Add plumbing for upcoming setFrameRate() api

Add plumbing from the app to surface flinger for the
ANativeWindow_setFrameRate() and ASurfaceTransaction_setFrameRate() api
calls we'll be adding soon.

We don't do anything in surface flinger with this data yet.

Bug: 143912624

Test: Added a new test, SetFrameRateTest.
Change-Id: I1cab87f3ce5afca4591a39d8e7a42cb1e86a368f
diff --git a/services/surfaceflinger/BufferQueueLayer.cpp b/services/surfaceflinger/BufferQueueLayer.cpp
index e4e4bc7..56b50eb 100644
--- a/services/surfaceflinger/BufferQueueLayer.cpp
+++ b/services/surfaceflinger/BufferQueueLayer.cpp
@@ -117,6 +117,18 @@
     return isDue || !isPlausible;
 }
 
+bool BufferQueueLayer::setFrameRate(float frameRate) {
+    float oldFrameRate = 0.f;
+    status_t result = mConsumer->getFrameRate(&oldFrameRate);
+    bool frameRateChanged = result < 0 || frameRate != oldFrameRate;
+    mConsumer->setFrameRate(frameRate);
+    return frameRateChanged;
+}
+
+float BufferQueueLayer::getFrameRate() const {
+    return mLatchedFrameRate;
+}
+
 // -----------------------------------------------------------------------
 // Interface implementation for BufferLayer
 // -----------------------------------------------------------------------
@@ -547,6 +559,9 @@
     mBufferInfo.mApi = mConsumer->getCurrentApi();
     mBufferInfo.mPixelFormat = mFormat;
     mBufferInfo.mTransformToDisplayInverse = mConsumer->getTransformToDisplayInverse();
+    float latchedFrameRate;
+    mConsumer->getFrameRate(&latchedFrameRate);
+    mLatchedFrameRate = latchedFrameRate;
 }
 
 sp<Layer> BufferQueueLayer::createClone() {
diff --git a/services/surfaceflinger/BufferQueueLayer.h b/services/surfaceflinger/BufferQueueLayer.h
index b040556..0777953 100644
--- a/services/surfaceflinger/BufferQueueLayer.h
+++ b/services/surfaceflinger/BufferQueueLayer.h
@@ -55,6 +55,10 @@
     int32_t getQueuedFrameCount() const override;
 
     bool shouldPresentNow(nsecs_t expectedPresentTime) const override;
+
+    bool setFrameRate(float frameRate) override;
+    float getFrameRate() const override;
+
     // -----------------------------------------------------------------------
 
     // -----------------------------------------------------------------------
@@ -151,6 +155,8 @@
     std::atomic<bool> mSidebandStreamChanged{false};
 
     sp<ContentsChangedListener> mContentsChangedListener;
+
+    std::atomic<float> mLatchedFrameRate = 0.f;
 };
 
 } // namespace android
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 5bba7d3..2e2d745 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -111,6 +111,7 @@
     mCurrentState.frameRateSelectionPriority = PRIORITY_UNSET;
     mCurrentState.metadata = args.metadata;
     mCurrentState.shadowRadius = 0.f;
+    mCurrentState.frameRate = 0.f;
 
     // drawing state & current state are identical
     mDrawingState = mCurrentState;
@@ -1221,6 +1222,22 @@
     return true;
 }
 
+bool Layer::setFrameRate(float frameRate) {
+    if (mCurrentState.frameRate == frameRate) {
+        return false;
+    }
+
+    mCurrentState.sequence++;
+    mCurrentState.frameRate = frameRate;
+    mCurrentState.modified = true;
+    setTransactionFlags(eTransactionNeeded);
+    return true;
+}
+
+float Layer::getFrameRate() const {
+    return getDrawingState().frameRate;
+}
+
 void Layer::deferTransactionUntil_legacy(const sp<Layer>& barrierLayer, uint64_t frameNumber) {
     ATRACE_CALL();
     mCurrentState.barrierLayer_legacy = barrierLayer;
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index b8a3539..0253098 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -224,6 +224,8 @@
 
         // Priority of the layer assigned by Window Manager.
         int32_t frameRateSelectionPriority;
+
+        float frameRate;
     };
 
     explicit Layer(const LayerCreationArgs& args);
@@ -737,6 +739,9 @@
      */
     Rect getCroppedBufferSize(const Layer::State& s) const;
 
+    virtual bool setFrameRate(float frameRate);
+    virtual float getFrameRate() const;
+
 protected:
     // constant
     sp<SurfaceFlinger> mFlinger;
diff --git a/services/surfaceflinger/MonitoredProducer.cpp b/services/surfaceflinger/MonitoredProducer.cpp
index 7a959f7..081f8db 100644
--- a/services/surfaceflinger/MonitoredProducer.cpp
+++ b/services/surfaceflinger/MonitoredProducer.cpp
@@ -158,6 +158,10 @@
     return mProducer->setAutoPrerotation(autoPrerotation);
 }
 
