Revert of "[heap] Fine-grained JSArrayBuffer tracking"

src/heap/array-buffer-tracker.cc

 // 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 "src/heap/array-buffer-tracker-inl.h"
 #include "src/heap/heap.h"
 #include "src/isolate.h"
+#include "src/objects.h"
 #include "src/objects-inl.h"
-#include "src/objects.h"
 #include "src/v8.h"
 
 namespace v8 {
 namespace internal {
 
-LocalArrayBufferTracker::~LocalArrayBufferTracker() {
+ArrayBufferTracker::~ArrayBufferTracker() {
+  Isolate* isolate = heap()->isolate();
   size_t freed_memory = 0;
-  for (auto& buffer : live_) {
-    heap_->isolate()->array_buffer_allocator()->Free(buffer.second.first,
-                                                     buffer.second.second);
-    freed_memory += buffer.second.second;
+  for (auto& buffer : live_array_buffers_) {
+    isolate->array_buffer_allocator()->Free(buffer.first, buffer.second);
+    freed_memory += buffer.second;
   }
+  for (auto& buffer : live_array_buffers_for_scavenge_) {
+    isolate->array_buffer_allocator()->Free(buffer.first, buffer.second);
+    freed_memory += buffer.second;
+  }
+  live_array_buffers_.clear();
+  live_array_buffers_for_scavenge_.clear();
+  not_yet_discovered_array_buffers_.clear();
+  not_yet_discovered_array_buffers_for_scavenge_.clear();
+
   if (freed_memory > 0) {
-    heap_->update_amount_of_external_allocated_freed_memory(
-        static_cast<intptr_t>(freed_memory));
-  }
-  live_.clear();
-  not_yet_discovered_.clear();
-}
-
-void LocalArrayBufferTracker::Add(Key key, const Value& value) {
-  live_[key] = value;
-  not_yet_discovered_[key] = value;
-}
-
-void LocalArrayBufferTracker::AddLive(Key key, const Value& value) {
-  DCHECK_EQ(not_yet_discovered_.count(key), 0);
-  live_[key] = value;
-}
-
-void LocalArrayBufferTracker::MarkLive(Key key) {
-  DCHECK_EQ(live_.count(key), 1);
-  not_yet_discovered_.erase(key);
-}
-
-LocalArrayBufferTracker::Value LocalArrayBufferTracker::Remove(Key key) {
-  DCHECK_EQ(live_.count(key), 1);
-  Value value = live_[key];
-  live_.erase(key);
-  not_yet_discovered_.erase(key);
-  return value;
-}
-
-void LocalArrayBufferTracker::FreeDead() {
-  size_t freed_memory = 0;
-  for (TrackingMap::iterator it = not_yet_discovered_.begin();
-       it != not_yet_discovered_.end();) {
-    heap_->isolate()->array_buffer_allocator()->Free(it->second.first,
-                                                     it->second.second);
-    freed_memory += it->second.second;
-    live_.erase(it->first);
-    not_yet_discovered_.erase(it++);
-  }
-  if (freed_memory > 0) {
-    heap_->update_amount_of_external_allocated_freed_memory(
-        static_cast<intptr_t>(freed_memory));
-  }
-  started_ = false;
-}
-
-void LocalArrayBufferTracker::Reset() {
-  if (!started_) {
-    not_yet_discovered_ = live_;
-    started_ = true;
+    heap()->update_amount_of_external_allocated_memory(
+        -static_cast<int64_t>(freed_memory));
   }
 }
 
-bool LocalArrayBufferTracker::IsEmpty() {
-  return live_.empty() && not_yet_discovered_.empty();
-}
-
-ArrayBufferTracker::~ArrayBufferTracker() {}
 
 void ArrayBufferTracker::RegisterNew(JSArrayBuffer* buffer) {
   void* data = buffer->backing_store();
   if (!data) return;
 
