| // Copyright 2016 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef V8_HEAP_REMEMBERED_SET_H_ |
| #define V8_HEAP_REMEMBERED_SET_H_ |
| |
| #include "src/base/memory.h" |
| #include "src/codegen/reloc-info.h" |
| #include "src/heap/heap.h" |
| #include "src/heap/slot-set.h" |
| #include "src/heap/spaces.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| enum RememberedSetIterationMode { SYNCHRONIZED, NON_SYNCHRONIZED }; |
| |
| // TODO(ulan): Investigate performance of de-templatizing this class. |
| template <RememberedSetType type> |
| class RememberedSet : public AllStatic { |
| public: |
| // Given a page and a slot in that page, this function adds the slot to the |
| // remembered set. |
| template <AccessMode access_mode = AccessMode::ATOMIC> |
| static void Insert(MemoryChunk* chunk, Address slot_addr) { |
| DCHECK(chunk->Contains(slot_addr)); |
| SlotSet* slot_set = chunk->slot_set<type, access_mode>(); |
| if (slot_set == nullptr) { |
| slot_set = chunk->AllocateSlotSet<type>(); |
| } |
| uintptr_t offset = slot_addr - chunk->address(); |
| slot_set[offset / Page::kPageSize].Insert<access_mode>(offset % |
| Page::kPageSize); |
| } |
| |
| // Given a page and a slot in that page, this function returns true if |
| // the remembered set contains the slot. |
| static bool Contains(MemoryChunk* chunk, Address slot_addr) { |
| DCHECK(chunk->Contains(slot_addr)); |
| SlotSet* slot_set = chunk->slot_set<type>(); |
| if (slot_set == nullptr) { |
| return false; |
| } |
| uintptr_t offset = slot_addr - chunk->address(); |
| return slot_set[offset / Page::kPageSize].Contains(offset % |
| Page::kPageSize); |
| } |
| |
| // Given a page and a slot in that page, this function removes the slot from |
| // the remembered set. |
| // If the slot was never added, then the function does nothing. |
| static void Remove(MemoryChunk* chunk, Address slot_addr) { |
| DCHECK(chunk->Contains(slot_addr)); |
| SlotSet* slot_set = chunk->slot_set<type>(); |
| if (slot_set != nullptr) { |
| uintptr_t offset = slot_addr - chunk->address(); |
| slot_set[offset / Page::kPageSize].Remove(offset % Page::kPageSize); |
| } |
| } |
| |
| // Given a page and a range of slots in that page, this function removes the |
| // slots from the remembered set. |
| static void RemoveRange(MemoryChunk* chunk, Address start, Address end, |
| SlotSet::EmptyBucketMode mode) { |
| SlotSet* slot_set = chunk->slot_set<type>(); |
| if (slot_set != nullptr) { |
| uintptr_t start_offset = start - chunk->address(); |
| uintptr_t end_offset = end - chunk->address(); |
| DCHECK_LT(start_offset, end_offset); |
| if (end_offset < static_cast<uintptr_t>(Page::kPageSize)) { |
| slot_set->RemoveRange(static_cast<int>(start_offset), |
| static_cast<int>(end_offset), mode); |
| } else { |
| // The large page has multiple slot sets. |
| // Compute slot set indicies for the range [start_offset, end_offset). |
| int start_chunk = static_cast<int>(start_offset / Page::kPageSize); |
| int end_chunk = static_cast<int>((end_offset - 1) / Page::kPageSize); |
| int offset_in_start_chunk = |
| static_cast<int>(start_offset % Page::kPageSize); |
| // Note that using end_offset % Page::kPageSize would be incorrect |
| // because end_offset is one beyond the last slot to clear. |
| int offset_in_end_chunk = static_cast<int>( |
| end_offset - static_cast<uintptr_t>(end_chunk) * Page::kPageSize); |
| if (start_chunk == end_chunk) { |
