Re^3: Memory Leak using Win32::OLE::Variant for a SafeArray passed by Reference

Unfortunately, ->DESTROY is not a valid method for the MSFileReader software.

Its not supposed to be. DESTROY is perl name for the destructor, destructors usually do things like break circular references (parent/child/parent) ... things that leak memory; Re: cpu, memory, and permissions issues with Win32::OLE

Win32::OLE::Variant provides a DESTROY method http://cpansearch.perl.org/src/JDB/Win32-OLE-0.1712/OLE.xs


void
DESTROY(self)
    SV *self
PPCODE:
{
    WINOLEVARIANTOBJECT *pVarObj = GetOleVariantObject(aTHX_ self);
    if (pVarObj) {
    RemoveFromObjectChain(aTHX_ (OBJECTHEADER*)pVarObj);
        ClearVariantObject(pVarObj);
    Safefree(pVarObj);
    }

    XSRETURN_EMPTY;
}
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I think I need a way to deallocate the SafeArray using perl (prefered) or a way to deallocate all memory associated with the MSFileReader.

undef does that -- if undef doesn't do it, something else is holding a reference ... say the dll itself

You have to find what MSFileReeader needs in the docs

Another thing to try http://search.cpan.org/grep?cpanid=JDB&release=Win32-OLE-0.1712&string=destroy&i=1&n=1&C=0 reveals SafeArrayDestroy is used internally. SafeArrayDestroy finds SafeArrayDestroy function (Automation) which says

Destroys an existing array descriptor and all of the data in the array. If objects are stored in the array, Release is called on each object in the array

So next you can try SafeArrayDestroy and Release

Also, from DESTROy above, there is ClearVariantObject, another one to try

If none of these works, you'll have to mine the MSFileReeader docs ...

I am not sure how a foreach loop helps ...

Its a tip about perl syntax, because of your writing my $woo; for( $woo=0; ... )

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Re^4: Memory Leak using Win32::OLE::Variant for a SafeArray passed by Reference by Anonymous Monk on Jun 24, 2014 at 05:57 UTC
Close method undef of Com object causes small deallocation of memory but bulk of problem remains. `$thermo_raw_file->Close;` `undef $thermo_raw_file;` I have looked for code examples on how to code ClearVariantObject, SafeArrayDestroy, or Win32::OLE::Destroy in perl without much sucess so I am not sure if my failures are based on approach or the wrong syntax. The $pvarMassList SafeArray changes type from VT_EMPTY to VT_R8 upon successful GetMassListFromScanNum. Could this change in type controlled by the DLL cause perl to loose control of the SafeArray? Thank you for the help. I appreciate all the suggestions.	[reply] [d/l] [select]
Re^5: Memory Leak using Win32::OLE::Variant for a SafeArray passed by Reference by Anonymous Monk on Jun 24, 2014 at 07:39 UTC
Close method undef of Com object causes small deallocation of memory but bulk of problem remains. Did you try Release-ing all the arguments to GetMassListFromScanNum? Could this change in type controlled by the DLL cause perl to loose control of the SafeArray? I don't think so ; what i've read so far, reference counting is how COM deals with keeping objects alive -- same as perl does ; its unlikely Win32::OLE is creating any circular references (:anymore:), so the problem is likely with MSFileReader... You might try VMMap or Virtual Memory Map Viewer to see if you can narrow it down say add a pause (scalar readline STDIN; ) before and after GetMassListFromScanNumk and see what you can see :/	[reply]