-  size_t length = NumberToSize(heap_->isolate(), buffer->byte_length());
-  Page* page = Page::FromAddress(buffer->address());
-  LocalArrayBufferTracker* tracker =
-      page->local_tracker<Page::kCreateIfNotPresent>();
-  DCHECK_NOT_NULL(tracker);
-  {
-    base::LockGuard<base::Mutex> guard(page->mutex());
-    if (Marking::IsBlack(Marking::MarkBitFrom(buffer))) {
-      tracker->AddLive(buffer, std::make_pair(data, length));
-    } else {
-      tracker->Add(buffer, std::make_pair(data, length));
-    }
+  bool in_new_space = heap()->InNewSpace(buffer);
+  size_t length = NumberToSize(heap()->isolate(), buffer->byte_length());
+  if (in_new_space) {
+    live_array_buffers_for_scavenge_[data] = length;
+  } else {
+    live_array_buffers_[data] = length;
   }
+
   // We may go over the limit of externally allocated memory here. We call the
   // api function to trigger a GC in this case.
-  reinterpret_cast<v8::Isolate*>(heap_->isolate())
+  reinterpret_cast<v8::Isolate*>(heap()->isolate())
       ->AdjustAmountOfExternalAllocatedMemory(length);
 }
 
 
 void ArrayBufferTracker::Unregister(JSArrayBuffer* buffer) {
   void* data = buffer->backing_store();
   if (!data) return;
 
-  Page* page = Page::FromAddress(buffer->address());
-  LocalArrayBufferTracker* tracker = page->local_tracker<Page::kDontCreate>();
-  DCHECK_NOT_NULL(tracker);
-  size_t length = 0;
-  {
-    base::LockGuard<base::Mutex> guard(page->mutex());
-    length = tracker->Remove(buffer).second;
-  }
-  heap_->update_amount_of_external_allocated_memory(
-      -static_cast<intptr_t>(length));
+  bool in_new_space = heap()->InNewSpace(buffer);
+  std::map<void*, size_t>* live_buffers =
+      in_new_space ? &live_array_buffers_for_scavenge_ : &live_array_buffers_;
+  std::map<void*, size_t>* not_yet_discovered_buffers =
+      in_new_space ? &not_yet_discovered_array_buffers_for_scavenge_
+                   : &not_yet_discovered_array_buffers_;
+
+  DCHECK(live_buffers->count(data) > 0);
+
+  size_t length = (*live_buffers)[data];
+  live_buffers->erase(data);
+  not_yet_discovered_buffers->erase(data);
+
+  heap()->update_amount_of_external_allocated_memory(
+      -static_cast<int64_t>(length));
 }
 
-void ArrayBufferTracker::FreeDeadInNewSpace() {
-  NewSpacePageIterator from_it(heap_->new_space()->FromSpaceStart(),
-                               heap_->new_space()->FromSpaceEnd());
-  while (from_it.has_next()) {
-    ScanAndFreeDeadArrayBuffers<LocalArrayBufferTracker::kForwardingPointer>(
-        from_it.next());
-  }
-  heap_->account_amount_of_external_allocated_freed_memory();
-}
-
-void ArrayBufferTracker::ResetTrackersInOldSpace() {
-  heap_->old_space()->ForAllPages([](Page* p) {
-    LocalArrayBufferTracker* tracker = p->local_tracker<Page::kDontCreate>();
-    if (tracker != nullptr) {
-      tracker->Reset();
-      if (tracker->IsEmpty()) {
-        p->ReleaseLocalTracker();
-      }
-    }
-  });
-}
 
 void ArrayBufferTracker::MarkLive(JSArrayBuffer* buffer) {
-  if (buffer->is_external()) return;
+  base::LockGuard<base::Mutex> guard(&mutex_);
   void* data = buffer->backing_store();
-  if (data == nullptr) return;
-  if (data == heap_->undefined_value()) return;
 
