errno, threads, Numeric etc... how to debug this?

[Steve Spicklemire]

Hi Folks,

I'm trying to build Numeric on MacOSX and while it basically works... it 
seems there are some problems. When I try to run the Demos/NumTut 
examples (using xfree86 and python2.2 from fink) I get random 
"unexpected math error" exceptions.

I checked the source and discovered that the errors are occuring in 
ufuncmodule. I edited ufuncmodule to get more info like so:

[spicklemire:~/Packages] steve% diff -c 
Numeric-20.3-orig/Src/ufuncobject.c Numeric-20.3/Src/ufuncobject.c
*** Numeric-20.3-orig/Src/ufuncobject.c Tue Aug 14 11:18:24 2001
--- Numeric-20.3/Src/ufuncobject.c      Mon Feb 25 15:42:08 2002
***************
*** 470,477 ****
         if (self->check_return) check_array(mps[i]);
       }

!     if (self->check_return && errno != 0) {math_error(); return -1;}
!
       return 0;
   }

--- 470,488 ----
         if (self->check_return) check_array(mps[i]);
       }

!     if (self->check_return && (errno != 0))
!       {
!       if ((errno == EDOM) || (errno == ERANGE))
!         {
!           math_error(); return -1;
!         }
!       else
!         {
!           fprintf(stderr, "Hmm.. error encountered -> %i\n", errno);
!           perror("error in ufunc generic function:");
!         }
!       }
!
       return 0;
   }


Now when I try to run the NumTut demo I see:

[spicklemire:~/Packages/Numeric-20.3/Demo] steve% python -c "import 
NumTut;NumTut.test()"
 >>> view(greece)
 >>> view(1.0-greece)
Hmm.. error encountered -> 35
error in ufunc generic function:: Resource temporarily unavailable
 >>> view(greeceBW)
 >>> view(greece*xgrade)
 >>> view(greece*ygrade)
 >>> negative = 1.0 - greece
 >>> view(greece*xgrade + negative*ygrade)
 >>> view(red)
 >>> view(green)
 >>> view(blue)
 >>> sine = sin(xgrade*6*pi)
 >>> view(green*sine + red*(1.0-sine))
 >>> view(green + red[::-1])
 >>> view(transpose(greece, (1,0,2)))
[spicklemire:~/Packages/Numeric-20.3/Demo] steve% python -c "import 
NumTut;NumTut.test()"
 >>> view(greece)
 >>> view(1.0-greece)
 >>> view(greeceBW)
 >>> view(greece*xgrade)
 >>> view(greece*ygrade)
 >>> negative = 1.0 - greece
 >>> view(greece*xgrade + negative*ygrade)
 >>> view(red)
 >>> view(green)
 >>> view(blue)
 >>> sine = sin(xgrade*6*pi)
 >>> view(green*sine + red*(1.0-sine))
 >>> view(green + red[::-1])
 >>> view(transpose(greece, (1,0,2)))
[spicklemire:~/Packages/Numeric-20.3/Demo] steve% python -c "import 
NumTut;NumTut.test()"
 >>> view(greece)
 >>> view(1.0-greece)
Hmm.. error encountered -> 35
error in ufunc generic function:: Resource temporarily unavailable
 >>> view(greeceBW)
 >>> view(greece*xgrade)
 >>> view(greece*ygrade)
 >>> negative = 1.0 - greece
 >>> view(greece*xgrade + negative*ygrade)
 >>> view(red)
 >>> view(green)
 >>> view(blue)
 >>> sine = sin(xgrade*6*pi)
 >>> view(green*sine + red*(1.0-sine))
 >>> view(green + red[::-1])
 >>> view(transpose(greece, (1,0,2)))

So... ufuncs just multiply, divide and suchlike! What "resources" are 
not available? It's fairly clear that it's thread related, since all the 
Numeric tests pass every time in a non-threaded example, as well as my 
own non-threaded testing to attempt to reproduce what I thought 
originally was a linking problem.

So... how can I track down where errno is actually getting set? Does the 
fact that it happens "randomly" mean that it's not due to some numerical 
computation, but more likely about timing between threads?

Also.. it seems that on MacOSX there is a separate "errno" value for 
each thread... so how could they be confused?

thanks for any insight. ;-)

-steve