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Clean up some code in SharedDisplayListHandle
https://bugs.webkit.org/show_bug.cgi?id=219089 Reviewed by Geoff Garen. Currently, `reservedCapacityAtStart` is defined as a constant 16 bytes, which is enough to encompass the contents of the header structure in a shared display list handle (i.e. an 8-byte atomic for the lock, and another 8 bytes for the unread count). Instead of hard-coding this, we could simply make this a constexpr function that returns the size of `DisplayListSharedMemoryHeader` (rounded up to ensure alignment of all display list item data). No change in behavior. * GPUProcess/graphics/RemoteRenderingBackend.cpp: (WebKit::RemoteRenderingBackend::wakeUpAndApplyDisplayList): (WebKit::RemoteRenderingBackend::didCreateSharedDisplayListHandle): * Shared/SharedDisplayListHandle.h: (WebKit::SharedDisplayListHandle::headerSize): * WebProcess/GPU/graphics/DisplayListWriterHandle.cpp: (WebKit::DisplayListWriterHandle::resetWritableOffsetIfPossible): * WebProcess/GPU/graphics/DisplayListWriterHandle.h: (WebKit::DisplayListWriterHandle::DisplayListWriterHandle): * WebProcess/GPU/graphics/RemoteRenderingBackendProxy.cpp: (WebKit::RemoteRenderingBackendProxy::createItemBuffer): Also add a static assert that the size of a newly allocated buffer is larger than the reserved header capacity. Canonical link: https://commits.webkit.org/231718@main git-svn-id: https://svn.webkit.org/repository/webkit/trunk@269969 268f45cc-cd09-0410-ab3c-d52691b4dbfc
1 parent 986be9d commit d564525

6 files changed

Lines changed: 42 additions & 8 deletions

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‎Source/WebKit/ChangeLog‎

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Original file line numberDiff line numberDiff line change
@@ -1,3 +1,33 @@
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2020-11-18 Wenson Hsieh <wenson_hsieh@apple.com>
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Clean up some code in SharedDisplayListHandle
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https://bugs.webkit.org/show_bug.cgi?id=219089
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Reviewed by Geoff Garen.
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Currently, `reservedCapacityAtStart` is defined as a constant 16 bytes, which is enough to encompass the
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contents of the header structure in a shared display list handle (i.e. an 8-byte atomic for the lock, and
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another 8 bytes for the unread count).
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Instead of hard-coding this, we could simply make this a constexpr function that returns the size of
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`DisplayListSharedMemoryHeader` (rounded up to ensure alignment of all display list item data).
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No change in behavior.
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* GPUProcess/graphics/RemoteRenderingBackend.cpp:
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(WebKit::RemoteRenderingBackend::wakeUpAndApplyDisplayList):
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(WebKit::RemoteRenderingBackend::didCreateSharedDisplayListHandle):
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* Shared/SharedDisplayListHandle.h:
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(WebKit::SharedDisplayListHandle::headerSize):
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* WebProcess/GPU/graphics/DisplayListWriterHandle.cpp:
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(WebKit::DisplayListWriterHandle::resetWritableOffsetIfPossible):
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* WebProcess/GPU/graphics/DisplayListWriterHandle.h:
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(WebKit::DisplayListWriterHandle::DisplayListWriterHandle):
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* WebProcess/GPU/graphics/RemoteRenderingBackendProxy.cpp:
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(WebKit::RemoteRenderingBackendProxy::createItemBuffer):
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Also add a static assert that the size of a newly allocated buffer is larger than the reserved header capacity.
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2020-11-18 Per Arne Vollan <pvollan@apple.com>
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[macOS] Fix message filter sandbox violation

