| // Copyright 2015 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. |
| |
| #include "src/heap/array-buffer-tracker.h" |
| |
| #include <vector> |
| |
| #include "src/heap/array-buffer-collector.h" |
| #include "src/heap/array-buffer-tracker-inl.h" |
| #include "src/heap/heap.h" |
| #include "src/heap/spaces.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| LocalArrayBufferTracker::~LocalArrayBufferTracker() { |
| CHECK(array_buffers_.empty()); |
| } |
| |
| template <typename Callback> |
| void LocalArrayBufferTracker::Process(Callback callback) { |
| std::vector<JSArrayBuffer::Allocation> backing_stores_to_free; |
| TrackingData kept_array_buffers; |
| |
| JSArrayBuffer new_buffer; |
| JSArrayBuffer old_buffer; |
| size_t freed_memory = 0; |
| for (TrackingData::iterator it = array_buffers_.begin(); |
| it != array_buffers_.end(); ++it) { |
| old_buffer = it->first; |
| DCHECK_EQ(page_, Page::FromHeapObject(old_buffer)); |
| const CallbackResult result = callback(old_buffer, &new_buffer); |
| if (result == kKeepEntry) { |
| kept_array_buffers.insert(*it); |
| } else if (result == kUpdateEntry) { |
| DCHECK(!new_buffer.is_null()); |
| Page* target_page = Page::FromHeapObject(new_buffer); |
| { |
| base::MutexGuard guard(target_page->mutex()); |
| LocalArrayBufferTracker* tracker = target_page->local_tracker(); |
| if (tracker == nullptr) { |
| target_page->AllocateLocalTracker(); |
| tracker = target_page->local_tracker(); |
| } |
| DCHECK_NOT_NULL(tracker); |
| const size_t length = it->second.length; |
| // We should decrement before adding to avoid potential overflows in |
| // the external memory counters. |
| DCHECK_EQ(it->first.is_wasm_memory(), it->second.is_wasm_memory); |
| tracker->AddInternal(new_buffer, length); |
| MemoryChunk::MoveExternalBackingStoreBytes( |
| ExternalBackingStoreType::kArrayBuffer, |
| static_cast<MemoryChunk*>(page_), |
| static_cast<MemoryChunk*>(target_page), length); |
| } |
| } else if (result == kRemoveEntry) { |
| freed_memory += it->second.length; |
| // We pass backing_store() and stored length to the collector for freeing |
| // the backing store. Wasm allocations will go through their own tracker |
| // based on the backing store. |
| backing_stores_to_free.push_back(it->second); |
| } else { |
| UNREACHABLE(); |
| } |
| } |
| if (freed_memory) { |
| page_->DecrementExternalBackingStoreBytes( |
| ExternalBackingStoreType::kArrayBuffer, freed_memory); |
| // TODO(wez): Remove backing-store from external memory accounting. |
| page_->heap()->update_external_memory_concurrently_freed( |
| static_cast<intptr_t>(freed_memory)); |
| } |
| |
| array_buffers_.swap(kept_array_buffers); |
| |
| // Pass the backing stores that need to be freed to the main thread for |
| // potential later distribution. |
| page_->heap()->array_buffer_collector()->QueueOrFreeGarbageAllocations( |
| std::move(backing_stores_to_free)); |
| } |
| |
| void ArrayBufferTracker::PrepareToFreeDeadInNewSpace(Heap* heap) { |
| DCHECK_EQ(heap->gc_state(), Heap::HeapState::SCAVENGE); |
| for (Page* page : |
| PageRange(heap->new_space()->from_space().first_page(), nullptr)) { |
| bool empty = ProcessBuffers(page, kUpdateForwardedRemoveOthers); |
| CHECK(empty); |
| } |
| } |
| |
| void ArrayBufferTracker::FreeAll(Page* page) { |
| LocalArrayBufferTracker* tracker = page->local_tracker(); |
| if (tracker == nullptr) return; |
| tracker->Free([](JSArrayBuffer buffer) { return true; }); |
| if (tracker->IsEmpty()) { |
| page->ReleaseLocalTracker(); |
| } |
| } |
| |
| bool ArrayBufferTracker::ProcessBuffers(Page* page, ProcessingMode mode) { |
| LocalArrayBufferTracker* tracker = page->local_tracker(); |
| if (tracker == nullptr) return true; |
| |
| DCHECK(page->SweepingDone()); |
| tracker->Process([mode](JSArrayBuffer old_buffer, JSArrayBuffer* new_buffer) { |
| MapWord map_word = old_buffer.map_word(); |
| if (map_word.IsForwardingAddress()) { |
| *new_buffer = JSArrayBuffer::cast(map_word.ToForwardingAddress()); |
| return LocalArrayBufferTracker::kUpdateEntry; |
| } |
| return mode == kUpdateForwardedKeepOthers |
| ? LocalArrayBufferTracker::kKeepEntry |
| : LocalArrayBufferTracker::kRemoveEntry; |
| }); |
| return tracker->IsEmpty(); |
| } |
| |
| bool ArrayBufferTracker::IsTracked(JSArrayBuffer buffer) { |
| Page* page = Page::FromHeapObject(buffer); |
| { |
| base::MutexGuard guard(page->mutex()); |
| LocalArrayBufferTracker* tracker = page->local_tracker(); |
| if (tracker == nullptr) return false; |
| return tracker->IsTracked(buffer); |
| } |
| } |
| |
| void ArrayBufferTracker::TearDown(Heap* heap) { |
| // ArrayBuffers can only be found in NEW_SPACE and OLD_SPACE. |
| for (Page* p : *heap->old_space()) { |
| FreeAll(p); |
| } |
| NewSpace* new_space = heap->new_space(); |
| if (new_space->to_space().is_committed()) { |
| for (Page* p : new_space->to_space()) { |
| FreeAll(p); |
| } |
| } |
| #ifdef DEBUG |
| if (new_space->from_space().is_committed()) { |
| for (Page* p : new_space->from_space()) { |
| DCHECK(!p->contains_array_buffers()); |
| } |
| } |
| #endif // DEBUG |
| } |
| |
| } // namespace internal |
| } // namespace v8 |