[Books] Returning from Lock Screen shows a flash of missing content

https://bugs.webkit.org/show_bug.cgi?id=267300 <rdar://119957147> Reviewed by Simon Fraser. If we've included an ImageBufferSet with an empty dirty region in the prepare for display set, then we always need to return a valid buffer handle. This happens when we think the front buffer is volatile (as happens when the screen is locked), and we want to confirm that the contents are still there. If they are, no drawing is needed, but we still need to update the buffer handle. * Source/WebKit/GPUProcess/graphics/RemoteImageBufferSet.cpp: (WebKit::RemoteImageBufferSet::ensureBufferForDisplay): * Source/WebKit/Shared/RemoteLayerTree/RemoteLayerBackingStore.h: * Source/WebKit/Shared/RemoteLayerTree/RemoteLayerBackingStoreCollection.mm: (WebKit::RemoteLayerBackingStoreCollection::prepareBackingStoresForDisplay): * Source/WebKit/Shared/RemoteLayerTree/RemoteLayerWithInProcessRenderingBackingStore.h: * Source/WebKit/Shared/RemoteLayerTree/RemoteLayerWithRemoteRenderingBackingStore.h: * Source/WebKit/Shared/RemoteLayerTree/RemoteLayerWithRemoteRenderingBackingStore.mm: (WebKit::RemoteLayerWithRemoteRenderingBackingStore::prepareToDisplay): Canonical link: https://commits.webkit.org/272932@main
xingri · Jan 11, 2024 · 39ec746 · 39ec746
1 parent d07ed3d
commit 39ec746
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Showing 6 changed files with 23 additions and 15 deletions.
diff --git a/Source/WebKit/GPUProcess/graphics/RemoteImageBufferSet.cpp b/Source/WebKit/GPUProcess/graphics/RemoteImageBufferSet.cpp
@@ -151,26 +151,28 @@ void RemoteImageBufferSet::ensureBufferForDisplay(ImageBufferSetPrepareBufferFor
         outputData.displayRequirement = needsFullDisplay ? SwapBuffersDisplayRequirement::NeedsFullDisplay : SwapBuffersDisplayRequirement::NeedsNormalDisplay;
 
         std::swap(m_frontBuffer, m_backBuffer);
+
+        if (m_frontBuffer) {
+            auto previousState = m_frontBuffer->setNonVolatile();
+            if (previousState == SetNonVolatileResult::Empty)
+                m_previouslyPaintedRect = std::nullopt;
+        }
     }
 
-    if (m_frontBuffer) {
-        auto previousState = m_frontBuffer->setNonVolatile();
-        if (previousState == SetNonVolatileResult::Empty)
-            m_previouslyPaintedRect = std::nullopt;
-    } else {
+    if (!m_frontBuffer) {
         m_frontBuffer = m_backend->allocateImageBuffer(m_logicalSize, m_renderingMode, WebCore::RenderingPurpose::LayerBacking, m_resolutionScale, m_colorSpace, m_pixelFormat, RenderingResourceIdentifier::generate());
         m_frontBufferIsCleared = true;
     }
 
     LOG_WITH_STREAM(RemoteLayerBuffers, stream << "GPU Process: ensureFrontBufferForDisplay - swapped to ["
         << m_frontBuffer << ", " << m_backBuffer << ", " << m_secondaryBackBuffer << "]");
 
-    if (outputData.displayRequirement != SwapBuffersDisplayRequirement::NeedsNoDisplay) {
+    if (outputData.displayRequirement != SwapBuffersDisplayRequirement::NeedsNoDisplay)
         m_backend->createDisplayListRecorder(m_frontBuffer, m_displayListIdentifier);
-        if (m_frontBuffer) {
-            auto* sharing = m_frontBuffer->toBackendSharing();
-            outputData.backendHandle = downcast<ImageBufferBackendHandleSharing>(*sharing).createBackendHandle();
-        }
+
+    if (m_frontBuffer) {
+        auto* sharing = m_frontBuffer->toBackendSharing();
+        outputData.backendHandle = downcast<ImageBufferBackendHandleSharing>(*sharing).createBackendHandle();
     }
 
