I'm trying to fix a serious bug in my Win32::SystemInfo module that affects Win9x. The fix involves including a DLL with the module that will determine the CPU speed. The DLL contains code released by Intel, and I have successfully used it in a Visual C++ based project at work. I can't seem to get it work with Win32::API, however.
The function I'm calling in the DLL is defined like this:
struct FREQ_INFO cpuspeed(int clocks);. FREQ_INFO is a struct that contains four unsigned longs.

My test code is this:
use strict;

use Win32::API;

my $FREQ_INFO = pack("L4",0,0,0,0);
my $CpuSpeed ||= new Win32::API
("cpuinf32", "cpuspeed", ["I"], "P")
 or die "Could not load DLL\n";

$FREQ_INFO = $CpuSpeed->Call(0);

my ($in_cycles, $ex_ticks, $raw_freq, $norm_freq) = unpack("L4",$FREQ_
+INFO);

print "In cycles: $in_cycles\n";
print "Ex ticks: $ex_ticks\n";
print "Raw freq: $raw_freq\n";
print "Norm freq: $norm_freq\n";

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Running this code generates a Privileged Instruction exception. I thought that the problem might lie in the code I'm calling, since it executes ring 0 operations on the CPU. I changed the Win32::API call to import a different function, called cpunormspeed, that takes an int and returns an unsigned long. When I make that function call, I get a generic application error.
Am I making an error in the return parameter? Should I just get the return value in an I or N and unpack it without packing first?

Guildenstern
Negaterd character class uber alles!

In reply to Difficulties with Win32::API by Guildenstern

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