resowner.c

来自「PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统」· C语言 代码 · 共 748 行 · 第 1/2 页

	if (newparent)
	{
		Assert(owner != newparent);
		owner->parent = newparent;
		owner->nextchild = newparent->firstchild;
		newparent->firstchild = owner;
	}
	else
	{
		owner->parent = NULL;
		owner->nextchild = NULL;
	}
}

/*
 * Register or deregister callback functions for resource cleanup
 *
 * These functions are intended for use by dynamically loaded modules.
 * For built-in modules we generally just hardwire the appropriate calls.
 *
 * Note that the callback occurs post-commit or post-abort, so the callback
 * functions can only do noncritical cleanup.
 */
void
RegisterResourceReleaseCallback(ResourceReleaseCallback callback, void *arg)
{
	ResourceReleaseCallbackItem *item;

	item = (ResourceReleaseCallbackItem *)
		MemoryContextAlloc(TopMemoryContext,
						   sizeof(ResourceReleaseCallbackItem));
	item->callback = callback;
	item->arg = arg;
	item->next = ResourceRelease_callbacks;
	ResourceRelease_callbacks = item;
}

void
UnregisterResourceReleaseCallback(ResourceReleaseCallback callback, void *arg)
{
	ResourceReleaseCallbackItem *item;
	ResourceReleaseCallbackItem *prev;

	prev = NULL;
	for (item = ResourceRelease_callbacks; item; prev = item, item = item->next)
	{
		if (item->callback == callback && item->arg == arg)
		{
			if (prev)
				prev->next = item->next;
			else
				ResourceRelease_callbacks = item->next;
			pfree(item);
			break;
		}
	}
}


/*
 * Make sure there is room for at least one more entry in a ResourceOwner's
 * buffer array.
 *
 * This is separate from actually inserting an entry because if we run out
 * of memory, it's critical to do so *before* acquiring the resource.
 *
 * We allow the case owner == NULL because the bufmgr is sometimes invoked
 * outside any transaction (for example, during WAL recovery).
 */
void
ResourceOwnerEnlargeBuffers(ResourceOwner owner)
{
	int			newmax;

	if (owner == NULL ||
		owner->nbuffers < owner->maxbuffers)
		return;					/* nothing to do */

	if (owner->buffers == NULL)
	{
		newmax = 16;
		owner->buffers = (Buffer *)
			MemoryContextAlloc(TopMemoryContext, newmax * sizeof(Buffer));
		owner->maxbuffers = newmax;
	}
	else
	{
		newmax = owner->maxbuffers * 2;
		owner->buffers = (Buffer *)
			repalloc(owner->buffers, newmax * sizeof(Buffer));
		owner->maxbuffers = newmax;
	}
}

/*
 * Remember that a buffer pin is owned by a ResourceOwner
 *
 * Caller must have previously done ResourceOwnerEnlargeBuffers()
 *
 * We allow the case owner == NULL because the bufmgr is sometimes invoked
 * outside any transaction (for example, during WAL recovery).
 */
void
ResourceOwnerRememberBuffer(ResourceOwner owner, Buffer buffer)
{
	if (owner != NULL)
	{
		Assert(owner->nbuffers < owner->maxbuffers);
		owner->buffers[owner->nbuffers] = buffer;
		owner->nbuffers++;
	}
}

/*
 * Forget that a buffer pin is owned by a ResourceOwner
 *
 * We allow the case owner == NULL because the bufmgr is sometimes invoked
 * outside any transaction (for example, during WAL recovery).
 */
void
ResourceOwnerForgetBuffer(ResourceOwner owner, Buffer buffer)
{
	if (owner != NULL)
	{
		Buffer	   *buffers = owner->buffers;
		int			nb1 = owner->nbuffers - 1;
		int			i;

		/*
		 * Scan back-to-front because it's more likely we are releasing a
		 * recently pinned buffer.	This isn't always the case of course, but
		 * it's the way to bet.
		 */
		for (i = nb1; i >= 0; i--)
		{
			if (buffers[i] == buffer)
			{
				while (i < nb1)
				{
					buffers[i] = buffers[i + 1];
					i++;
				}
				owner->nbuffers = nb1;
				return;
			}
		}
		elog(ERROR, "buffer %d is not owned by resource owner %s",
			 buffer, owner->name);
	}
}

/*
 * Make sure there is room for at least one more entry in a ResourceOwner's
 * catcache reference array.
 *
 * This is separate from actually inserting an entry because if we run out
 * of memory, it's critical to do so *before* acquiring the resource.
 */
void
ResourceOwnerEnlargeCatCacheRefs(ResourceOwner owner)
{
	int			newmax;

	if (owner->ncatrefs < owner->maxcatrefs)
		return;					/* nothing to do */

	if (owner->catrefs == NULL)
	{
		newmax = 16;
		owner->catrefs = (HeapTuple *)
			MemoryContextAlloc(TopMemoryContext, newmax * sizeof(HeapTuple));
		owner->maxcatrefs = newmax;
	}
	else
	{
		newmax = owner->maxcatrefs * 2;
		owner->catrefs = (HeapTuple *)
			repalloc(owner->catrefs, newmax * sizeof(HeapTuple));
		owner->maxcatrefs = newmax;
	}
}

