C++ AllocSizeIsValid函數代碼示例

/*
 * MemoryContextAllocZeroAligned
 *		MemoryContextAllocZero where length is suitable for MemSetLoop
 *
 *	This might seem overly specialized, but it's not because newNode()
 *	is so often called with compile-time-constant sizes.
 */
void *
MemoryContextAllocZeroAligned(MemoryContext context, Size size)
{
	void	   *ret;

	AssertArg(MemoryContextIsValid(context));
	AssertNotInCriticalSection(context);

	if (!AllocSizeIsValid(size))
		elog(ERROR, "invalid memory alloc request size %zu", size);

	context->isReset = false;

	ret = (*context->methods->alloc) (context, size);
	if (ret == NULL)
	{
		MemoryContextStats(TopMemoryContext);
		ereport(ERROR,
				(errcode(ERRCODE_OUT_OF_MEMORY),
				 errmsg("out of memory"),
				 errdetail("Failed on request of size %zu.", size)));
	}

	VALGRIND_MEMPOOL_ALLOC(context, ret, size);

	MemSetLoop(ret, 0, size);

	return ret;
}

/*
 * MemoryContextContains
 *		Detect whether an allocated chunk of memory belongs to a given
 *		context or not.
 *
 * Caution: this test is reliable as long as 'pointer' does point to
 * a chunk of memory allocated from *some* context.  If 'pointer' points
 * at memory obtained in some other way, there is a small chance of a
 * false-positive result, since the bits right before it might look like
 * a valid chunk header by chance.
 */
bool
MemoryContextContains(MemoryContext context, void *pointer)
{
	StandardChunkHeader *header;

	/*
	 * Try to detect bogus pointers handed to us, poorly though we can.
	 * Presumably, a pointer that isn't MAXALIGNED isn't pointing at an
	 * allocated chunk.
	 */
	if (pointer == NULL || pointer != (void *) MAXALIGN(pointer))
		return false;

	/*
	 * OK, it's probably safe to look at the chunk header.
	 */
	header = (StandardChunkHeader *)
		((char *) pointer - STANDARDCHUNKHEADERSIZE);

	/*
	 * If the context link doesn't match then we certainly have a non-member
	 * chunk.  Also check for a reasonable-looking size as extra guard against
	 * being fooled by bogus pointers.
	 */
	if (header->context == context && AllocSizeIsValid(header->size))
		return true;
	return false;
}

/*
 * repalloc
 *		Adjust the size of a previously allocated chunk.
 */
void *
repalloc(void *pointer, Size size)
{
	MemoryContext context;
	void	   *ret;

	if (!AllocSizeIsValid(size))
		elog(ERROR, "invalid memory alloc request size %zu", size);

	/* pgpool hack by Muhammad Usama <[email protected]> */
	if(pointer == NULL)
		return palloc(size);

	context = GetMemoryChunkContext(pointer);

	AssertNotInCriticalSection(context);

	/* isReset must be false already */
	Assert(!context->isReset);

	ret = (*context->methods->realloc) (context, pointer, size);
	if (ret == NULL)
	{
		MemoryContextStats(TopMemoryContext);
		ereport(ERROR,
				(errcode(ERRCODE_OUT_OF_MEMORY),
				 errmsg("out of memory"),
				 errdetail("Failed on request of size %zu.", size)));
	}

	VALGRIND_MEMPOOL_CHANGE(context, pointer, ret, size);

	return ret;
}

/*
 * MemoryContextAllocExtended
 *		Allocate space within the specified context using the given flags.
 */
void *
MemoryContextAllocExtended(MemoryContext context, Size size, int flags)
{
	void	   *ret;

