[heap] Fine-grained JSArrayBuffer tracking

src/heap/spaces.h

 // Copyright 2011 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_SPACES_H_
 #define V8_HEAP_SPACES_H_
 
 #include <list>
 
 #include "src/allocation.h"
 #include "src/base/atomic-utils.h"
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/base/platform/mutex.h"
 #include "src/flags.h"
 #include "src/hashmap.h"
+#include "src/heap/array-buffer-tracker.h"
 #include "src/list.h"
 #include "src/objects.h"
 #include "src/utils.h"
 
 namespace v8 {
 namespace internal {
 
 class AllocationInfo;
 class AllocationObserver;
 class CompactionSpace;
@@ skipping 489 matching lines @@
   static const size_t kMinHeaderSize =
       kWriteBarrierCounterOffset +
       kIntptrSize         // intptr_t write_barrier_counter_
       + kPointerSize      // AtomicValue high_water_mark_
       + kPointerSize      // base::Mutex* mutex_
       + kPointerSize      // base::AtomicWord concurrent_sweeping_
       + 2 * kPointerSize  // AtomicNumber free-list statistics
       + kPointerSize      // AtomicValue next_chunk_
       + kPointerSize      // AtomicValue prev_chunk_
       // FreeListCategory categories_[kNumberOfCategories]
-      + FreeListCategory::kSize * kNumberOfCategories;
+      + FreeListCategory::kSize * kNumberOfCategories +
+      kPointerSize;  // LocalArrayBufferTracker tracker_
 
   // We add some more space to the computed header size to amount for missing
   // alignment requirements in our computation.
   // Try to get kHeaderSize properly aligned on 32-bit and 64-bit machines.
   static const size_t kHeaderSize = kMinHeaderSize;
 
   static const int kBodyOffset =
       CODE_POINTER_ALIGN(kHeaderSize + Bitmap::kSize);
 
   // The start offset of the object area in a page. Aligned to both maps and
@@ skipping 280 matching lines @@
   base::AtomicNumber<intptr_t> available_in_free_list_;
   base::AtomicNumber<intptr_t> wasted_memory_;
 
   // next_chunk_ holds a pointer of type MemoryChunk
   base::AtomicValue<MemoryChunk*> next_chunk_;
   // prev_chunk_ holds a pointer of type MemoryChunk
   base::AtomicValue<MemoryChunk*> prev_chunk_;
 
   FreeListCategory categories_[kNumberOfCategories];
 
+  LocalArrayBufferTracker* local_tracker_;
+
  private:
   void InitializeReservedMemory() { reservation_.Reset(); }
 
   friend class MemoryAllocator;
   friend class MemoryChunkValidator;
 };
 
 // -----------------------------------------------------------------------------
 // A page is a memory chunk of a size 1MB. Large object pages may be larger.
 //
@@ skipping 110 matching lines @@
 
   bool is_anchor() { return IsFlagSet(Page::ANCHOR); }
 
   intptr_t wasted_memory() { return wasted_memory_.Value(); }
   void add_wasted_memory(intptr_t waste) { wasted_memory_.Increment(waste); }
   intptr_t available_in_free_list() { return available_in_free_list_.Value(); }
   void add_available_in_free_list(intptr_t available) {
     available_in_free_list_.Increment(available);
   }
 
+  LocalArrayBufferTracker* local_tracker() {
+    if (local_tracker_ == nullptr) {
+      local_tracker_ = new LocalArrayBufferTracker(heap_);
+    }
+    return local_tracker_;
+  }
+
+  void FreeDeadArrayBuffers() {
+    if (local_tracker_ != nullptr) {
+      local_tracker_->FreeDead();
+      if (local_tracker_->IsEmpty()) {
+        delete local_tracker_;
+        local_tracker_ = nullptr;
+      }
+    }
+  }
+
+  template <LocalArrayBufferTracker::LivenessIndicator liveness_indicator>
+  void ScanAndFreeDeadArrayBuffers() {
+    if (local_tracker_ != nullptr) {
+      local_tracker_->ScanAndFreeDead<liveness_indicator>();
+      if (local_tracker_->IsEmpty()) {
+        delete local_tracker_;
+        local_tracker_ = nullptr;
+      }
+    }
+  }
+
+  void ResetTracker() {
+    if (local_tracker_ != nullptr) {
+      local_tracker_->Reset();
+    }
+  }
+
 #ifdef DEBUG
   void Print();
 #endif  // DEBUG
 
  private:
   enum InitializationMode { kFreeMemory, kDoNotFreeMemory };
 
   template <InitializationMode mode = kFreeMemory>
   static inline Page* Initialize(Heap* heap, MemoryChunk* chunk,
                                  Executability executable, PagedSpace* owner);
@@ skipping 1321 matching lines @@
   // sweeper.
   virtual void RefillFreeList();
 
   FreeList* free_list() { return &free_list_; }
 
   base::Mutex* mutex() { return &space_mutex_; }
 
   inline void UnlinkFreeListCategories(Page* page);
   inline intptr_t RelinkFreeListCategories(Page* page);
 
+  // Callback signature:
+  //   void Callback(Page*);
+  template <typename Callback>
+  void ForAllPages(Callback callback) {
+    PageIterator it(this);
+    while (it.has_next()) {
+      callback(it.next());
+    }
+  }
+
  protected:
   // PagedSpaces that should be included in snapshots have different, i.e.,
   // smaller, initial pages.
   virtual bool snapshotable() { return true; }
 
   bool HasPages() { return anchor_.next_page() != &anchor_; }
 
   // Cleans up the space, frees all pages in this space except those belonging
   // to the initial chunk, uncommits addresses in the initial chunk.
   void TearDown();
@@ skipping 841 matching lines @@
     count = 0;
   }
   // Must be small, since an iteration is used for lookup.
   static const int kMaxComments = 64;
 };
 #endif
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_SPACES_H_