Bug 1462355 - Part 1a. Make imgFrame animation parameters threadsafe.

We currently choose to set the animation parameters (blend method, blend
rect, disposal method, timeout) in imgFrame::Finish instead of
imgFrame::InitForDecoder. The decoders themselves already have access to
the necessary information at the time InitForDecoder is called, so there
is no reason to do this. Moving the configuration to initialization will
allow us to relax the mutex protection on these parameters.

This part simply reorganizes imgFrame, and subsequent parts will
introduce the necessary changes to SurfacePipe and decoders.

3 files changed, 91 insertions, 65 deletions

diff --git a/image/AnimationParams.h b/image/AnimationParams.h
new file mode 100644
index 0000000000..916ba7e407
--- /dev/null
+++ b/image/AnimationParams.h
@@ -0,0 +1,45 @@
+/* -*- Mode: C++; tab-width: 2; 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_image_AnimationParams_h
+#define mozilla_image_AnimationParams_h
+
+#include <stdint.h>
+#include "mozilla/gfx/Rect.h"
+#include "FrameTimeout.h"
+
+namespace mozilla {
+namespace image {
+
+enum class BlendMethod : int8_t {
+  // All color components of the frame, including alpha, overwrite the current
+  // contents of the frame's output buffer region.
+  SOURCE,
+
+  // The frame should be composited onto the output buffer based on its alpha,
+  // using a simple OVER operation.
+  OVER
+};
+
+enum class DisposalMethod : int8_t {
+  CLEAR_ALL = -1,  // Clear the whole image, revealing what's underneath.
+  NOT_SPECIFIED,   // Leave the frame and let the new frame draw on top.
+  KEEP,            // Leave the frame and let the new frame draw on top.
+  CLEAR,           // Clear the frame's area, revealing what's underneath.
+  RESTORE_PREVIOUS // Restore the previous (composited) frame.
+};
+
+struct AnimationParams
+{
+  gfx::IntRect mBlendRect;
+  FrameTimeout mTimeout;
+  uint32_t mFrameNum;
+  BlendMethod mBlendMethod;
+  DisposalMethod mDisposalMethod;
+};
+
+} // namespace image
+} // namespace mozilla
diff --git a/image/imgFrame.cpp b/image/imgFrame.cpp
index 5da2ccec5d..af84d8cbbc 100644
--- a/image/imgFrame.cpp
+++ b/image/imgFrame.cpp
@@ -161,13 +161,13 @@ imgFrame::imgFrame()
   : mMonitor("imgFrame")
   , mDecoded(0, 0, 0, 0)
   , mLockCount(0)
+  , mAborted(false)
+  , mFinished(false)
+  , mOptimizable(false)
   , mTimeout(FrameTimeout::FromRawMilliseconds(100))
   , mDisposalMethod(DisposalMethod::NOT_SPECIFIED)
   , mBlendMethod(BlendMethod::OVER)
   , mHasNoAlpha(false)
-  , mAborted(false)
-  , mFinished(false)
-  , mOptimizable(false)
   , mPalettedImageData(nullptr)
   , mPaletteDepth(0)
   , mNonPremult(false)
@@ -192,7 +192,8 @@ imgFrame::InitForDecoder(const nsIntSize& aImageSize,
                          const nsIntRect& aRect,
                          SurfaceFormat aFormat,
                          uint8_t aPaletteDepth /* = 0 */,
-                         bool aNonPremult /* = false */)
+                         bool aNonPremult /* = false */,
+                         const Maybe<AnimationParams>& aAnimParams /* = Nothing() */)
 {
   // Assert for properties that should be verified by decoders,
   // warn for properties related to bad content.
@@ -205,6 +206,15 @@ imgFrame::InitForDecoder(const nsIntSize& aImageSize,
   mImageSize = aImageSize;
   mFrameRect = aRect;
 
+  if (aAnimParams) {
+    mBlendRect = aAnimParams->mBlendRect;
+    mTimeout = aAnimParams->mTimeout;
+    mBlendMethod = aAnimParams->mBlendMethod;
+    mDisposalMethod = aAnimParams->mDisposalMethod;
+  } else {
+    mBlendRect = aRect;
+  }
+
   // We only allow a non-trivial frame rect (i.e., a frame rect that doesn't
   // cover the entire image) for paletted animation frames. We never draw those
   // frames directly; we just use FrameAnimator to composite them and produce a
@@ -242,13 +252,13 @@ imgFrame::InitForDecoder(const nsIntSize& aImageSize,
   } else {
     MOZ_ASSERT(!mImageSurface, "Called imgFrame::InitForDecoder() twice?");
 
