From: Yuval Ronen (ronen_yuval_at_[hidden])
Date: 2007-08-26 17:47:31
Howard Hinnant wrote:
>
> At this point I'm really leaning towards getting back to basics:
<snip options for class condition>
It seems I wasn't very successful in convincing, so I'll try one last
time. I strongly recommend you seriously consider
template <class Mutex>
class condition
{
condition();
explicit condition(Mutex &); // or Mutex*
void set_mutex(Mutex &); // or Mutex*
void wait();
// more wait() overloads with predicate and timeout
// and of course the notify functions
};
I'll repeat the advantages I see for this approach:
1. It can work for any user-defined mutex.
2. Yet it can be specialized for better sizeof for std::mutex.
3. It can be made to check for errors (not assigning a mutex or not
locking the mutex) when calling wait().
4. Yet it can be made to be as-fast-as-possible.
5. It can dynamically switch the mutex which the condition works for
(for the rare cases when it is needed).
6. It allows easily using the condition in a deeper function than the
one that locked the mutex.
7. It doesn't force using locks (which I see as a plus, because there's
a reason we brought mutex back his lock/unlock).
8. It doesn't introduce an unprecedented technique of "encouraging"
users to lock (by passing a lock to a function). A technique which I
find to be cumbersome and misleading (because it works only partially).
Unfortunately I have to leave in an hour for two weeks, so I'm out of
this discussion for now, but please don't dismiss this idea without
careful thought.
Yuval