Bug 897452 - Part 15 - Introduce a AtomicRefCountedWithFinalize class to factor our custom-refcounting needs - r=nical

gfx/layers/AtomicRefCountedWithFinalize.h

@@ -0,0 +1,47 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MOZILLA_ATOMICREFCOUNTEDWITHFINALIZE_H_
+#define MOZILLA_ATOMICREFCOUNTEDWITHFINALIZE_H_
+
+#include "mozilla/RefPtr.h"
+
+namespace mozilla {
+
+template<typename T>
+class AtomicRefCountedWithFinalize
+{
+  protected:
+    AtomicRefCountedWithFinalize()
+      : mRefCount(0)
+    {}
+
+    ~AtomicRefCountedWithFinalize() {}
+
+  public:
+    void AddRef() {
+      MOZ_ASSERT(mRefCount >= 0);
+      ++mRefCount;
+    }
+
+    void Release() {
+      MOZ_ASSERT(mRefCount > 0);
+      if (0 == --mRefCount) {
+#ifdef DEBUG
+        mRefCount = detail::DEAD;
+#endif
+        T* derived = static_cast<T*>(this);
+        derived->Finalize();
+        delete derived;
+      }
+    }
+
+private:
+    Atomic<int> mRefCount;
+};
+
+}
+
+#endif

gfx/layers/client/TextureClient.cpp

@@ -233,8 +233,7 @@ ShmemTextureClient::DropTextureData()
 }
 
 TextureClient::TextureClient(TextureFlags aFlags)
-  : mRefCount(0)
-  , mActor(nullptr)
+  : mActor(nullptr)
   , mFlags(aFlags)
   , mShared(false)
   , mValid(true)

gfx/layers/client/TextureClient.h

@@ -24,6 +24,7 @@
 #include "nsAutoPtr.h"                  // for nsRefPtr
 #include "nsCOMPtr.h"                   // for already_AddRefed
 #include "nsISupportsImpl.h"            // for TextureImage::AddRef, etc
+#include "mozilla/layers/AtomicRefCountedWithFinalize.h"
 
 class gfxReusableSurfaceWrapper;
 class gfxASurface;
@@ -151,27 +152,12 @@ public:
  * several TextureClients.
  */
 class TextureClient
+  : public AtomicRefCountedWithFinalize<TextureClient>
 {
 public:
   TextureClient(TextureFlags aFlags = TEXTURE_FLAGS_DEFAULT);
   virtual ~TextureClient();
 
-  void AddRef() {
-    MOZ_ASSERT(mRefCount >= 0);
-    ++mRefCount;
-  }
-
-  void Release() {
-    MOZ_ASSERT(mRefCount > 0);
-    if (0 == --mRefCount) {
-#ifdef DEBUG
-      mRefCount = detail::DEAD;
-#endif
-      Finalize();
-      delete this;
-    }
-  }
-
   virtual TextureClientSurface* AsTextureClientSurface() { return nullptr; }
   virtual TextureClientDrawTarget* AsTextureClientDrawTarget() { return nullptr; }
   virtual TextureClientYCbCr* AsTextureClientYCbCr() { return nullptr; }
@@ -274,8 +260,6 @@ public:
   void ForceRemove();
 
 private:
-  Atomic<int> mRefCount;
-
   /**
    * Called once, just before the destructor.
    *
@@ -284,6 +268,8 @@ private:
    */
   void Finalize();
 
+  friend class AtomicRefCountedWithFinalize<TextureClient>;
+
 protected:
   void AddFlags(TextureFlags  aFlags)
   {

gfx/layers/composite/TextureHost.cpp

@@ -212,8 +212,7 @@ TextureHost::SetCompositableBackendSpecificData(CompositableBackendSpecificData*
 
 
 TextureHost::TextureHost(TextureFlags aFlags)
-    : mRefCount(0)
-    , mFlags(aFlags)
+    : mFlags(aFlags)
 {}
 
 TextureHost::~TextureHost()

gfx/layers/composite/TextureHost.h

@@ -23,6 +23,7 @@
 #include "nsRegion.h"                   // for nsIntRegion
 #include "nsTraceRefcnt.h"              // for MOZ_COUNT_CTOR, etc
 #include "nscore.h"                     // for nsACString
+#include "mozilla/layers/AtomicRefCountedWithFinalize.h"
 
 class gfxImageSurface;
 class gfxReusableSurfaceWrapper;
@@ -259,9 +260,8 @@ private:
  *
  */
 class TextureHost
+  : public AtomicRefCountedWithFinalize<TextureHost>
 {
-  Atomic<int> mRefCount;
-
   /**
    * Called once, just before the destructor.
    *
@@ -270,27 +270,13 @@ class TextureHost
    */
   void Finalize();
 
+  friend class AtomicRefCountedWithFinalize<TextureHost>;
+
 public:
   TextureHost(TextureFlags aFlags);
 
   virtual ~TextureHost();
 
-  void AddRef() {
-    MOZ_ASSERT(mRefCount >= 0);
-    ++mRefCount;
-  }
-
-  void Release() {
-    MOZ_ASSERT(mRefCount > 0);
-    if (0 == --mRefCount) {
-#ifdef DEBUG
-      mRefCount = detail::DEAD;
-#endif
-      Finalize();
-      delete this;
-    }
-  }
-
   /**
    * Factory method.
    */

gfx/layers/moz.build

@@ -98,6 +98,7 @@ EXPORTS.gfxipc += [
 ]
 
 EXPORTS.mozilla.layers += [
+    'AtomicRefCountedWithFinalize.h',
     'basic/BasicCompositor.h',
     'basic/MacIOSurfaceTextureHostBasic.h',
     'basic/TextureHostBasic.h',