[XERCESC-987] Memory leak in xerces library

• Type: Bug
• Status: Resolved
• Resolution: Incomplete
• Affects Version/s: 2.3.0
• Component/s: Validating Parser (DTD)
• Environment: Operating System: Solaris; Platform: Sun
• Bugzilla Id: 22693
• Assignee: Unassigned
• Reporter: Siddharth Toshniwal
• Created: 25/Aug/03 21:40
• Updated: 22/Apr/04 12:36
• Resolved: 22/Apr/04 12:36

Description

Hi,

Am developing an application on Solaris 2.8 using the
Xerces SAX2 parser (library
version 2.3.0) in which I
do validation using an external DTD. Am facing a memory
leak in the
app in both the following cases:

a. XML document gets parsed successfully,
b. XML
document fails to parse due to DTD validation failure.

To verify whether this leak is in the
library code or
my application, I instrumented the SAX2Count application
(provided in the
Xerces package) with purify (Version
2003.06.00 Solaris 2) and ran the same giving it
the
XML document written below. I got the following purify
report.

-------------- Purify report for
sample begin --------------
MLK: 24 bytes leaked at 0xcceb8

• This memory was allocated from:
  malloc
  [rtlib.o]
  new_eh_context [libgcc2.c]
  eh_context_specific
  [libgcc2.c]
  eh_context_initialize [libgcc2.c]
  __get_eh_info
  [libgcc2.c]
  __cp_push_exception
  [exception.cc:215]
  xercesc_2_3::XMLURL::setURL(const unsigned short*,const
  unsigned short*) [libxerces-
  c.so.23]
  xercesc_2_3::XMLURL::xercesc_2_3::XMLURL(const unsigned short*,const
  unsigned short*,xercesc_2_3::MemoryManager*) [libxerces-
  c.so.23]
  xercesc_2_3::ReaderMgr::createReader(const unsigned short*,const unsigned
  short*,bool,xercesc_2_3::XMLReader::RefFrom,xercesc_2_3::XMLReader::Types,xercesc_2_3::XMLReader::Sources,xercesc_2_3::InputSource*&,bool)
  [libxerces-c.so.23]
  xercesc_2_3::IGXMLScanner::scanDocTypeDecl() [libxerces-
  c.so.23]
  xercesc_2_3::XMLScanner::scanProlog() [libxerces-
  c.so.23]
  xercesc_2_3::IGXMLScanner::scanDocument(const
  xercesc_2_3::InputSource&) [libxerces-
  c.so.23]
  xercesc_2_3::XMLScanner::scanDocument(const unsigned short*) [libxerces-
  c.so.23]
  xercesc_2_3::XMLScanner::scanDocument(const char*) [libxerces-
  c.so.23]
  xercesc_2_3::SAX2XMLReaderImpl::parse(const char*) [libxerces-
  c.so.23]
  main [SAX2Count.o]
  _start [crt1.o]
  • • • • • • • • • • • • • • Purify report for sample end ---------------

The
leak is not in the same location as where I got it
for my app, but even my leak is caused due to an
exception
thrown within the Xerces DTDValidator code. Is there an
issue in which the
exceptions are thrown? Or is there
some problem with purify?

The difference between
SAX2Count and my app is that I've
implemented the resolveEntity(), error() and
fatalError()
callbacks in my cbk handler.

-------------- Purify report for my app begin --------------
MLK: 24 bytes
leaked at 0x116f50

• This memory was allocated from:
  malloc [rtlib.o]
  new_eh_context
  [libgcc2.c]
  eh_context_specific [libgcc2.c]
  eh_context_initialize
  [libgcc2.c]
  __get_eh_info [libgcc2.c]
  __cp_push_exception
  [exception.cc:215]
  xercesc_2_3::ReaderMgr::popReader() [libxerces-
  c.so.23]
  xercesc_2_3::ReaderMgr::skipPastSpaces() [libxerces-
  c.so.23]
  xercesc_2_3::DTDScanner::scanExtSubsetDecl(bool,bool) [libxerces-
  c.so.23]
  xercesc_2_3::IGXMLScanner::scanDocTypeDecl() [libxerces-
  c.so.23]
  xercesc_2_3::XMLScanner::scanProlog() [libxerces-
  c.so.23]
  xercesc_2_3::IGXMLScanner::scanDocument(const
  xercesc_2_3::InputSource&) [libxerces-
  c.so.23]
  xercesc_2_3::XMLScanner::scanDocument(const unsigned short*) [libxerces-
  c.so.23]
  xercesc_2_3::XMLScanner::scanDocument(const char*) [libxerces-
  c.so.23]
  xercesc_2_3::SAX2XMLReaderImpl::parse(const char*) [libxerces-
  c.so.23]
  Sdf_fn_parseCPL(const char*,Sdf_tg_cplStruct*,unsigned int)
  [sdfcplxerparser.cpp:1220]
  main [sdfcplutility.cpp:1443]
  _start [crt1.o]

  • • • • • • • • • • • • • • Purify report for my app end ---------------

Can you please investigate? Also, please let me know
in case
you need any further inputs? I would have liked
to attatch the XML and the DTD files, but I don't
see
a way of doing that in the web interface. Please mail
me in case you need those to
investigate.

Thanks for your help.
Siddharth.