[heap] introduce ArrayBufferTracker

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 9c6a2a1690cdba36130ba3147302a84acf43d45d..b8ea63e94d37bf6eaf95f7ea6e5e7163a4a79b20 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -17,6 +17,7 @@
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/global-handles.h"
+#include "src/heap/array-buffer-tracker.h"
 #include "src/heap/gc-idle-time-handler.h"
 #include "src/heap/gc-tracer.h"
 #include "src/heap/incremental-marking.h"
@@ -144,7 +145,8 @@ Heap::Heap()
       gc_callbacks_depth_(0),
       deserialization_complete_(false),
       concurrent_sweeping_enabled_(false),
-      strong_roots_list_(NULL) {
+      strong_roots_list_(NULL),
+      array_buffer_tracker_(NULL) {
 // Allow build-time customization of the max semispace size. Building
 // V8 with snapshots and a non-default max semispace size is much
 // easier if you can define it as part of the build environment.
@@ -1547,7 +1549,7 @@ void Heap::Scavenge() {
 
   SelectScavengingVisitorsTable();
 
-  PrepareArrayBufferDiscoveryInNewSpace();
+  array_buffer_tracker()->PrepareDiscoveryInNewSpace();
 
   // Flip the semispaces.  After flipping, to space is empty, from space has
   // live objects.
@@ -1649,7 +1651,7 @@ void Heap::Scavenge() {
   new_space_.LowerInlineAllocationLimit(
       new_space_.inline_allocation_limit_step());
 
-  FreeDeadArrayBuffers(true);
+  array_buffer_tracker()->FreeDead(true);
 
   // Update how much has survived scavenge.
   IncrementYoungSurvivorsCounter(static_cast<int>(
@@ -1744,120 +1746,6 @@ void Heap::ProcessNativeContexts(WeakObjectRetainer* retainer) {
 }
 
 
-void Heap::RegisterNewArrayBuffer(bool in_new_space, void* data,
-                                  size_t length) {
-  if (!data) return;
-  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*>(isolate_)
-      ->AdjustAmountOfExternalAllocatedMemory(length);
-}
-
-
-void Heap::UnregisterArrayBuffer(bool in_new_space, void* data) {
-  if (!data) return;
-
-  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);
-
-  amount_of_external_allocated_memory_ -= length;
-}
-
-
-void Heap::RegisterLiveArrayBuffer(bool in_new_space, void* data) {
-  // ArrayBuffer might be in the middle of being constructed.
-  if (data == undefined_value()) return;
-  if (in_new_space) {
-    not_yet_discovered_array_buffers_for_scavenge_.erase(data);
-  } else {
-    not_yet_discovered_array_buffers_.erase(data);
-  }
-}
-
-
-void Heap::FreeDeadArrayBuffers(bool from_scavenge) {
-  size_t freed_memory = 0;
-  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.
-  amount_of_external_allocated_memory_ -= freed_memory;
-}
-
-
-void Heap::TearDownArrayBuffers() {
-  size_t freed_memory = 0;
-  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) {
-    reinterpret_cast<v8::Isolate*>(isolate_)
-        ->AdjustAmountOfExternalAllocatedMemory(
-            -static_cast<int64_t>(freed_memory));
-  }
-}
-
-
-void Heap::PrepareArrayBufferDiscoveryInNewSpace() {
-  not_yet_discovered_array_buffers_for_scavenge_ =
-      live_array_buffers_for_scavenge_;
-}
-
-
-void Heap::PromoteArrayBuffer(Object* obj) {
-  JSArrayBuffer* buffer = JSArrayBuffer::cast(obj);
-  if (buffer->is_external()) return;
-  void* data = buffer->backing_store();
-  if (!data) return;
-  // ArrayBuffer might be in the middle of being constructed.
-  if (data == 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);
-}
-
-
 void Heap::ProcessAllocationSites(WeakObjectRetainer* retainer) {
   Object* allocation_site_obj =
       VisitWeakList<AllocationSite>(this, allocation_sites_list(), retainer);
@@ -2087,6 +1975,17 @@ HeapObject* Heap::DoubleAlignForDeserialization(HeapObject* object, int size) {
 }
 
 
+void Heap::RegisterNewArrayBuffer(bool in_new_space, void* data,

[Michael Lippautz, 2015/09/04 09:09:57]

Anything holding us back to change the signature to take a JSArrayBuffer*
buffer? If not, please adjust.

[fedor.indutny, 2015/09/04 17:21:01]

Acknowledged.

+                                  size_t length) {
+  return array_buffer_tracker()->RegisterNew(in_new_space, data, length);
+}
+
+
+void Heap::UnregisterArrayBuffer(JSArrayBuffer* buffer) {
+  return array_buffer_tracker()->Unregister(buffer);
+}
+
+
 enum LoggingAndProfiling {
   LOGGING_AND_PROFILING_ENABLED,
   LOGGING_AND_PROFILING_DISABLED
@@ -2388,7 +2287,9 @@ class ScavengingVisitor : public StaticVisitorBase {
     MapWord map_word = object->map_word();
     DCHECK(map_word.IsForwardingAddress());
     HeapObject* target = map_word.ToForwardingAddress();
-    if (!heap->InNewSpace(target)) heap->PromoteArrayBuffer(target);
+    if (!heap->InNewSpace(target)) {
+      heap->array_buffer_tracker()->Promote(JSArrayBuffer::cast(target));
+    }
   }
 
 
@@ -5646,6 +5547,8 @@ bool Heap::SetUp() {
   object_stats_ = new ObjectStats(this);
   object_stats_->ClearObjectStats(true);
 
+  array_buffer_tracker_ = new ArrayBufferTracker(this);
+
   LOG(isolate_, IntPtrTEvent("heap-capacity", Capacity()));
   LOG(isolate_, IntPtrTEvent("heap-available", Available()));
 
@@ -5761,7 +5664,7 @@ void Heap::TearDown() {
 
   WaitUntilUnmappingOfFreeChunksCompleted();
 
-  TearDownArrayBuffers();
+  array_buffer_tracker()->TearDown();
 
   isolate_->global_handles()->TearDown();