	AssertArg(MemoryContextIsValid(context));
	AssertNotInCriticalSection(context);

	if (((flags & MCXT_ALLOC_HUGE) != 0 && !AllocHugeSizeIsValid(size)) ||
		((flags & MCXT_ALLOC_HUGE) == 0 && !AllocSizeIsValid(size)))
		elog(ERROR, "invalid memory alloc request size %zu", size);

	context->isReset = false;

	ret = (*context->methods->alloc) (context, size);
	if (ret == NULL)
	{
		if ((flags & MCXT_ALLOC_NO_OOM) == 0)
		{
			MemoryContextStats(TopMemoryContext);
			ereport(ERROR,
					(errcode(ERRCODE_OUT_OF_MEMORY),
					 errmsg("out of memory"),
					 errdetail("Failed on request of size %zu.", size)));
		}
		return NULL;
	}

	VALGRIND_MEMPOOL_ALLOC(context, ret, size);

	if ((flags & MCXT_ALLOC_ZERO) != 0)
		MemSetAligned(ret, 0, size);

	return ret;
}

/*
 * MemoryContextAllocZeroAligned
 *		MemoryContextAllocZero where length is suitable for MemSetLoop
 *
 *	This might seem overly specialized, but it's not because newNode()
 *	is so often called with compile-time-constant sizes.
 */
void *
MemoryContextAllocZeroAlignedImpl(MemoryContext context, Size size, const char* sfile, const char *sfunc, int sline)
{
	void	   *ret;

#ifdef PGTRACE_ENABLED
	StandardChunkHeader *header;
#endif

	AssertArg(MemoryContextIsValid(context));

#ifdef CDB_PALLOC_CALLER_ID
	context->callerFile = sfile;
	context->callerLine = sline;
#endif

	if (!AllocSizeIsValid(size))
		MemoryContextError(ERRCODE_INTERNAL_ERROR,
				context, CDB_MCXT_WHERE(context),
				"invalid memory alloc request size %lu",
				(unsigned long)size);

	ret = (*context->methods.alloc) (context, size);

	MemSetLoop(ret, 0, size);

#ifdef PGTRACE_ENABLED
	header = (StandardChunkHeader *)
		((char *) ret - STANDARDCHUNKHEADERSIZE);
	PG_TRACE5(memctxt__alloc, size, header->size, 0, 0, (long) context->name);
#endif

	return ret;
}

/*
 * repalloc
 *		Adjust the size of a previously allocated chunk.
 */
void *
repalloc(void *pointer, Size size)
{
	MemoryContext context;
	void	   *ret;

	if (!AllocSizeIsValid(size))
		elog(ERROR, "invalid memory alloc request size %zu", size);

	/*
	 * Try to detect bogus pointers handed to us, poorly though we can.
	 * Presumably, a pointer that isn't MAXALIGNED isn't pointing at an
	 * allocated chunk.
	 */
	Assert(pointer != NULL);
	Assert(pointer == (void *) MAXALIGN(pointer));

	/*
	 * OK, it's probably safe to look at the chunk header.
	 */
	context = ((StandardChunkHeader *)
			   ((char *) pointer - STANDARDCHUNKHEADERSIZE))->context;

	AssertArg(MemoryContextIsValid(context));
	AssertNotInCriticalSection(context);

	/* isReset must be false already */
	Assert(!context->isReset);

	ret = (*context->methods->realloc) (context, pointer, size);
	VALGRIND_MEMPOOL_CHANGE(context, pointer, ret, size);

	return ret;
}

/*
 * repalloc
 *		Adjust the size of a previously allocated chunk.
 */
void *
repalloc(void *pointer, Size size)
{
	StandardChunkHeader *header;

	/*
	 * Try to detect bogus pointers handed to us, poorly though we can.
	 * Presumably, a pointer that isn't MAXALIGNED isn't pointing at an
	 * allocated chunk.
	 */
	Assert(pointer != NULL);
	Assert(pointer == (void *) MAXALIGN(pointer));

	/*
	 * OK, it's probably safe to look at the chunk header.
	 */
	header = (StandardChunkHeader *)
		((char *) pointer - STANDARDCHUNKHEADERSIZE);

	AssertArg(MemoryContextIsValid(header->context));

	if (!AllocSizeIsValid(size))
		elog(ERROR, "invalid memory alloc request size %lu",
			 (unsigned long) size);

