Test pmrr1 reveals weird (but common) pattern of non-deterministic failure. (Direct)
rrnewton opened this issue · comments
When running the test suite generated by --enable-tests
for the monad-par package, in revision 60aabe6, I see non-determinstic failures on the Direct scheduler.
Specifically, if I try to run this command 10 times:
./dist/build/test-monad-par/test-monad-par -j1
It will fail. However, the weird part is that it depends on running multiple tests together. If I run JUST the pmrr1 test, even 1000 times, I cannot reproduce the error:
./dist/build/test-monad-par/test-monad-par -j1 -t pmrr1
This is exactly the same pattern I've seen in other projects that use test-framework to drive parallel tests, including lattice-par
and haskell-lockfree
-- the outcome depends on what set of tests is run. I haven't figured out WHY this is yet.
Let's see, referring to you by name, @aturon, should bring you into this thread. This was the same problem we were having with SNZI counters right?