Merge "[Shadows] Add shadow vertex generation code and shaders [8/n]"
diff --git a/cmds/dumpsys/dumpsys.cpp b/cmds/dumpsys/dumpsys.cpp
index abdf168..5597bcd 100644
--- a/cmds/dumpsys/dumpsys.cpp
+++ b/cmds/dumpsys/dumpsys.cpp
@@ -364,7 +364,7 @@
         }
 
         if (err != OK) {
-            aerr << "Error dumping service info status_t: (" << err << ") "
+            aerr << "Error dumping service info status_t: " << statusToString(err) << " "
                  << serviceName << endl;
         }
     });
diff --git a/libs/ui/Region.cpp b/libs/ui/Region.cpp
index 83ebeca..bf487c4 100644
--- a/libs/ui/Region.cpp
+++ b/libs/ui/Region.cpp
@@ -280,6 +280,20 @@
     return begin() == region.begin();
 }
 
+bool Region::hasSameRects(const Region& other) const {
+    size_t thisRectCount = 0;
+    android::Rect const* thisRects = getArray(&thisRectCount);
+    size_t otherRectCount = 0;
+    android::Rect const* otherRects = other.getArray(&otherRectCount);
+
+    if (thisRectCount != otherRectCount) return false;
+
+    for (size_t i = 0; i < thisRectCount; i++) {
+        if (thisRects[i] != otherRects[i]) return false;
+    }
+    return true;
+}
+
 // ----------------------------------------------------------------------------
 
 void Region::addRectUnchecked(int l, int t, int r, int b)
diff --git a/libs/ui/Transform.cpp b/libs/ui/Transform.cpp
index 85abb38..06b6bfe 100644
--- a/libs/ui/Transform.cpp
+++ b/libs/ui/Transform.cpp
@@ -49,6 +49,15 @@
     return isZero(fabs(f) - 1.0f);
 }
 
+bool Transform::operator==(const Transform& other) const {
+    return mMatrix[0][0] == other.mMatrix[0][0] && mMatrix[0][1] == other.mMatrix[0][1] &&
+            mMatrix[0][2] == other.mMatrix[0][2] && mMatrix[1][0] == other.mMatrix[1][0] &&
+            mMatrix[1][1] == other.mMatrix[1][1] && mMatrix[1][2] == other.mMatrix[1][2] &&
+            mMatrix[2][0] == other.mMatrix[2][0] && mMatrix[2][1] == other.mMatrix[2][1] &&
+            mMatrix[2][2] == other.mMatrix[2][2];
+    ;
+}
+
 Transform Transform::operator * (const Transform& rhs) const
 {
     if (CC_LIKELY(mType == IDENTITY))
diff --git a/libs/ui/include/ui/FloatRect.h b/libs/ui/include/ui/FloatRect.h
index 4cd9a0b..bec2552 100644
--- a/libs/ui/include/ui/FloatRect.h
+++ b/libs/ui/include/ui/FloatRect.h
@@ -16,6 +16,8 @@
 
 #pragma once
 
+#include <ostream>
+
 namespace android {
 
 class FloatRect {
@@ -52,4 +54,9 @@
     return a.left == b.left && a.top == b.top && a.right == b.right && a.bottom == b.bottom;
 }
 
+static inline void PrintTo(const FloatRect& rect, ::std::ostream* os) {
+    *os << "FloatRect(" << rect.left << ", " << rect.top << ", " << rect.right << ", "
+        << rect.bottom << ")";
+}
+
 }  // namespace android
diff --git a/libs/ui/include/ui/Rect.h b/libs/ui/include/ui/Rect.h
index 1768805..2f2229e 100644
--- a/libs/ui/include/ui/Rect.h
+++ b/libs/ui/include/ui/Rect.h
@@ -17,6 +17,8 @@
 #ifndef ANDROID_UI_RECT
 #define ANDROID_UI_RECT
 
+#include <ostream>
+
 #include <utils/Flattenable.h>
 #include <utils/Log.h>
 #include <utils/TypeHelpers.h>
@@ -214,6 +216,12 @@
     }
 };
 
+// Defining PrintTo helps with Google Tests.
+static inline void PrintTo(const Rect& rect, ::std::ostream* os) {
+    *os << "Rect(" << rect.left << ", " << rect.top << ", " << rect.right << ", " << rect.bottom
+        << ")";
+}
+
 ANDROID_BASIC_TYPES_TRAITS(Rect)
 
 }; // namespace android
diff --git a/libs/ui/include/ui/Region.h b/libs/ui/include/ui/Region.h
index 79642ae..2db3b10 100644
--- a/libs/ui/include/ui/Region.h
+++ b/libs/ui/include/ui/Region.h
@@ -19,6 +19,7 @@
 
 #include <stdint.h>
 #include <sys/types.h>
+#include <ostream>
 
 #include <utils/Vector.h>
 
@@ -119,6 +120,8 @@
     // returns true if the regions share the same underlying storage
     bool isTriviallyEqual(const Region& region) const;
 
+    // returns true if the regions consist of the same rectangle sequence
+    bool hasSameRects(const Region& region) const;
 
