Hi costin,
I think you can solve this problem by creating objects in
proper order. For instance, first you declare global object of dom_initialiser
and followed by static variables declaration.
Regards
Raman
> From: [EMAIL PROTECTED]> To: [EMAIL PROTECTED]> CC: [email protected]>
> Subject: FW: calling Initialize/Terminate from a static object generates mem
> leaks> Date: Wed, 28 May 2008 17:21:09 +0200> > Hi,> > I'm using xerces 2.7
> on Windows XP SP3, Visual Studio 2003. Everything was> fine until I needed to
> declare a static variable (at file scope) which, in> turn, contained
> references to xerces objects that need xercesc_2_7> ::Initialize/
> xercesc_2_7::Terminate pair functions to be called first.> Thus, I had to
> find a way to call xercesc_2_7::Initialize before entering> main function.
> Here is my file:> > #include <xercesc/util/PlatformUtils.hpp>> > struct
> dom_initialiser> {> dom_initialiser ()> {>
> xercesc_2_7::XMLPlatformUtils::Initialize();> }> > ~ dom_initialiser ()> {>
> xercesc_2_7::XMLPlatformUtils::Terminate();> }> };> > dom_initialiser t; > >
> int main(int argc, char* argv[])> {> return 0;> }> > > > Although the program
> is trivial, Rational Purify reports memory leaks! I> investigated to see how
> serious the warnings/memory leaks are and I> discovered the following:> > 1.
> xerces uses XMLRegisterCleanup to clean up some stuff. Static objects of>
> type XMLRegisterCleanup are instantiated through xerces cpp files and>
> XMLRegisterCleanup::registerCleanup method is afterwards called to register>
> pointers to functions that will do the actual clean up. Internally, the>
> class holds two pointers which serve to implement a doubly linked list,>
> gXMLCleanupList. > > 2. XMLPlatformUtils::Terminate() (platformsutils.cpp
> file) method iterates> over gXMLCleanupList and calls doCleanup(). > > > >
> The problem with this approach is that some of (all) the static objects are>
> used BEFORE their initialization! That's the reason why rational purify>
> detects memory leaks! For instance, in file TransService.cpp the objects> >
> static XMLRegisterCleanup mappingsCleanup;> static XMLRegisterCleanup
> mappingsRecognizerCleanup;> > are used in the constructor
> XMLTransService::XMLTransService() before their> initialization (lines 94,
> 107):> > mappingsCleanup.registerCleanup(reinitMappings); // mappingsCleanup
> not> initialized!!!!> > > I solved this by creating a new function(s):>
> XMLRegisterCleanup & mappingsCleanup()> {> static XMLRegisterCleanup
> mappingsCleanup;> return mappingsCleanup;> }> and calling
> mappingsCleanup().registerCleanup(reinitMappings);> > > Question: do you
> think guys that this approach is ok? Can you spot any> hidden issue that is
> not so obvious? Do you think that it would be a good> idea to change all
> static instances of XMLRegisterCleanup objects to> functions?> > > If you
> look inside the file XMLRegisterCleanup.hpp there is a comment> saying:> >
> "// N.B. These objects need to be statically allocated. I couldn't think> //
> of a neat way of ensuring this - can anyone else?"> > > > That is all with
> the static construction. Now, let's move on destruction: > >
> xercesc_2_7::XMLPlatformUtils::Terminate() must be called last. Therefore, I>
> isolated struct test into an hpp that is included FIRST by any project hpp>
> that uses xerces. The files (hpp and cpp) look like this:> > >
> ########################################dom_init.hpp#####################> >
> #ifndef DOM_INIT_HPP> #define DOM_INIT_HPP> > class dom_initialiser> {>
> public:> ~dom_initialiser();> dom_initialiser();> > };> > namespace > {> /**>
> * Dummy object that forces the creation of dom_initialiser.> * This will
> ensure that creating static or file scope> * instances of xml::str is not
> done before the XML lib is> * properly initialised AND
> XMLPlatformUtils::Terminate() is> called> last (after all xerce objects have
> been destroyed) > */> > dom_initialiser __dummy__dom_initialiser__;> }>
> #endif> > > > #########################dom_init.cpp#########################>
> > #include "dom_init.hpp"> using namespace xercesc; > >
> dom_initialiser::dom_initialiser()> {> XMLPlatformUtils::Initialize();> }> >
> dom_initialiser::~dom_initialiser()> {> XMLPlatformUtils::Terminate();> }> >
> With this approach I completely eliminated the need of explicit call to>
> Initialize/Terminate! > > > > Please feel free to criticize. Any comments are
> welcomed!> > > Costin. > > >
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