Hi all,

I am trying to parse a few thousands of XML documents using multiple threads and XML::LibXML, but this always ends up in "Segmentation fault", with the following backtrace :

#0  0x0000000000000000 in ?? ()
#1  0x00002aaaab9d632b in __xmlParserInputBufferCreateFilename (URI=0x
+1341e60 "src/local/surfex/OFFLIN/error_write_surf_bin.F90.xml", enc=X
+ML_CHAR_ENCODING_NONE) at xmlIO.c:2633
#2  0x00002aaaab9ad20b in xmlNewInputFromFile__internal_alias (ctxt=0x
+2aaaac9c99d0, filename=0x1341e60 "src/local/surfex/OFFLIN/error_write
+_surf_bin.F90.xml") at parserInternals.c:1511
#3  0x00002aaaab9b0d04 in xmlCreateURLParserCtxt__internal_alias (file
+name=0x1341e60 "src/local/surfex/OFFLIN/error_write_surf_bin.F90.xml"
+, options=0) at parser.c:13964
#4  0x00002aaaab858bd2 in XS_XML__LibXML__parse_file () from /cnrm/gp/
+mrpm/mrpm609/install/yukisc2/perl-5.16.2/lib/site_perl/5.16.2/x86_64-
+linux-thread-multi/auto/XML/LibXML/LibXML.so
#5  0x000000000049b33f in Perl_pp_entersub ()
#6  0x0000000000499afe in Perl_runops_standard ()
#7  0x0000000000431e70 in Perl_call_sv ()
#8  0x00002aaaabde2c05 in S_ithread_run () from /cnrm/gp/mrpm/mrpm609/
+install/yukisc2/perl-5.16.2/lib/5.16.2/x86_64-linux-thread-multi/auto
+/threads/threads.so
#9  0x00002aaaab179193 in start_thread () from /lib64/libpthread.so.0
#10 0x00002aaaab34df0d in clone () from /lib64/libc.so.6

[download]

I am using perl 5.16.2 and libxml2 2.9.0, both configured with threads.

Here is what my perl code looks like :

use strict;
use Data::Dumper;
use XML::LibXML;
use threads;

my @file = <DATA>; 
chomp for (@file);

my $n = shift () || 4;

my @t = map { 'threads'->create (sub 
                                   { 
                                     for my $file (@file) 
                                       {
                                         print "$file\n";
                                         eval {  
                                           my $d = 'XML::LibXML'->load
+_xml (location => "$file.xml");
                                         };
                                         $@ && print "@=$@\n";
                                       }
                                     print "done...\n";
                                     return 0;
                                   }
                                )
            } (1 .. $n); 


for my $t (@t) 
  {
    $t->join ();
  }

__DATA__

[download]

I have written a pure C/libxml2/pthread program which does the very same thing, and it appears to work correctly, so I am stuck and do not have a clue on how to solve the failure in my perl script.

Does someone have an idea on what I should do to have XML::LibXML working with perl threads ?

Cheers,

Philippe

In reply to XML::LibXML and threads by philou

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