Petr Jelinek <p...@2ndquadrant.com> writes: > On 03/04/2020 17:51, Tom Lane wrote: >> But the forked-off children have to write the gcov files independently, >> don't they?
> Hmm that's very good point. I did see these missing coverage issue when > running tests that explicitly start more instances of postgres before > though. And with some quick googling, parallel testing seems to be issue > with gcov for more people. I poked around and found this: https://gcc.gnu.org/legacy-ml/gcc-help/2005-11/msg00074.html which says gcov instrumentation is multi-process safe, but not multi-thread safe. The multi-processing safety relies on OS level file locking, which is not available on some systems. That would explain why it works for me, but then there's a question of why it doesn't work for you ... regards, tom lane
