of nested project directories, i.e. 
b2 executed for some upper directory runs the tests in the test-suite in 
this directory and then follows nested projects defined by build-project 
directives, so runs the tests recursively. So e.g. if b2 was executed on 
some virtual machine for the most-top-level directory all of the tests 
would be built anyway.

Do you have an idea how this could be solved without altering the tests 
structure?

Is it currently somehow possible (though AFAIK it isn't) or would be 
possible to implement options allowing to e.g.:
- run b2 only for a certain directory/Jamfile, e.g. --non-recursive
- ignore arbitrary Jamfile directive, e.g. --ignore-build-project
- run only 1 per N tests, an option used together with -jX but running 
tests only for one thread, e.g. b2 -i2 -j4 running only 1 per 4 commands 
starting from 2nd command
?

The last option would be the most convenient for me. The tests would be 
divided as evenly as possible. It wouldn't require to use some 
workarounds i.e. traversing test directories recursively and running b2 
manually for them which could result in low-quality redistribution, e.g. 
if some directory contained many tests and other small number of tests.

Regards,
Adam