-    mVBuf = AllocateBufferForImage(mFrameRect.Size(), mFormat);
-    if (!mVBuf) {
+    mRawSurface = AllocateBufferForImage(mFrameRect.Size(), mFormat);
+    if (!mRawSurface) {
       mAborted = true;
       return NS_ERROR_OUT_OF_MEMORY;
     }
 
-    mImageSurface = CreateLockedSurface(mVBuf, mFrameRect.Size(), mFormat);
+    mImageSurface = CreateLockedSurface(mRawSurface, mFrameRect.Size(), mFormat);
 
     if (!mImageSurface) {
       NS_WARNING("Failed to create ImageSurface");
@@ -256,7 +266,7 @@ imgFrame::InitForDecoder(const nsIntSize& aImageSize,
       return NS_ERROR_OUT_OF_MEMORY;
     }
 
-    if (!ClearSurface(mVBuf, mFrameRect.Size(), mFormat)) {
+    if (!ClearSurface(mRawSurface, mFrameRect.Size(), mFormat)) {
       NS_WARNING("Could not clear allocated buffer");
       mAborted = true;
       return NS_ERROR_OUT_OF_MEMORY;
@@ -607,12 +617,7 @@ imgFrame::ImageUpdatedInternal(const nsIntRect& aUpdateRect)
 }
 
 void
-imgFrame::Finish(Opacity aFrameOpacity /* = Opacity::SOME_TRANSPARENCY */,
-                 DisposalMethod aDisposalMethod /* = DisposalMethod::KEEP */,
-                 FrameTimeout aTimeout
-                   /* = FrameTimeout::FromRawMilliseconds(0) */,
-                 BlendMethod aBlendMethod /* = BlendMethod::OVER */,
-                 const Maybe<IntRect>& aBlendRect /* = Nothing() */)
+imgFrame::Finish(Opacity aFrameOpacity /* = Opacity::SOME_TRANSPARENCY */)
 {
   MonitorAutoLock lock(mMonitor);
   MOZ_ASSERT(mLockCount > 0, "Image data should be locked");
@@ -621,10 +626,6 @@ imgFrame::Finish(Opacity aFrameOpacity /* = Opacity::SOME_TRANSPARENCY */,
     mHasNoAlpha = true;
   }
 
-  mDisposalMethod = aDisposalMethod;
-  mTimeout = aTimeout;
-  mBlendMethod = aBlendMethod;
-  mBlendRect = aBlendRect;
   ImageUpdatedInternal(GetRect());
   mFinished = true;
 
@@ -844,7 +845,7 @@ imgFrame::GetAnimationData() const
   bool hasAlpha = mFormat == SurfaceFormat::B8G8R8A8;
 
   return AnimationData(data, PaletteDataLength(), mTimeout, GetRect(),
-                       mBlendMethod, mBlendRect, mDisposalMethod, hasAlpha);
+                       mBlendMethod, Some(mBlendRect), mDisposalMethod, hasAlpha);
 }
 
 void
diff --git a/image/imgFrame.h b/image/imgFrame.h
index e864aca7f7..32aabacaed 100644
--- a/image/imgFrame.h
+++ b/image/imgFrame.h
@@ -12,6 +12,7 @@
 #include "mozilla/Monitor.h"
 #include "mozilla/Move.h"
 #include "mozilla/VolatileBuffer.h"
+#include "AnimationParams.h"
 #include "gfxDrawable.h"
 #include "imgIContainer.h"
 #include "MainThreadUtils.h"
@@ -23,24 +24,6 @@ class ImageRegion;
 class DrawableFrameRef;
 class RawAccessFrameRef;
 
-enum class BlendMethod : int8_t {
-  // All color components of the frame, including alpha, overwrite the current
-  // contents of the frame's output buffer region.
-  SOURCE,
-
-  // The frame should be composited onto the output buffer based on its alpha,
-  // using a simple OVER operation.
-  OVER
-};
-
-enum class DisposalMethod : int8_t {
-  CLEAR_ALL = -1,  // Clear the whole image, revealing what's underneath.
-  NOT_SPECIFIED,   // Leave the frame and let the new frame draw on top.
-  KEEP,            // Leave the frame and let the new frame draw on top.
-  CLEAR,           // Clear the frame's area, revealing what's underneath.
-  RESTORE_PREVIOUS // Restore the previous (composited) frame.
-};
-
 enum class Opacity : uint8_t {
   FULLY_OPAQUE,
   SOME_TRANSPARENCY
@@ -210,14 +193,19 @@ public:
                           const nsIntRect& aRect,
                           SurfaceFormat aFormat,
                           uint8_t aPaletteDepth = 0,
-                          bool aNonPremult = false);
+                          bool aNonPremult = false,
+                          const Maybe<AnimationParams>& aAnimParams = Nothing());
 
