I'm with James Berry on this. We currently have some circumstantial evidence that 8-byte alignment might sometimes be a problem on Windows. It seems premature to commit code that will affect all Windows users in the absence of clear evidence that 16-byte alignment is actually required (ideally a document to that effect), and a clear understanding of what the relevant circumstances are. Even then, a FAQ might be preferable, if a small minority of users are deemed likely to be affected.
> -----Original Message----- > From: Ronald Landheer-Cieslak > [mailto:[EMAIL PROTECTED] > Sent: Monday, October 27, 2003 10:38 AM > To: Xerces-C XML parser developers > Subject: Memory (pointer) alignment on Win32 platform > > > As of version 2.3.0, the new memory management class (XMemory) aligns > memory according to the value returned by > XMLPlatformUtils::alignPointerForNewBlockAllocation. This > value is 8 on > Win32 (using MSVC6 - haven't tried with Borland or MSVC7 yet). > > In a COM object we're using that uses Xerces-C for its XML > parsing we've > been having some problems that I suspect are caused by this > alignment: the > debug CRTL that comes with MSVC6 aligns to an offset of 16 > bytes and tests > with the alignment set to 16 bytes (using > XML_PLATFORM_NEW_BLOCK_ALIGNMENT) > have not reproduced the problem. Hence, I'd like to propose a > patch that > sets XML_PLATFORM_NEW_BLOCK_ALIGNMENT to 16 on Windows. > > Before I do that, I need to know the following: > * should I patch Win32Defs.hpp or some other file (like, e.g. > MVSCPPDefs.hpp) > * would such a patch be acceptable? > > The test case used can't be published because the code is > proprietary. I should > say that the bug appears random and appears after a very, > very long time using > the component with 5 separate concurrent clients, using > mostly the DOM parser. > > rlc > > NB: this does not affect the previous thread that questions > the way Xerces > should deal with XML_PLATFORM_NEW_BLOCK_ALIGNMENT < sizeof(void*) > > -- > Can anyone remember when the times were not hard, and money > not scarce? --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