	/* isReset must be false already */
	Assert(!header->context->isReset);

	return (*header->context->methods->realloc) (header->context,
												 pointer, size);
}

void *
palloc0(Size size)
{
	/* duplicates MemoryContextAllocZero to avoid increased overhead */
	void	   *ret;

	AssertArg(MemoryContextIsValid(CurrentMemoryContext));
	AssertNotInCriticalSection(CurrentMemoryContext);

	if (!AllocSizeIsValid(size))
		elog(ERROR, "invalid memory alloc request size %zu", size);

	CurrentMemoryContext->isReset = false;

	ret = (*CurrentMemoryContext->methods->alloc) (CurrentMemoryContext, size);
	if (ret == NULL)
	{
		MemoryContextStats(TopMemoryContext);
		ereport(ERROR,
				(errcode(ERRCODE_OUT_OF_MEMORY),
				 errmsg("out of memory"),
				 errdetail("Failed on request of size %zu.", size)));
	}

	VALGRIND_MEMPOOL_ALLOC(CurrentMemoryContext, ret, size);

	MemSetAligned(ret, 0, size);

	return ret;
}

/*
 * repalloc
 *		Adjust the size of a previously allocated chunk.
 */
void *
MemoryContextReallocImpl(void *pointer, Size size, const char *sfile, const char *sfunc, int sline)
{
	StandardChunkHeader *header;
	void *ret;

#ifdef PGTRACE_ENABLED 
	long old_reqsize;
	long old_size;
#endif

	/*
	 * Try to detect bogus pointers handed to us, poorly though we can.
	 * Presumably, a pointer that isn't MAXALIGNED isn't pointing at an
	 * allocated chunk.
	 */
	Assert(pointer != NULL);
	Assert(pointer == (void *) MAXALIGN(pointer));

	/*
	 * OK, it's probably safe to look at the chunk header.
	 */
	header = (StandardChunkHeader *)
		((char *) pointer - STANDARDCHUNKHEADERSIZE);

	AssertArg(MemoryContextIsValid(header->sharedHeader->context));

#ifdef PGTRACE_ENABLED
#ifdef MEMORY_CONTEXT_CHECKING
	old_reqsize = header->requested_size;
#else
	old_reqsize = 0;
#endif
	old_size = header->size;
#endif

#ifdef CDB_PALLOC_CALLER_ID
	header->sharedHeader->context->callerFile = sfile;
	header->sharedHeader->context->callerLine = sline;
#endif

	if (!AllocSizeIsValid(size))
		MemoryContextError(ERRCODE_INTERNAL_ERROR,
				header->sharedHeader->context, CDB_MCXT_WHERE(header->sharedHeader->context),
				"invalid memory alloc request size %lu",
				(unsigned long)size);

	ret = (*header->sharedHeader->context->methods.realloc) (header->sharedHeader->context, pointer, size);

#ifdef PGTRACE_ENABLED
	header = (StandardChunkHeader *)
		((char *) ret - STANDARDCHUNKHEADERSIZE);
	PG_TRACE5(memctxt__realloc, size, header->size, old_reqsize, old_size, (long) header->sharedHeader->context->name);
#endif

	return ret;
}

/*
 * get_flat_size method for expanded arrays
 */
static Size
EA_get_flat_size(ExpandedObjectHeader *eohptr)
{
	ExpandedArrayHeader *eah = (ExpandedArrayHeader *) eohptr;
	int			nelems;
	int			ndims;
	Datum	   *dvalues;
	bool	   *dnulls;
	Size		nbytes;
	int			i;

	Assert(eah->ea_magic == EA_MAGIC);

	/* Easy if we have a valid flattened value */
	if (eah->fvalue)
		return ARR_SIZE(eah->fvalue);

	/* If we have a cached size value, believe that */
	if (eah->flat_size)
		return eah->flat_size;

