Re: [Help-glpk] Multithreading/parallelization

[Harley Mackenzie]

Sorry about the lack of full stops. Here is some more to keep you
going...........

C11 would be a great option if not for the complete lack of support in
Windows.  Quoting from the excellent book 21st Century C:

“Microsoft provides a C++ compiler, in the form of Visual Studio, which has an 
ANSI C compatibility mode. This is the only means of compiling C code currently 
provided by Microsoft. Many representatives from the company have made it clear 
that C99 support (let alone C11 support) is not forthcoming. Visual Studio is 
the only major compiler that is still stuck on C89, so we’ll have to find 
alternative offerings elsewhere.”

Excerpt From: Klemens, Ben. “21st Century C.” O'Reilly Media,
2012-10-15. iBooks. 
This material may be protected by copyright.

I believe that native support for Windows is a key requirement of GLPK
as I suspect it is the most common implementation used. Mandating Cygwin
on Windows would severely limit the potential reach of GLPK and so I
believe that we are limited to the present level of C89 used in GLPK.

Harley

On Sun, Dec 16, 2012, at 3:57, Robbie Morrison wrote:
> 
> Hi Harley, all
> 
> A couple of minor thoughts on the topic.
> 
> ------------------------------------------------------------
> To:           address@hidden
> Subject:      Re: [Help-glpk] Multithreading/parallelization
> From:         Harley Mackenzie <address@hidden>
> Date:         Sat, 15 Dec 2012 12:45:14 +1100
> ------------------------------------------------------------
> 
> > From my investigation the two main libraries for
> > the implementation of multi-threaded support for
> > GLPK are the pthread library for linux systems
> > and the pthread library for Windows that has
> > been released under LPGL and is therefore
> > compatible with the license of GLPK and could be
> > included as part of the source with the
> > appropriate inclusion of the license.
> 
> The new C standard, C11, supports multithreading
> natively:
> 
>   http://en.wikipedia.org/wiki/C11_%28C_standard_revision%29
> 
> It would be worth considering coding to this
> standard.
> 
> The downside is compiler support: wikipedia
> reports incomplete support support by:
> 
>   - GCC starting with version 4.6
>   - Clang starting with version 3.1
>   - IBM XL C starting with version 12.1
> 
> It would be possible to code GLPK to two
> standards, C11 for the threadsafe version and C99
> for the default version using conditional
> compilation.  But some well designed test suites
> would be advisable!
> 
> > I certainly would like to do this within the
> > existing project management of GLPK, but a
> > possible way of coordinating the development of
> > this relatively major change to the GLPK code
> > would be to temporarily fork the project and
> > host on GitHub where multiple participants could
> > contribute to the project with a view to merging
> > the changes back into the main GLPK source code
> > at a later time.
> 
> Another long sentence!  Are full stops scarce or
> expensive in Australia?
> 
> I would endorse the use of 'git' and 'GitHub'.
> 
> Indeed, the unstated question is really whether
> the entire project should migrate to 'GitHub' (or
> similar).  That would solve the reintegration
> problem too (though this is not a major issue).
> 
> Robbie
> ---
> Robbie Morrison
> PhD student -- policy-oriented energy system simulation
> Institute for Energy Engineering (IET)
> Technical University of Berlin (TU-Berlin), Germany
> University email (redirected) : address@hidden
> Webmail (preferred)           : address@hidden
> [from Webmail client]
> 
> 
-----
  Dr. Harley Mackenzie
  HARD software

  address@hidden
  www.hardsoftware.com
  + 61 3 5222 3435