Bug 1382645: Part 1 - Add memory reporter for StructuredCloneHolder binding implementation. r=billm

MozReview-Commit-ID: aK3ljfCJVi

--HG--
extra : rebase_source : d788c6c686cc72b423ca100795a379d343c398db

dom/base/StructuredCloneBlob.cpp

@@ -22,7 +22,12 @@ namespace dom {
 StructuredCloneBlob::StructuredCloneBlob()
     : StructuredCloneHolder(CloningSupported, TransferringNotSupported,
                             StructuredCloneScope::DifferentProcess)
-{};
+{}
+
+StructuredCloneBlob::~StructuredCloneBlob()
+{
+  UnregisterWeakMemoryReporter(this);
+}
 
 
 /* static */ already_AddRefed<StructuredCloneBlob>
@@ -32,7 +37,7 @@ StructuredCloneBlob::Constructor(GlobalObject& aGlobal, JS::HandleValue aValue,
 {
   JSContext* cx = aGlobal.Context();
 
-  RefPtr<StructuredCloneBlob> holder = new StructuredCloneBlob();
+  RefPtr<StructuredCloneBlob> holder = StructuredCloneBlob::Create();
 
   Maybe<JSAutoCompartment> ac;
   JS::RootedValue value(cx, aValue);
@@ -104,7 +109,7 @@ StructuredCloneBlob::ReadStructuredClone(JSContext* aCx, JSStructuredCloneReader
 {
   JS::RootedObject obj(aCx);
   {
-    RefPtr<StructuredCloneBlob> holder = new StructuredCloneBlob();
+    RefPtr<StructuredCloneBlob> holder = StructuredCloneBlob::Create();
 
     if (!holder->ReadStructuredCloneInternal(aCx, aReader, aHolder) ||
         !holder->WrapObject(aCx, nullptr, &obj)) {
@@ -181,5 +186,20 @@ StructuredCloneBlob::WrapObject(JSContext* aCx, JS::HandleObject aGivenProto, JS
     return StructuredCloneHolderBinding::Wrap(aCx, this, aGivenProto, aResult);
 }
 
+
+NS_IMETHODIMP
+StructuredCloneBlob::CollectReports(nsIHandleReportCallback* aHandleReport,
+                                    nsISupports* aData, bool aAnonymize)
+{
+  MOZ_COLLECT_REPORT(
+    "explicit/dom/structured-clone-holder", KIND_HEAP, UNITS_BYTES,
+    MallocSizeOf(this) + SizeOfExcludingThis(MallocSizeOf),
+    "Memory used by StructuredCloneHolder DOM objects.");
+
+  return NS_OK;
+}
+
+NS_IMPL_ISUPPORTS(StructuredCloneBlob, nsIMemoryReporter)
+
 } // namespace dom
 } // namespace mozilla

dom/base/StructuredCloneBlob.h

@@ -9,22 +9,23 @@
 #include "mozilla/dom/BindingDeclarations.h"
 #include "mozilla/dom/StructuredCloneHolder.h"
 #include "mozilla/dom/StructuredCloneHolderBinding.h"
-#include "mozilla/RefCounted.h"
 
 #include "jsapi.h"
 
+#include "nsIMemoryReporter.h"
 #include "nsISupports.h"
 
 namespace mozilla {
 namespace dom {
 
-class StructuredCloneBlob : public StructuredCloneHolder
-                          , public RefCounted<StructuredCloneBlob>
+class StructuredCloneBlob final : public nsIMemoryReporter
+                                , public StructuredCloneHolder
 {
-public:
-  MOZ_DECLARE_REFCOUNTED_TYPENAME(StructuredCloneBlob)
+  MOZ_DEFINE_MALLOC_SIZE_OF(MallocSizeOf)
 
