Re: [Boost-users] Multithread event handling

Subject: Re: [Boost-users] Multithread event handling
From: Rutger ter Borg (rutger_at_[hidden])
Date: 2010-03-21 16:37:13

Matthias Vallentin wrote:

>> I've written something quite simple that is also able to do 2), semantics
>> are Asio-like,
>> 
>> reference_counter m_counter;
>> ios.post( m_counter.wrap( task1 ) );
>> ios.post( m_counter.wrap( task2 ) );
>> ios.post( m_counter.wrap( task3 ) );
>> m_counter.async_wait( all_complete_handler );
> 
> How does the task structure look like here? It looks like the tasks
> execute concurrently and increment a counter on start/finish -
> atomically, as you say. What I mean with structure are for example
> hierarchical (e.g., tree-like) groupings of tasks.

Right. Tasks are wrapped/bound handlers (like in Asio). Hierarchical stuff 
would look like

reference_counter m_counter_1;
reference_counter m_counter_2;
ios.post( m_counter_1.wrap( task1 ) );
ios.post( m_counter_1.wrap( task2 ) );
ios.post( m_counter_2.wrap( task3 ) );
m_counter_1.async_wait( m_counter_2.wrap( task4 ) );
m_counter_2.async_wait( task5 );

Execution dependencies and order will be
1) task1, task2, task3
2) task4
3) task5

> I haven't looked at it in detail, but Oliver Kowalke's task and fiber
> implementation in the Boost vault look like a good starting point. From
> the documentation, it seems there is some support for structuring tasks
> via sub-tasks. The libraries support atomic operations via
> Boost.Atomic.

I haven't look at those in detail, yet. For atomic stuff, I just borrowed 
the atomic counter from boost/detail. 

Cheers,

Rutger