diff options
Diffstat (limited to 'gfx/layers/apz/src/APZUpdater.cpp')
| -rw-r--r-- | gfx/layers/apz/src/APZUpdater.cpp | 546 |
1 files changed, 546 insertions, 0 deletions
diff --git a/gfx/layers/apz/src/APZUpdater.cpp b/gfx/layers/apz/src/APZUpdater.cpp new file mode 100644 index 0000000000..2bbad6e1a7 --- /dev/null +++ b/gfx/layers/apz/src/APZUpdater.cpp @@ -0,0 +1,546 @@ +/* -*- 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/. */ + +#include "mozilla/layers/APZUpdater.h" + +#include "APZCTreeManager.h" +#include "AsyncPanZoomController.h" +#include "base/task.h" +#include "mozilla/ClearOnShutdown.h" +#include "mozilla/layers/APZThreadUtils.h" +#include "mozilla/layers/CompositorThread.h" +#include "mozilla/layers/SynchronousTask.h" +#include "mozilla/layers/WebRenderScrollDataWrapper.h" +#include "mozilla/webrender/WebRenderAPI.h" + +namespace mozilla { +namespace layers { + +StaticMutex APZUpdater::sWindowIdLock; +StaticAutoPtr<std::unordered_map<uint64_t, APZUpdater*>> + APZUpdater::sWindowIdMap; + +APZUpdater::APZUpdater(const RefPtr<APZCTreeManager>& aApz, + bool aConnectedToWebRender) + : mApz(aApz), + mDestroyed(false), + mConnectedToWebRender(aConnectedToWebRender), + mThreadIdLock("APZUpdater::ThreadIdLock"), + mQueueLock("APZUpdater::QueueLock") { + MOZ_ASSERT(aApz); + mApz->SetUpdater(this); +} + +APZUpdater::~APZUpdater() { + mApz->SetUpdater(nullptr); + + StaticMutexAutoLock lock(sWindowIdLock); + if (mWindowId) { + MOZ_ASSERT(sWindowIdMap); + // Ensure that ClearTree was called and the task got run + MOZ_ASSERT(sWindowIdMap->find(wr::AsUint64(*mWindowId)) == + sWindowIdMap->end()); + } +} + +bool APZUpdater::HasTreeManager(const RefPtr<APZCTreeManager>& aApz) { + return aApz.get() == mApz.get(); +} + +void APZUpdater::SetWebRenderWindowId(const wr::WindowId& aWindowId) { + StaticMutexAutoLock lock(sWindowIdLock); + MOZ_ASSERT(!mWindowId); + mWindowId = Some(aWindowId); + if (!sWindowIdMap) { + sWindowIdMap = new std::unordered_map<uint64_t, APZUpdater*>(); + NS_DispatchToMainThread(NS_NewRunnableFunction( + "APZUpdater::ClearOnShutdown", [] { ClearOnShutdown(&sWindowIdMap); })); + } + (*sWindowIdMap)[wr::AsUint64(aWindowId)] = this; +} + +/*static*/ +void APZUpdater::SetUpdaterThread(const wr::WrWindowId& aWindowId) { + if (RefPtr<APZUpdater> updater = GetUpdater(aWindowId)) { + MutexAutoLock lock(updater->mThreadIdLock); + updater->mUpdaterThreadId = Some(PlatformThread::CurrentId()); + } +} + +// Takes a conditional lock! +/*static*/ +void APZUpdater::PrepareForSceneSwap(const wr::WrWindowId& aWindowId) + MOZ_NO_THREAD_SAFETY_ANALYSIS { + if (RefPtr<APZUpdater> updater = GetUpdater(aWindowId)) { + updater->mApz->LockTree(); + } +} + +// Assumes we took a conditional lock! +/*static*/ +void APZUpdater::CompleteSceneSwap(const wr::WrWindowId& aWindowId, + const wr::WrPipelineInfo& aInfo) { + RefPtr<APZUpdater> updater = GetUpdater(aWindowId); + if (!updater) { + // This should only happen in cases where PrepareForSceneSwap also got a + // null updater. No updater-thread tasks get run between PrepareForSceneSwap + // and this function, so there is no opportunity for the updater mapping + // to have gotten removed from sWindowIdMap in between the two calls. + return; + } + updater->mApz->mTreeLock.AssertCurrentThreadIn(); + + for (const auto& removedPipeline : aInfo.removed_pipelines) { + LayersId layersId = wr::AsLayersId(removedPipeline.pipeline_id); + updater->mEpochData.erase(layersId); + } + // Reset the built info for all pipelines, then put it back for the ones + // that got built in this scene swap. + for (auto& i : updater->mEpochData) { + i.second.mBuilt = Nothing(); + } + for (const auto& epoch : aInfo.epochs) { + LayersId layersId = wr::AsLayersId(epoch.pipeline_id); + updater->mEpochData[layersId].mBuilt = Some(epoch.epoch); + } + + // Run any tasks that got unblocked, then unlock the tree. The order is + // important because we want to run all the tasks up to and