potential parallel issues for function objects used a patchSet
In function objects such as wallShearStress, the patches can be restricted using a "patches" keyword. The retrieved indices are stored as a labelHashSet (ensures that they are unique). This is generally mostly OK, except that there is no absolute 100% guarantee ™ that iterating across will be the same across all ranks - which means that any global operations such as gMin/gMax etc could potentially block.
This is admittedly a bit of a stretch (since the hash insertion operations will be the same on all ranks, and all ranks have the same hasher), but should be adjusted for v2312.