Re: [boost] [fiber] new version in vault

Subject: Re: [boost] [fiber] new version in vault
From: Stefan Strasser (strasser_at_[hidden])
Date: 2009-11-29 18:30:35

Am Sunday 29 November 2009 22:25:21 schrieb Vicente Botet Escriba:
> Oliver Kowalke-2 wrote:
> > I've uploaded a new version of boost.fiber - main features are:
>

I haven't found it in the vault, is it still there?
is the version in the sandbox the most current?

> I have a question. I understand we need fibers::mutex and
> fibers::condition_variable, but could you explain why do we need a
> separated fibers::lock_guard and fibers::unique_lock template classes? Why
> the ones from Boost.Thread are not usable in the fiber context, at the end
> the Mutex parameter can be any model of lockable?

the mutexes are also almost independent of fibers, aren't they?
they are CAS-based mutexes that could be used with threads as well, except for 
the call to this_fiber::yield().
CAS-based mutexes are long overdue for Boost.Thread. (I've even used random 
mutex sharing just to avoid the 24 bytes overhead a pthreads mutex is worth, 
for something that's basically a CAS-protected bool). so a mutex template 
with a parameter on what to do to waste some time (this_fiber::yield, 
this_thread::yield, spinning...) could clean this up.
Boost.Interprocess also has its share of mutexes AND its own 
scoped_lock/shared_lock/upgrade_lock.

it doesn't make much sense to have seperate synchronization code for 
Processes, Threads and Fibers.
(with some exceptions, like named mutexes in Boost:Interprocess)