	/*
	 * Compute space needed by examining dvalues/dnulls.  Note that the result
	 * array will have a nulls bitmap if dnulls isn't NULL, even if the array
	 * doesn't actually contain any nulls now.
	 */
	nelems = eah->nelems;
	ndims = eah->ndims;
	Assert(nelems == ArrayGetNItems(ndims, eah->dims));
	dvalues = eah->dvalues;
	dnulls = eah->dnulls;
	nbytes = 0;
	for (i = 0; i < nelems; i++)
	{
		if (dnulls && dnulls[i])
			continue;
		nbytes = att_addlength_datum(nbytes, eah->typlen, dvalues[i]);
		nbytes = att_align_nominal(nbytes, eah->typalign);
		/* check for overflow of total request */
		if (!AllocSizeIsValid(nbytes))
			ereport(ERROR,
					(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
					 errmsg("array size exceeds the maximum allowed (%d)",
							(int) MaxAllocSize)));
	}

	if (dnulls)
		nbytes += ARR_OVERHEAD_WITHNULLS(ndims, nelems);
	else
		nbytes += ARR_OVERHEAD_NONULLS(ndims);

	/* cache for next time */
	eah->flat_size = nbytes;

	return nbytes;
}

/*
 * MemoryContextAlloc
 *		Allocate space within the specified context.
 *
 * This could be turned into a macro, but we'd have to import
 * nodes/memnodes.h into postgres.h which seems a bad idea.
 */
void *
MemoryContextAlloc(MemoryContext context, Size size)
{
	AssertArg(MemoryContextIsValid(context));

	if (!AllocSizeIsValid(size))
		elog(ERROR, "invalid memory alloc request size %lu",
			 (unsigned long) size);

	context->isReset = false;

	return (*context->methods->alloc) (context, size);
}

void *
palloc(Size size)
{
	/* duplicates MemoryContextAlloc to avoid increased overhead */
	AssertArg(MemoryContextIsValid(CurrentMemoryContext));

	if (!AllocSizeIsValid(size))
		elog(ERROR, "invalid memory alloc request size %lu",
			 (unsigned long) size);

	CurrentMemoryContext->isReset = false;

	return (*CurrentMemoryContext->methods->alloc) (CurrentMemoryContext, size);
}

/*
 * MemoryContextAlloc
 *		Allocate space within the specified context.
 *
 * This could be turned into a macro, but we'd have to import
 * nodes/memnodes.h into postgres.h which seems a bad idea.
 */
void *
MemoryContextAlloc(MemoryContext context, Size size)
{
	void	   *ret;

	AssertArg(MemoryContextIsValid(context));

	if (!AllocSizeIsValid(size))
		elog(ERROR, "invalid memory alloc request size %lu",
			 (unsigned long) size);

	context->isReset = false;

	ret = (*context->methods->alloc) (context, size);
	VALGRIND_MEMPOOL_ALLOC(context, ret, size);

	return ret;
}

void *
palloc(Size size)
{
	/* duplicates MemoryContextAlloc to avoid increased overhead */
	void	   *ret;

	AssertArg(MemoryContextIsValid(CurrentMemoryContext));
	AssertNotInCriticalSection(CurrentMemoryContext);

	if (!AllocSizeIsValid(size))
		elog(ERROR, "invalid memory alloc request size %zu", size);

	CurrentMemoryContext->isReset = false;

	ret = (*CurrentMemoryContext->methods->alloc) (CurrentMemoryContext, size);
	VALGRIND_MEMPOOL_ALLOC(CurrentMemoryContext, ret, size);

	return ret;
}

/*
 * MemoryContextAllocZeroAligned
 *		MemoryContextAllocZero where length is suitable for MemSetLoop
 *
 *	This might seem overly specialized, but it's not because newNode()
 *	is so often called with compile-time-constant sizes.
 */
void *
MemoryContextAllocZeroAligned(MemoryContext context, Size size)
{
	void	   *ret;

	AssertArg(MemoryContextIsValid(context));

	if (!AllocSizeIsValid(size))
		elog(ERROR, "invalid memory alloc request size %lu",
			 (unsigned long) size);

	context->isReset = false;

	ret = (*context->methods->alloc) (context, size);

	MemSetLoop(ret, 0, size);

	return ret;
}