Re: [Boost-users] Using boost::asio::async_write to stream out data

Subject: Re: [Boost-users] Using boost::asio::async_write to stream out data
From: Alex Black (alex_at_[hidden])
Date: 2009-07-17 15:36:44

Thanks for the feedback on this Matheus and Michael.

I think I have a good idea now of what I need to do.

The point about whether or not you can call async_write before the first one has completed seems important.  Right now, I've only got one thread calling io_service.run(), and only 1 thread calling async_write, so it sounds like I don't have to wait, nor do I need to queue, but I do need to manage the buffers' lifetime properly.

- Alex

> -----Original Message-----
> From: boost-users-bounces_at_[hidden] 
> [mailto:boost-users-bounces_at_[hidden]] On Behalf Of 
> Michael Caisse
> Sent: Friday, July 17, 2009 3:14 PM
> To: boost-users_at_[hidden]
> Subject: Re: [Boost-users] Using boost::asio::async_write to 
> stream out data
> 
> Matheus Araújo Aguiar wrote:
> >
> >
> >
> >         Then in my handle_write method should I check the 
> queue, if at
> >         least one
> >         buffer is in the queue then I should start a new 
> async_write?
> >          
> >
> >
> >     Exactly.
> >
> >
> > I disagree. I don't have much technical knowledge about how 
> it is done 
> > on the O.S layer, but for what i've experienced, you can 
> call several 
> > async_write, one after another, without having to wait for the 
> > completion of any of the operations. If you call async_write from 
> > diferent threads, then data could be interleaved. And with 
> TCP you may 
> > get data concatenated, but it has to do with the protocol.
> >
> > Maybe i'm wrong, but for now that's what i think. A third 
> (and fourth, 
> > fifth and so on) opinion would be nice.
> 
> Matheus -
> 
> This is true if you have only called io_sevice::run from one 
> thread. If you have multiple threads processing events you 
> will have issues because each thread may be writing to the 
> socket at the same time. This would not be a TCP layer 
> issue... it would be an application problem.
> 
> Best Regards -
> 
> -- 
> 
> ----------------------------------
> Michael Caisse
> Object Modeling Designs
> www.objectmodelingdesigns.com
> 
> 
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