synchronization primitives

[Vladimir T. <vtz...@gm...>]

Hi,

Just committed the mutex and POSIX conditions to the CVS.
In threads.lisp there is LOCK structure that is supposed to be a  
mutex. Currently there is no any relation between it in the mutexes.

Since it is really helpful to know the owner thread of the mutex/lock  
- we have two way to do it.
1. Wrap the mutex object in the LOCK structure.
2. Remove LOCK structure and add the owner to the Mutex record.

I am not sure which one is better choice?

Basically I would prefer the latter one - but since the exposed mutex  
is always recursive, by using LOCK structure it is easy to have non- 
recursive as well (if needed). There are other advantages as well.

Vladimir