My bad, thanks for correcting! Of course single thread freeing a lot of heap allocations will not pause other threads by itsel. What I had to write was: calling

My bad, thanks for correcting! Of course single thread freeing a lot of heap allocations will not pause other threads by itsel. What I had to write was: calling destructor of an object that in turn calls destructors of other objects (because a large tree of reference counted objects loses last reference to it's root) stops that thread, until all deallocation is done.