#! perl -slw
use strict;
use IO::File;
use threads;
use threads::shared;

BEGIN {
	$| = 1;
	our $TRACE ||= 0;
	print "TRACE=$TRACE";
	*CORE::GLOBAL::warn = sub {} unless $TRACE;
}

sub processData {
	printf @_;
}

sub getDataT {
	my ( $handle, $sharedDataRef, $doneRef ) = @_;
	while( !$handle->eof ) {
			warn "t-Locking" . $/;
		lock $$sharedDataRef;
			warn 't-Waiting' . $/;
		cond_wait( $$sharedDataRef ) while $$sharedDataRef;
			warn 't-Setting' . $/;
		$$sharedDataRef = $handle->getline;
			warn 't-Signalling' . $/;
		cond_signal( $$sharedDataRef );
	}
	$$doneRef = 1;
	return;
}

my $handle = IO::File->new( $ARGV[ 0 ], 'r' );
my $sharedData :shared;
my $done :shared = 0;
threads->create( \&getDataT, $handle, \$sharedData, \$done );

while( !$done ) {
		warn 'm-locking' . $/;
	lock $sharedData;
		warn 'm-waiting' . $/;
	cond_wait $sharedData until $sharedData;
		warn 'm-Copying' . $/;
	my $localCopy = $sharedData;
		warn 'm-undefing' . $/;
	undef( $sharedData );
		warn 'm-signalling' . $/;
	cond_signal $sharedData;
		warn 'm-processing' . $/;
	processData( $localCopy );
}