Re: [pygame] Preventing multiple instances of your game from running (and activating the running copy?)

[Bob Ippolito <bob@xxxxxxxxxx>]

On Aug 4, 2006, at 6:26 PM, Brian Fisher wrote:

> Hey all,
>  I want to write some code to make my pygame apps prevent multiple
> instances from running, and if possible (although I doubt it is...)
> make the currently running copy of the game activated if another
> instance gets run.
>
> Also, I want to use some method that works great cross-platform, and I
> don't want to use any method that could break with a crashed app (like
> marker files or whatever... I mention this cause the 2 samples I found
> in google were using mutex's with win32 extensions and using a marker
> file)
>
> So do you guys have a feature like that in your games? What approach
> do you guys take?

I've don't recall ever seeing a game on unix that really cared if it  
was running already or not. Seems like YAGNI.

I can see it making some sense on win32, but is it actually a problem  
worth solving?

On Mac OS X, if using an application bundle anyway, this is the  
default behavior. You have to specifically ask for an application  
that can be run multiple times simultaneously for the same user.

If I really had to do something like this, I'd do it with TCP on  
127.0.0.1 plus a marker file in a user-specific directory that said  
which port to look for (which is determined at runtime by asking for  
port 0). Connecting to that port would spit out some expected  
handshake (e.g. the name of the game and then disconnect). This would  
let you know that the game is still running on the same machine by  
the same user.

-bob