What sync object should i use?

[Heinz]

Ok, here's a summary in case someone else is in the same need:

1) Want to know what "mutex/condition" are, how do they work and 
when to use them? Here's a good resource: 
http://stackoverflow.com/a/4742236

2) If you come to the question "Why a condition needs a mutex?": 
http://stackoverflow.com/questions/2763714/why-do-pthreads-condition-variable-functions-require-a-mutex

3) Need a working example in D? (by Steven Schveighoffer): 
http://forum.dlang.org/thread/j7sdte$25qm$1@digitalmars.com