including the + // UpdateHitTestingTree calls corresponding to the built epochs, and we + // want to run those before we release the lock (i.e. atomically with the + // scene swap). This ensures that any hit-tests always encounter a consistent + // state between the APZ tree and the built scene in WR. + // + // While we could add additional information to the queued tasks to figure + // out the minimal set of tasks we want to run here, it's easier and harmless + // to just run all the queued and now-unblocked tasks inside the lock. + // + // Note that the ProcessQueue here might remove the window id -> APZUpdater + // mapping from sWindowIdMap, but we still unlock the tree successfully to + // leave things in a good state. + updater->ProcessQueue(); + + updater->mApz->UnlockTree(); +} + +/*static*/ +void APZUpdater::ProcessPendingTasks(const wr::WrWindowId& aWindowId) { + if (RefPtr<APZUpdater> updater = GetUpdater(aWindowId)) { + updater->ProcessQueue(); + } +} + +void APZUpdater::ClearTree(LayersId aRootLayersId) { + MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread()); + RefPtr<APZUpdater> self = this; + RunOnUpdaterThread(aRootLayersId, + NS_NewRunnableFunction("APZUpdater::ClearTree", [=]() { + self->mApz->ClearTree(); + self->mDestroyed = true; + + // Once ClearTree is called on the APZCTreeManager, we + // are in a shutdown phase. After this point it's ok if + // WebRender cannot get a hold of the updater via the + // window id, and it's a good point to remove the mapping + // and avoid leaving a dangling pointer to this object. + StaticMutexAutoLock lock(sWindowIdLock); + if (self->mWindowId) { + MOZ_ASSERT(sWindowIdMap); + sWindowIdMap->erase(wr::AsUint64(*(self->mWindowId))); + } + })); +} + +void APZUpdater::UpdateFocusState(LayersId aRootLayerTreeId, + LayersId aOriginatingLayersId, + const FocusTarget& aFocusTarget) { + MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread()); + RunOnUpdaterThread(aOriginatingLayersId, + NewRunnableMethod<LayersId, LayersId, FocusTarget>( + "APZUpdater::UpdateFocusState", mApz, + &APZCTreeManager::UpdateFocusState, aRootLayerTreeId, + aOriginatingLayersId, aFocusTarget)); +} + +void APZUpdater::UpdateScrollDataAndTreeState( + LayersId aRootLayerTreeId, LayersId aOriginatingLayersId, + const wr::Epoch& aEpoch, WebRenderScrollData&& aScrollData) { + MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread()); + RefPtr<APZUpdater> self = this; + // Insert an epoch requirement update into the queue, so that + // tasks inserted into the queue after this point only get executed + // once the epoch requirement is satisfied. In particular, the + // UpdateHitTestingTree call below needs to wait until the epoch requirement + // is satisfied, which is why it is a separate task in the queue. + RunOnUpdaterThread( + aOriginatingLayersId, + NS_NewRunnableFunction("APZUpdater::UpdateEpochRequirement", [=]() { + if (aRootLayerTreeId == aOriginatingLayersId) { + self->mEpochData[aOriginatingLayersId].mIsRoot = true; + } + self->mEpochData[aOriginatingLayersId].mRequired = aEpoch; + })); + RunOnUpdaterThread( + aOriginatingLayersId, + NS_NewRunnableFunction( + "APZUpdater::UpdateHitTestingTree", + [=, aScrollData = std::move(aScrollData)]() mutable { + auto isFirstPaint = aScrollData.IsFirstPaint(); + auto paintSequenceNumber = aScrollData.GetPaintSequenceNumber(); + + self->mScrollData[aOriginatingLayersId] = std::move(aScrollData); + auto root = self->mScrollData.find(aRootLayerTreeId); + if (root == self->mScrollData.end()) { + return; + } + self->mApz->UpdateHitTestingTree( + WebRenderScrollDataWrapper(*self, &(root->second)), + isFirstPaint, aOriginatingLayersId, paintSequenceNumber); + })); +} + +void APZUpdater::UpdateScrollOffsets(LayersId aRootLayerTreeId, + LayersId aOriginatingLayersId, + ScrollUpdatesMap&& aUpdates, + uint32_t aPaintSequenceNumber) { + MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread()); + RefPtr<APZUpdater> self = this; + RunOnUpdaterThread( + aOriginatingLayersId, + NS_NewRunnableFunction( + "APZUpdater::UpdateScrollOffsets", + [=, updates = std::move(aUpdates)]() mutable { + self->mScrollData[aOriginatingLayersId].ApplyUpdates( + std::move(updates), aPaintSequenceNumber); + auto root = self->mScrollData.find(aRootLayerTreeId); + if (root == self->mScrollData.end()) { + return; + } + self->mApz->UpdateHitTestingTree( + WebRenderScrollDataWrapper(*self, &(root->second)), + /*isFirstPaint*/ false, aOriginatingLayersId, + aPaintSequenceNumber); + })); +} + +void APZUpdater::NotifyLayerTreeAdopted(LayersId aLayersId, + const RefPtr<APZUpdater>& aOldUpdater) { + MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread()); + RunOnUpdaterThread(aLayersId, + NewRunnableMethod<LayersId, RefPtr<APZCTreeManager>>( + "APZUpdater::NotifyLayerTreeAdopted", mApz, + &APZCTreeManager::NotifyLayerTreeAdopted, aLayersId, + aOldUpdater ? aOldUpdater->mApz : nullptr)); +} + +void APZUpdater::NotifyLayerTreeRemoved(LayersId aLayersId) { + MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread()); + RefPtr<APZUpdater> self = this; + RunOnUpdaterThread( + aLayersId, + NS_NewRunnableFunction("APZUpdater::NotifyLayerTreeRemoved", [=]() { + self->mEpochData.erase(aLayersId); + self->mScrollData.erase(aLayersId); + self->mApz->NotifyLayerTreeRemoved(aLayersId); + })); +} + +bool APZUpdater::GetAPZTestData(LayersId aLayersId, APZTestData* aOutData) { + MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread()); + + RefPtr<APZCTreeManager> apz = mApz; + bool ret = false; + SynchronousTask waiter("APZUpdater::GetAPZTestData"); + RunOnUpdaterThread( + aLayersId, NS_NewRunnableFunction("APZUpdater::GetAPZTestData", [&]() { + AutoCompleteTask notifier(&waiter); + ret = apz->GetAPZTestData(aLayersId, aOutData); + })); + + // Wait until the task posted above has run and populated aOutData and ret + waiter.Wait(); + + return ret; +} + +void APZUpdater::SetTestAsyncScrollOffset( + LayersId aLayersId, const ScrollableLayerGuid::ViewID& aScrollId, + const CSSPoint& aOffset) { + MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread()); + RefPtr<APZCTreeManager> apz = mApz; + RunOnUpdaterThread( + aLayersId, + NS_NewRunnableFunction("APZUpdater::SetTestAsyncScrollOffset", [=]() { + RefPtr<AsyncPanZoomController> apzc = + apz->GetTargetAPZC(aLayersId, aScrollId); + if (apzc) { + apzc->SetTestAsyncScrollOffset(aOffset); + } else { + NS_WARNING("Unable to find APZC in SetTestAsyncScrollOffset"); + } + })); +} + +void APZUpdater::SetTestAsyncZoom(LayersId aLayersId, + const ScrollableLayerGuid::ViewID& aScrollId, + const LayerToParentLayerScale& aZoom) { + MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread()); + RefPtr<APZCTreeManager> apz = mApz; + RunOnUpdaterThread( + aLayersId, NS_NewRunnableFunction("APZUpdater::SetTestAsyncZoom", [=]() { + RefPtr<AsyncPanZoomController> apzc = + apz->GetTargetAPZC(aLayersId, aScrollId); + if (apzc) { + apzc->SetTestAsyncZoom(aZoom); + } else { + NS_WARNING("Unable to find APZC in SetTestAsyncZoom"); + } + })); +} + +const WebRenderScrollData* APZUpdater::GetScrollData(LayersId aLayersId) const { + AssertOnUpdaterThread(); + auto it = mScrollData.find(aLayersId); + return (it == mScrollData.end() ? nullptr : &(it->second)); +} + +void APZUpdater::AssertOnUpdaterThread() const { + if (APZThreadUtils::GetThreadAssertionsEnabled()) { + MOZ_ASSERT(IsUpdaterThread()); + } +} + +void APZUpdater::RunOnUpdaterThread(LayersId aLayersId, + already_AddRefed<Runnable> aTask) { + RefPtr<Runnable> task = aTask; + + // In the scenario where IsConnectedToWebRender() is true, this function + // might get called early (before mUpdaterThreadId is set). In that case + // IsUpdaterThread() will return false and we'll queue the task onto + // mUpdaterQueue. This is fine; the task is still guaranteed to run (barring + // catastrophic failure) because the WakeSceneBuilder call will still trigger + // the callback to