parallely execution of perl language - perl

Question

I have a perl program that read the packets of a flow from a pcap file, but it takes a lot of time,I want to make it parallel,but I don't know is it possible or not?if yes can I do it with MPI?and another question, the best way for making this code parallel,here is the piece of my code ( I think I should work on this part for paralleling, but I don't know the best way!)
while (!eof($inFileH))
{
#inFileH is the handler of the pcap file
#in each while I read one packet
$ts_sec = readBytes($inFileH,4);
$ts_usec = readBytes($inFileH,4);
$incl_len = readBytes($inFileH,4);
$orig_len = readBytes($inFileH,4);
if ($totalLen == 0) # it is the 1st packet
{
$startTime = $ts_sec + $ts_usec/1000000;
}
$timeStamp = $ts_sec + $ts_usec/1000000 - $startTime;
$totalLen += $orig_len;
$#packet = -1; n # initing the array
for (my $i=0 ; $i<$incl_len ; $i++) #read all included octects of the current packet
{
read $inFileH, $packet[$i], 1;
$packet[$i] = ord($packet[$i]);
}
#and after that I will work on the "packet" and analyze it
so how should I send the file content for other processors to work on it in parallel.....

Answer 1

First you need to determine the bottleneck. If it is really CPU usage (i.e. CPU usage is at 100% while you are running the script), you need to figure out where the processing spends its time.
This may well be in the way that you are parsing the input. There may be obvious ways to speed this up. For instance, if you use complex regular expressions, and focus exclusively on matching input correctly, there may be ways to make the matching a lot faster by rewriting the expressions or doing simpler matches before trying more complex ones.
If you can't reduce CPU usage far enough in this way, and you really want to parallelize, see if you can employ the mechanism with which Perl was born: Unix pipes. You can write Perl scripts that pass data through to each other in a pipeline, or you can do the creation of the processes and pipes within Perl itself (see perlopentut, and if that isn't enough, perlipc).
As a general rule, I would consider these options first before trying other mechanisms, but it really depends of the details of what you're trying to do and the context in which you need to do it.