[fpc-pascal] Re: getting started with threads

David W Noon david.w.noon at ntlworld.com
Sat Sep 19 16:43:38 CEST 2009

On Sat, 19 Sep 2009 10:25:20 +0200, Micha Nelissen wrote about Re:
[fpc-pascal] Re: getting started with threads:

> Graeme Geldenhuys wrote:
> > So far I have single interface for create/destroy/lock/unlock of
> > semaphores for Windows, Linux, *BSD. The latter two is actually for
> > all
> A semaphore is not "locked" and "unlocked", it is posted and waited
> for.

An event semaphore (or "condition" in POSIX-speak) is "waited for" and

A simple mutex semaphore is "locked" and "unlocked" -- or, more
idiomatically, "acquired" and "released".

A read/write mutex semaphore (or "rwlock" in POSIX-speak) is "acquired
for sharing" or "acquired for exclusion" and "released".

A Dijkstra semaphore is "upped" or "downed". This is the original usage
of the term "semaphore" in computing. It is largely useless in
comparison to the other types of semaphore.

Dave  [RLU #314465]
david.w.noon at ntlworld.com (David W Noon)

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