Hi
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 lock_ops::unlock(mutex, state); and m_impl.do_wait(); 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: void condition_impl::do_wait() 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. waiting. -- Mariusz Kędzierawski M(dot)Kedzierawski@gmail.com