run tasks. + + if (IsUpdaterThread()) { + // This function should only be called from the updater thread in test + // scenarios where we are not connected to WebRender. If it were called from + // the updater thread when we are connected to WebRender, running the task + // right away would be incorrect (we'd need to check that |aLayersId| + // isn't blocked, and if it is then enqueue the task instead). + MOZ_ASSERT(!IsConnectedToWebRender()); + task->Run(); + return; + } + + if (IsConnectedToWebRender()) { + // If the updater thread is a WebRender thread, and we're not on it + // right now, save the task in the queue. We will run tasks from the queue + // during the callback from the updater thread, which we trigger by the + // call to WakeSceneBuilder. + + bool sendWakeMessage = true; + { // scope lock + MutexAutoLock lock(mQueueLock); + for (const auto& queuedTask : mUpdaterQueue) { + if (queuedTask.mLayersId == aLayersId) { + // If there's already a task in the queue with this layers id, then + // we must have previously sent a WakeSceneBuilder message (when + // adding the first task with this layers id to the queue). Either + // that hasn't been fully processed yet, or the layers id is blocked + // waiting for an epoch - in either case there's no point in sending + // another WakeSceneBuilder message. + sendWakeMessage = false; + break; + } + } + mUpdaterQueue.push_back(QueuedTask{aLayersId, task}); + } + if (sendWakeMessage) { + RefPtr<wr::WebRenderAPI> api = mApz->GetWebRenderAPI(); + if (api) { + api->WakeSceneBuilder(); + } else { + // Not sure if this can happen, but it might be possible. If it does, + // the task is in the queue, but if we didn't get a WebRenderAPI it + // might never run, or it might run later if we manage to get a + // WebRenderAPI later. For now let's just emit a warning, this can + // probably be upgraded to an assert later. + NS_WARNING("Possibly dropping task posted to updater thread"); + } + } + return; + } + + if (CompositorThread()) { + CompositorThread()->Dispatch(task.forget()); + } else { + // Could happen during startup + NS_WARNING("Dropping task posted to updater thread"); + } +} + +bool APZUpdater::IsUpdaterThread() const { + if (IsConnectedToWebRender()) { + // If the updater thread id isn't set yet then we cannot be running on the + // updater thread (because we will have the thread id before we run any + // C++ code on it, and this function is only ever invoked from C++ code), + // so return false in that scenario. + MutexAutoLock lock(mThreadIdLock); + return mUpdaterThreadId && PlatformThread::CurrentId() == *mUpdaterThreadId; + } + return CompositorThreadHolder::IsInCompositorThread(); +} + +void APZUpdater::RunOnControllerThread(LayersId aLayersId, + already_AddRefed<Runnable> aTask) { + MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread()); + + RefPtr<Runnable> task = aTask; + + RunOnUpdaterThread( + aLayersId, + NewRunnableFunction("APZUpdater::RunOnControllerThread", + &APZThreadUtils::RunOnControllerThread, + std::move(task), nsIThread::DISPATCH_NORMAL)); +} + +bool APZUpdater::IsConnectedToWebRender() const { + return mConnectedToWebRender; +} + +/*static*/ +already_AddRefed<APZUpdater> APZUpdater::GetUpdater( + const wr::WrWindowId& aWindowId) { + RefPtr<APZUpdater> updater; + StaticMutexAutoLock lock(sWindowIdLock); + if (sWindowIdMap) { + auto it = sWindowIdMap->find(wr::AsUint64(aWindowId)); + if (it != sWindowIdMap->end()) { + updater = it->second; + } + } + return updater.forget(); +} + +void APZUpdater::ProcessQueue() { + MOZ_ASSERT(!mDestroyed); + + { // scope lock to check for emptiness + MutexAutoLock lock(mQueueLock); + if (mUpdaterQueue.empty()) { + return; + } + } + + std::deque<QueuedTask> blockedTasks; + while (true) { + QueuedTask task; + + { // scope lock to extract a task + MutexAutoLock lock(mQueueLock); + if (mUpdaterQueue.empty()) { + // If we're done processing mUpdaterQueue, swap the tasks that are + // still blocked