static void
major_copy_or_mark_object (void **ptr, SgenGrayQueue *queue)
{
	void *obj = *ptr;
	MSBlockInfo *block;

	HEAVY_STAT (++stat_copy_object_called_major);

	DEBUG (9, g_assert (obj));
	DEBUG (9, g_assert (current_collection_generation == GENERATION_OLD));

	if (ptr_in_nursery (obj)) {
		int word, bit;
		char *forwarded;

		if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj))) {
			*ptr = forwarded;
			return;
		}
		if (SGEN_OBJECT_IS_PINNED (obj))
			return;

		HEAVY_STAT (++stat_objects_copied_major);

		obj = copy_object_no_checks (obj, queue);
		*ptr = obj;

		/*
		 * FIXME: See comment for copy_object_no_checks().  If
		 * we have that, we can let the allocation function
		 * give us the block info, too, and we won't have to
		 * re-fetch it.
		 */
		block = MS_BLOCK_FOR_OBJ (obj);
		MS_CALC_MARK_BIT (word, bit, obj);
		DEBUG (9, g_assert (!MS_MARK_BIT (block, word, bit)));
		MS_SET_MARK_BIT (block, word, bit);
	} else {
#ifdef FIXED_HEAP
		if (MS_PTR_IN_SMALL_MAJOR_HEAP (obj))
#else
		mword objsize;

		objsize = SGEN_ALIGN_UP (mono_sgen_safe_object_get_size ((MonoObject*)obj));

		if (objsize <= SGEN_MAX_SMALL_OBJ_SIZE)
#endif
		{
			block = MS_BLOCK_FOR_OBJ (obj);
			MS_MARK_OBJECT_AND_ENQUEUE (obj, block, queue);
		} else {
			if (SGEN_OBJECT_IS_PINNED (obj))
				return;
			binary_protocol_pin (obj, (gpointer)SGEN_LOAD_VTABLE (obj), mono_sgen_safe_object_get_size ((MonoObject*)obj));
			SGEN_PIN_OBJECT (obj);
			/* FIXME: only enqueue if object has references */
			GRAY_OBJECT_ENQUEUE (queue, obj);
		}
	}
}
Example #2
0
static void
major_copy_or_mark_object (void **obj_slot, SgenGrayQueue *queue)
{
	char *forwarded;
	char *obj = *obj_slot;
	mword objsize;

	DEBUG (9, g_assert (current_collection_generation == GENERATION_OLD));

	HEAVY_STAT (++stat_copy_object_called_major);

	DEBUG (9, fprintf (gc_debug_file, "Precise copy of %p from %p", obj, obj_slot));

	/*
	 * obj must belong to one of:
	 *
	 * 1. the nursery
	 * 2. the LOS
	 * 3. a pinned chunk
	 * 4. a non-to-space section of the major heap
	 * 5. a to-space section of the major heap
	 *
	 * In addition, objects in 1, 2 and 4 might also be pinned.
	 * Objects in 1 and 4 might be forwarded.
	 *
	 * Before we can copy the object we must make sure that we are
	 * allowed to, i.e. that the object not pinned, not already
	 * forwarded, not in the nursery To Space and doesn't belong
	 * to the LOS, a pinned chunk, or a to-space section.
	 *
	 * We are usually called for to-space objects (5) when we have
	 * two remset entries for the same reference.  The first entry
	 * copies the object and updates the reference and the second
	 * calls us with the updated reference that points into
	 * to-space.  There might also be other circumstances where we
	 * get to-space objects.
	 */

	if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj))) {
		DEBUG (9, g_assert (((MonoVTable*)SGEN_LOAD_VTABLE(obj))->gc_descr));
		DEBUG (9, fprintf (gc_debug_file, " (already forwarded to %p)\n", forwarded));
		HEAVY_STAT (++stat_major_copy_object_failed_forwarded);
		*obj_slot = forwarded;
		return;
	}
	if (SGEN_OBJECT_IS_PINNED (obj)) {
		DEBUG (9, g_assert (((MonoVTable*)SGEN_LOAD_VTABLE(obj))->gc_descr));
		DEBUG (9, fprintf (gc_debug_file, " (pinned, no change)\n"));
		HEAVY_STAT (++stat_major_copy_object_failed_pinned);
		return;
	}

	if (ptr_in_nursery (obj)) {
		/* A To Space object is already on its final destination for the current collection. */
		if (sgen_nursery_is_to_space (obj))
			return;
		goto copy;
	}