| slot_set[start_chunk].RemoveRange(offset_in_start_chunk, |
| offset_in_end_chunk, mode); |
| } else { |
| // Clear all slots from start_offset to the end of first chunk. |
| slot_set[start_chunk].RemoveRange(offset_in_start_chunk, |
| Page::kPageSize, mode); |
| // Clear all slots in intermediate chunks. |
| for (int i = start_chunk + 1; i < end_chunk; i++) { |
| slot_set[i].RemoveRange(0, Page::kPageSize, mode); |
| } |
| // Clear slots from the beginning of the last page to end_offset. |
| slot_set[end_chunk].RemoveRange(0, offset_in_end_chunk, mode); |
| } |
| } |
| } |
| } |
| |
| // Iterates and filters the remembered set with the given callback. |
| // The callback should take (Address slot) and return SlotCallbackResult. |
| template <typename Callback> |
| static void Iterate(Heap* heap, RememberedSetIterationMode mode, |
| Callback callback) { |
| IterateMemoryChunks(heap, [mode, callback](MemoryChunk* chunk) { |
| if (mode == SYNCHRONIZED) chunk->mutex()->Lock(); |
| Iterate(chunk, callback); |
| if (mode == SYNCHRONIZED) chunk->mutex()->Unlock(); |
| }); |
| } |
| |
| // Iterates over all memory chunks that contains non-empty slot sets. |
| // The callback should take (MemoryChunk* chunk) and return void. |
| template <typename Callback> |
| static void IterateMemoryChunks(Heap* heap, Callback callback) { |
| OldGenerationMemoryChunkIterator it(heap); |
| MemoryChunk* chunk; |
| while ((chunk = it.next()) != nullptr) { |
| SlotSet* slots = chunk->slot_set<type>(); |
| TypedSlotSet* typed_slots = chunk->typed_slot_set<type>(); |
| if (slots != nullptr || typed_slots != nullptr || |
| chunk->invalidated_slots() != nullptr) { |
| callback(chunk); |
| } |
| } |
| } |
| |
| // Iterates and filters the remembered set in the given memory chunk with |
| // the given callback. The callback should take (Address slot) and return |
| // SlotCallbackResult. |
| // |
| // Notice that |mode| can only be of FREE* or PREFREE* if there are no other |
| // threads concurrently inserting slots. |
| template <typename Callback> |
| static void Iterate(MemoryChunk* chunk, Callback callback, |
| SlotSet::EmptyBucketMode mode) { |
| SlotSet* slots = chunk->slot_set<type>(); |
| if (slots != nullptr) { |
| size_t pages = (chunk->size() + Page::kPageSize - 1) / Page::kPageSize; |
| int new_count = 0; |
| for (size_t page = 0; page < pages; page++) { |
| new_count += slots[page].Iterate(callback, mode); |
| } |
| // Only old-to-old slot sets are released eagerly. Old-new-slot sets are |
| // released by the sweeper threads. |
| if (type == OLD_TO_OLD && new_count == 0) { |
| chunk->ReleaseSlotSet<OLD_TO_OLD>(); |
| } |
| } |
| } |
| |
| static int NumberOfPreFreedEmptyBuckets(MemoryChunk* chunk) { |
| DCHECK(type == OLD_TO_NEW); |
| int result = 0; |
| SlotSet* slots = chunk->slot_set<type>(); |
| if (slots != nullptr) { |
| size_t pages = (chunk->size() + Page::kPageSize - 1) / Page::kPageSize; |
| for (size_t page = 0; page < pages; page++) { |
| result += slots[page].NumberOfPreFreedEmptyBuckets(); |
| } |
| } |
| return result; |
| } |
| |
| static void PreFreeEmptyBuckets(MemoryChunk* chunk) { |
| DCHECK(type == OLD_TO_NEW); |
| SlotSet* slots = chunk->slot_set<type>(); |
| if (slots != nullptr) { |
| size_t pages = (chunk->size() + Page::kPageSize - 1) / Page::kPageSize; |
| for (size_t page = 0; page < pages; page++) { |
| slots[page].PreFreeEmptyBuckets(); |
| } |
| } |
| } |
| |
| static void FreeEmptyBuckets(MemoryChunk* chunk) { |
