Re: Memory Leak?

Chris Cheung <[email protected]> writes:

>   I need to use Xerces-Perl to repeatedly
>  
>     - parse XML to DOM tree
>     - manipulate the DOM tree
>     - pretty-print the DOM tree
> 
> It seems that serious memory leak occurs. I do not hold any reference to 
> the Perl Xerces object used in the programme and hence the Perl objects 
> should be DESTROYed after use, but memory usage keeps on increasing as 
> reported by the OS.

Hi Chris,

So I think I've solved this. First use DOMBuilder, and second ensure
that resetDocumentPool() gets called after you are finished with the
DOM tree. Here's some code stolen from my memtest.pl:

my $impl = XML::Xerces::DOMImplementationRegistry::getDOMImplementation('LS');
my $parser = $impl->createDOMBuilder($XML::Xerces::DOMImplementationLS::MODE_SYNCHRONOUS,'');


sub validate_builder {
  my $xml = shift ;
  my $parser = shift;

  eval {
    $parser->setFeature("$XML::Xerces::XMLUni::fgDOMNamespaces", $namespace) ;
    $parser->setFeature("$XML::Xerces::XMLUni::fgXercesSchema", $schema) ;
    $parser->setFeature("$XML::Xerces::XMLUni::fgXercesSchemaFullChecking", $schema) ;
#    $parser->setFeature("http://apache.org/xml/features/validation-error-as-fatal", $validate) ;
  };
  XML::Xerces::error($@) if $@;


  eval {
    $parser->setFeature("$XML::Xerces::XMLUni::fgDOMValidation", $validate) ;
#    $parser->setFeature("$XML::Xerces::XMLUni::fgDOMValidateIfSchema", 0) ;
  };
  XML::Xerces::error($@) if $@;

  eval {
    # my $is = XML::Xerces::MemBufInputSource->new($xml);
    # my $is = XML::Xerces::LocalFileInputSource->new($OPTIONS{file});
    $parser->parseURI($OPTIONS{file}) ;
  } ;
  XML::Xerces::error($@) if $@;
  $parser->resetDocumentPool();
}

Using this code I'm not getting any perceptable leaks with 2.3.0-4.

Let me know if this helps,
jas.