Bag of scheduling tweaks

 Bug: 15118640

 * Prevent over-stuffing the queue by dropping frames
 * Prevent double-drawing in one pulse by RT by deferring
   vsync registration until post-draw so that it catches
   the next vsync pulse instead of the current one
 * Bias vsync race condition towards the UI thread
 * Fix queueDelay to actually work

Change-Id: Ibf584258bd93ebcbba058bd976dc8b307f1c6155

9 files changed, 130 insertions, 32 deletions

diff --git a/libs/hwui/TreeInfo.h b/libs/hwui/TreeInfo.h
index d4a23b8..8355f83 100644
--- a/libs/hwui/TreeInfo.h
+++ b/libs/hwui/TreeInfo.h
@@ -52,6 +52,7 @@ struct TreeInfo {
             : hasFunctors(false)
             , hasAnimations(false)
             , requiresUiRedraw(false)
+            , canDrawThisFrame(true)
         {}
         bool hasFunctors;
         // This is only updated if evaluateAnimations is true
@@ -60,6 +61,13 @@ struct TreeInfo {
         // animate itself, such as if hasFunctors is true
         // This is only set if hasAnimations is true
         bool requiresUiRedraw;
+        // This is set to true if draw() can be called this frame
+        // false means that we must delay until the next vsync pulse as frame
+        // production is outrunning consumption
+        // NOTE that if this is false CanvasContext will set either requiresUiRedraw
+        // *OR* will post itself for the next vsync automatically, use this
+        // only to avoid calling draw()
+        bool canDrawThisFrame;
     } out;
 
     // TODO: Damage calculations
diff --git a/libs/hwui/renderthread/CanvasContext.cpp b/libs/hwui/renderthread/CanvasContext.cpp
index 839ef91..b6b3428 100644
--- a/libs/hwui/renderthread/CanvasContext.cpp
+++ b/libs/hwui/renderthread/CanvasContext.cpp
@@ -360,7 +360,9 @@ void CanvasContext::destroyCanvasAndSurface() {
     setSurface(NULL);
 }
 
-void CanvasContext::setSurface(EGLNativeWindowType window) {
+void CanvasContext::setSurface(ANativeWindow* window) {
+    mNativeWindow = window;
+
     if (mEglSurface != EGL_NO_SURFACE) {
         mGlobalContext->destroySurface(mEglSurface);
         mEglSurface = EGL_NO_SURFACE;
@@ -393,7 +395,7 @@ void CanvasContext::requireSurface() {
     makeCurrent();
 }
 
-bool CanvasContext::initialize(EGLNativeWindowType window) {
+bool CanvasContext::initialize(ANativeWindow* window) {
     if (mCanvas) return false;
     setSurface(window);
     mCanvas = new OpenGLRenderer();
@@ -401,11 +403,11 @@ bool CanvasContext::initialize(EGLNativeWindowType window) {
     return true;
 }
 
-void CanvasContext::updateSurface(EGLNativeWindowType window) {
+void CanvasContext::updateSurface(ANativeWindow* window) {
     setSurface(window);
 }
 
-void CanvasContext::pauseSurface(EGLNativeWindowType window) {
+void CanvasContext::pauseSurface(ANativeWindow* window) {
     // TODO: For now we just need a fence, in the future suspend any animations
     // and such to prevent from trying to render into this surface
 }
@@ -456,7 +458,15 @@ void CanvasContext::prepareTree(TreeInfo& info) {
     info.frameTimeMs = mRenderThread.timeLord().frameTimeMs();
     mRootRenderNode->prepareTree(info);
 
-    if (info.out.hasAnimations) {
+    int runningBehind = 0;
+    // TODO: This query is moderately expensive, investigate adding some sort
+    // of fast-path based off when we last called eglSwapBuffers() as well as
+    // last vsync time. Or something.
+    mNativeWindow->query(mNativeWindow.get(),
+            NATIVE_WINDOW_CONSUMER_RUNNING_BEHIND, &runningBehind);
+    info.out.canDrawThisFrame = !runningBehind;
+
+    if (info.out.hasAnimations || !info.out.canDrawThisFrame) {
         if (info.out.hasFunctors) {
             info.out.requiresUiRedraw = true;
         } else if (!info.out.requiresUiRedraw) {
@@ -467,6 +477,11 @@ void CanvasContext::prepareTree(TreeInfo& info) {
     }
 }
 
