Re: [boost] [threadpool] draft n2276 - launch_in_pool

Subject: Re: [boost] [threadpool] draft n2276 - launch_in_pool
From: Dean Michael Berris (mikhailberis_at_[hidden])
Date: 2008-11-21 09:34:35

On Fri, Nov 21, 2008 at 10:25 PM, Oliver Kowalke <k-oli_at_[hidden]> wrote:
> Hi Dean,
>
>> // version 1
>> template <ThreadPool pool_type, PackagedTask task_type>
>> typename task_type::future_type launch_in_pool(task_type task,
>> pool_type & pool) {
>>   pool.post(task);
>>   return task.get_future();
>> }
>
> sorry, but i don't see the benefit
>
> Maybe some additional functions are required which create customized pool accessible over launch_in_pool. Singleton from Andrei Alexandrescu comes into my mind (tracks the order of creation/destruction of singletons) - a implementaion was announced some months ago in the mailing list.
>

The version you quoted allowed you to create your own thread pool and
pass that in as the second parameter to the launch_in_pool(...)
function. That means, any type that models the ThreadPool concept
should qualify as a thread pool.

If you want a special type of thread pool with a different
configuration from the default (as presented in version 2) that's
controllable using compile-time definitions (for strategies used,
etc.) then you'll just have to write your own thread pool
implementation and make sure you write a concept_map to adapt your
implementation to the ThreadPool concept.

Of course this assumes three things:
1. The ThreadPool concept is defined.
2. The local static initialization and destruction sequence is
standardized across vendors as what the C++0x standard proposes.
3. The implementation of the standard thread pool is defined by the
standard and not vendor-specific.

In case 3, then vendors may be able to give more options about how the
default thread pool can be configured at compile time. If all else
fails, version 1 (which you have quoted) will be the implementation
that you can use -- write your own or use an existing thread pool
adapted to the ThreadPool concept.

-- 
Dean Michael C. Berris
Software Engineer, Friendster, Inc.