LOS Thread Freeze

A number of players using the VASL module having reported their games freezing if both players activate the los thread at the same time. Since VASL uses a custom los thread which extends the VASSAL classes, it could be something happening in the VASL code or in VASSAL.

Has this behaviour been noticed before in other modules? Any wild guesses as to what might cause such a freeze?

Users report that:

  • sometimes only one player freezes and the other can unfreeze him by clicking on the los button
  • sometimes the freeze will thaw on its own after several minutes
  • sometimes a restart is necessary


Me and my opponent struggle with random LOS freezes in GBACW. We have experienced all of the three conditions. Any solution for this?

Interesting. About 2 months ago I was actually working on that custom class to improve its functionality. I haven’t noticed that bug but I also replaced some of its code. What module is this happening in?


Further to this, players using VASL continue to report that the los string freezes if both players use it at the same time. Often the freeze requires a restart of the game with loss of all the unsaved actions so it is quite annoying.

In the VASL module, we have developed some detailed custom code to extend the los string functionality. I have been trying to determine where in that code we might be triggering the freeze but with no luck. The most common event that players report as triggering the freeze is if both players use the los string at the same time. But I am not sure that is the only way it is triggered.

One idea that I have is to try and prevent both players from triggering the los string at the same time. ONce the LOS button was triggered on one device it would disable the button on any other devices playing the game. Of course, it would have to be re-activated once the los string was turned off on the first device.

Does this seem reasonable and doable? Any thoughts about how best to do so?