+void CanvasContext::notifyFramePending() {
+    ATRACE_CALL();
+    mRenderThread.pushBackFrameCallback(this);
+}
+
 void CanvasContext::draw(Rect* dirty) {
     LOG_ALWAYS_FATAL_IF(!mCanvas || mEglSurface == EGL_NO_SURFACE,
             "drawDisplayList called on a context with no canvas or surface!");
@@ -515,7 +530,9 @@ void CanvasContext::doFrame() {
     info.prepareTextures = false;
 
     prepareTree(info);
-    draw(NULL);
+    if (info.out.canDrawThisFrame) {
+        draw(NULL);
+    }
 }
 
 void CanvasContext::invokeFunctor(Functor* functor) {
diff --git a/libs/hwui/renderthread/CanvasContext.h b/libs/hwui/renderthread/CanvasContext.h
index 4232f27..a54b33e 100644
--- a/libs/hwui/renderthread/CanvasContext.h
+++ b/libs/hwui/renderthread/CanvasContext.h
@@ -48,9 +48,9 @@ public:
     CanvasContext(bool translucent, RenderNode* rootRenderNode);
     virtual ~CanvasContext();
 
-    bool initialize(EGLNativeWindowType window);
-    void updateSurface(EGLNativeWindowType window);
-    void pauseSurface(EGLNativeWindowType window);
+    bool initialize(ANativeWindow* window);
+    void updateSurface(ANativeWindow* window);
+    void pauseSurface(ANativeWindow* window);
     void setup(int width, int height, const Vector3& lightCenter, float lightRadius);
     void setOpaque(bool opaque);
     void makeCurrent();
@@ -73,11 +73,15 @@ public:
     ANDROID_API static void setTextureAtlas(const sp<GraphicBuffer>& buffer,
             int64_t* map, size_t mapSize);
 
+    void notifyFramePending();
+
 private:
+    friend class RegisterFrameCallbackTask;
+
     void processLayerUpdates(const Vector<DeferredLayerUpdater*>* layerUpdaters, TreeInfo& info);
     void prepareTree(TreeInfo& info);
 
-    void setSurface(EGLNativeWindowType window);
+    void setSurface(ANativeWindow* window);
     void swapBuffers();
     void requireSurface();
 
@@ -85,6 +89,7 @@ private:
 
     GlobalContext* mGlobalContext;
     RenderThread& mRenderThread;
+    sp<ANativeWindow> mNativeWindow;
     EGLSurface mEglSurface;
     bool mDirtyRegionsEnabled;
 
diff --git a/libs/hwui/renderthread/DrawFrameTask.cpp b/libs/hwui/renderthread/DrawFrameTask.cpp
index 3b8786c..ee3e059 100644
--- a/libs/hwui/renderthread/DrawFrameTask.cpp
+++ b/libs/hwui/renderthread/DrawFrameTask.cpp
@@ -87,7 +87,13 @@ void DrawFrameTask::postAndWait() {
 void DrawFrameTask::run() {
     ATRACE_NAME("DrawFrame");
 
-    bool canUnblockUiThread = syncFrameState();
+    bool canUnblockUiThread;
+    bool canDrawThisFrame;
+    {
+        TreeInfo info;
+        canUnblockUiThread = syncFrameState(info);
+        canDrawThisFrame = info.out.canDrawThisFrame;
+    }
 
     // Grab a copy of everything we need
     Rect dirty(mDirty);
@@ -98,7 +104,9 @@ void DrawFrameTask::run() {
         unblockUiThread();
     }
 
-    context->draw(&dirty);
+    if (CC_LIKELY(canDrawThisFrame)) {
+        context->draw(&dirty);
+    }
 
     if (!canUnblockUiThread) {
         unblockUiThread();
@@ -111,12 +119,11 @@ static void initTreeInfo(TreeInfo& info) {
     info.evaluateAnimations = true;
 }
 
