Re: [boost] [process] Formal Review

Subject: Re: [boost] [process] Formal Review
From: Klemens Morgenstern (klemens.morgenstern_at_[hidden])
Date: 2016-11-06 06:40:45

Am 06.11.2016 um 12:26 schrieb Bjorn Reese:
> On 11/06/2016 02:10 AM, Klemens Morgenstern wrote:
>
>> To be honest, I haven't looked that deep into boost.fiber, not sure how
>> that would look. I'm open for any suggestions; async_pipe implements an
>> asio-I/O object, so you probably can already use that with the interface
>> boost.fiber provides to boost.asio.
>
> The pattern used in Asio is to have both synchronous and asynchronous
> functions:
>
>   return_value foo(args);
>   return_value foo(args, error_code);
>   void async_foo(args, void (*)(return_value, error_code));
>
> If async_foo supports boost::asio::async_result, then the coroutine and
> fiber support can be implemented seperately from your library.
Well there are two things. First you can use async_pipe as any asio 
I/O-Object, thus this should work with fiber. Secondly there's a special 
case for process::system, where you can suspend the coroutine for the 
time the process runs. This requires a custom solution, since the event 
handler is different - and must be. The reason is, that I need to start 
the async-wait on posix before launching the process, which would be 
sort of difficult, if the corutine get's suspendend when I do that. 
Therefore this application needs an extra implementation, where I 
imagined something like that:

void build(boost::asio::yield_context yield)
{
     bp::system("g++", "-c", "foo.cpp", "-o", "foo.o", yield);
     bp::system("g++", "-o", "foo.exe", "foo.o", yield);
};

I don't know really if anyone would like to use boost.fiber here; this 
however would require an implementation inside process/system.hpp. So I 
wouldn't add this now.