Re: [boost] Proposal for a thread synchronisation primitive: future_queue

Subject: Re: [boost] Proposal for a thread synchronisation primitive: future_queue
From: Tim Blechmann (tim_at_[hidden])
Date: 2018-05-21 02:37:14

>> I would love to see a portable eventcount 
>> (http://www.1024cores.net/home/lock-free-algorithms/eventcounts) 
>> implementation in Boost.Lockfree.
> 
> I would anyway offer to work on a portable semaphore, but I am afraid
> I don't have much experience with platform independent
> implementations. I will probably soon extend my simple semaphore
> class from the future_queue library to work with other values than 0
> or 1 (since I need that for a better implementation of the
> future_queue) and I can also try to make a good implementation for
> Mac OS X, if this helps you. I don't really have access to
> development tools on Windows any more and basically no experience on
> other platforms. Maybe someone else can add more implementations?

https://github.com/boostorg/sync/blob/develop/include/boost/sync/semaphore.hpp

unfortunately we never got it finished/reviewed. iirc obtaining the
semaphore count doesn't really map to all OS apis ...

as for macos iirc the different semaphore apis have quite different
performance characteristics (iirc unnamed semaphores were not
implemented while dispatch semaphores had the best throughput).