-bool DrawFrameTask::syncFrameState() {
+bool DrawFrameTask::syncFrameState(TreeInfo& info) {
     ATRACE_CALL();
     mRenderThread->timeLord().vsyncReceived(mFrameTimeNanos);
     mContext->makeCurrent();
     Caches::getInstance().textureCache.resetMarkInUse();
-    TreeInfo info;
     initTreeInfo(info);
     mContext->prepareDraw(&mLayers, info);
     if (info.out.hasAnimations) {
diff --git a/libs/hwui/renderthread/DrawFrameTask.h b/libs/hwui/renderthread/DrawFrameTask.h
index b9307e1..acbc02a 100644
--- a/libs/hwui/renderthread/DrawFrameTask.h
+++ b/libs/hwui/renderthread/DrawFrameTask.h
@@ -24,6 +24,7 @@
 #include "RenderTask.h"
 
 #include "../Rect.h"
+#include "../TreeInfo.h"
 
 namespace android {
 namespace uirenderer {
@@ -65,7 +66,7 @@ public:
 
 private:
     void postAndWait();
-    bool syncFrameState();
+    bool syncFrameState(TreeInfo& info);
     void unblockUiThread();
 
     Mutex mLock;
diff --git a/libs/hwui/renderthread/RenderProxy.cpp b/libs/hwui/renderthread/RenderProxy.cpp
index ef8e45b..2e103d8 100644
--- a/libs/hwui/renderthread/RenderProxy.cpp
+++ b/libs/hwui/renderthread/RenderProxy.cpp
@@ -112,7 +112,7 @@ bool RenderProxy::loadSystemProperties() {
     return (bool) postAndWait(task);
 }
 
-CREATE_BRIDGE2(initialize, CanvasContext* context, EGLNativeWindowType window) {
+CREATE_BRIDGE2(initialize, CanvasContext* context, ANativeWindow* window) {
     return (void*) args->context->initialize(args->window);
 }
 
@@ -123,7 +123,7 @@ bool RenderProxy::initialize(const sp<ANativeWindow>& window) {
     return (bool) postAndWait(task);
 }
 
-CREATE_BRIDGE2(updateSurface, CanvasContext* context, EGLNativeWindowType window) {
+CREATE_BRIDGE2(updateSurface, CanvasContext* context, ANativeWindow* window) {
     args->context->updateSurface(args->window);
     return NULL;
 }
@@ -135,7 +135,7 @@ void RenderProxy::updateSurface(const sp<ANativeWindow>& window) {
     postAndWait(task);
 }
 
-CREATE_BRIDGE2(pauseSurface, CanvasContext* context, EGLNativeWindowType window) {
+CREATE_BRIDGE2(pauseSurface, CanvasContext* context, ANativeWindow* window) {
     args->context->pauseSurface(args->window);
     return NULL;
 }
@@ -292,6 +292,17 @@ void RenderProxy::fence() {
     postAndWait(task);
 }
 
+CREATE_BRIDGE1(notifyFramePending, CanvasContext* context) {
+    args->context->notifyFramePending();
+    return NULL;
+}
+
+void RenderProxy::notifyFramePending() {
+    SETUP_TASK(notifyFramePending);
+    args->context = mContext;
+    mRenderThread.queueAtFront(task);
+}
+
 void RenderProxy::post(RenderTask* task) {
     mRenderThread.queue(task);
 }
diff --git a/libs/hwui/renderthread/RenderProxy.h b/libs/hwui/renderthread/RenderProxy.h
index 4d3499e..8aeb264 100644
--- a/libs/hwui/renderthread/RenderProxy.h
+++ b/libs/hwui/renderthread/RenderProxy.h
@@ -82,6 +82,7 @@ public:
     ANDROID_API void destroyLayer(DeferredLayerUpdater* layer);
 
