Avoid copying ROBFragment objects and use a different mode of tbb::concurrent_unordered_map insertion instead of operator[] with assignment. Not entirely sure why but this seems to fix ATR-22380 which was supposedly caused by copy-insertion race condition:
For concurrent_unordered_map, insert and emplace methods may create a temporary item that is destroyed if another thread inserts an item with the same key concurrently.
Rafal Bielski authored