| DCHECK(type == OLD_TO_NEW); |
| SlotSet* slots = chunk->slot_set<type>(); |
| if (slots != nullptr) { |
| size_t pages = (chunk->size() + Page::kPageSize - 1) / Page::kPageSize; |
| for (size_t page = 0; page < pages; page++) { |
| slots[page].FreeEmptyBuckets(); |
| slots[page].FreeToBeFreedBuckets(); |
| } |
| } |
| } |
| |
| // Given a page and a typed slot in that page, this function adds the slot |
| // to the remembered set. |
| static void InsertTyped(MemoryChunk* memory_chunk, SlotType slot_type, |
| uint32_t offset) { |
| TypedSlotSet* slot_set = memory_chunk->typed_slot_set<type>(); |
| if (slot_set == nullptr) { |
| slot_set = memory_chunk->AllocateTypedSlotSet<type>(); |
| } |
| slot_set->Insert(slot_type, offset); |
| } |
| |
| static void MergeTyped(MemoryChunk* page, std::unique_ptr<TypedSlots> slots) { |
| TypedSlotSet* slot_set = page->typed_slot_set<type>(); |
| if (slot_set == nullptr) { |
| slot_set = page->AllocateTypedSlotSet<type>(); |
| } |
| slot_set->Merge(slots.get()); |
| } |
| |
| // Given a page and a range of typed slots in that page, this function removes |
| // the slots from the remembered set. |
| static void RemoveRangeTyped(MemoryChunk* page, Address start, Address end) { |
| TypedSlotSet* slots = page->typed_slot_set<type>(); |
| if (slots != nullptr) { |
| slots->Iterate( |
| [=](SlotType slot_type, Address slot_addr) { |
| return start <= slot_addr && slot_addr < end ? REMOVE_SLOT |
| : KEEP_SLOT; |
| }, |
| TypedSlotSet::PREFREE_EMPTY_CHUNKS); |
| } |
| } |
| |
| // Iterates and filters the remembered set with the given callback. |
| // The callback should take (SlotType slot_type, Address addr) and return |
| // SlotCallbackResult. |
| template <typename Callback> |
| static void IterateTyped(Heap* heap, RememberedSetIterationMode mode, |
| Callback callback) { |
| IterateMemoryChunks(heap, [mode, callback](MemoryChunk* chunk) { |
| if (mode == SYNCHRONIZED) chunk->mutex()->Lock(); |
| IterateTyped(chunk, callback); |
| if (mode == SYNCHRONIZED) chunk->mutex()->Unlock(); |
| }); |
| } |
| |
| // Iterates and filters typed old to old pointers in the given memory chunk |
| // with the given callback. The callback should take (SlotType slot_type, |
| // Address addr) and return SlotCallbackResult. |
| template <typename Callback> |
| static void IterateTyped(MemoryChunk* chunk, Callback callback) { |
| TypedSlotSet* slots = chunk->typed_slot_set<type>(); |
| if (slots != nullptr) { |
| int new_count = slots->Iterate(callback, TypedSlotSet::KEEP_EMPTY_CHUNKS); |
| if (new_count == 0) { |
| chunk->ReleaseTypedSlotSet<type>(); |
| } |
| } |
| } |
| |
| // Clear all old to old slots from the remembered set. |
| static void ClearAll(Heap* heap) { |
| STATIC_ASSERT(type == OLD_TO_OLD); |
| OldGenerationMemoryChunkIterator it(heap); |
| MemoryChunk* chunk; |
| while ((chunk = it.next()) != nullptr) { |
| chunk->ReleaseSlotSet<OLD_TO_OLD>(); |
| chunk->ReleaseTypedSlotSet<OLD_TO_OLD>(); |
| chunk->ReleaseInvalidatedSlots(); |
| } |
| } |
| |
| private: |
| static bool IsValidSlot(Heap* heap, MemoryChunk* chunk, ObjectSlot slot); |
| }; |
| |
| class UpdateTypedSlotHelper { |
| public: |
| // Updates a typed slot using an untyped slot callback where |addr| depending |
| // on slot type represents either address for respective RelocInfo or address |
| // of the uncompressed constant pool entry. |
