#! perl -slw
use strict;
use Win32::API::Prototype;

ApiLink( 'kernel32', q[
	BOOL QueryPerformanceCounter( LARGE_INTEGER *lpPerformanceCount )
]) or die $^E;

ApiLink( 'kernel32', q[
	BOOL QueryPerformanceFrequency( LARGE_INTEGER *lpPerformanceCount )
]) or die $^E;

sub int64_to_NV {
	my( $lo, $hi ) = unpack 'VV', $_[ 0 ];
	return $hi * 2**32 + $lo;
}

my $frequency = ' ' x 10;
QueryPerformanceFrequency( $frequency ) or die $^E;

print 'Counter changes ', int64_to_NV( $frequency ), ' times/second';

for ( 1 .. 10 ) {
	QueryPerformanceCounter( $frequency )or die $^E;
	print int64_to_NV( $frequency );
}
__END__
P:\test>375475
Counter changes 3579545 times/second
699092440218
699092440527
699092440794
699092441059
699092441312
699092441566
699092441820
699092442073
699092442322
699092442576