🚀 go-pugleaf

In article <713.6612T338T2196@und.ida.liu.se>, c92manen@und.ida.liu.se
(Mans Engman) wrote:

> [snip]
> 
> >I already posted that the Language Systems and Absoft fortran compilers
> >will do exactly what you want. I run many computationally intensive codes
> >on a PowerMac with perfectly smooth background execution "via a simple
> >compilation". The compilers put in the proper code to support the Mac OS
> >multitasking and it works just fine. The source code remains absolutely
> >unchanged portable ANSI 77 fortran.
> 
> "Proper code"?

Let's try different phrasing: Code that works correctly and causes the
program to multitask.
> 
> Ok, I'm rather ignorant about McI****h programming, but I just wonder
under what
> circumstances the compilers put in that code? Does it put taskswitching code
> every XXX loops? And how can I be sure it doesn't put that code there
when it's
> not necessary?

It puts it where you tell it to, through compiler options, like this:

-bkg=0         never yield time to other processes
-bkg=1         yield time when the program stops at an i/o statement
-bkg=2         yield time when you hit a subroutine entry point
-bkg=3         yield time at the top of every loop
-bkg=4         yield time whenever you hit a statement with a line #

Each "level" includes the context switches implied by all the lower
levels. In addition you can tell the compiler how many ticks (1/60th
second) must elapse between times when your code is swapped out. I
typically set this to some number comparable to my reaction time, so then
I can let my fortran codes run in the background, then just click on
something and "instantly" I have control over the computer running my word
processor or whatever.

I have no idea why it is only the fortran compilers that support this on
the Mac. It is a wonderful feature and works flawlessly.

I've even ported "real time" data collection codes and gotten them to work
in the background while I run data analysis codes in the foreground. The
big lie is that the Mac can't do that, but it does. And note, this is done
on a Mac IIci, not the latest
PowerMac.