On Wed, 30 Apr 2014 11:43:31 -0400, Andrei Alexandrescu
<seewebsiteforem...@erdani.org> wrote:
Hello,
A coworker mentioned the idea that unittests could be run in parallel
(using e.g. a thread pool). I've rigged things to run in parallel
unittests across modules, and that works well. However, this is too
coarse-grained - it would be great if each unittest could be pooled
across the thread pool. That's more difficult to implement.
I am not sure, but are unit-test blocks one function each, or one function
per module? If the latter, that would have to be changed.
This brings up the issue of naming unittests. It's becoming increasingly
obvious that anonymous unittests don't quite scale - coworkers are
increasingly talking about "the unittest at line 2035 is failing" and
such. With unittests executing in multiple threads and issuing e.g.
logging output, this is only likely to become more exacerbated. We've
resisted named unittests but I think there's enough evidence to make the
change.
I would note this enhancement, which Walter agreed should be done at DConf
'13 ;)
https://issues.dlang.org/show_bug.cgi?id=10023
Jacob Carlborg has tried to make this work, but the PR has not been pulled
yet (I think it needs some updating at least, and there were some
unresolved questions IIRC).
Last but not least, virtually nobody I know runs unittests and then
main. This is quickly becoming an idiom:
version(unittest) void main() {}
else void main()
{
...
}
I think it's time to change that. We could do it the
non-backward-compatible way by redefining -unittest to instruct the
compiler to not run main. Or we could define another flag such as
-unittest-only and then deprecate the existing one.
The runtime can intercept this parameter. I would like a mechanism to run
main decided at runtime.
We need no compiler modifications to effect this.
Thoughts? Would anyone want to work on such stuff?
I can probably take a look at changing the unittests to avoid main without
a runtime parameter. I have a good grasp on how the pre-main runtime
works, having rewritten the module constructor algorithm a while back.
I am hesitant to run all unit tests in parallel without an opt-out
mechanism. The above enhancement being implemented would give us some ways
to play around, though.
-Steve
