Hi
No its not expected. In fact it appears to happen even for max-jobs=1 when you compile the same file twice on the same run. I will try to track that down too.
okay, thanks. Is this related to IdentityHashMaps ?
Well I've found it. Don't know why it took so long as it was exactly what I thought it might be in the first place!
It is FakeIdGenerator - there is only one that is shared across all maps, rather than a separate one being used for each map.
Because of the way that it is used, this is difficult to fix.
If you modify it to always return the same id then the differences go away on my test map. However the map is smaller than the one made without the mod, so it looks like it is absolutely essential that the ids are different and this is no solution, maybe not even for testing of performance changes.
..Steve
Maybe it's possible to seperate the id ranges of the FakeIdGenerator? Example: startId = 1L << 62 + (tile no - starting with 0) * (1L << 62 / noOfTiles) But that would require that all calls to the FakeIdGenerator are no longer static (or they must use the ThreadLocal object?). WanMil