Re: [Boost-users] single thread in loop

Subject: Re: [Boost-users] single thread in loop
From: SRD (software.research.development_at_[hidden])
Date: 2013-07-02 17:12:01

In trying to set this up before the loop, I'm getting the following error.

    boost::asio::io_service worker_service;

    shared_ptr<boost::asio::io_service::work>
        work(new boost::asio::io_service::work(worker_service));

    boost::thread worker_thread(&boost::asio::io_service::run,
worker_service));
    worker_thread.detach();

    while (1) {
        // ...
        worker_service.post(task);

    }

2>taskm.cpp(454): error C2059: syntax error : ')'
2>taskm.cpp(454): error C2664:
'boost::thread::thread<boost::asio::io_service&>(const
boost::thread::attributes &,F)' : cannot convert parameter 1 from
'overloaded-function' to 'const boost::thread::attributes &'
2>          with
2>          [
2>              F=boost::asio::io_service &
2>          ]
2>          Reason: cannot convert from 'overloaded-function' to 'const
boost::thread::attributes'
2>          No constructor could take the source type, or constructor
overload resolution was ambiguous

On Tue, Jul 2, 2013 at 1:09 AM, Igor R <boost.lists_at_[hidden]> wrote:

> > I'm using boost 1.53 on windows 7. I have a main loop which runs some
> checks
> > and when events are received, results in callbacks that add tasks onto a
> > queue. I then pull a task off the queue, wish to start a thread (and only
> > one thread) to handle the task, and continue to loop checking for certain
> > events. And each time I go through the loop, I want to check to see if
> the
> > current thread has completed before pulling off another task to process.
> >
> > My problem is that I'm not sure how to write the thread in to do this and
> > not join because I have to keep looping to check for certain events.
>
>
> You can use timed_join, as in your example, but note that the thread
> might exit anytime.
> Instead of complicated management of tasks and threads, why would't
> you use asio::io_service? Just run it in 1 thread, and post your tasks
> to it. When io_service doesn't have any "active" work, its thread
> would be idle.
>
> //setup io_serivce before the loop
> asio::io_service io_service;
> // give it some "work", to prevent premature exit
> shared_ptr<asio::io_service::work> work(new
> asio::io_service::work(io_service));
> boost::thread t(&asio::io_service::run, &io_service);
> t.detach();
> //...
> // from within your loop, post tasks
> io_service.post(yourFunctor); // yourFunctor will be executed in the
> separate thread
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