#SIMPLY FORTRAN THREADING UPDATE#
#SIMPLY FORTRAN THREADING CODE#

#SIMPLY FORTRAN THREADING CODE#

Here is a simple example of code to start a thread: EXTERNAL foo. The issue is that MPI only has official bindings for C and Fortran, so the only real choice I have is to keep programing in C or Fortran if I want to use MPI.ДЄny thoughts on this? Personally I would love to move towards more modern languages but without the proper libraries it is still a tough decision. Thus you can choose to start several threads using the same subroutine but with different values of ICODE to distinguish the cases. I've been writing new Fortran code only because I want the simulation to be able to scale to this kind of size. To me the biggest issue is that some simulations just need to run on 1000s or hundreds of 1000s of cores, and the primary technology that lets this happen is MPI (Message Passing Interface). But I do think that the article ignored what I think is the biggest issue. The article touched on the some of the issues (and the ever present issue of 'If it isn't broke, don't fix it'). In the end I've always reluctantly stayed in C or Fortran for scientific simulations. I have often wondered if there would be benefits to porting scientific simulation codes to more modern languages.

This is always a fun thing to revisit now that I'm really far away from having to maintain any FORTRAN code any more :) There's a ton relating to precision - we had a huge ordeal converting our 32-bit space weather model to 64-bit because the change in precision changed our results, so we couldn't publish (in good conscious) without making sure the results weren't within a good margin of error.

#SIMPLY FORTRAN THREADING UPDATE#

I'll see if I can find it, but I remember attending a conference talk at AGU in ~'08-10 called 'Do-over or make-do' that analyzed how many people-hours it would take to update all the climate modeling software (earth and space sciences are really huge on legacy FORTRAN code), and the conclusion of that talk was: use modern code/tools for glue, keep your climate models in FORTRAN. This question is revisited a lot, but the general consensus has been that FORTRAN is fast, simple, easy to understand and code, and the compilers used are super optimized (Intel's FORTRAN compiler was really a gem - it managed to do a ton of automatic parallelization on modern hardware) The idling state can be exited if the procedure stopidle is called, usually via a callback from a menu or button. Idles the main program thread for aspecified amount of time while allowing the graphical user interface to continue processing events. I used to maintain a large FORTRAN codebase - it seemed like every time new grad students showed up, everyone got a wise idea to re-build everything in a modern language. Fortran subroutine startidle (wait) Description.

Simply fortran threading