/*
+ * sgen-minor-copy-object.h: Copy functions for nursery collections.
+ *
* Copyright 2001-2003 Ximian, Inc
* Copyright 2003-2010 Novell, Inc.
- *
- * Permission is hereby granted, free of charge, to any person obtaining
- * a copy of this software and associated documentation files (the
- * "Software"), to deal in the Software without restriction, including
- * without limitation the rights to use, copy, modify, merge, publish,
- * distribute, sublicense, and/or sell copies of the Software, and to
- * permit persons to whom the Software is furnished to do so, subject to
- * the following conditions:
- *
- * The above copyright notice and this permission notice shall be
- * included in all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
- * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
- * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
- * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
- * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- */
-
-/*
- * This file defines copy functions for nursery collections.
+ * Copyright (C) 2012 Xamarin Inc
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License 2.0 as published by the Free Software Foundation;
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License 2.0 along with this library; if not, write to the Free
+ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#define collector_pin_object(obj, queue) sgen_pin_object (obj, queue);
char *forwarded;
char *obj = *obj_slot;
- DEBUG (9, g_assert (current_collection_generation == GENERATION_NURSERY));
+ SGEN_ASSERT (9, current_collection_generation == GENERATION_NURSERY, "calling minor-serial-copy from a %d generation collection", current_collection_generation);
HEAVY_STAT (++stat_copy_object_called_nursery);
return;
}
- DEBUG (9, fprintf (gc_debug_file, "Precise copy of %p from %p", obj, obj_slot));
+ SGEN_LOG (9, "Precise copy of %p from %p", obj, obj_slot);
/*
* Before we can copy the object we must make sure that we are
*/
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));
+ SGEN_ASSERT (9, (*(MonoVTable**)SGEN_LOAD_VTABLE (obj))->gc_descr, "forwarded object %p has no gc descriptor", forwarded);
+ SGEN_LOG (9, " (already forwarded to %p)", forwarded);
HEAVY_STAT (++stat_nursery_copy_object_failed_forwarded);
*obj_slot = forwarded;
return;
}
if (G_UNLIKELY (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"));
+ SGEN_ASSERT (9, ((MonoVTable*)SGEN_LOAD_VTABLE(obj))->gc_descr, "pinned object %p has no gc descriptor", obj);
+ SGEN_LOG (9, " (pinned, no change)");
HEAVY_STAT (++stat_nursery_copy_object_failed_pinned);
return;
}
#ifndef SGEN_SIMPLE_NURSERY
if (sgen_nursery_is_to_space (obj)) {
- DEBUG (9, g_assert (((MonoVTable*)SGEN_LOAD_VTABLE(obj))->gc_descr));
- DEBUG (9, fprintf (gc_debug_file, " (tospace, no change)\n"));
+ SGEN_ASSERT (9, ((MonoVTable*)SGEN_LOAD_VTABLE(obj))->gc_descr, "to space object %p has no gc descriptor", obj);
+ SGEN_LOG (9, " (tospace, no change)");
HEAVY_STAT (++stat_nursery_copy_object_failed_to_space);
return;
}
{
char *forwarded;
char *obj = *obj_slot;
+ void *copy;
- DEBUG (9, g_assert (current_collection_generation == GENERATION_NURSERY));
+ SGEN_ASSERT (9, current_collection_generation == GENERATION_NURSERY, "calling minor-serial-copy-from-obj from a %d generation collection", current_collection_generation);
HEAVY_STAT (++stat_copy_object_called_nursery);
return;
}
- DEBUG (9, fprintf (gc_debug_file, "Precise copy of %p from %p", obj, obj_slot));
+ SGEN_LOG (9, "Precise copy of %p from %p", obj, obj_slot);
/*
* Before we can copy the object we must make sure that we are
*/
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));
+ SGEN_ASSERT (9, (*(MonoVTable**)SGEN_LOAD_VTABLE (obj))->gc_descr, "forwarded object %p has no gc descriptor", forwarded);
+ SGEN_LOG (9, " (already forwarded to %p)", forwarded);
HEAVY_STAT (++stat_nursery_copy_object_failed_forwarded);
*obj_slot = forwarded;