-  Page* page = Page::FromAddress(buffer->address());
-  LocalArrayBufferTracker* tracker =
-      page->local_tracker<Page::kCreateIfNotPresent>();
-  DCHECK_NOT_NULL(tracker);
-  if (tracker->IsTracked(buffer)) {
-    base::LockGuard<base::Mutex> guard(page->mutex());
-    tracker->MarkLive((buffer));
+  // ArrayBuffer might be in the middle of being constructed.
+  if (data == heap()->undefined_value()) return;
+  if (heap()->InNewSpace(buffer)) {
+    not_yet_discovered_array_buffers_for_scavenge_.erase(data);
   } else {
-    RegisterNew(buffer);
+    not_yet_discovered_array_buffers_.erase(data);
   }
 }
 
-void ArrayBufferTracker::FreeDead(Page* page) {
-  // Only called from the sweeper, which already holds the page lock.
-  LocalArrayBufferTracker* tracker = page->local_tracker<Page::kDontCreate>();
-  if (tracker != nullptr) {
-    tracker->FreeDead();
+
+void ArrayBufferTracker::FreeDead(bool from_scavenge) {
+  size_t freed_memory = 0;
+  Isolate* isolate = heap()->isolate();
+  for (auto& buffer : not_yet_discovered_array_buffers_for_scavenge_) {
+    isolate->array_buffer_allocator()->Free(buffer.first, buffer.second);
+    freed_memory += buffer.second;
+    live_array_buffers_for_scavenge_.erase(buffer.first);
   }
+
+  if (!from_scavenge) {
+    for (auto& buffer : not_yet_discovered_array_buffers_) {
+      isolate->array_buffer_allocator()->Free(buffer.first, buffer.second);
+      freed_memory += buffer.second;
+      live_array_buffers_.erase(buffer.first);
+    }
+  }
+
+  not_yet_discovered_array_buffers_for_scavenge_ =
+      live_array_buffers_for_scavenge_;
+  if (!from_scavenge) not_yet_discovered_array_buffers_ = live_array_buffers_;
+
+  // Do not call through the api as this code is triggered while doing a GC.
+  heap()->update_amount_of_external_allocated_memory(
+      -static_cast<int64_t>(freed_memory));
 }
 
-template <LocalArrayBufferTracker::LivenessIndicator liveness_indicator>
-void ArrayBufferTracker::ScanAndFreeDeadArrayBuffers(Page* page) {
-  LocalArrayBufferTracker* tracker = page->local_tracker<Page::kDontCreate>();
-  if (tracker != nullptr) {
-    base::LockGuard<base::Mutex> guard(page->mutex());
-    tracker->ScanAndFreeDead<liveness_indicator>();
-  }
+
+void ArrayBufferTracker::PrepareDiscoveryInNewSpace() {
+  not_yet_discovered_array_buffers_for_scavenge_ =
+      live_array_buffers_for_scavenge_;
 }
 
-template void ArrayBufferTracker::ScanAndFreeDeadArrayBuffers<
-    LocalArrayBufferTracker::LivenessIndicator::kForwardingPointer>(Page* page);
-template void ArrayBufferTracker::ScanAndFreeDeadArrayBuffers<
-    LocalArrayBufferTracker::LivenessIndicator::kMarkBit>(Page* page);
+
+void ArrayBufferTracker::Promote(JSArrayBuffer* buffer) {
+  base::LockGuard<base::Mutex> guard(&mutex_);
+
+  if (buffer->is_external()) return;
+  void* data = buffer->backing_store();
+  if (!data) return;
+  // ArrayBuffer might be in the middle of being constructed.
+  if (data == heap()->undefined_value()) return;
+  DCHECK(live_array_buffers_for_scavenge_.count(data) > 0);
+  live_array_buffers_[data] = live_array_buffers_for_scavenge_[data];
+  live_array_buffers_for_scavenge_.erase(data);
+  not_yet_discovered_array_buffers_for_scavenge_.erase(data);
+}
 
 }  // namespace internal
 }  // namespace v8