Refactor and remove copy mark bits.
Refactor code GC realted code to be in a GC folder.
Remove copy mark bits by using pointer changing instead.
Enable concurrent sweeping of system weaks.
Fix non concurrent GC plan.
Change-Id: I9c71478be27d21a75f8a4e6af6faabe896e5e263
diff --git a/src/gc/card_table.h b/src/gc/card_table.h
new file mode 100644
index 0000000..2715f52
--- /dev/null
+++ b/src/gc/card_table.h
@@ -0,0 +1,163 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_SRC_GC_CARDTABLE_H_
+#define ART_SRC_GC_CARDTABLE_H_
+
+#include "globals.h"
+#include "logging.h"
+#include "mem_map.h"
+#include "space_bitmap.h"
+#include "UniquePtr.h"
+
+namespace art {
+
+class Heap;
+class ContinuousSpace;
+class SpaceBitmap;
+class Object;
+
+// Maintain a card table from the the write barrier. All writes of
+// non-NULL values to heap addresses should go through an entry in
+// WriteBarrier, and from there to here.
+class CardTable {
+ public:
+ static const size_t kCardShift = 7;
+ static const size_t kCardSize = (1 << kCardShift);
+ static const uint8_t kCardClean = 0x0;
+ static const uint8_t kCardDirty = 0x70;
+
+ static CardTable* Create(const byte* heap_begin, size_t heap_capacity);
+
+ // Set the card associated with the given address to GC_CARD_DIRTY.
+ void MarkCard(const void *addr) {
+ byte* card_addr = CardFromAddr(addr);
+ *card_addr = kCardDirty;
+ }
+
+ // Is the object on a dirty card?
+ bool IsDirty(const Object* obj) const {
+ return *CardFromAddr(obj) == kCardDirty;
+ }
+
+ // Visit and clear cards within memory range, only visits dirty cards.
+ template <typename Visitor>
+ void VisitClear(const void* start, const void* end, const Visitor& visitor) {
+ byte* card_start = CardFromAddr(start);
+ byte* card_end = CardFromAddr(end);
+ for (byte* it = card_start; it != card_end; ++it) {
+ if (*it == kCardDirty) {
+ *it = kCardClean;
+ visitor(it);
+ }
+ }
+ }
+
+ // Returns a value that when added to a heap address >> GC_CARD_SHIFT will address the appropriate
+ // card table byte. For convenience this value is cached in every Thread
+ byte* GetBiasedBegin() const {
+ return biased_begin_;
+ }
+
+ // For every dirty card between begin and end invoke the visitor with the specified argument.
+ template <typename Visitor, typename FingerVisitor>
+ void Scan(SpaceBitmap* bitmap, byte* scan_begin, byte* scan_end,
+ const Visitor& visitor, const FingerVisitor& finger_visitor) const
+ EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_)
+ SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+ DCHECK(bitmap->HasAddress(scan_begin));
+ DCHECK(bitmap->HasAddress(scan_end - 1)); // scan_end is the byte after the last byte we scan.
+ byte* card_cur = CardFromAddr(scan_begin);
+ byte* card_end = CardFromAddr(scan_end);
+ while (card_cur < card_end) {
+ // Find the first dirty card.
+ card_cur = reinterpret_cast<byte*>(memchr(card_cur, kCardDirty, card_end - card_cur));
+ if (card_cur == NULL) {
+ break;
+ }
+ byte* run_start = card_cur++;
+
+ while (*card_cur == kCardDirty && card_cur < card_end) {
+ card_cur++;
+ }
+ byte* run_end = card_cur;
+
+ uintptr_t start = reinterpret_cast<uintptr_t>(AddrFromCard(run_start));
+ uintptr_t end = reinterpret_cast<uintptr_t>(AddrFromCard(run_end));
+ bitmap->VisitMarkedRange(start, end, visitor, finger_visitor);
+ }
+ }
+
+ // Assertion used to check the given address is covered by the card table
+ void CheckAddrIsInCardTable(const byte* addr) const;
+
+ // Resets all of the bytes in the card table to clean.
+ void ClearCardTable();
+
+ // Resets all of the bytes in the card table which do not map to the image space.
+ void ClearSpaceCards(ContinuousSpace* space);
+
+ // Clean all the cards which map to a space.
+ void PreClearCards(ContinuousSpace* space, std::vector<byte*>& out_cards);
+
+ // Returns all of the dirty cards which map to a space.
+ void GetDirtyCards(ContinuousSpace* space, std::vector<byte*>& out_cards) const;
+
+ // Returns the first address in the heap which maps to this card.
+ void* AddrFromCard(const byte *card_addr) const {
+ DCHECK(IsValidCard(card_addr))
+ << " card_addr: " << reinterpret_cast<const void*>(card_addr)
+ << " begin: " << reinterpret_cast<void*>(mem_map_->Begin() + offset_)
+ << " end: " << reinterpret_cast<void*>(mem_map_->End());
+ uintptr_t offset = card_addr - biased_begin_;
+ return reinterpret_cast<void*>(offset << kCardShift);
+ }
+
+ // Returns the address of the relevant byte in the card table, given an address on the heap.
+ byte* CardFromAddr(const void *addr) const {
+ byte *card_addr = biased_begin_ + ((uintptr_t)addr >> kCardShift);
+ // Sanity check the caller was asking for address covered by the card table
+ DCHECK(IsValidCard(card_addr)) << "addr: " << addr
+ << " card_addr: " << reinterpret_cast<void*>(card_addr);
+ return card_addr;
+ }
+
+ bool AddrIsInCardTable(const void* addr) const;
+
+ private:
+ CardTable(MemMap* begin, byte* biased_begin, size_t offset);
+
+ // Returns true iff the card table address is within the bounds of the card table.
+ bool IsValidCard(const byte* card_addr) const {
+ byte* begin = mem_map_->Begin() + offset_;
+ byte* end = mem_map_->End();
+ return card_addr >= begin && card_addr < end;
+ }
+
+ // Verifies that all gray objects are on a dirty card.
+ void VerifyCardTable();
+
+ // Mmapped pages for the card table
+ UniquePtr<MemMap> mem_map_;
+ // Value used to compute card table addresses from object addresses, see GetBiasedBegin
+ byte* const biased_begin_;
+ // Card table doesn't begin at the beginning of the mem_map_, instead it is displaced by offset
+ // to allow the byte value of biased_begin_ to equal GC_CARD_DIRTY
+ const size_t offset_;
+};
+
+} // namespace art
+#endif // DALVIK_ALLOC_CARDTABLE_H_