   nsresult InitForDecoder(const nsIntSize& aSize,
                           SurfaceFormat aFormat,
                           uint8_t aPaletteDepth = 0)
   {
-    return InitForDecoder(aSize, nsIntRect(0, 0, aSize.width, aSize.height),
-                          aFormat, aPaletteDepth);
+    nsIntRect frameRect(0, 0, aSize.width, aSize.height);
+    AnimationParams animParams { frameRect, FrameTimeout::Forever(),
+                                 /* aFrameNum */ 1, BlendMethod::OVER,
+                                 DisposalMethod::NOT_SPECIFIED };
+    return InitForDecoder(aSize, frameRect,
+                          aFormat, aPaletteDepth, false, Some(animParams));
   }
 
 
@@ -268,22 +256,8 @@ public:
    * RawAccessFrameRef pointing to an imgFrame.
    *
    * @param aFrameOpacity    Whether this imgFrame is opaque.
-   * @param aDisposalMethod  For animation frames, how this imgFrame is cleared
-   *                         from the compositing frame before the next frame is
-   *                         displayed.
-   * @param aTimeout         For animation frames, the timeout before the next
-   *                         frame is displayed.
-   * @param aBlendMethod     For animation frames, a blending method to be used
-   *                         when compositing this frame.
-   * @param aBlendRect       For animation frames, if present, the subrect in
-   *                         which @aBlendMethod applies. Outside of this
-   *                         subrect, BlendMethod::OVER is always used.
    */
-  void Finish(Opacity aFrameOpacity = Opacity::SOME_TRANSPARENCY,
-              DisposalMethod aDisposalMethod = DisposalMethod::KEEP,
-              FrameTimeout aTimeout = FrameTimeout::FromRawMilliseconds(0),
-              BlendMethod aBlendMethod = BlendMethod::OVER,
-              const Maybe<IntRect>& aBlendRect = Nothing());
+  void Finish(Opacity aFrameOpacity = Opacity::SOME_TRANSPARENCY);
 
   /**
    * Mark this imgFrame as aborted. This informs the imgFrame that if it isn't
@@ -322,9 +296,15 @@ public:
    */
   uint32_t GetBytesPerPixel() const { return GetIsPaletted() ? 1 : 4; }
 
-  IntSize GetImageSize() const { return mImageSize; }
-  IntRect GetRect() const { return mFrameRect; }
+  const IntSize& GetImageSize() const { return mImageSize; }
+  const IntRect& GetRect() const { return mFrameRect; }
   IntSize GetSize() const { return mFrameRect.Size(); }
+  const IntRect& GetBlendRect() const { return mBlendRect; }
+  IntRect GetBoundedBlendRect() const { return mBlendRect.Intersect(mFrameRect); }
+  FrameTimeout GetTimeout() const { return mTimeout; }
+  BlendMethod GetBlendMethod() const { return mBlendMethod; }
+  DisposalMethod GetDisposalMethod() const { return mDisposalMethod; }
+  bool FormatHasAlpha() const { return mFormat == SurfaceFormat::B8G8R8A8; }
   void GetImageData(uint8_t** aData, uint32_t* length) const;
   uint8_t* GetImageData() const;
 
@@ -406,14 +386,6 @@ private: // data
   //! Number of RawAccessFrameRefs currently alive for this imgFrame.
   int32_t mLockCount;
 
-  //! The timeout for this frame.
-  FrameTimeout mTimeout;
-
-  DisposalMethod mDisposalMethod;
-  BlendMethod    mBlendMethod;
-  Maybe<IntRect> mBlendRect;
-  SurfaceFormat  mFormat;
-
   bool mHasNoAlpha;
   bool mAborted;
   bool mFinished;
@@ -426,6 +398,14 @@ private: // data
 
   IntSize      mImageSize;
   IntRect      mFrameRect;
+  IntRect      mBlendRect;
+
+  //! The timeout for this frame.
+  FrameTimeout mTimeout;
+
+  DisposalMethod mDisposalMethod;
+  BlendMethod    mBlendMethod;
+  SurfaceFormat  mFormat;
 
   // The palette and image data for images that are paletted, since Cairo
   // doesn't support these images.