Function wipeWithPattern

DevIL/test/Stress/mmgr.cpp:445–497

// ---------------------------------------------------------------------------------------------------------------------------------

static	void	wipeWithPattern(sAllocUnit *allocUnit, unsigned long pattern, const unsigned int originalReportedSize = 0)
{
	// For a serious test run, we use wipes of random a random value. However, if this causes a crash, we don't want it to
	// crash in a differnt place each time, so we specifically DO NOT call srand. If, by chance your program calls srand(),
	// you may wish to disable that when running with a random wipe test. This will make any crashes more consistent so they
	// can be tracked down easier.

	if (randomWipe)
	{
		pattern = ((rand() & 0xff) << 24) | ((rand() & 0xff) << 16) | ((rand() & 0xff) << 8) | (rand() & 0xff);
	}

	// -DOC- We should wipe with 0's if we're not in debug mode, so we can help hide bugs if possible when we release the
	// product. So uncomment the following line for releases.
	//
	// Note that the "alwaysWipeAll" should be turned on for this to have effect, otherwise it won't do much good. But we'll
	// leave it this way (as an option) because this does slow things down.
//	pattern = 0;

	// This part of the operation is optional

	if (alwaysWipeAll && allocUnit->reportedSize > originalReportedSize)
	{
		// Fill the bulk

		long	*lptr = reinterpret_cast<long *>(reinterpret_cast<char *>(allocUnit->reportedAddress) + originalReportedSize);
		int	length = static_cast<int>(allocUnit->reportedSize - originalReportedSize);
		int	i;
		for (i = 0; i < (length >> 2); i++, lptr++)
		{
			*lptr = pattern;
		}

		// Fill the remainder

		unsigned int	shiftCount = 0;
		char		*cptr = reinterpret_cast<char *>(lptr);
		for (i = 0; i < (length & 0x3); i++, cptr++, shiftCount += 8)
		{
			*cptr = static_cast<char>((pattern & (0xff << shiftCount)) >> shiftCount);
		}
	}

	// Write in the prefix/postfix bytes

	long		*pre = reinterpret_cast<long *>(allocUnit->actualAddress);
	long		*post = reinterpret_cast<long *>(reinterpret_cast<char *>(allocUnit->actualAddress) + allocUnit->actualSize - paddingSize * sizeof(long));
	for (unsigned int i = 0; i < paddingSize; i++, pre++, post++)
	{
		*pre = prefixPattern;
		*post = postfixPattern;
	}
}

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