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Diffstat (limited to 'gfx/layers/apz/public/APZUpdater.h')
| -rw-r--r-- | gfx/layers/apz/public/APZUpdater.h | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/gfx/layers/apz/public/APZUpdater.h b/gfx/layers/apz/public/APZUpdater.h new file mode 100644 index 0000000000..66d040b356 --- /dev/null +++ b/gfx/layers/apz/public/APZUpdater.h @@ -0,0 +1,236 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* 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_layers_APZUpdater_h +#define mozilla_layers_APZUpdater_h + +#include <deque> +#include <unordered_map> + +#include "base/platform_thread.h" // for PlatformThreadId +#include "LayersTypes.h" +#include "mozilla/layers/APZTestData.h" +#include "mozilla/layers/WebRenderScrollData.h" +#include "mozilla/StaticMutex.h" +#include "mozilla/StaticPtr.h" +#include "mozilla/webrender/WebRenderTypes.h" +#include "nsThreadUtils.h" +#include "Units.h" + +namespace mozilla { + +namespace layers { + +class APZCTreeManager; +class FocusTarget; +class WebRenderScrollData; + +/** + * This interface is used to send updates or otherwise mutate APZ internal + * state. These functions is usually called from the compositor thread in + * response to IPC messages. The method implementations internally redispatch + * themselves to the updater thread in the case where the compositor thread + * is not the updater thread. + */ +class APZUpdater { + NS_INLINE_DECL_THREADSAFE_REFCOUNTING(APZUpdater) + + public: + APZUpdater(const RefPtr<APZCTreeManager>& aApz, bool aConnectedToWebRender); + + bool HasTreeManager(const RefPtr<APZCTreeManager>& aApz); + void SetWebRenderWindowId(const wr::WindowId& aWindowId); + + /** + * This function is invoked from rust on the scene builder thread when it + * is created. It effectively tells the APZUpdater "the current thread is + * the updater thread for this window id" and allows APZUpdater to remember + * which thread it is. + */ + static void SetUpdaterThread(const wr::WrWindowId& aWindowId); + static void PrepareForSceneSwap(const wr::WrWindowId& aWindowId); + static void CompleteSceneSwap(const wr::WrWindowId& aWindowId, + const wr::WrPipelineInfo& aInfo); + static void ProcessPendingTasks(const wr::WrWindowId& aWindowId); + + void ClearTree(LayersId aRootLayersId); + void UpdateFocusState(LayersId aRootLayerTreeId, + LayersId aOriginatingLayersId, + const FocusTarget& aFocusTarget); + /** + * This should be called (in the WR-enabled case) when the compositor receives + * a new WebRenderScrollData for a layers id. The |aScrollData| parameter is + * the scroll data for |aOriginatingLayersId| and |aEpoch| is the + * corresponding epoch for the transaction that transferred the scroll data. + * This function will store the new scroll data and update the focus state and + * hit-testing tree. + */ + void UpdateScrollDataAndTreeState(LayersId aRootLayerTreeId, + LayersId aOriginatingLayersId, + const wr::Epoch& aEpoch, + WebRenderScrollData&& aScrollData); + /** + * This is called in the WR-enabled case when we get an empty transaction that + * has some scroll offset updates (from paint-skipped scrolling on the content + * side). This function will update the stored scroll offsets and the + * hit-testing tree. + */ + void UpdateScrollOffsets(LayersId aRootLayerTreeId, + LayersId aOriginatingLayersId, + ScrollUpdatesMap&& aUpdates, + uint32_t aPaintSequenceNumber); + + void NotifyLayerTreeAdopted(LayersId aLayersId, + const RefPtr<APZUpdater>& aOldUpdater); + void NotifyLayerTreeRemoved(LayersId aLayersId); + + bool GetAPZTestData(LayersId aLayersId, APZTestData* aOutData); + + void SetTestAsyncScrollOffset(LayersId aLayersId, + const ScrollableLayerGuid::ViewID& aScrollId, + const CSSPoint& aOffset); + void SetTestAsyncZoom(LayersId aLayersId, + const ScrollableLayerGuid::ViewID& aScrollId, + const LayerToParentLayerScale& aZoom); + + // This can only be called on the updater thread. + const WebRenderScrollData* GetScrollData(LayersId aLayersId) const; + + /** + * This can be used to assert that the current thread is the + * updater thread (which samples the async transform). + * This does nothing if thread assertions are disabled. + */ + void AssertOnUpdaterThread() const; + + /** + * Runs the given task on the APZ "updater thread" for this APZUpdater. If + * this function is called from the updater thread itself then the task is + * run immediately without getting queued. + * + * The layers id argument should be the id of the layer tree that is + * requesting this task to be run. Conceptually each layer tree has a separate + * task queue, so that if one layer tree is blocked waiting for a scene build + * then tasks for the other layer trees can still be processed. + */ + void RunOnUpdaterThread(LayersId aLayersId, already_AddRefed<Runnable> aTask); + + /** + * Returns true if currently on the