     /* various ways to access the rectangle list */
 
@@ -213,6 +216,21 @@
 Region& Region::operator += (const Point& pt) {
     return translateSelf(pt.x, pt.y);
 }
+
+// Defining PrintTo helps with Google Tests.
+static inline void PrintTo(const Region& region, ::std::ostream* os) {
+    Region::const_iterator head = region.begin();
+    Region::const_iterator const tail = region.end();
+    bool first = true;
+    while (head != tail) {
+        *os << (first ? "Region(" : ", ");
+        PrintTo(*head, os);
+        head++;
+        first = false;
+    }
+    *os << ")";
+}
+
 // ---------------------------------------------------------------------------
 }; // namespace android
 
diff --git a/libs/ui/include/ui/Transform.h b/libs/ui/include/ui/Transform.h
index fab2d9e..de07684 100644
--- a/libs/ui/include/ui/Transform.h
+++ b/libs/ui/include/ui/Transform.h
@@ -19,6 +19,7 @@
 
 #include <stdint.h>
 #include <sys/types.h>
+#include <ostream>
 #include <string>
 
 #include <hardware/hardware.h>
@@ -63,6 +64,7 @@
     bool        preserveRects() const;
     uint32_t    getType() const;
     uint32_t    getOrientation() const;
+    bool operator==(const Transform& other) const;
 
     const vec3& operator [] (size_t i) const;  // returns column i
     float   tx() const;
@@ -115,6 +117,12 @@
     mutable uint32_t    mType;
 };
 
+static inline void PrintTo(const Transform& t, ::std::ostream* os) {
+    std::string out;
+    t.dump(out, "ui::Transform");
+    *os << out;
+}
+
 }  // namespace ui
 }  // namespace android
 
diff --git a/services/inputflinger/InputClassifier.cpp b/services/inputflinger/InputClassifier.cpp
index 7c061c5..ae9a348 100644
--- a/services/inputflinger/InputClassifier.cpp
+++ b/services/inputflinger/InputClassifier.cpp
@@ -82,7 +82,7 @@
 // Check if the "deep touch" feature is on.
 static bool deepPressEnabled() {
     std::string flag_value = server_configurable_flags::GetServerConfigurableFlag(
-            INPUT_NATIVE_BOOT, DEEP_PRESS_ENABLED, "false");
+            INPUT_NATIVE_BOOT, DEEP_PRESS_ENABLED, "true");
     std::transform(flag_value.begin(), flag_value.end(), flag_value.begin(), ::tolower);
     if (flag_value == "1" || flag_value == "true") {
         ALOGI("Deep press feature enabled.");
diff --git a/services/surfaceflinger/CompositionEngine/tests/FloatRectMatcher.h b/services/surfaceflinger/CompositionEngine/tests/FloatRectMatcher.h
deleted file mode 100644
index 6741cc9..0000000
--- a/services/surfaceflinger/CompositionEngine/tests/FloatRectMatcher.h
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
- * Copyright 2019 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.
- */
-
-#pragma once
-
-#include <string>
-
-#include <android-base/stringprintf.h>
-#include <gmock/gmock.h>
-
-namespace {
-
-using android::base::StringAppendF;
-using FloatRect = android::FloatRect;
-
-void dumpFloatRect(const FloatRect& rect, std::string& result, const char* name) {
-    StringAppendF(&result, "%s (%f %f %f %f) ", name, rect.left, rect.top, rect.right, rect.bottom);
-}
-
-// Checks for a region match
-MATCHER_P(FloatRectEq, expected, "") {
-    std::string buf;
-    buf.append("FloatRects are not equal\n");
-    dumpFloatRect(expected, buf, "expected rect");
-    dumpFloatRect(arg, buf, "actual rect");
-    *result_listener << buf;
-
-    const float TOLERANCE = 1e-3f;
-    return (std::fabs(expected.left - arg.left) < TOLERANCE) &&
-            (std::fabs(expected.top - arg.top) < TOLERANCE) &&
-            (std::fabs(expected.right - arg.right) < TOLERANCE) &&
-            (std::fabs(expected.bottom - arg.bottom) < TOLERANCE);
-}
-
-} // namespace
diff --git a/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp b/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
index 88acd04..2e030a1 100644
--- a/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
@@ -23,10 +23,8 @@
 #include <compositionengine/mock/Output.h>
 #include <gtest/gtest.h>
 
-#include "FloatRectMatcher.h"
 #include "MockHWC2.h"
 #include "MockHWComposer.h"
-#include "RectMatcher.h"
 #include "RegionMatcher.h"
 
 namespace android::compositionengine {
@@ -159,19 +157,19 @@
     mLayerFEState.geomUsesSourceCrop = false;
 
     const FloatRect expected{};
-    EXPECT_THAT(calculateOutputSourceCrop(), FloatRectEq(expected));
+    EXPECT_THAT(calculateOutputSourceCrop(), expected);
 }
 
 TEST_F(OutputLayerSourceCropTest, correctForSimpleDefaultCase) {
     const FloatRect expected{0.f, 0.f, 1920.f, 1080.f};
-    EXPECT_THAT(calculateOutputSourceCrop(), FloatRectEq(expected));
+    EXPECT_THAT(calculateOutputSourceCrop(), expected);
 }
 
 TEST_F(OutputLayerSourceCropTest, handlesBoundsOutsideViewport) {
     mLayerFEState.geomLayerBounds = FloatRect{-2000.f, -2000.f, 2000.f, 2000.f};
 
     const FloatRect expected{0.f, 0.f, 1920.f, 1080.f};
-    EXPECT_THAT(calculateOutputSourceCrop(), FloatRectEq(expected));
+    EXPECT_THAT(calculateOutputSourceCrop(), expected);
 }
 
