I'm using multithreading in a Perl script. However, I get segmentation fault and I believe its when the threads are joined. I'm not sure what I might be doing wrong. I have used print statements to indicate when threads start and end and a print statement in the join block and finally the print statement to indicate the end of the program. Here's a snippet.

#!/usr/bin/perl

use DBI;
use POSIX;
use Data::Dumper;
use Fcntl ':flock';
use strict;
use warnings;
use threads;
use threads::shared;
use "some IPAM system's package name";

my $host = "1.1.1.1";
my $database = "some_db";
my $user = "some_user";
my $pswd = "some_pswd";

my @threads;

my $dbh = DBI->connect("DBI:mysql:$database;host=$host", $user, $pswd 
+,) || die "Could not connect to database: $DBI::errstr";
$dbh->{'mysql_auto_reconnect'} = 1;

my $sql = qq{
    #a select statement
};

my $sth = $dbh->prepare($sql);
$sth->execute();
my $rows = 0;
my @uni_array;

while(my @request = $sth->fetchrow_array())
{

    #initiated IPAM session


    my @retrieved_objs = #searching for some results

    push @uni_array, @retrieved_objs;

    foreach(@retrieved_objs)
    {
        $rows++;        
    }
}

my $number = $rows/10;
my $ceil = ceil($number);

for ( my $count = 1; $count <= $ceil; $count++) {
        my $t = threads->new(\&sub1, $count);
        push(@threads,$t);
}

foreach (@threads) {

        my $num = $_->join();
        print "done with $num\n";
}

print "End of main program\n";

sub sub1 {
        my $num = shift;

        print "started thread $num\n";
        #some code

        sleep($num);
        print "done with thread $num\n";
        return $num;
}
$sth->finish();
$dbh->disconnect;

[download]

In reply to segmentation fault issue while joining threads in perl by userr_1

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.