     ANDROID_API void fence();
+    ANDROID_API void notifyFramePending();
 
 private:
     RenderThread& mRenderThread;
diff --git a/libs/hwui/renderthread/RenderThread.cpp b/libs/hwui/renderthread/RenderThread.cpp
index 35a3eab..4a4e254 100644
--- a/libs/hwui/renderthread/RenderThread.cpp
+++ b/libs/hwui/renderthread/RenderThread.cpp
@@ -37,7 +37,7 @@ namespace renderthread {
 static const size_t EVENT_BUFFER_SIZE = 100;
 
 // Slight delay to give the UI time to push us a new frame before we replay
-static const int DISPATCH_FRAME_CALLBACKS_DELAY = 0;
+static const int DISPATCH_FRAME_CALLBACKS_DELAY = 4;
 
 TaskQueue::TaskQueue() : mHead(0), mTail(0) {}
 
@@ -91,6 +91,15 @@ void TaskQueue::queue(RenderTask* task) {
     }
 }
 
+void TaskQueue::queueAtFront(RenderTask* task) {
+    if (mTail) {
+        task->mNext = mHead;
+        mHead = task;
+    } else {
+        mTail = mHead = task;
+    }
+}
+
 void TaskQueue::remove(RenderTask* task) {
     // TaskQueue is strict here to enforce that users are keeping track of
     // their RenderTasks due to how their memory is managed
@@ -188,20 +197,22 @@ static nsecs_t latestVsyncEvent(DisplayEventReceiver* receiver) {
     return latest;
 }
 
-void RenderThread::drainDisplayEventQueue() {
+void RenderThread::drainDisplayEventQueue(bool skipCallbacks) {
+    ATRACE_CALL();
     nsecs_t vsyncEvent = latestVsyncEvent(mDisplayEventReceiver);
     if (vsyncEvent > 0) {
         mVsyncRequested = false;
         mTimeLord.vsyncReceived(vsyncEvent);
-        if (!mFrameCallbackTaskPending) {
+        if (!skipCallbacks && !mFrameCallbackTaskPending) {
+            ATRACE_NAME("queue mFrameCallbackTask");
             mFrameCallbackTaskPending = true;
-            //queueDelayed(mFrameCallbackTask, DISPATCH_FRAME_CALLBACKS_DELAY);
-            queue(mFrameCallbackTask);
+            queueDelayed(mFrameCallbackTask, DISPATCH_FRAME_CALLBACKS_DELAY);
         }
     }
 }
 
 void RenderThread::dispatchFrameCallbacks() {
+    ATRACE_CALL();
     mFrameCallbackTaskPending = false;
 
     std::set<IFrameCallback*> callbacks;
@@ -212,6 +223,15 @@ void RenderThread::dispatchFrameCallbacks() {
     }
 }
 
+void RenderThread::requestVsync() {
+    if (!mVsyncRequested) {
+        mVsyncRequested = true;
+        status_t status = mDisplayEventReceiver->requestNextVsync();
+        LOG_ALWAYS_FATAL_IF(status != NO_ERROR,
+                "requestNextVsync failed with status: %d", status);
+    }
+}
+
 bool RenderThread::threadLoop() {
     initializeDisplayEventReceiver();
 
@@ -236,6 +256,14 @@ bool RenderThread::threadLoop() {
                 timeoutMillis = 0;
             }
         }
+
+        if (mPendingRegistrationFrameCallbacks.size() && !mFrameCallbackTaskPending) {
+            drainDisplayEventQueue(true);
+            mFrameCallbacks.insert(
+                    mPendingRegistrationFrameCallbacks.begin(), mPendingRegistrationFrameCallbacks.end());
+            mPendingRegistrationFrameCallbacks.clear();
+            requestVsync();
+        }
     }
 
     return false;
@@ -250,6 +278,12 @@ void RenderThread::queue(RenderTask* task) {
     }
 }
 