 TEST_F(OutputLayerSourceCropTest, handlesBoundsOutsideViewportRotated) {
@@ -179,7 +177,7 @@
     mLayerFEState.geomLayerTransform.set(HAL_TRANSFORM_ROT_90, 1920, 1080);
 
     const FloatRect expected{0.f, 0.f, 1080.f, 1080.f};
-    EXPECT_THAT(calculateOutputSourceCrop(), FloatRectEq(expected));
+    EXPECT_THAT(calculateOutputSourceCrop(), expected);
 }
 
 TEST_F(OutputLayerSourceCropTest, calculateOutputSourceCropWorksWithATransformedBuffer) {
@@ -218,7 +216,7 @@
         mLayerFEState.geomBufferTransform = entry.buffer;
         mOutputState.orientation = entry.display;
 
-        EXPECT_THAT(calculateOutputSourceCrop(), FloatRectEq(entry.expected)) << "entry " << i;
+        EXPECT_THAT(calculateOutputSourceCrop(), entry.expected) << "entry " << i;
     }
 }
 
@@ -226,14 +224,14 @@
     mLayerFEState.geomContentCrop = Rect{0, 0, 960, 540};
 
     const FloatRect expected{0.f, 0.f, 960.f, 540.f};
-    EXPECT_THAT(calculateOutputSourceCrop(), FloatRectEq(expected));
+    EXPECT_THAT(calculateOutputSourceCrop(), expected);
 }
 
 TEST_F(OutputLayerSourceCropTest, viewportAffectsCrop) {
     mOutputState.viewport = Rect{0, 0, 960, 540};
 
     const FloatRect expected{0.f, 0.f, 960.f, 540.f};
-    EXPECT_THAT(calculateOutputSourceCrop(), FloatRectEq(expected));
+    EXPECT_THAT(calculateOutputSourceCrop(), expected);
 }
 
 /*
@@ -265,50 +263,50 @@
 
 TEST_F(OutputLayerDisplayFrameTest, correctForSimpleDefaultCase) {
     const Rect expected{0, 0, 1920, 1080};
-    EXPECT_THAT(calculateOutputDisplayFrame(), RectEq(expected));
+    EXPECT_THAT(calculateOutputDisplayFrame(), expected);
 }
 
 TEST_F(OutputLayerDisplayFrameTest, fullActiveTransparentRegionReturnsEmptyFrame) {
     mLayerFEState.transparentRegionHint = Region{Rect{0, 0, 1920, 1080}};
     const Rect expected{0, 0, 0, 0};
-    EXPECT_THAT(calculateOutputDisplayFrame(), RectEq(expected));
+    EXPECT_THAT(calculateOutputDisplayFrame(), expected);
 }
 
 TEST_F(OutputLayerDisplayFrameTest, cropAffectsDisplayFrame) {
     mLayerFEState.geomCrop = Rect{100, 200, 300, 500};
     const Rect expected{100, 200, 300, 500};
-    EXPECT_THAT(calculateOutputDisplayFrame(), RectEq(expected));
+    EXPECT_THAT(calculateOutputDisplayFrame(), expected);
 }
 
 TEST_F(OutputLayerDisplayFrameTest, cropAffectsDisplayFrameRotated) {
     mLayerFEState.geomCrop = Rect{100, 200, 300, 500};
     mLayerFEState.geomLayerTransform.set(HAL_TRANSFORM_ROT_90, 1920, 1080);
     const Rect expected{1420, 100, 1720, 300};
-    EXPECT_THAT(calculateOutputDisplayFrame(), RectEq(expected));
+    EXPECT_THAT(calculateOutputDisplayFrame(), expected);
 }
 
 TEST_F(OutputLayerDisplayFrameTest, emptyGeomCropIsNotUsedToComputeFrame) {
     mLayerFEState.geomCrop = Rect{};
     const Rect expected{0, 0, 1920, 1080};
-    EXPECT_THAT(calculateOutputDisplayFrame(), RectEq(expected));
+    EXPECT_THAT(calculateOutputDisplayFrame(), expected);
 }
 
 TEST_F(OutputLayerDisplayFrameTest, geomLayerBoundsAffectsFrame) {
     mLayerFEState.geomLayerBounds = FloatRect{0.f, 0.f, 960.f, 540.f};
     const Rect expected{0, 0, 960, 540};
-    EXPECT_THAT(calculateOutputDisplayFrame(), RectEq(expected));
+    EXPECT_THAT(calculateOutputDisplayFrame(), expected);
 }
 
 TEST_F(OutputLayerDisplayFrameTest, viewportAffectsFrame) {
     mOutputState.viewport = Rect{0, 0, 960, 540};
     const Rect expected{0, 0, 960, 540};
-    EXPECT_THAT(calculateOutputDisplayFrame(), RectEq(expected));
+    EXPECT_THAT(calculateOutputDisplayFrame(), expected);
 }
 
 TEST_F(OutputLayerDisplayFrameTest, outputTransformAffectsDisplayFrame) {
     mOutputState.transform = ui::Transform{HAL_TRANSFORM_ROT_90};
     const Rect expected{-1080, 0, 0, 1920};
-    EXPECT_THAT(calculateOutputDisplayFrame(), RectEq(expected));
+    EXPECT_THAT(calculateOutputDisplayFrame(), expected);
 }
 