| // The callback accepts FullMaybeObjectSlot and returns SlotCallbackResult. |
| template <typename Callback> |
| static SlotCallbackResult UpdateTypedSlot(Heap* heap, SlotType slot_type, |
| Address addr, Callback callback) { |
| switch (slot_type) { |
| case CODE_TARGET_SLOT: { |
| RelocInfo rinfo(addr, RelocInfo::CODE_TARGET, 0, Code()); |
| return UpdateCodeTarget(&rinfo, callback); |
| } |
| case CODE_ENTRY_SLOT: { |
| return UpdateCodeEntry(addr, callback); |
| } |
| case COMPRESSED_EMBEDDED_OBJECT_SLOT: { |
| RelocInfo rinfo(addr, RelocInfo::COMPRESSED_EMBEDDED_OBJECT, 0, Code()); |
| return UpdateEmbeddedPointer(heap, &rinfo, callback); |
| } |
| case FULL_EMBEDDED_OBJECT_SLOT: { |
| RelocInfo rinfo(addr, RelocInfo::FULL_EMBEDDED_OBJECT, 0, Code()); |
| return UpdateEmbeddedPointer(heap, &rinfo, callback); |
| } |
| case OBJECT_SLOT: { |
| return callback(FullMaybeObjectSlot(addr)); |
| } |
| case CLEARED_SLOT: |
| break; |
| } |
| UNREACHABLE(); |
| } |
| |
| private: |
| // Updates a code entry slot using an untyped slot callback. |
| // The callback accepts FullMaybeObjectSlot and returns SlotCallbackResult. |
| template <typename Callback> |
| static SlotCallbackResult UpdateCodeEntry(Address entry_address, |
| Callback callback) { |
| Code code = Code::GetObjectFromEntryAddress(entry_address); |
| Code old_code = code; |
| SlotCallbackResult result = callback(FullMaybeObjectSlot(&code)); |
| DCHECK(!HasWeakHeapObjectTag(code)); |
| if (code != old_code) { |
| base::Memory<Address>(entry_address) = code.entry(); |
| } |
| return result; |
| } |
| |
| // Updates a code target slot using an untyped slot callback. |
| // The callback accepts FullMaybeObjectSlot and returns SlotCallbackResult. |
| template <typename Callback> |
| static SlotCallbackResult UpdateCodeTarget(RelocInfo* rinfo, |
| Callback callback) { |
| DCHECK(RelocInfo::IsCodeTargetMode(rinfo->rmode())); |
| Code old_target = Code::GetCodeFromTargetAddress(rinfo->target_address()); |
| Code new_target = old_target; |
| SlotCallbackResult result = callback(FullMaybeObjectSlot(&new_target)); |
| DCHECK(!HasWeakHeapObjectTag(new_target)); |
| if (new_target != old_target) { |
| rinfo->set_target_address(Code::cast(new_target).raw_instruction_start()); |
| } |
| return result; |
| } |
| |
| // Updates an embedded pointer slot using an untyped slot callback. |
| // The callback accepts FullMaybeObjectSlot and returns SlotCallbackResult. |
| template <typename Callback> |
| static SlotCallbackResult UpdateEmbeddedPointer(Heap* heap, RelocInfo* rinfo, |
| Callback callback) { |
| DCHECK(RelocInfo::IsEmbeddedObjectMode(rinfo->rmode())); |
| HeapObject old_target = rinfo->target_object_no_host(heap->isolate()); |
| HeapObject new_target = old_target; |
| SlotCallbackResult result = callback(FullMaybeObjectSlot(&new_target)); |
| DCHECK(!HasWeakHeapObjectTag(new_target)); |
| if (new_target != old_target) { |
| rinfo->set_target_object(heap, HeapObject::cast(new_target)); |
| } |
| return result; |
| } |
| }; |
| |
| inline SlotType SlotTypeForRelocInfoMode(RelocInfo::Mode rmode) { |
| if (RelocInfo::IsCodeTargetMode(rmode)) { |
| return CODE_TARGET_SLOT; |
| } else if (RelocInfo::IsFullEmbeddedObject(rmode)) { |
| return FULL_EMBEDDED_OBJECT_SLOT; |
| } else if (RelocInfo::IsCompressedEmbeddedObject(rmode)) { |
| return COMPRESSED_EMBEDDED_OBJECT_SLOT; |
| } |
| UNREACHABLE(); |
| } |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_HEAP_REMEMBERED_SET_H_ |