Re: [boost] [thread] Is there interest in shared_lock_prioritized?

Subject: Re: [boost] [thread] Is there interest in shared_lock_prioritized?
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2013-02-20 01:45:36

Le 20/02/13 07:00, Antony Polukhin a écrit :
> Hi,
>
> I've got a very basic implementation and tests of
> shared_lock_prioritized, that can be used like that:
>
> // Events are written down in order of
> // their execution in different threads
>
> shared_lock_prioritized<2 /*priorities count*/ > lock;
>
> // thread #1
> // Lock with minimal priority
> lock_shared();
>
> // thread #2
> // Lock with minimal priority
> lock_shared(0);
>
> // thread #3
> // Lock for writing with priority
> // greater than locks of threads 1 and 2
> // Waits till already acquired locks in #1 and #2 finish
> // and then writes
> lock(1);
>
> // thread #4
> // Will wait till thread #3 finishes, only then acquire lock
> lock_shared(0);
>
> Such shared lock gives us ability to manage order/priority of different
> lock attempts, we can make write locks have bigger priority that read
> locks, have multiple priorities writes (ordered write locks) and so
> on...
>
> Is there an interest in it?
Hi,

Fredrik Orderud is working on a  templated version (See  [Threads-devel] 
Extend shared_mutex with support for priority policies?) 
"shared_pri_mutex" with support for the following prioritization 
policies: UNSPECIFIED_PRIORITY, EXCLUSIVE_PRIORITY and SHARED_PRIORITY."

IIUC, your approach is dynamic, that is, it the user that choose the 
priority while locking, while IIRC his approach is static, that is, the 
priority is given by the type of mutex, preserving in this way the 
boost::shared_mutex interface.

Best,
Vicente