 /*
diff --git a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
index 37b62d8..08b8818 100644
--- a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
@@ -35,7 +35,6 @@
 #include "CallOrderStateMachineHelper.h"
 #include "MockHWC2.h"
 #include "RegionMatcher.h"
-#include "TransformMatcher.h"
 
 namespace android::compositionengine {
 namespace {
@@ -244,7 +243,7 @@
 
     mOutput->setProjection(transform, orientation, frame, viewport, scissor, needsFiltering);
 
-    EXPECT_THAT(mOutput->getState().transform, TransformEq(transform));
+    EXPECT_THAT(mOutput->getState().transform, transform);
     EXPECT_EQ(orientation, mOutput->getState().orientation);
     EXPECT_EQ(frame, mOutput->getState().frame);
     EXPECT_EQ(viewport, mOutput->getState().viewport);
diff --git a/services/surfaceflinger/CompositionEngine/tests/RectMatcher.h b/services/surfaceflinger/CompositionEngine/tests/RectMatcher.h
deleted file mode 100644
index d4c76bc..0000000
--- a/services/surfaceflinger/CompositionEngine/tests/RectMatcher.h
+++ /dev/null
@@ -1,45 +0,0 @@
-/*
- * Copyright 2019 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.
- */
-
-#pragma once
-
-#include <string>
-
-#include <android-base/stringprintf.h>
-#include <gmock/gmock.h>
-
-namespace {
-
-using android::base::StringAppendF;
-using Rect = android::Rect;
-
-void dumpRect(const Rect& rect, std::string& result, const char* name) {
-    StringAppendF(&result, "%s (%d %d %d %d) ", name, rect.left, rect.top, rect.right, rect.bottom);
-}
-
-// Checks for a region match
-MATCHER_P(RectEq, expected, "") {
-    std::string buf;
-    buf.append("Rects are not equal\n");
-    dumpRect(expected, buf, "expected rect");
-    dumpRect(arg, buf, "actual rect");
-    *result_listener << buf;
-
-    return (expected.left == arg.left) && (expected.top == arg.top) &&
-            (expected.right == arg.right) && (expected.bottom == arg.bottom);
-}
-
-} // namespace
diff --git a/services/surfaceflinger/CompositionEngine/tests/RegionMatcher.h b/services/surfaceflinger/CompositionEngine/tests/RegionMatcher.h
index 5a4efa9..2adde23 100644
--- a/services/surfaceflinger/CompositionEngine/tests/RegionMatcher.h
+++ b/services/surfaceflinger/CompositionEngine/tests/RegionMatcher.h
@@ -20,24 +20,22 @@
 
 namespace {
 
-// Checks for a region match
-MATCHER_P(RegionEq, expected, "") {
-    std::string buf;
-    buf.append("Regions are not equal\n");
-    expected.dump(buf, "expected region");
-    arg.dump(buf, "actual region");
-    *result_listener << buf;
+using Region = android::Region;
 
-    size_t expectedRectCount = 0;
-    android::Rect const* expectedRects = expected.getArray(&expectedRectCount);
-    size_t actualRectCount = 0;
-    android::Rect const* actualRects = arg.getArray(&actualRectCount);
+struct RegionMatcher : public testing::MatcherInterface<const Region&> {
+    const Region expected;
 
-    if (expectedRectCount != actualRectCount) return false;
-    for (size_t i = 0; i < expectedRectCount; i++) {
-        if (expectedRects[i] != actualRects[i]) return false;
+    explicit RegionMatcher(const Region& expectedValue) : expected(expectedValue) {}
+
+    bool MatchAndExplain(const Region& actual, testing::MatchResultListener*) const override {
+        return expected.hasSameRects(actual);
     }
-    return true;
+
+    void DescribeTo(::std::ostream* os) const override { PrintTo(expected, os); }
+};
+
+testing::Matcher<const Region&> RegionEq(const Region& expected) {
+    return MakeMatcher(new RegionMatcher(expected));
 }
 
 } // namespace
diff --git a/services/surfaceflinger/CompositionEngine/tests/TransformMatcher.h b/services/surfaceflinger/CompositionEngine/tests/TransformMatcher.h
deleted file mode 100644
index ea07bed..0000000
--- a/services/surfaceflinger/CompositionEngine/tests/TransformMatcher.h
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
- * Copyright 2019 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.
- */
-
-#pragma once
-
-#include <string>
-
-#include <gmock/gmock.h>
-
-namespace {
-
-// Check for a transform match
-MATCHER_P(TransformEq, expected, "") {
-    std::string buf;
-    buf.append("Transforms are not equal\n");
-    expected.dump(buf, "expected transform");
-    arg.dump(buf, "actual transform");
-    *result_listener << buf;
-
-    const float TOLERANCE = 1e-3f;
-
-    for (int i = 0; i < 3; i++) {
-        for (int j = 0; j < 3; j++) {
-            if (std::fabs(expected[i][j] - arg[i][j]) > TOLERANCE) {
-                return false;
-            }
-        }
-    }
-
-    return true;
-}
-
-} // namespace
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index d480f7c..d8dad0b 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -247,8 +247,8 @@
     // the refresh period and whatever closest timestamp we have.
     std::lock_guard lock(displayData.lastHwVsyncLock);
     nsecs_t now = systemTime(CLOCK_MONOTONIC);
-    auto vsyncPeriod = getActiveConfig(displayId)->getVsyncPeriod();
-    return now - ((now - displayData.lastHwVsync) % vsyncPeriod);
+    auto vsyncPeriodNanos = getDisplayVsyncPeriod(displayId);
+    return now - ((now - displayData.lastHwVsync) % vsyncPeriodNanos);
 }
 
 bool HWComposer::isConnected(DisplayId displayId) const {
@@ -291,6 +291,23 @@
     return config;
 }
 
