Re: [asio-users] strand - first call to dispatch() queues it

[Christopher K. <ch...@ko...>]

Andrey Tcherepanov wrote:
> Thanks Christopher.
> 
> So, if I have one socket that I issue 3 write ops on it, how can I be sure  
> that they are
> 
> a. not overlapping (second did not start till first is not finished  
> completely)

Don't issue the second one until the first one is finished, and ...

> b. ordered by any way?

... issue them in the order you want them to be sent :)

> Say, if I have a code that has 3 async_writes one  
> by one in one function, may I assume that they will be executed as they  
> are called? Would _really_ clean up some of my code, when I could pipeline  
> write requests from different places/threads just by issueing them :)

A composed function such as async_write, which is implemented in terms 
of multiple calls to the async_write_some member function, cannot be 
performed at the same time as another async_write. If you do, you could 
end up with interleaved writes. You'll need to build your own pipeline, 
as in the chat example's client.

You *can* have multiple outstanding async_read_some or async_write_some 
operations on a single socket, but in the case of async_write_some 
whether that does something meaningful is platform and transport dependent.

Cheers,
Chris