back in and finish + std::swap(mUpdaterQueue, blockedTasks); + break; + } + task = mUpdaterQueue.front(); + mUpdaterQueue.pop_front(); + } + + // We check the task to see if it is blocked. Note that while this + // ProcessQueue function is executing, a particular layers id cannot go + // from blocked to unblocked, because only CompleteSceneSwap can unblock + // a layers id, and that also runs on the updater thread. If somehow + // a layers id gets unblocked while we're processing the queue, then it + // might result in tasks getting executed out of order. + + auto it = mEpochData.find(task.mLayersId); + if (it != mEpochData.end() && it->second.IsBlocked()) { + // If this task is blocked, put it into the blockedTasks queue that + // we will replace mUpdaterQueue with + blockedTasks.push_back(task); + } else { + // Run and discard the task + task.mRunnable->Run(); + } + } + + if (mDestroyed) { + // If we get here, then we must have just run the ClearTree task for + // this updater. There might be tasks in the queue from content subtrees + // of this window that are blocked due to stale epochs. This can happen + // if the tasks were queued after the root pipeline was removed in + // WebRender, which prevents scene builds (and therefore prevents us + // from getting updated epochs via CompleteSceneSwap). See bug 1465658 + // comment 43 for some more context. + // To avoid leaking these tasks, we discard the contents of the queue. + // This happens during window shutdown so if we don't run the tasks it's + // not going to matter much. + MutexAutoLock lock(mQueueLock); + if (!mUpdaterQueue.empty()) { + mUpdaterQueue.clear(); + } + } +} + +void APZUpdater::MarkAsDetached(LayersId aLayersId) { + mApz->MarkAsDetached(aLayersId); +} + +APZUpdater::EpochState::EpochState() : mRequired{0}, mIsRoot(false) {} + +bool APZUpdater::EpochState::IsBlocked() const { + // The root is a special case because we basically assume it is "visible" + // even before it is built for the first time. This is because building the + // scene automatically makes it visible, and we need to make sure the APZ + // scroll data gets applied atomically with that happening. + // + // Layer subtrees on the other hand do not automatically become visible upon + // being built, because there must be a another layer tree update to change + // the visibility (i.e. an ancestor layer tree update that adds the necessary + // reflayer to complete the chain of reflayers). + // + // So in the case of non-visible subtrees, we know that no hit-test will + // actually end up hitting that subtree either before or after the scene swap, + // because the subtree will remain non-visible. That in turns means that we + // can apply the APZ scroll data for that subtree epoch before the scene is + // built, because it's not going to get used anyway. And that means we don't + // need to block the queue for non-visible subtrees. Which is a good thing, + // because in practice it seems like we often have non-visible subtrees sent + // to the compositor from content. + if (mIsRoot && !mBuilt) { + return true; + } + return mBuilt && (*mBuilt < mRequired); +} + +} // namespace layers +} // namespace mozilla + +// Rust callback implementations + +void apz_register_updater(mozilla::wr::WrWindowId aWindowId) { + mozilla::layers::APZUpdater::SetUpdaterThread(aWindowId); +} + +void apz_pre_scene_swap(mozilla::wr::WrWindowId aWindowId) { + mozilla::layers::APZUpdater::PrepareForSceneSwap(aWindowId); +} + +void apz_post_scene_swap(mozilla::wr::WrWindowId aWindowId, + const mozilla::wr::WrPipelineInfo* aInfo) { + mozilla::layers::APZUpdater::CompleteSceneSwap(aWindowId, *aInfo); +} + +void apz_run_updater(mozilla::wr::WrWindowId aWindowId) { + mozilla::layers::APZUpdater::ProcessPendingTasks(aWindowId); +} + +void apz_deregister_updater(mozilla::wr::WrWindowId aWindowId) { + // Run anything that's still left. + mozilla::layers::APZUpdater::ProcessPendingTasks(aWindowId); +} |