+// Composer 2.4
+
+bool HWComposer::isVsyncPeriodSwitchSupported(DisplayId displayId) const {
+    return mDisplayData.at(displayId).hwcDisplay->isVsyncPeriodSwitchSupported();
+}
+
+nsecs_t HWComposer::getDisplayVsyncPeriod(DisplayId displayId) const {
+    nsecs_t vsyncPeriodNanos;
+    auto error = mDisplayData.at(displayId).hwcDisplay->getDisplayVsyncPeriod(&vsyncPeriodNanos);
+    if (error != HWC2::Error::None) {
+        LOG_DISPLAY_ERROR(displayId, "Failed to get Vsync Period");
+        return 0;
+    }
+
+    return vsyncPeriodNanos;
+}
+
 int HWComposer::getActiveConfigIndex(DisplayId displayId) const {
     RETURN_IF_INVALID_DISPLAY(displayId, -1);
 
@@ -541,7 +558,9 @@
     return NO_ERROR;
 }
 
-status_t HWComposer::setActiveConfig(DisplayId displayId, size_t configId) {
+status_t HWComposer::setActiveConfigWithConstraints(
+        DisplayId displayId, size_t configId, const HWC2::VsyncPeriodChangeConstraints& constraints,
+        HWC2::VsyncPeriodChangeTimeline* outTimeline) {
     RETURN_IF_INVALID_DISPLAY(displayId, BAD_INDEX);
 
     auto& displayData = mDisplayData[displayId];
@@ -550,7 +569,9 @@
         return BAD_INDEX;
     }
 
-    auto error = displayData.hwcDisplay->setActiveConfig(displayData.configMap[configId]);
+    auto error =
+            displayData.hwcDisplay->setActiveConfigWithConstraints(displayData.configMap[configId],
+                                                                   constraints, outTimeline);
     RETURN_IF_HWC_ERROR(error, displayId, UNKNOWN_ERROR);
     return NO_ERROR;
 }
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index e87c5c3..077e452 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -102,9 +102,6 @@
     // set power mode
     virtual status_t setPowerMode(DisplayId displayId, int mode) = 0;
 
-    // set active config
-    virtual status_t setActiveConfig(DisplayId displayId, size_t configId) = 0;
-
     // Sets a color transform to be applied to the result of composition
     virtual status_t setColorTransform(DisplayId displayId, const mat4& transform) = 0;
 
@@ -180,6 +177,14 @@
 
     virtual bool isUsingVrComposer() const = 0;
 
+    // Composer 2.4
+    virtual bool isVsyncPeriodSwitchSupported(DisplayId displayId) const = 0;
+    virtual nsecs_t getDisplayVsyncPeriod(DisplayId displayId) const = 0;
+    virtual status_t setActiveConfigWithConstraints(
+            DisplayId displayId, size_t configId,
+            const HWC2::VsyncPeriodChangeConstraints& constraints,
+            HWC2::VsyncPeriodChangeTimeline* outTimeline) = 0;
+
     // for debugging ----------------------------------------------------------
     virtual void dump(std::string& out) const = 0;
 
@@ -232,9 +237,6 @@
     // set power mode
     status_t setPowerMode(DisplayId displayId, int mode) override;
 
-    // set active config
-    status_t setActiveConfig(DisplayId displayId, size_t configId) override;
-
     // Sets a color transform to be applied to the result of composition
     status_t setColorTransform(DisplayId displayId, const mat4& transform) override;
 
@@ -305,6 +307,13 @@
 
     bool isUsingVrComposer() const override;
 
+    // Composer 2.4
+    bool isVsyncPeriodSwitchSupported(DisplayId displayId) const override;
+    nsecs_t getDisplayVsyncPeriod(DisplayId displayId) const override;
+    status_t setActiveConfigWithConstraints(DisplayId displayId, size_t configId,
+                                            const HWC2::VsyncPeriodChangeConstraints& constraints,
+                                            HWC2::VsyncPeriodChangeTimeline* outTimeline) override;
+
     // for debugging ----------------------------------------------------------
     void dump(std::string& out) const override;
 
diff --git a/services/surfaceflinger/Scheduler/Scheduler.cpp b/services/surfaceflinger/Scheduler/Scheduler.cpp
index 1d50fe1..71a6a2f 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -59,11 +59,13 @@
 namespace android {
 
 Scheduler::Scheduler(impl::EventControlThread::SetVSyncEnabledFunction function,
-                     const scheduler::RefreshRateConfigs& refreshRateConfig)
+                     const scheduler::RefreshRateConfigs& refreshRateConfig,
+                     ISchedulerCallback& schedulerCallback)
       : mPrimaryDispSync(new impl::DispSync("SchedulerDispSync",
                                             sysprop::running_without_sync_framework(true))),
         mEventControlThread(new impl::EventControlThread(std::move(function))),
         mSupportKernelTimer(sysprop::support_kernel_idle_timer(false)),
+        mSchedulerCallback(schedulerCallback),
         mRefreshRateConfigs(refreshRateConfig) {
     using namespace sysprop;
 
