[fpc-devel] Threads and alot of crap

[Micha Nelissen]

Jonas Maebe wrote:
>> By implication this means you need a mutex to protect against race 
>> conditions.
> 
> Not necessarily, it is at least possible to implement an atomic linked 
> list without requiring a mutex-style lock.

That's irrelevant. If thread 1 lets thread 2 do something, and thread 2 
would signal thread 1 after completion, then thread 1 might not have 
started to wait yet (descheduled just before cond_wait). Could happen 
for example with TThread.Synchronize.

Windows events do not have this problem since they are stateful. In 
hindsight, a semaphore might have been a better emulation of an 'Event' 
(although I've not thought this through completely), but at the time 
condition variables seemed to be the logical way to go.

Micha