#ifndef SGEN_SIMPLE_NURSERY
if (G_UNLIKELY (sgen_ptr_in_nursery (forwarded) && !sgen_ptr_in_nursery (obj_slot)))
- sgen_add_to_global_remset (obj_slot);
+ sgen_add_to_global_remset (obj_slot, forwarded);
#endif
return;
}
if (G_UNLIKELY (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"));
+ SGEN_ASSERT (9, ((MonoVTable*)SGEN_LOAD_VTABLE(obj))->gc_descr, "pinned object %p has no gc descriptor", obj);
+ SGEN_LOG (9, " (pinned, no change)");
HEAVY_STAT (++stat_nursery_copy_object_failed_pinned);
if (!sgen_ptr_in_nursery (obj_slot))
- sgen_add_to_global_remset (obj_slot);
+ sgen_add_to_global_remset (obj_slot, obj);
return;
}
#ifndef SGEN_SIMPLE_NURSERY
if (sgen_nursery_is_to_space (obj)) {
- DEBUG (9, g_assert (((MonoVTable*)SGEN_LOAD_VTABLE(obj))->gc_descr));
- DEBUG (9, fprintf (gc_debug_file, " (tospace, no change)\n"));
+ SGEN_ASSERT (9, ((MonoVTable*)SGEN_LOAD_VTABLE(obj))->gc_descr, "to space object %p has no gc descriptor", obj);
+ SGEN_LOG (9, " (tospace, no change)");
HEAVY_STAT (++stat_nursery_copy_object_failed_to_space);
+
+ /*
+ * FIXME:
+ *
+ * The card table scanning code sometimes clears cards
+ * that have just been set for a global remset. In
+ * the split nursery the following situation can
+ * occur:
+ *
+ * Let's say object A starts in card C but continues
+ * into C+1. Within A, at offset O there's a
+ * reference to a new nursery object X. A+O is in
+ * card C+1. Now card C is scanned, and as part of
+ * it, object A. The reference at A+O is processed by
+ * copying X into nursery to-space at Y. Since it's
+ * still in the nursery, a global remset must be added
+ * for A+O, so card C+1 is marked. Now, however, card
+ * C+1 is scanned, which means that it's cleared
+ * first. This wouldn't be terribly bad if reference
+ * A+O were re-scanned and the global remset re-added,
+ * but since the reference points to to-space, that
+ * doesn't happen, and C+1 remains cleared: the remset
+ * is lost.
+ *
+ * There's at least two ways to fix this. The easy
+ * one is to re-add the remset on the re-scan. This
+ * is that - the following two lines of code.
+ *
+ * The proper solution appears to be to first make a
+ * copy of the cards before scanning a block, then to
+ * clear all the cards and scan from the copy, so no
+ * remsets will be overwritten. Scanning objects at
+ * most once would be the icing on the cake.
+ */
+ if (!sgen_ptr_in_nursery (obj_slot))
+ sgen_add_to_global_remset (obj_slot, obj);
+
return;
}
#endif
HEAVY_STAT (++stat_objects_copied_nursery);
- *obj_slot = copy_object_no_checks (obj, queue);
+ copy = copy_object_no_checks (obj, queue);
+ *obj_slot = copy;
#ifndef SGEN_SIMPLE_NURSERY
- if (G_UNLIKELY (sgen_ptr_in_nursery (*obj_slot) && !sgen_ptr_in_nursery (obj_slot)))
- sgen_add_to_global_remset (obj_slot);
+ if (G_UNLIKELY (sgen_ptr_in_nursery (copy) && !sgen_ptr_in_nursery (obj_slot)))
+ sgen_add_to_global_remset (obj_slot, copy);
+#else
+ /* copy_object_no_checks () can return obj on OOM */
+ if (G_UNLIKELY (obj == copy)) {
+ if (G_UNLIKELY (sgen_ptr_in_nursery (copy) && !sgen_ptr_in_nursery (obj_slot)))
+ sgen_add_to_global_remset (obj_slot, copy);
+ }
#endif
}
void *destination;
gboolean has_references;
- DEBUG (9, g_assert (current_collection_generation == GENERATION_NURSERY));
+ SGEN_ASSERT (9, current_collection_generation == GENERATION_NURSERY, "calling minor-par-copy from a %d generation collection", current_collection_generation);
HEAVY_STAT (++stat_copy_object_called_nursery);
objsize = SGEN_ALIGN_UP (sgen_par_object_get_size (vt, (MonoObject*)obj));
has_references = SGEN_VTABLE_HAS_REFERENCES (vt);
- destination = COLLECTOR_PARALLEL_ALLOC_FOR_PROMOTION (obj, objsize, has_references);
+ destination = COLLECTOR_PARALLEL_ALLOC_FOR_PROMOTION (vt, obj, objsize, has_references);
if (G_UNLIKELY (!destination)) {
sgen_parallel_pin_or_update (obj_slot, obj, vt, queue);
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