‎Source/WebKit/GPUProcess/graphics/RemoteRenderingBackend.cpp‎

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -198,7 +198,7 @@ void RemoteRenderingBackend::wakeUpAndApplyDisplayList(DisplayList::ItemBufferId
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}
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// Otherwise, continue reading the next display list item buffer from the start.
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m_nextItemBufferToRead = { };
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applyDisplayListsFromHandle(*imageBuffer, *nextHandle, SharedDisplayListHandle::reservedCapacityAtStart);
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applyDisplayListsFromHandle(*imageBuffer, *nextHandle, SharedDisplayListHandle::headerSize());
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}
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}
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@@ -243,7 +243,7 @@ void RemoteRenderingBackend::didCreateSharedDisplayListHandle(DisplayList::ItemB
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if (m_nextItemBufferToRead == identifier) {
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m_nextItemBufferToRead = { };
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wakeUpAndApplyDisplayList(identifier, SharedDisplayListHandle::reservedCapacityAtStart, destinationBufferIdentifier);
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wakeUpAndApplyDisplayList(identifier, SharedDisplayListHandle::headerSize(), destinationBufferIdentifier);
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}
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}
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‎Source/WebKit/Shared/SharedDisplayListHandle.h‎

Lines changed: 4 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -37,7 +37,10 @@ class SharedDisplayListHandle : public RefCounted<SharedDisplayListHandle> {
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public:
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virtual ~SharedDisplayListHandle() = default;
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static constexpr auto reservedCapacityAtStart = 2 * sizeof(uint64_t);
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static constexpr size_t headerSize()
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{
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return roundUpToMultipleOf<sizeof(std::max_align_t)>(sizeof(DisplayListSharedMemoryHeader));
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}
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SharedMemory& sharedMemory() { return m_sharedMemory.get(); }
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const SharedMemory& sharedMemory() const { return m_sharedMemory.get(); }

‎Source/WebKit/WebProcess/GPU/graphics/DisplayListWriterHandle.cpp‎

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -68,15 +68,15 @@ DisplayList::ItemBufferHandle DisplayListWriterHandle::createHandle() const
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bool DisplayListWriterHandle::resetWritableOffsetIfPossible()
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{
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if (m_writableOffset <= SharedDisplayListHandle::reservedCapacityAtStart) {
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RELEASE_ASSERT(m_writableOffset == SharedDisplayListHandle::reservedCapacityAtStart);
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if (m_writableOffset <= SharedDisplayListHandle::headerSize()) {
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RELEASE_ASSERT(m_writableOffset == SharedDisplayListHandle::headerSize());
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return true;
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}
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if (unreadBytes())
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return false;
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m_writableOffset = SharedDisplayListHandle::reservedCapacityAtStart;
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m_writableOffset = SharedDisplayListHandle::headerSize();
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return true;
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}
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‎Source/WebKit/WebProcess/GPU/graphics/DisplayListWriterHandle.h‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -49,7 +49,7 @@ class DisplayListWriterHandle : public SharedDisplayListHandle {
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private:
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DisplayListWriterHandle(WebCore::DisplayList::ItemBufferIdentifier identifier, Ref<SharedMemory>&& sharedMemory)
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: SharedDisplayListHandle(identifier, WTFMove(sharedMemory))
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, m_writableOffset(SharedDisplayListHandle::reservedCapacityAtStart)
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, m_writableOffset(SharedDisplayListHandle::headerSize())
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{
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}
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‎Source/WebKit/WebProcess/GPU/graphics/RemoteRenderingBackendProxy.cpp‎

Lines changed: 2 additions & 1 deletion
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@@ -239,8 +239,9 @@ DisplayList::ItemBufferHandle RemoteRenderingBackendProxy::createItemBuffer(size
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}
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static constexpr size_t defaultSharedItemBufferSize = 1 << 16;
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static_assert(defaultSharedItemBufferSize > SharedDisplayListHandle::headerSize());
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auto sharedMemory = SharedMemory::allocate(std::max(defaultSharedItemBufferSize, capacity + SharedDisplayListHandle::reservedCapacityAtStart));
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auto sharedMemory = SharedMemory::allocate(std::max(defaultSharedItemBufferSize, capacity + SharedDisplayListHandle::headerSize()));
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if (!sharedMemory)
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return { };
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