From: Mariusz Kedzierawski (m.kedzierawski_at_[hidden])
Date: 2006-09-29 05:46:42
> What is OS20?
Its operating system from STMicroelectronics designed & implemented
for their chips.
> If you do have a pthread library, I recommend using this instead, since
> the implementation of condition variables contains a lot of traps.
Unefortunatelly I don't have pthreads on OS20. I know implementation
of synchronizing primitives is very tricky, thats why I haven't
started to write one by myself. I picked up boost code which I assume
is well designed/implemented/tested. I just have to replace mutex/sem
calls to that I have on os20. But traps you are talking about means
that boost implementation for example for win is not error free and
have well known flaws ? :)
While analyzing conditionals impl. for win I found myself with more questions:
Like I said earlier, unlocking a mutex and hanging on sem should be atomic. In
template <typename M> void condition::do_wait(M& mutex)....
however it is not. Doesn't that mean that we can miss notification between
and possibly lock forever on sem ?
I must admit that I don't fully understand all code from
conditional.cpp. Its somewhat twisted, especially m_gone var. usage
for example in function:
there is a line:
else if (++m_gone == ((std::numeric_limits<unsigned>::max)() / 2))
which checks if m_gone reached halfway to unsigned max value...
Another question: since m_gone is handled in non timed waiting
routine: do_wait() does it mean that I can use on single conditional
object both: timed and infinitive waiting and it just works ? On OS20
for example there are separate mutex/sem object types for timed/inf.
-- Mariusz Kêdzierawski M(dot)Kedzierawski_at_[hidden]
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