+status_t MonitoredProducer::setFrameRate(float frameRate) {
+    return mProducer->setFrameRate(frameRate);
+}
+
 IBinder* MonitoredProducer::onAsBinder() {
     return this;
 }
diff --git a/services/surfaceflinger/MonitoredProducer.h b/services/surfaceflinger/MonitoredProducer.h
index 788919b..4bda831 100644
--- a/services/surfaceflinger/MonitoredProducer.h
+++ b/services/surfaceflinger/MonitoredProducer.h
@@ -71,6 +71,7 @@
     virtual status_t getUniqueId(uint64_t* outId) const override;
     virtual status_t getConsumerUsage(uint64_t* outUsage) const override;
     virtual status_t setAutoPrerotation(bool autoPrerotation) override;
+    virtual status_t setFrameRate(float frameRate) override;
 
     // The Layer which created this producer, and on which queued Buffer's will be displayed.
     sp<Layer> getLayer() const;
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index e90cf41..4f042db 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -3480,6 +3480,9 @@
             flags |= eTraversalNeeded;
         }
     }
+    if (what & layer_state_t::eFrameRateChanged) {
+        if (layer->setFrameRate(s.frameRate)) flags |= eTraversalNeeded;
+    }
     // This has to happen after we reparent children because when we reparent to null we remove
     // child layers from current state and remove its relative z. If the children are reparented in
     // the same transaction, then we have to make sure we reparent the children first so we do not
diff --git a/services/surfaceflinger/tests/Android.bp b/services/surfaceflinger/tests/Android.bp
index 1c8199a..94ebe89 100644
--- a/services/surfaceflinger/tests/Android.bp
+++ b/services/surfaceflinger/tests/Android.bp
@@ -32,6 +32,7 @@
         "MirrorLayer_test.cpp",
         "MultiDisplayLayerBounds_test.cpp",
         "RelativeZ_test.cpp",
+        "SetFrameRate_test.cpp",
         "SetGeometry_test.cpp",
         "Stress_test.cpp",
         "SurfaceInterceptor_test.cpp",
diff --git a/services/surfaceflinger/tests/SetFrameRate_test.cpp b/services/surfaceflinger/tests/SetFrameRate_test.cpp
new file mode 100644
index 0000000..4d1477c
--- /dev/null
+++ b/services/surfaceflinger/tests/SetFrameRate_test.cpp
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <system/window.h>
+
+#include <thread>
+
+#include "LayerTransactionTest.h"
+
+namespace android {
+
+class SetFrameRateTest : public LayerTransactionTest {
+protected:
+    void TearDown() {
+        mLayer = nullptr;
+        LayerTransactionTest::TearDown();
+    }
+
+    void CreateLayer(uint32_t layerType) {
+        ASSERT_EQ(nullptr, mLayer.get());
+        mLayerType = layerType;
+        ASSERT_NO_FATAL_FAILURE(mLayer = createLayer("TestLayer", mLayerWidth, mLayerHeight,
+                                                     /*flags=*/mLayerType));
+        ASSERT_NE(nullptr, mLayer.get());
+    }
+
+    void PostBuffers(const Color& color) {
+        auto startTime = systemTime();
+        while (systemTime() - startTime < s2ns(1)) {
+            ASSERT_NO_FATAL_FAILURE(
+                    fillLayerColor(mLayerType, mLayer, color, mLayerWidth, mLayerHeight));
+            std::this_thread::sleep_for(100ms);
+        }
+    }
+
+    const int mLayerWidth = 32;
+    const int mLayerHeight = 32;
+    sp<SurfaceControl> mLayer;
+    uint32_t mLayerType;
+};
+
+TEST_F(SetFrameRateTest, BufferQueueLayerSetFrameRate) {
+    CreateLayer(ISurfaceComposerClient::eFXSurfaceBufferQueue);
+    native_window_set_frame_rate(mLayer->getSurface().get(), 100.f);
+    ASSERT_NO_FATAL_FAILURE(PostBuffers(Color::RED));
+    Transaction().setFrameRate(mLayer, 200.f).apply();
+    ASSERT_NO_FATAL_FAILURE(PostBuffers(Color::RED));
+    native_window_set_frame_rate(mLayer->getSurface().get(), 300.f);
+    ASSERT_NO_FATAL_FAILURE(PostBuffers(Color::RED));
+}
+
+TEST_F(SetFrameRateTest, BufferStateLayerSetFrameRate) {
+    CreateLayer(ISurfaceComposerClient::eFXSurfaceBufferState);
+    Transaction().setFrameRate(mLayer, 400.f).apply();
+    ASSERT_NO_FATAL_FAILURE(PostBuffers(Color::GREEN));
+}
+
+} // namespace android