[sgen] Don't reallocate mod_union at each major

[mono.git] / mono / sgen / sgen-los.c

diff --git a/mono/sgen/sgen-los.c b/mono/sgen/sgen-los.c
index c0ea17bb329982efe49392adda5ff15df6bdfe1d..c22afd22f21d01c67998ee4e75dadedc444eb737 100644 (file)
--- a/mono/sgen/sgen-los.c
+++ b/mono/sgen/sgen-los.c
@@ -15,18 +15,7 @@
  * Copyright 2003-2010 Novell, Inc.
  * 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.
+ * Licensed under the MIT license. See LICENSE file in the project root for full license information.
  */
 
 #include "config.h"
@@ -73,6 +62,7 @@ struct _LOSSection {
        unsigned char *free_chunk_map;
 };
 
+/* We allow read only access on the list while sweep is not running */
 LOSObject *los_object_list = NULL;
 mword los_memory_usage = 0;
 
@@ -317,7 +307,8 @@ free_los_section_memory (LOSObject *obj, size_t size)
 void
 sgen_los_free_object (LOSObject *obj)
 {
-       SGEN_ASSERT (0, !obj->cardtable_mod_union, "We should never free a LOS object with a mod-union table.");
+       if (obj->cardtable_mod_union)
+               sgen_card_table_free_mod_union (obj->cardtable_mod_union, (char*)obj->data, sgen_los_object_size (obj));
 
 #ifndef LOS_DUMMY
        mword size = sgen_los_object_size (obj);
@@ -380,7 +371,7 @@ sgen_los_alloc_large_inner (GCVTable vtable, size_t size)
        los_segment_index += size + sizeof (LOSObject);
        g_assert (los_segment_index <= LOS_SEGMENT_SIZE);
 #else
-       sgen_ensure_free_space (size);
+       sgen_ensure_free_space (size, GENERATION_OLD);
 
 #ifdef USE_MALLOC
        obj = malloc (size + sizeof (LOSObject));
@@ -410,6 +401,11 @@ sgen_los_alloc_large_inner (GCVTable vtable, size_t size)
        *vtslot = vtable;
        sgen_update_heap_boundaries ((mword)obj->data, (mword)obj->data + size);
        obj->next = los_object_list;
+       /*
+        * We need a memory barrier so we don't expose as head of the los object list
+        * a LOSObject that doesn't have its fields initialized.
+        */
+       mono_memory_write_barrier ();
        los_object_list = obj;
        los_memory_usage += size;
        los_num_objects++;
@@ -438,12 +434,13 @@ sgen_los_sweep (void)
        for (bigobj = los_object_list; bigobj;) {
                SGEN_ASSERT (0, !SGEN_OBJECT_IS_PINNED (bigobj->data), "Who pinned a LOS object?");
 
-               if (bigobj->cardtable_mod_union) {
-                       sgen_card_table_free_mod_union (bigobj->cardtable_mod_union, (char*)bigobj->data, sgen_los_object_size (bigobj));
-                       bigobj->cardtable_mod_union = NULL;
-               }
-
                if (sgen_los_object_is_pinned (bigobj->data)) {
+                       if (bigobj->cardtable_mod_union) {
+                               mword obj_size = sgen_los_object_size (bigobj);
+                               mword num_cards = sgen_card_table_number_of_cards_in_range ((mword) bigobj->data, obj_size);
+                               memset (bigobj->cardtable_mod_union, 0, num_cards);
+                       }
+
                        sgen_los_unpin_object (bigobj->data);
                        sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + sgen_los_object_size (bigobj));
                } else {
@@ -617,28 +614,44 @@ get_cardtable_mod_union_for_object (LOSObject *obj)
 }
 
 void
-sgen_los_scan_card_table (gboolean mod_union, ScanCopyContext ctx)
+sgen_los_scan_card_table (CardTableScanType scan_type, ScanCopyContext ctx)
 {
        LOSObject *obj;
 
+       binary_protocol_los_card_table_scan_start (sgen_timestamp (), scan_type & CARDTABLE_SCAN_MOD_UNION);
        for (obj = los_object_list; obj; obj = obj->next) {
+               mword num_cards = 0;
                guint8 *cards;
 
                if (!SGEN_OBJECT_HAS_REFERENCES (obj->data))
                        continue;
 
-               if (mod_union) {
+               if (scan_type & CARDTABLE_SCAN_MOD_UNION) {
                        if (!sgen_los_object_is_pinned (obj->data))
                                continue;
 
                        cards = get_cardtable_mod_union_for_object (obj);
                        g_assert (cards);
+                       if (scan_type == CARDTABLE_SCAN_MOD_UNION_PRECLEAN) {
+                               guint8 *cards_preclean;
+                               mword obj_size = sgen_los_object_size (obj);
+                               num_cards = sgen_card_table_number_of_cards_in_range ((mword) obj->data, obj_size);
+                               cards_preclean = (guint8 *)sgen_alloc_internal_dynamic (num_cards, INTERNAL_MEM_CARDTABLE_MOD_UNION, TRUE);
+
+                               sgen_card_table_preclean_mod_union (cards, cards_preclean, num_cards);
+
+                               cards = cards_preclean;
+                       }
                } else {
                        cards = NULL;
                }
 
-               sgen_cardtable_scan_object (obj->data, sgen_los_object_size (obj), cards, mod_union, ctx);
+               sgen_cardtable_scan_object (obj->data, sgen_los_object_size (obj), cards, ctx);
+
+               if (scan_type == CARDTABLE_SCAN_MOD_UNION_PRECLEAN)
+                       sgen_free_internal_dynamic (cards, num_cards, INTERNAL_MEM_CARDTABLE_MOD_UNION);
        }
+       binary_protocol_los_card_table_scan_end (sgen_timestamp (), scan_type & CARDTABLE_SCAN_MOD_UNION);
 }
 
 void