Threading / Concurrency Problem

[Bauss]

Working on a 2nd simple webserver in D. However I am facing a 
problem with some threading. I want the receiving of connections 
to happen in a 2nd thread, but after adding the connections to 
the collection it seems like the receive thread never loops 
through them, as if no connections were ever added. However I 
have checked and it is added.

The thread for receiving is also working as I have checked if 
code outside of the foreach loop works and it does, so it's 
probably a problem with the collection.

This makes me assume it's a concurrency issue and I'm not sure 
how to fix it.

I'm using an associative array for the connections. Class[int] is 
the format I'm using.

You can view my code here:

If anyone knows the solution to this, it would be appreciated. I 
can't seem to figure it out.

Code:
http://pastebin.com/A61NPWUq