-  explicit StructuredCloneBlob();
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIMEMORYREPORTER
 
   static JSObject* ReadStructuredClone(JSContext* aCx, JSStructuredCloneReader* aReader,
                                        StructuredCloneHolder* aHolder);
@@ -43,12 +44,18 @@ public:
   bool WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto, JS::MutableHandleObject aResult);
 
 protected:
-  template <typename T, detail::RefCountAtomicity>
-  friend class detail::RefCounted;
-
-  ~StructuredCloneBlob() = default;
+  virtual ~StructuredCloneBlob();
 
 private:
+  explicit StructuredCloneBlob();
+
+  static already_AddRefed<StructuredCloneBlob> Create()
+  {
+    RefPtr<StructuredCloneBlob> holder = new StructuredCloneBlob();
+    RegisterWeakMemoryReporter(holder);
+    return holder.forget();
+  }
+
   bool ReadStructuredCloneInternal(JSContext* aCx, JSStructuredCloneReader* aReader,
                                    StructuredCloneHolder* aHolder);
 };

dom/base/StructuredCloneHolder.h

@@ -8,6 +8,7 @@
 
 #include "jsapi.h"
 #include "js/StructuredClone.h"
+#include "mozilla/MemoryReporting.h"
 #include "mozilla/Move.h"
 #include "mozilla/UniquePtr.h"
 #include "mozilla/dom/BindingDeclarations.h"
@@ -116,6 +117,15 @@ public:
     return mBuffer->data();
   }
 
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf)
+  {
+    size_t size = 0;
+    if (HasData()) {
+      size += mBuffer->sizeOfIncludingThis(aMallocSizeOf);
+    }
+    return size;
+  }
+
 protected:
   UniquePtr<JSAutoStructuredCloneBuffer> mBuffer;
 
@@ -306,6 +316,12 @@ protected:
   bool mSupportsCloning;
   bool mSupportsTransferring;
 
+  // SizeOfExcludingThis is inherited from StructuredCloneHolderBase. It doesn't
+  // account for objects in the following arrays because a) they're not expected
+  // to be stored in long-lived StructuredCloneHolder objects, and b) in the
+  // case of BlobImpl objects, MemoryBlobImpls have their own memory reporters,
+  // and the other types do not hold significant amounts of memory alive.
+
   // Used for cloning blobs in the structured cloning algorithm.
   nsTArray<RefPtr<BlobImpl>> mBlobImplArray;
 

js/public/StructuredClone.h

@@ -9,6 +9,7 @@
 
 #include "mozilla/Attributes.h"
 #include "mozilla/BufferList.h"
+#include "mozilla/MemoryReporting.h"
 
 #include <stdint.h>
 
@@ -339,6 +340,16 @@ class JS_PUBLIC_API(JSAutoStructuredCloneBuffer) {
                JS::CloneDataPolicy cloneDataPolicy,
                const JSStructuredCloneCallbacks* optionalCallbacks=nullptr, void* closure=nullptr);
 
+    size_t sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf)
+    {
+        return data_.SizeOfExcludingThis(mallocSizeOf);
+    }
+
+    size_t sizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf)
+    {
+        return mallocSizeOf(this) + sizeOfExcludingThis(mallocSizeOf);
+    }
+
   private:
     // Copy and assignment are not supported.
     JSAutoStructuredCloneBuffer(const JSAutoStructuredCloneBuffer& other) = delete;

mfbt/BufferList.h

@@ -9,6 +9,7 @@
 
 #include <algorithm>
 #include "mozilla/AllocPolicy.h"
+#include "mozilla/MemoryReporting.h"
 #include "mozilla/Move.h"
 #include "mozilla/ScopeExit.h"
 #include "mozilla/Types.h"
@@ -136,6 +137,15 @@ class BufferList : private AllocPolicy
   // Returns the sum of the sizes of all the buffers.
   size_t Size() const { return mSize; }
 
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf)
+  {
+    size_t size = mSegments.sizeOfExcludingThis(aMallocSizeOf);
+    for (Segment& segment : mSegments) {
+      size += aMallocSizeOf(segment.Start());
+    }
+    return size;
+  }
+
   void Clear()
   {
     if (mOwning) {