From: Bill Kelly <billk@...>
Date: 2008-03-28T09:45:19+09:00
Subject: Re: embedding ruby (*not* extending)


From: "John Smith" <ka5427-536@online.de>
>
> BTW: I am developing inside a cross-platform application. It uses:
> 
>  * Microsoft Visual Studion 2008
>  * gcc - at least v3.3.3 (for Linux and MacOS)

Hi,

We embed ruby into a cross-platform application, as well.
(MSVC 2003 on Windows, gcc 4.0.1 on OS X, at the moment.)

The embedding code we use today is still very similar to what
I posted a couple years ago here:

http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/178389

Looks like the main difference now is that we now longer 
call NtInitialize (our own program startup has already taken
care of that stuff.)

We also ship a subset of the ruby standard library with our
app, as we don't want to depend on any particular version
of ruby being preinstalled on the system.  So we set up some
include paths for ruby to point to the application-local
stdlib.  For ex:

#ifdef PLATFORM_WINDOWS
    inc_path = PathOps::concat(application_path, "ruby/lib/ruby/1.8");
    ruby_incpush(inc_path.c_str());
    inc_path = PathOps::concat(application_path, "ruby/lib/ruby/1.8/i386-mswin32");
    ruby_incpush(inc_path.c_str());
#endif
#ifdef PLATFORM_MACOSX
    inc_path = PathOps::concat(application_path, "ruby/lib/ruby/1.8");
    ruby_incpush(inc_path.c_str());
    inc_path = PathOps::concat(application_path, "ruby/lib/ruby/1.8/powerpc-darwin8.3.0");
    ruby_incpush(inc_path.c_str());
#endif


Architecturally, we run ruby (1.8.4) on its own native thread,
and communicate between the ruby thread and native application
threads via a bridge (using boost::recursive_mutex and
boost::condition.)  (Actually the ruby side doesn't use
boost::condition, but polls at about 10Hz.  When we switch to
ruby 1.9, we'll be able to eliminate the polling on the ruby
side.)

Be careful if you run ruby on a different thread than the 
main thread, as the default pthread stack size for threads
other than the main thread is very small.  We modified the
boost thread library to specify a much larger stack size
when creating threads on OS X.


Hope this helps,

Bill