     outputData.bufferCacheIdentifiers = BufferIdentifierSet { bufferIdentifier(m_frontBuffer), bufferIdentifier(m_backBuffer), bufferIdentifier(m_secondaryBackBuffer) };

diff --git a/Source/WebKit/Shared/RemoteLayerTree/RemoteLayerBackingStore.h b/Source/WebKit/Shared/RemoteLayerTree/RemoteLayerBackingStore.h
@@ -112,6 +112,7 @@ class RemoteLayerBackingStore : public CanMakeWeakPtr<RemoteLayerBackingStore> {
     bool performDelegatedLayerDisplay();
 
     void paintContents();
+    virtual void prepareToDisplay() = 0;
     virtual void createContextAndPaintContents() = 0;
 
     virtual Vector<std::unique_ptr<WebCore::ThreadSafeImageBufferFlusher>> createFlushers() = 0;

diff --git a/Source/WebKit/Shared/RemoteLayerTree/RemoteLayerBackingStoreCollection.mm b/Source/WebKit/Shared/RemoteLayerTree/RemoteLayerBackingStoreCollection.mm
@@ -78,8 +78,6 @@
             if (!remoteBackingStore->hasFrontBuffer() || !remoteBackingStore->supportsPartialRepaint())
                 remoteBackingStore->setNeedsDisplay();
 
-            remoteBackingStore->clearBackingStore();
-
             prepareBuffersData.append({
                 bufferSet,
                 remoteBackingStore->dirtyRegion(),
@@ -89,8 +87,9 @@
             });
 
             backingStoreList.append(*remoteBackingStore);
-        } else
-            downcast<RemoteLayerWithInProcessRenderingBackingStore>(backingStore).prepareToDisplay();
+        }
+
+        backingStore.prepareToDisplay();
     }
 
     if (prepareBuffersData.size()) {

diff --git a/Source/WebKit/Shared/RemoteLayerTree/RemoteLayerWithInProcessRenderingBackingStore.h b/Source/WebKit/Shared/RemoteLayerTree/RemoteLayerWithInProcessRenderingBackingStore.h
@@ -35,7 +35,7 @@ class RemoteLayerWithInProcessRenderingBackingStore : public RemoteLayerBackingS
 
     bool isRemoteLayerWithInProcessRenderingBackingStore() const final { return true; }
 
-    void prepareToDisplay();
+    void prepareToDisplay() final;
     void createContextAndPaintContents() final;
     Vector<std::unique_ptr<WebCore::ThreadSafeImageBufferFlusher>> createFlushers() final;
 

diff --git a/Source/WebKit/Shared/RemoteLayerTree/RemoteLayerWithRemoteRenderingBackingStore.h b/Source/WebKit/Shared/RemoteLayerTree/RemoteLayerWithRemoteRenderingBackingStore.h
@@ -38,6 +38,7 @@ class RemoteLayerWithRemoteRenderingBackingStore : public RemoteLayerBackingStor
 
     bool isRemoteLayerWithRemoteRenderingBackingStore() const final { return true; }
 
+    void prepareToDisplay() final;
     void clearBackingStore() final;
     void createContextAndPaintContents() final;
 

diff --git a/Source/WebKit/Shared/RemoteLayerTree/RemoteLayerWithRemoteRenderingBackingStore.mm b/Source/WebKit/Shared/RemoteLayerTree/RemoteLayerWithRemoteRenderingBackingStore.mm
@@ -62,6 +62,11 @@
     return m_bufferSet->requestedVolatility().contains(BufferInSetType::Front);
 }
 
+void RemoteLayerWithRemoteRenderingBackingStore::prepareToDisplay()
+{
+    m_contentsBufferHandle = std::nullopt;
+}
+
 void RemoteLayerWithRemoteRenderingBackingStore::clearBackingStore()
 {
     m_contentsBufferHandle = std::nullopt;