Well,

2 little beautifying amandements:

1. to prevent a warning if you enable at line 117 cond_broadcast(@chat) just add

       lock(@chat);
   [download]

   right the line before.
2. to prevent that all Writers go through their writing loop, if a Reader makes the 'kill-broadcast' from the above mentioned line, enter

        next unless (@chat);
   [download]

   right after last if ($Elm ..); within the endless loop of the Writer.

Enjoy,
Carl