Deadlock at Map::UnloadGrid

Sometimes the core hangs trying to obtain the lock at Map::UnloadGrid (e.g. when an instance map is reset):

Code:

WriteGuard Guard(GetLock(MAP_LOCK_TYPE_MAPOBJECTS));
delete getNGrid(x, y); // waits here

as the getNGrid() method has the line:

Code:

ReadGuard Guard(const_cast<Map*>(this)->GetLock(MAP_LOCK_TYPE_MAPOBJECTS));

Is it really necessary to have the double check? If we have a write lock can we obtain the read lock?

If I replace the first line with

Code:

delete i_grids[x][y];

The deadlock never occurs.

Windows problem. Exception for win maked in https://github.com/mangosR2/mangos/commit/797fbe88bfe51aed1ba249d641bb449c0f8c38b1
need move to master. unfortunately, no real multithreading in windows...

Thanks.

Hoping this will be moved to master soon as this problem almost screw up Random Bot feature in Ai Playerbot on Windows

Pity that multithreading is not supported in Windows. The problem is fixed anyway.

multithreading supported, not supported only separate map workers and inter-map object locking. this really not has any effects with online < 400.