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.cc b/src/gc/card_table.cc
new file mode 100644
index 0000000..5a1e9b5
--- /dev/null
+++ b/src/gc/card_table.cc
@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) 2010 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.
+ */
+
+#include "card_table.h"
+
+#include <dynamic_annotations.h>
+
+#include "heap.h"
+#include "heap_bitmap.h"
+#include "logging.h"
+#include "runtime.h"
+#include "space.h"
+#include "utils.h"
+
+namespace art {
+/*
+ * Maintain a card table from the write barrier. All writes of
+ * non-NULL values to heap addresses should go through an entry in
+ * WriteBarrier, and from there to here.
+ *
+ * The heap is divided into "cards" of GC_CARD_SIZE bytes, as
+ * determined by GC_CARD_SHIFT. The card table contains one byte of
+ * data per card, to be used by the GC. The value of the byte will be
+ * one of GC_CARD_CLEAN or GC_CARD_DIRTY.
+ *
+ * After any store of a non-NULL object pointer into a heap object,
+ * code is obliged to mark the card dirty. The setters in
+ * object.h [such as SetFieldObject] do this for you. The
+ * compiler also contains code to mark cards as dirty.
+ *
+ * The card table's base [the "biased card table"] gets set to a
+ * rather strange value. In order to keep the JIT from having to
+ * fabricate or load GC_DIRTY_CARD to store into the card table,
+ * biased base is within the mmap allocation at a point where its low
+ * byte is equal to GC_DIRTY_CARD. See CardTable::Create for details.
+ */
+
+CardTable* CardTable::Create(const byte* heap_begin, size_t heap_capacity) {
+ /* Set up the card table */
+ size_t capacity = heap_capacity / kCardSize;
+ /* Allocate an extra 256 bytes to allow fixed low-byte of base */
+ UniquePtr<MemMap> mem_map(MemMap::MapAnonymous("dalvik-card-table", NULL,
+ capacity + 256, PROT_READ | PROT_WRITE));
+ if (mem_map.get() == NULL) {
+ std::string maps;
+ ReadFileToString("/proc/self/maps", &maps);
+ LOG(FATAL) << "couldn't allocate card table\n" << maps;
+ }
+ // All zeros is the correct initial value; all clean. Anonymous mmaps are initialized to zero, we
+ // don't clear the card table to avoid unnecessary pages being allocated
+ COMPILE_ASSERT(kCardClean == 0, card_clean_must_be_0);
+
+ byte* cardtable_begin = mem_map->Begin();
+ CHECK(cardtable_begin != NULL);
+
+ // We allocated up to a bytes worth of extra space to allow biased_begin's byte value to equal
+ // GC_CARD_DIRTY, compute a offset value to make this the case
+ size_t offset = 0;
+ byte* biased_begin = reinterpret_cast<byte*>(reinterpret_cast<uintptr_t>(cardtable_begin) -
+ (reinterpret_cast<uintptr_t>(heap_begin) >> kCardShift));
+ if (((uintptr_t)biased_begin & 0xff) != kCardDirty) {
+ int delta = kCardDirty - (reinterpret_cast<int>(biased_begin) & 0xff);
+ offset = delta + (delta < 0 ? 0x100 : 0);
+ biased_begin += offset;
+ }
+ CHECK_EQ(reinterpret_cast<int>(biased_begin) & 0xff, kCardDirty);
+
+ return new CardTable(mem_map.release(), biased_begin, offset);
+}
+
+CardTable::CardTable(MemMap* mem_map, byte* biased_begin, size_t offset)
+ : mem_map_(mem_map), biased_begin_(biased_begin), offset_(offset) {
+ byte* __attribute__((unused)) begin = mem_map_->Begin() + offset_;
+ byte* __attribute__((unused)) end = mem_map_->End();
+ ANNOTATE_BENIGN_RACE_SIZED(begin, (end - begin), "writes to GC card table");
+}
+
+void CardTable::ClearSpaceCards(ContinuousSpace* space) {
+ // TODO: clear just the range of the table that has been modified
+ byte* card_start = CardFromAddr(space->Begin());
+ byte* card_end = CardFromAddr(space->End()); // Make sure to round up.
+ memset(reinterpret_cast<void*>(card_start), kCardClean, card_end - card_start);
+}
+
+void CardTable::ClearCardTable() {
+ // TODO: clear just the range of the table that has been modified
+ memset(mem_map_->Begin(), kCardClean, mem_map_->Size());
+}
+
+void CardTable::PreClearCards(ContinuousSpace* space, std::vector<byte*>& out_cards) {
+ byte* card_end = CardFromAddr(space->End());
+ for (byte* card_cur = CardFromAddr(space->Begin()); card_cur < card_end; ++card_cur) {
+ if (*card_cur == kCardDirty) {
+ out_cards.push_back(card_cur);
+ *card_cur = kCardClean;
+ }
+ }
+}
+
+void CardTable::GetDirtyCards(ContinuousSpace* space, std::vector<byte*>& out_cards) const {
+ byte* card_end = CardFromAddr(space->End());
+ for (byte* card_cur = CardFromAddr(space->Begin());card_cur < card_end; ++card_cur) {
+ if (*card_cur == kCardDirty) {
+ out_cards.push_back(card_cur);
+ }
+ }
+}
+
+bool CardTable::AddrIsInCardTable(const void* addr) const {
+ return IsValidCard(biased_begin_ + ((uintptr_t)addr >> kCardShift));
+}
+
+void CardTable::CheckAddrIsInCardTable(const byte* addr) const {
+ byte* card_addr = biased_begin_ + ((uintptr_t)addr >> kCardShift);
+ byte* begin = mem_map_->Begin() + offset_;
+ byte* end = mem_map_->End();
+ CHECK(AddrIsInCardTable(addr))
+ << "Card table " << this
+ << " begin: " << reinterpret_cast<void*>(begin)
+ << " end: " << reinterpret_cast<void*>(end)
+ << " card_addr: " << reinterpret_cast<void*>(card_addr)
+ << " heap begin: " << AddrFromCard(begin)
+ << " heap end: " << AddrFromCard(end)
+ << " addr: " << reinterpret_cast<const void*>(addr);
+}
+
+void CardTable::VerifyCardTable() {
+ UNIMPLEMENTED(WARNING) << "Card table verification";
+}
+
+} // namespace art