	/*
	 * At this point we know obj is not pinned, not forwarded and
	 * belongs to 2, 3, 4, or 5.
	 *
	 * LOS object (2) are simple, at least until we always follow
	 * the rule: if objsize > SGEN_MAX_SMALL_OBJ_SIZE, pin the
	 * object and return it.  At the end of major collections, we
	 * walk the los list and if the object is pinned, it is
	 * marked, otherwise it can be freed.
	 *
	 * Pinned chunks (3) and major heap sections (4, 5) both
	 * reside in blocks, which are always aligned, so once we've
	 * eliminated LOS objects, we can just access the block and
	 * see whether it's a pinned chunk or a major heap section.
	 */

	objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)obj));

	if (G_UNLIKELY (objsize > SGEN_MAX_SMALL_OBJ_SIZE || obj_is_from_pinned_alloc (obj))) {
		if (SGEN_OBJECT_IS_PINNED (obj))
			return;
		DEBUG (9, fprintf (gc_debug_file, " (marked LOS/Pinned %p (%s), size: %td)\n", obj, sgen_safe_name (obj), objsize));
		binary_protocol_pin (obj, (gpointer)SGEN_LOAD_VTABLE (obj), sgen_safe_object_get_size ((MonoObject*)obj));
		SGEN_PIN_OBJECT (obj);
		GRAY_OBJECT_ENQUEUE (queue, obj);
		HEAVY_STAT (++stat_major_copy_object_failed_large_pinned);
		return;
	}

	/*
	 * Now we know the object is in a major heap section.  All we
	 * need to do is check whether it's already in to-space (5) or
	 * not (4).
	 */
	if (MAJOR_OBJ_IS_IN_TO_SPACE (obj)) {
		DEBUG (9, g_assert (objsize <= SGEN_MAX_SMALL_OBJ_SIZE));
		DEBUG (9, fprintf (gc_debug_file, " (already copied)\n"));
		HEAVY_STAT (++stat_major_copy_object_failed_to_space);
		return;
	}

 copy:
	HEAVY_STAT (++stat_objects_copied_major);

	*obj_slot = copy_object_no_checks (obj, queue);
}
Example #3
0
static void
major_copy_or_mark_object (void **ptr, SgenGrayQueue *queue)
{
	void *obj = *ptr;
	MSBlockInfo *block;

	HEAVY_STAT (++stat_copy_object_called_major);

	DEBUG (9, g_assert (obj));
	DEBUG (9, g_assert (current_collection_generation == GENERATION_OLD));

	if (ptr_in_nursery (obj)) {
		int word, bit;
		char *forwarded, *old_obj;

		if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj))) {
			*ptr = forwarded;
			return;
		}
		if (SGEN_OBJECT_IS_PINNED (obj))
			return;

		HEAVY_STAT (++stat_objects_copied_major);

	do_copy_object:
		old_obj = obj;
		obj = copy_object_no_checks (obj, queue);
		if (G_UNLIKELY (old_obj == obj)) {
			/*If we fail to evacuate an object we just stop doing it for a given block size as all other will surely fail too.*/
			if (!ptr_in_nursery (obj)) {
				int size_index;
				block = MS_BLOCK_FOR_OBJ (obj);
				size_index = block->obj_size_index;
				evacuate_block_obj_sizes [size_index] = FALSE;
				MS_MARK_OBJECT_AND_ENQUEUE (obj, block, queue);
			}
			return;
		}
		*ptr = obj;

		/*
		 * FIXME: See comment for copy_object_no_checks().  If
		 * we have that, we can let the allocation function
		 * give us the block info, too, and we won't have to
		 * re-fetch it.
		 */
		block = MS_BLOCK_FOR_OBJ (obj);
		MS_CALC_MARK_BIT (word, bit, obj);
		DEBUG (9, g_assert (!MS_MARK_BIT (block, word, bit)));
		MS_SET_MARK_BIT (block, word, bit);
	} else {
		char *forwarded;
#ifndef FIXED_HEAP
		mword objsize;
#endif

		if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj))) {
			*ptr = forwarded;
			return;
		}

#ifdef FIXED_HEAP
		if (MS_PTR_IN_SMALL_MAJOR_HEAP (obj))
#else
		objsize = SGEN_ALIGN_UP (mono_sgen_safe_object_get_size ((MonoObject*)obj));

		if (objsize <= SGEN_MAX_SMALL_OBJ_SIZE)
#endif
		{
			int size_index;

			block = MS_BLOCK_FOR_OBJ (obj);
			size_index = block->obj_size_index;

			if (!block->has_pinned && evacuate_block_obj_sizes [size_index]) {
				if (block->is_to_space)
					return;
				HEAVY_STAT (++stat_major_objects_evacuated);
				goto do_copy_object;
			} else {
				MS_MARK_OBJECT_AND_ENQUEUE (obj, block, queue);
			}
		} else {
			if (SGEN_OBJECT_IS_PINNED (obj))
				return;
			binary_protocol_pin (obj, (gpointer)SGEN_LOAD_VTABLE (obj), mono_sgen_safe_object_get_size ((MonoObject*)obj));
			SGEN_PIN_OBJECT (obj);
			/* FIXME: only enqueue if object has references */
			GRAY_OBJECT_ENQUEUE (queue, obj);
		}
	}
}