@@ -104,10 +106,12 @@
 
 Scheduler::Scheduler(std::unique_ptr<DispSync> primaryDispSync,
                      std::unique_ptr<EventControlThread> eventControlThread,
-                     const scheduler::RefreshRateConfigs& configs)
+                     const scheduler::RefreshRateConfigs& configs,
+                     ISchedulerCallback& schedulerCallback)
       : mPrimaryDispSync(std::move(primaryDispSync)),
         mEventControlThread(std::move(eventControlThread)),
         mSupportKernelTimer(false),
+        mSchedulerCallback(schedulerCallback),
         mRefreshRateConfigs(configs) {}
 
 Scheduler::~Scheduler() {
@@ -368,12 +372,7 @@
         mFeatures.configId = newConfigId;
     };
     auto newRefreshRate = mRefreshRateConfigs.getRefreshRateFromConfigId(newConfigId);
-    changeRefreshRate(newRefreshRate, ConfigEvent::Changed);
-}
-
-void Scheduler::setSchedulerCallback(android::Scheduler::ISchedulerCallback* callback) {
-    std::lock_guard<std::mutex> lock(mCallbackLock);
-    mSchedulerCallback = callback;
+    mSchedulerCallback.changeRefreshRate(newRefreshRate, ConfigEvent::Changed);
 }
 
 void Scheduler::resetIdleTimer() {
@@ -486,7 +485,7 @@
         }
     }
     const RefreshRate& newRefreshRate = mRefreshRateConfigs.getRefreshRateFromConfigId(newConfigId);
-    changeRefreshRate(newRefreshRate, event);
+    mSchedulerCallback.changeRefreshRate(newRefreshRate, event);
 }
 
 HwcConfigIndexType Scheduler::calculateRefreshRateType() {
@@ -526,10 +525,36 @@
     return mFeatures.configId;
 }
 
-void Scheduler::changeRefreshRate(const RefreshRate& refreshRate, ConfigEvent configEvent) {
-    std::lock_guard<std::mutex> lock(mCallbackLock);
-    if (mSchedulerCallback) {
-        mSchedulerCallback->changeRefreshRate(refreshRate, configEvent);
+void Scheduler::onNewVsyncPeriodChangeTimeline(const HWC2::VsyncPeriodChangeTimeline& timeline) {
+    if (timeline.refreshRequired) {
+        mSchedulerCallback.repaintEverythingForHWC();
+    }
+
+    std::lock_guard<std::mutex> lock(mVsyncTimelineLock);
+    mLastVsyncPeriodChangeTimeline = std::make_optional(timeline);
+
+    const auto maxAppliedTime = systemTime() + MAX_VSYNC_APPLIED_TIME.count();
+    if (timeline.newVsyncAppliedTimeNanos > maxAppliedTime) {
+        mLastVsyncPeriodChangeTimeline->newVsyncAppliedTimeNanos = maxAppliedTime;
+    }
+}
+
+void Scheduler::onDisplayRefreshed(nsecs_t timestamp) {
+    bool callRepaint = false;
+    {
+        std::lock_guard<std::mutex> lock(mVsyncTimelineLock);
+        if (mLastVsyncPeriodChangeTimeline && mLastVsyncPeriodChangeTimeline->refreshRequired) {
+            if (mLastVsyncPeriodChangeTimeline->refreshTimeNanos < timestamp) {
+                mLastVsyncPeriodChangeTimeline->refreshRequired = false;
+            } else {
+                // We need to send another refresh as refreshTimeNanos is still in the future
+                callRepaint = true;
+            }
+        }
+    }
+
+    if (callRepaint) {
+        mSchedulerCallback.repaintEverythingForHWC();
     }
 }
 
diff --git a/services/surfaceflinger/Scheduler/Scheduler.h b/services/surfaceflinger/Scheduler/Scheduler.h
index 04a8390..15277ce 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.h
+++ b/services/surfaceflinger/Scheduler/Scheduler.h
@@ -41,22 +41,24 @@
 class InjectVSyncSource;
 struct DisplayStateInfo;
 
+class ISchedulerCallback {
+public:
+    virtual ~ISchedulerCallback() = default;
+    virtual void changeRefreshRate(const scheduler::RefreshRateConfigs::RefreshRate&,
+                                   scheduler::RefreshRateConfigEvent) = 0;
+    virtual void repaintEverythingForHWC() = 0;
+};
+
 class Scheduler {
 public:
     using RefreshRate = scheduler::RefreshRateConfigs::RefreshRate;
     using ConfigEvent = scheduler::RefreshRateConfigEvent;
 
-    class ISchedulerCallback {
-    public:
-        virtual ~ISchedulerCallback() = default;
-        virtual void changeRefreshRate(const RefreshRate&, ConfigEvent) = 0;
-    };
-
     // Indicates whether to start the transaction early, or at vsync time.
     enum class TransactionStart { EARLY, NORMAL };
 
     Scheduler(impl::EventControlThread::SetVSyncEnabledFunction,
-              const scheduler::RefreshRateConfigs&);
+              const scheduler::RefreshRateConfigs&, ISchedulerCallback& schedulerCallback);
 
     virtual ~Scheduler();
 
@@ -114,9 +116,6 @@
     // Detects content using layer history, and selects a matching refresh rate.
     void chooseRefreshRateForContent();
 
