Change Details

Ported from #4324 . See comments for warning.

This implements threading of the pathfinder workers. Details of the architecture: - Workers are dispatched paths in a round-robin-ish fashion. It's naive, but it works well enough for now. - Paths are then fetched in reverse order and messages are sent. The Long pathfinder grid is owned by the pathfinder and so safe to use across turns. The obstructions manager' shapes aren't, so protected behind a mutex.

Ported from #4324 This implements threading of the pathfinder workers. See comments for warningDetails of the architecture: - Workers are dispatched paths in a round-robin-ish fashion. It's naive, but it works well enough for now. - Paths are then fetched in reverse order and messages are sent. The Long pathfinder grid is owned by the pathfinder and so safe to use across turns. The obstructions manager' shapes aren't, so protected behind a mutex.