Hi!

Mission: Collect data from various sources and write to xml-file as soon as the data is available using multithreading.

Code:
use XML::Writer;
use IO::File;
use threads;
use strict;

my $output = new IO::File(">output.xml");

my $writer = new XML::Writer(OUTPUT => $output, DATA_MODE=>1, DATA_IND
+ENT=>1,CHECK_PRINT=>1);

$writer->xmlDecl("UTF-8");




$writer->startTag('operations');

my $thr1 = threads->new(\&writeArticleData1);
my $thr2 = threads->new(\&writeArticleData2);


while (!(($thr1->join) && ($thr2->join)))
{
    # Wait for threads to finish
}

$writer->endTag("operations");
$writer->end();
$output->close();



sub writeArticleData1()
{
    lock($writer);

    $writer->startTag('product');
    $writer->characters("Hello, world!");
    $writer->endTag("product");
    
    sleep 2;
    
    return 1;
    
}

sub writeArticleData2()
{
    lock($writer);

    $writer->startTag('product');
    $writer->characters("Hello, world2!");
    $writer->endTag("product");
    
    return 1;
}

1;

[download]

Output:
<?xml version="1.0" encoding="UTF-8"?>

<operations>
 <product>Hello, world2!</product>
 <product>Hello, world!</product></operations>

[download]

I'm very close to reach my goal as you can see, but for some reason, the closing tag for operations doesn't get it's own row as supposed. Which makes me questioning my way of doing it. So, questions:

1. Am I using threads in the right way?
2. Am I thinking correct regarding the "lock" usage?
3. Do you see any other pitfalls regarding scoping and such?
4. Can I fix the particular problem?

The resulting document _doesn't_ need to be formatted as such, I'm just questioning my own ways of using threading in this case. Maybe XML::Writer doesn't support it? Or maybe a filehandle issue?

In reply to Multithreaded xml writing using XML::Writer by DreamT

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