-    // Called by Scheduler to control SurfaceFlinger operations.
-    void setSchedulerCallback(ISchedulerCallback*);
-
     bool isIdleTimerEnabled() const { return mIdleTimer.has_value(); }
     void resetIdleTimer();
 
@@ -131,6 +130,12 @@
     // Get the appropriate refresh for current conditions.
     std::optional<HwcConfigIndexType> getPreferredConfigId();
 
+    // Notifies the scheduler about a refresh rate timeline change.
+    void onNewVsyncPeriodChangeTimeline(const HWC2::VsyncPeriodChangeTimeline& timeline);
+
+    // Notifies the scheduler when the display was refreshed
+    void onDisplayRefreshed(nsecs_t timestamp);
+
 private:
     friend class TestableScheduler;
 
@@ -142,7 +147,7 @@
 
     // Used by tests to inject mocks.
     Scheduler(std::unique_ptr<DispSync>, std::unique_ptr<EventControlThread>,
-              const scheduler::RefreshRateConfigs&);
+              const scheduler::RefreshRateConfigs&, ISchedulerCallback& schedulerCallback);
 
     std::unique_ptr<VSyncSource> makePrimaryDispSyncSource(const char* name, nsecs_t phaseOffsetNs,
                                                            nsecs_t offsetThresholdForNextVsync);
@@ -165,8 +170,6 @@
     void setVsyncPeriod(nsecs_t period);
 
     HwcConfigIndexType calculateRefreshRateType() REQUIRES(mFeatureStateLock);
-    // Acquires a lock and calls the ChangeRefreshRateCallback with given parameters.
-    void changeRefreshRate(const RefreshRate&, ConfigEvent);
 
     // Stores EventThread associated with a given VSyncSource, and an initial EventThreadConnection.
     struct Connection {
@@ -203,8 +206,7 @@
     // Timer used to monitor display power mode.
     std::optional<scheduler::OneShotTimer> mDisplayPowerTimer;
 
-    std::mutex mCallbackLock;
-    ISchedulerCallback* mSchedulerCallback GUARDED_BY(mCallbackLock) = nullptr;
+    ISchedulerCallback& mSchedulerCallback;
 
     // In order to make sure that the features don't override themselves, we need a state machine
     // to keep track which feature requested the config change.
@@ -223,6 +225,11 @@
     } mFeatures GUARDED_BY(mFeatureStateLock);
 
     const scheduler::RefreshRateConfigs& mRefreshRateConfigs;
+
+    std::mutex mVsyncTimelineLock;
+    std::optional<HWC2::VsyncPeriodChangeTimeline> mLastVsyncPeriodChangeTimeline
+            GUARDED_BY(mVsyncTimelineLock);
+    static constexpr std::chrono::nanoseconds MAX_VSYNC_APPLIED_TIME = 200ms;
 };
 
 } // namespace android
diff --git a/services/surfaceflinger/Scheduler/Timer.cpp b/services/surfaceflinger/Scheduler/Timer.cpp
index 2394ed2..fb4f315 100644
--- a/services/surfaceflinger/Scheduler/Timer.cpp
+++ b/services/surfaceflinger/Scheduler/Timer.cpp
@@ -85,7 +85,7 @@
     };
 
     if (timerfd_settime(mTimerFd, 0, &new_timer, &old_timer)) {
-        ALOGW("Failed to set timerfd");
+        ALOGW("Failed to set timerfd %s (%i)", strerror(errno), errno);
     }
 }
 
diff --git a/services/surfaceflinger/Scheduler/VSyncPredictor.cpp b/services/surfaceflinger/Scheduler/VSyncPredictor.cpp
index 3894992..3b99a58 100644
--- a/services/surfaceflinger/Scheduler/VSyncPredictor.cpp
+++ b/services/surfaceflinger/Scheduler/VSyncPredictor.cpp
@@ -23,6 +23,7 @@
 #include <utils/Trace.h>
 #include <algorithm>
 #include <chrono>
+#include <sstream>
 #include "SchedulerUtils.h"
 
 namespace android::scheduler {
@@ -153,12 +154,24 @@
     }
 
     auto const oldest = *std::min_element(timestamps.begin(), timestamps.end());
-    auto const ordinalRequest = (timePoint - oldest + slope) / slope;
+
+    // See b/145667109, the ordinal calculation must take into account the intercept.
+    auto const zeroPoint = oldest + intercept;
+    auto const ordinalRequest = (timePoint - zeroPoint + slope) / slope;
     auto const prediction = (ordinalRequest * slope) + intercept + oldest;
 
-    ALOGV("prediction made from: %" PRId64 " prediction: %" PRId64 " (+%" PRId64 ") slope: %" PRId64
-          " intercept: %" PRId64,
-          timePoint, prediction, prediction - timePoint, slope, intercept);
+    auto const printer = [&, slope = slope, intercept = intercept] {
+        std::stringstream str;
+        str << "prediction made from: " << timePoint << "prediction: " << prediction << " (+"
+            << prediction - timePoint << ") slope: " << slope << " intercept: " << intercept
+            << "oldestTS: " << oldest << " ordinal: " << ordinalRequest;
+        return str.str();
+    };
+
+    ALOGV("%s", printer().c_str());
+    LOG_ALWAYS_FATAL_IF(prediction < timePoint, "VSyncPredictor: model miscalculation: %s",
+                        printer().c_str());
+
     return prediction;
 }
 
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 9f4dd2b..8e94529 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -1004,11 +1004,25 @@
     LOG_ALWAYS_FATAL_IF(!displayId);
 
