Re: [boost] [thread] semaphore

On 9/18/2013 12:04 PM, Gottlob Frege wrote:

On Wed, Sep 18, 2013 at 12:33 PM, Jonathan Wakely wrote:

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On 18 September 2013 17:28, Gottlob Frege wrote:

...

But it still doesn't make it easy to use. It might have been easier to somehow wrap the lock and CV together (and a lambda for the condition?) and tell people to make sure they also lock the same CV+lock thing when pushing/pulling from the queue.

I think the problem with wrapping them together is that the binding of the three things is dynamic, not static. It's OK to use the same CV with different mutexes (as long as no waits using different mutexes ever overlap) although doing so correctly can be tricky :)

I wouldn't let that stop a wrapping - most cases don't need that, and you could still use "raw" CVs and locks for that.

I think it is more likely that the "devil is in the details". If we actually sat down and tried to make a simple+powerful class, we would find the gotchas. (Tends to happen with simple+powerful.)

But it might be worth trying.

FWIW latch is one such all-in-one class albeit without a customizable predicate. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3666.html