Use RAII for more TextureClient locking cases. (bug 1222863 part 2, r=nical)

gfx/layers/client/CanvasClient.cpp

@@ -98,22 +98,20 @@ CanvasClient2D::Update(gfx::IntSize aSize, ClientCanvasLayer* aLayer)
     bufferCreated = true;
   }
 
-  if (!mBuffer->Lock(OpenMode::OPEN_WRITE_ONLY)) {
-    mBuffer = nullptr;
-    return;
-  }
-
   bool updated = false;
   {
-    // Restrict drawTarget to a scope so that terminates before Unlock.
-    RefPtr<DrawTarget> target =
-      mBuffer->BorrowDrawTarget();
+    TextureClientAutoLock autoLock(mBuffer, OpenMode::OPEN_WRITE_ONLY);
+    if (!autoLock.Succeeded()) {
+      mBuffer = nullptr;
+      return;
+    }
+
+    RefPtr<DrawTarget> target = mBuffer->BorrowDrawTarget();
     if (target) {
       aLayer->UpdateTarget(target);
       updated = true;
     }
   }
-  mBuffer->Unlock();
 
   if (bufferCreated && !AddTextureClient(mBuffer)) {
     mBuffer = nullptr;
@@ -286,7 +284,9 @@ TexClientFromReadback(SharedSurface* src, ISurfaceAllocator* allocator,
         return nullptr;
 
     // With a texClient, we can lock for writing.
-    MOZ_ALWAYS_TRUE( texClient->Lock(OpenMode::OPEN_WRITE) );
+    TextureClientAutoLock autoLock(texClient, OpenMode::OPEN_WRITE);
+    DebugOnly<bool> succeeded = autoLock.Succeeded();
+    MOZ_ASSERT(succeeded, "texture should have locked");
 
     uint8_t* lockedBytes = texClient->GetLockedData();
 
@@ -318,8 +318,6 @@ TexClientFromReadback(SharedSurface* src, ISurfaceAllocator* allocator,
 
       texClient->RemoveFlags(TextureFlags::RB_SWAPPED);
     }
-
-    texClient->Unlock();
   }
 
   return texClient.forget();

gfx/layers/client/ContentClient.cpp

@@ -14,6 +14,7 @@
 #include "gfxUtils.h"                   // for gfxUtils
 #include "ipc/ShadowLayers.h"           // for ShadowLayerForwarder
 #include "mozilla/ArrayUtils.h"         // for ArrayLength
+#include "mozilla/Maybe.h"
 #include "mozilla/gfx/2D.h"             // for DrawTarget, Factory
 #include "mozilla/gfx/BasePoint.h"      // for BasePoint
 #include "mozilla/gfx/BaseSize.h"       // for BaseSize
@@ -570,33 +571,30 @@ ContentClientDoubleBuffered::FinalizeFrame(const nsIntRegion& aRegionToDraw)
 
   // We need to ensure that we lock these two buffers in the same
   // order as the compositor to prevent deadlocks.
-  if (!mFrontClient->Lock(OpenMode::OPEN_READ_ONLY)) {
+  TextureClientAutoLock frontLock(mFrontClient, OpenMode::OPEN_READ_ONLY);
+  if (!frontLock.Succeeded()) {
     return;
   }
-  if (mFrontClientOnWhite &&
-      !mFrontClientOnWhite->Lock(OpenMode::OPEN_READ_ONLY)) {
-    mFrontClient->Unlock();
-    return;
-  }
-  {
-    // Restrict the DrawTargets and frontBuffer to a scope to make
-    // sure there is no more external references to the DrawTargets
-    // when we Unlock the TextureClients.
-    RefPtr<SourceSurface> surf = mFrontClient->BorrowDrawTarget()->Snapshot();
-    RefPtr<SourceSurface> surfOnWhite = mFrontClientOnWhite
-      ? mFrontClientOnWhite->BorrowDrawTarget()->Snapshot()
-      : nullptr;
-    SourceRotatedBuffer frontBuffer(surf,
-                                    surfOnWhite,
-                                    mFrontBufferRect,
-                                    mFrontBufferRotation);
-    UpdateDestinationFrom(frontBuffer, updateRegion);
+  Maybe<TextureClientAutoLock> frontOnWhiteLock;
+  if (mFrontClientOnWhite) {
+    frontOnWhiteLock.emplace(mFrontClientOnWhite, OpenMode::OPEN_READ_ONLY);
+    if (!frontOnWhiteLock->Succeeded()) {
+      return;
+    }
   }
 
-  mFrontClient->Unlock();
-  if (mFrontClientOnWhite) {
-    mFrontClientOnWhite->Unlock();
-  }
+  // Restrict the DrawTargets and frontBuffer to a scope to make
+  // sure there is no more external references to the DrawTargets
+  // when we Unlock the TextureClients.
+  RefPtr<SourceSurface> surf = mFrontClient->BorrowDrawTarget()->Snapshot();
+  RefPtr<SourceSurface> surfOnWhite = mFrontClientOnWhite
+    ? mFrontClientOnWhite->BorrowDrawTarget()->Snapshot()
+    : nullptr;
+  SourceRotatedBuffer frontBuffer(surf,
+                                  surfOnWhite,
+                                  mFrontBufferRect,
+                                  mFrontBufferRotation);
+  UpdateDestinationFrom(frontBuffer, updateRegion);
 }
 
 void

gfx/layers/client/ImageClient.cpp

@@ -185,17 +185,20 @@ ImageClientSingle::UpdateImage(ImageContainer* aContainer, uint32_t aContentFlag
           data->mYSize, data->mCbCrSize, data->mStereoMode,
           TextureFlags::DEFAULT | mTextureFlags
         );
-        if (!texture || !texture->Lock(OpenMode::OPEN_WRITE_ONLY)) {
+        if (!texture) {
           return false;
         }
+
+        TextureClientAutoLock autoLock(texture, OpenMode::OPEN_WRITE_ONLY);
+        if (!autoLock.Succeeded()) {
+          return false;
+        }
+
         bool status = texture->AsTextureClientYCbCr()->UpdateYCbCr(*data);
         MOZ_ASSERT(status);
-
-        texture->Unlock();
         if (!status) {
           return false;
         }
-
       } else if (image->GetFormat() == ImageFormat::SURFACE_TEXTURE ||
                  image->GetFormat() == ImageFormat::EGLIMAGE) {
         gfx::IntSize size = image->GetSize();

gfx/layers/client/TiledContentClient.cpp

@@ -601,7 +601,8 @@ CopyFrontToBack(TextureClient* aFront,
                 TextureClient* aBack,
                 const gfx::IntRect& aRectToCopy)
 {
-  if (!aFront->Lock(OpenMode::OPEN_READ)) {
+  TextureClientAutoLock frontLock(aFront, OpenMode::OPEN_READ);
+  if (!frontLock.Succeeded()) {
     gfxCriticalError() << "[Tiling:Client] Failed to lock the tile's front buffer";
     return false;
   }
@@ -613,8 +614,6 @@ CopyFrontToBack(TextureClient* aFront,
 
   gfx::IntPoint rectToCopyTopLeft = aRectToCopy.TopLeft();
   aFront->CopyToTextureClient(aBack, &aRectToCopy, &rectToCopyTopLeft);
-
-  aFront->Unlock();
   return true;
 }