/*
 * Remember that a catcache reference is owned by a ResourceOwner
 *
 * Caller must have previously done ResourceOwnerEnlargeCatCacheRefs()
 */
void
ResourceOwnerRememberCatCacheRef(ResourceOwner owner, HeapTuple tuple)
{
	Assert(owner->ncatrefs < owner->maxcatrefs);
	owner->catrefs[owner->ncatrefs] = tuple;
	owner->ncatrefs++;
}

/*
 * Forget that a catcache reference is owned by a ResourceOwner
 */
void
ResourceOwnerForgetCatCacheRef(ResourceOwner owner, HeapTuple tuple)
{
	HeapTuple  *catrefs = owner->catrefs;
	int			nc1 = owner->ncatrefs - 1;
	int			i;

	for (i = nc1; i >= 0; i--)
	{
		if (catrefs[i] == tuple)
		{
			while (i < nc1)
			{
				catrefs[i] = catrefs[i + 1];
				i++;
			}
			owner->ncatrefs = nc1;
			return;
		}
	}
	elog(ERROR, "catcache reference %p is not owned by resource owner %s",
		 tuple, owner->name);
}

/*
 * Make sure there is room for at least one more entry in a ResourceOwner's
 * catcache-list reference array.
 *
 * This is separate from actually inserting an entry because if we run out
 * of memory, it's critical to do so *before* acquiring the resource.
 */
void
ResourceOwnerEnlargeCatCacheListRefs(ResourceOwner owner)
{
	int			newmax;

	if (owner->ncatlistrefs < owner->maxcatlistrefs)
		return;					/* nothing to do */

	if (owner->catlistrefs == NULL)
	{
		newmax = 16;
		owner->catlistrefs = (CatCList **)
			MemoryContextAlloc(TopMemoryContext, newmax * sizeof(CatCList *));
		owner->maxcatlistrefs = newmax;
	}
	else
	{
		newmax = owner->maxcatlistrefs * 2;
		owner->catlistrefs = (CatCList **)
			repalloc(owner->catlistrefs, newmax * sizeof(CatCList *));
		owner->maxcatlistrefs = newmax;
	}
}

/*
 * Remember that a catcache-list reference is owned by a ResourceOwner
 *
 * Caller must have previously done ResourceOwnerEnlargeCatCacheListRefs()
 */
void
ResourceOwnerRememberCatCacheListRef(ResourceOwner owner, CatCList *list)
{
	Assert(owner->ncatlistrefs < owner->maxcatlistrefs);
	owner->catlistrefs[owner->ncatlistrefs] = list;
	owner->ncatlistrefs++;
}

/*
 * Forget that a catcache-list reference is owned by a ResourceOwner
 */
void
ResourceOwnerForgetCatCacheListRef(ResourceOwner owner, CatCList *list)
{
	CatCList  **catlistrefs = owner->catlistrefs;
	int			nc1 = owner->ncatlistrefs - 1;
	int			i;

	for (i = nc1; i >= 0; i--)
	{
		if (catlistrefs[i] == list)
		{
			while (i < nc1)
			{
				catlistrefs[i] = catlistrefs[i + 1];
				i++;
			}
			owner->ncatlistrefs = nc1;
			return;
		}
	}
	elog(ERROR, "catcache list reference %p is not owned by resource owner %s",
		 list, owner->name);
}

/*
 * Make sure there is room for at least one more entry in a ResourceOwner's
 * relcache reference array.
 *
 * This is separate from actually inserting an entry because if we run out
 * of memory, it's critical to do so *before* acquiring the resource.
 */
void
ResourceOwnerEnlargeRelationRefs(ResourceOwner owner)
{
	int			newmax;

	if (owner->nrelrefs < owner->maxrelrefs)
		return;					/* nothing to do */

	if (owner->relrefs == NULL)
	{
		newmax = 16;
		owner->relrefs = (Relation *)
			MemoryContextAlloc(TopMemoryContext, newmax * sizeof(Relation));
		owner->maxrelrefs = newmax;
	}
	else
	{
		newmax = owner->maxrelrefs * 2;
		owner->relrefs = (Relation *)
			repalloc(owner->relrefs, newmax * sizeof(Relation));
		owner->maxrelrefs = newmax;
	}
}

/*
 * Remember that a relcache reference is owned by a ResourceOwner
 *
 * Caller must have previously done ResourceOwnerEnlargeRelationRefs()
 */
void
ResourceOwnerRememberRelationRef(ResourceOwner owner, Relation rel)
{
	Assert(owner->nrelrefs < owner->maxrelrefs);
	owner->relrefs[owner->nrelrefs] = rel;
	owner->nrelrefs++;
}

/*
 * Forget that a relcache reference is owned by a ResourceOwner
 */
void
ResourceOwnerForgetRelationRef(ResourceOwner owner, Relation rel)
{
	Relation   *relrefs = owner->relrefs;
	int			nr1 = owner->nrelrefs - 1;
	int			i;

	for (i = nr1; i >= 0; i--)
	{
		if (relrefs[i] == rel)
		{
			while (i < nr1)
			{
				relrefs[i] = relrefs[i + 1];
				i++;
			}
			owner->nrelrefs = nr1;
			return;
		}
	}
	elog(ERROR, "relcache reference %s is not owned by resource owner %s",
		 RelationGetRelationName(rel), owner->name);
}

/*
 * Debugging subroutine
 */
static void
PrintRelCacheLeakWarning(Relation rel)
{
	elog(WARNING, "relcache reference leak: relation \"%s\" not closed",
		 RelationGetRelationName(rel));
}