Need help with communication between multiple threads

[Chad J]

I'm a bit of a newbie to this whole multithreading thing, so I'm hoping 
someone can help me with this.

First, what I know (or what I think I know):  So I've been reading about 
this, and apparently there's this problem where two threads that are 
reading a value from the same address in memory at the same time may end 
up with two completely different values.  Apparently this is because 
when you write something, it may just end up in the cache and not be 
updated in global memory.  Also, when reading, you may end up with 
something that is just an outdated copy in the cache, and not the actual 
thing from global memory.  But it doesn't stop there, apparently x86 
computers are very forgiving on this stuff so if you make a mistake you 
won't know it until your program is run on some more obscure hardware.

Now then, my question:  In D, how do I ensure that when I write 
something, the write is to global memory, and when I read something, the 
read is from global memory?

Some more info:  This comes up because I am trying to write a Timer 
class for Tango, and it will include timers that trigger events at a 
later date, which requires multithreading.  So it'd be most helpful if I 
could accomplish this using only D features and/or Tango.