APZUpdater's "updater thread". + */ + bool IsUpdaterThread() const; + + /** + * Dispatches the given task to the APZ "controller thread", but does it + * *from* the updater thread. That is, if the thread on which this function is + * called is not the updater thread, the task is first dispatched to the + * updater thread. When the updater thread runs it (or if this is called + * directly on the updater thread), that is when the task gets dispatched to + * the controller thread. The controller thread then actually runs the task. + * + * See the RunOnUpdaterThread method for details on the layers id argument. + */ + void RunOnControllerThread(LayersId aLayersId, + already_AddRefed<Runnable> aTask); + + void MarkAsDetached(LayersId aLayersId); + + protected: + virtual ~APZUpdater(); + + // Return true if the APZUpdater is connected to WebRender and is + // using a WebRender scene builder thread as its updater thread. + // This is only false during GTests, and a shutdown codepath during + // which we create a dummy APZUpdater. + bool IsConnectedToWebRender() const; + + static already_AddRefed<APZUpdater> GetUpdater( + const wr::WrWindowId& aWindowId); + + void ProcessQueue(); + + private: + RefPtr<APZCTreeManager> mApz; + bool mDestroyed; + bool mConnectedToWebRender; + + // Map from layers id to WebRenderScrollData. This can only be touched on + // the updater thread. + std::unordered_map<LayersId, WebRenderScrollData, LayersId::HashFn> + mScrollData; + + // Stores epoch state for a particular layers id. This structure is only + // accessed on the updater thread. + struct EpochState { + // The epoch for the most recent scroll data sent from the content side. + wr::Epoch mRequired; + // The epoch for the most recent scene built and swapped in on the WR side. + Maybe<wr::Epoch> mBuilt; + // True if and only if the layers id is the root layers id for the + // compositor + bool mIsRoot; + + EpochState(); + + // Whether or not the state for this layers id is such that it blocks + // processing of tasks for the layer tree. This happens if the root layers + // id or a "visible" layers id has scroll data for an epoch newer than what + // has been built. A "visible" layers id is one that is attached to the full + // layer tree (i.e. there is a chain of reflayer items from the root layer + // tree to the relevant layer subtree). This is not always the case; for + // instance a content process may send the compositor layers for a document + // before the chrome has attached the remote iframe to the root document. + // Since WR only builds pipelines for "visible" layers ids, |mBuilt| being + // populated means that the layers id is "visible". + bool IsBlocked() const; + }; + + // Map from layers id to epoch state. + // This data structure can only be touched on the updater thread. + std::unordered_map<LayersId, EpochState, LayersId::HashFn> mEpochData; + + // Used to manage the mapping from a WR window id to APZUpdater. These are + // only used if WebRender is enabled. Both sWindowIdMap and mWindowId should + // only be used while holding the sWindowIdLock. Note that we use a + // StaticAutoPtr wrapper on sWindowIdMap to avoid a static initializer for the + // unordered_map. This also avoids the initializer/memory allocation in cases + // where we're not using WebRender. + static StaticMutex sWindowIdLock MOZ_UNANNOTATED; + static StaticAutoPtr<std::unordered_map<uint64_t, APZUpdater*>> sWindowIdMap; + Maybe<wr::WrWindowId> mWindowId; + + // Lock used to protected mUpdaterThreadId; + mutable Mutex mThreadIdLock MOZ_UNANNOTATED; + // If WebRender and async scene building are enabled, this holds the thread id + // of the scene builder thread (which is the updater thread) for the + // compositor associated with this APZUpdater instance. It may be populated + // even if async scene building is not enabled, but in that case we don't + // care about the contents. + Maybe<PlatformThreadId> mUpdaterThreadId; + + // Helper struct that pairs each queued runnable with the layers id that it is + // associated with. This allows us to easily implement the conceptual + // separation of mUpdaterQueue into independent queues per layers id. + struct QueuedTask { + LayersId mLayersId; + RefPtr<Runnable> mRunnable; + }; + + // Lock used to protect mUpdaterQueue + Mutex mQueueLock MOZ_UNANNOTATED; + // Holds a queue of tasks to be run on the updater thread, when the updater + // thread is a WebRender thread, since it won't have a message loop we can + // dispatch to. Note that although this is a single queue it is conceptually + // separated into multiple ones, one per layers id. Tasks for a given layers + // id will always run in FIFO order, but there is no guaranteed ordering for + // tasks with different layers ids. + std::deque<QueuedTask> mUpdaterQueue; +}; + +} // namespace layers +} // namespace mozilla + +#endif // mozilla_layers_APZUpdater_h |