+void RenderThread::queueAtFront(RenderTask* task) {
+    AutoMutex _lock(mLock);
+    mQueue.queueAtFront(task);
+    mLooper->wake();
+}
+
 void RenderThread::queueDelayed(RenderTask* task, int delayMs) {
     nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
     task->mRunAt = now + milliseconds_to_nanoseconds(delayMs);
@@ -262,17 +296,18 @@ void RenderThread::remove(RenderTask* task) {
 }
 
 void RenderThread::postFrameCallback(IFrameCallback* callback) {
-    mFrameCallbacks.insert(callback);
-    if (!mVsyncRequested) {
-        mVsyncRequested = true;
-        status_t status = mDisplayEventReceiver->requestNextVsync();
-        LOG_ALWAYS_FATAL_IF(status != NO_ERROR,
-                "requestNextVsync failed with status: %d", status);
-    }
+    mPendingRegistrationFrameCallbacks.insert(callback);
 }
 
 void RenderThread::removeFrameCallback(IFrameCallback* callback) {
     mFrameCallbacks.erase(callback);
+    mPendingRegistrationFrameCallbacks.erase(callback);
+}
+
+void RenderThread::pushBackFrameCallback(IFrameCallback* callback) {
+    if (mFrameCallbacks.erase(callback)) {
+        mPendingRegistrationFrameCallbacks.insert(callback);
+    }
 }
 
 RenderTask* RenderThread::nextTask(nsecs_t* nextWakeup) {
@@ -281,11 +316,13 @@ RenderTask* RenderThread::nextTask(nsecs_t* nextWakeup) {
     if (!next) {
         mNextWakeup = LLONG_MAX;
     } else {
+        mNextWakeup = next->mRunAt;
         // Most tasks won't be delayed, so avoid unnecessary systemTime() calls
         if (next->mRunAt <= 0 || next->mRunAt <= systemTime(SYSTEM_TIME_MONOTONIC)) {
             next = mQueue.next();
+        } else {
+            next = 0;
         }
-        mNextWakeup = next->mRunAt;
     }
     if (nextWakeup) {
         *nextWakeup = mNextWakeup;
diff --git a/libs/hwui/renderthread/RenderThread.h b/libs/hwui/renderthread/RenderThread.h
index 215d294..4412584 100644
--- a/libs/hwui/renderthread/RenderThread.h
+++ b/libs/hwui/renderthread/RenderThread.h
@@ -44,6 +44,7 @@ public:
 
     RenderTask* next();
     void queue(RenderTask* task);
+    void queueAtFront(RenderTask* task);
     RenderTask* peek();
     void remove(RenderTask* task);
 
@@ -66,12 +67,16 @@ public:
     // RenderThread takes complete ownership of tasks that are queued
     // and will delete them after they are run
     ANDROID_API void queue(RenderTask* task);
+    ANDROID_API void queueAtFront(RenderTask* task);
     void queueDelayed(RenderTask* task, int delayMs);
     void remove(RenderTask* task);
 
     // Mimics android.view.Choreographer
     void postFrameCallback(IFrameCallback* callback);
     void removeFrameCallback(IFrameCallback* callback);
+    // If the callback is currently registered, it will be pushed back until
+    // the next vsync. If it is not currently registered this does nothing.
+    void pushBackFrameCallback(IFrameCallback* callback);
 
     TimeLord& timeLord() { return mTimeLord; }
 
@@ -87,8 +92,9 @@ private:
 
     void initializeDisplayEventReceiver();
     static int displayEventReceiverCallback(int fd, int events, void* data);
-    void drainDisplayEventQueue();
+    void drainDisplayEventQueue(bool skipCallbacks = false);
     void dispatchFrameCallbacks();
+    void requestVsync();
 
     // Returns the next task to be run. If this returns NULL nextWakeup is set
     // to the time to requery for the nextTask to run. mNextWakeup is also
@@ -104,6 +110,11 @@ private:
     DisplayEventReceiver* mDisplayEventReceiver;
     bool mVsyncRequested;
     std::set<IFrameCallback*> mFrameCallbacks;
+    // We defer the actual registration of these callbacks until
+    // both mQueue *and* mDisplayEventReceiver have been drained off all
+    // immediate events. This makes sure that we catch the next vsync, not
+    // the previous one
+    std::set<IFrameCallback*> mPendingRegistrationFrameCallbacks;
     bool mFrameCallbackTaskPending;
     DispatchFrameCallbacks* mFrameCallbackTask;