     ATRACE_INT("ActiveConfigFPS_HWC", refreshRate.fps);
-    getHwComposer().setActiveConfig(*displayId, mUpcomingActiveConfig.configId.value());
 
-    // we need to submit an empty frame to HWC to start the process
+    // TODO(b/142753666) use constrains
+    HWC2::VsyncPeriodChangeConstraints constraints;
+    constraints.desiredTimeNanos = systemTime();
+    constraints.seamlessRequired = false;
+
+    HWC2::VsyncPeriodChangeTimeline outTimeline;
+    auto status =
+            getHwComposer().setActiveConfigWithConstraints(*displayId,
+                                                           mUpcomingActiveConfig.configId.value(),
+                                                           constraints, &outTimeline);
+    if (status != NO_ERROR) {
+        LOG_ALWAYS_FATAL("setActiveConfigWithConstraints failed: %d", status);
+        return false;
+    }
+
+    mScheduler->onNewVsyncPeriodChangeTimeline(outTimeline);
+    // Scheduler will submit an empty frame to HWC if needed.
     mCheckPendingFence = true;
-    mEventQueue->invalidate();
     return false;
 }
 
@@ -1361,8 +1375,7 @@
         return 0;
     }
 
-    const auto config = getHwComposer().getActiveConfig(*displayId);
-    return config ? config->getVsyncPeriod() : 0;
+    return getHwComposer().getDisplayVsyncPeriod(*displayId);
 }
 
 void SurfaceFlinger::onVsyncReceived(int32_t sequenceId, hwc2_display_t hwcDisplayId,
@@ -1448,9 +1461,13 @@
 }
 
 void SurfaceFlinger::onVsyncPeriodTimingChangedReceived(
-        int32_t /*sequenceId*/, hwc2_display_t /*display*/,
-        const hwc_vsync_period_change_timeline_t& /*updatedTimeline*/) {
-    // TODO(b/142753004): use timeline when changing refresh rate
+        int32_t sequenceId, hwc2_display_t /*display*/,
+        const hwc_vsync_period_change_timeline_t& updatedTimeline) {
+    Mutex::Autolock lock(mStateLock);
+    if (sequenceId != getBE().mComposerSequenceId) {
+        return;
+    }
+    mScheduler->onNewVsyncPeriodChangeTimeline(updatedTimeline);
 }
 
 void SurfaceFlinger::onRefreshReceived(int sequenceId, hwc2_display_t /*hwcDisplayId*/) {
@@ -1761,11 +1778,17 @@
 
     mGeometryInvalid = false;
 
+    // Store the present time just before calling to the composition engine so we could notify
+    // the scheduler.
+    const auto presentTime = systemTime();
+
     mCompositionEngine->present(refreshArgs);
     mTimeStats->recordFrameDuration(mFrameStartTime, systemTime());
     // Reset the frame start time now that we've recorded this frame.
     mFrameStartTime = 0;
 
+    mScheduler->onDisplayRefreshed(presentTime);
+
     postFrame();
     postComposition();
 
@@ -2551,7 +2574,7 @@
     // start the EventThread
     mScheduler =
             getFactory().createScheduler([this](bool enabled) { setPrimaryVsyncEnabled(enabled); },
-                                         *mRefreshRateConfigs);
+                                         *mRefreshRateConfigs, *this);
     mAppConnectionHandle =
             mScheduler->createConnection("app", mPhaseOffsets->getCurrentAppOffset(),
                                          mPhaseOffsets->getOffsetThresholdForNextVsync(),
@@ -2570,8 +2593,6 @@
     mRegionSamplingThread =
             new RegionSamplingThread(*this, *mScheduler,
                                      RegionSamplingThread::EnvironmentTimingTunables());
-
-    mScheduler->setSchedulerCallback(this);
 }
 
 void SurfaceFlinger::commitTransaction()
@@ -4316,8 +4337,8 @@
                       "  refresh-rate              : %f fps\n"
                       "  x-dpi                     : %f\n"
                       "  y-dpi                     : %f\n",
-                      1e9 / activeConfig->getVsyncPeriod(), activeConfig->getDpiX(),
-                      activeConfig->getDpiY());
+                      1e9 / getHwComposer().getDisplayVsyncPeriod(*displayId),
+                      activeConfig->getDpiX(), activeConfig->getDpiY());
     }
 
     StringAppendF(&result, "  transaction time: %f us\n", inTransactionDuration / 1000.0);
@@ -5438,6 +5459,27 @@
 void SurfaceFlinger::setAllowedDisplayConfigsInternal(const sp<DisplayDevice>& display,
                                                       const std::vector<int32_t>& allowedConfigs) {
     if (!display->isPrimary()) {
+        // TODO(b/144711714): For non-primary displays we should be able to set an active config
+        // as well. For now, just call directly to setActiveConfigWithConstraints but ideally
+        // it should go thru setDesiredActiveConfig, similar to primary display.
+        ALOGV("setAllowedDisplayConfigsInternal for non-primary display");
+        const auto displayId = display->getId();
+        LOG_ALWAYS_FATAL_IF(!displayId);
+
+        HWC2::VsyncPeriodChangeConstraints constraints;
+        constraints.desiredTimeNanos = systemTime();
+        constraints.seamlessRequired = false;
+
+        HWC2::VsyncPeriodChangeTimeline timeline = {0, 0, 0};
+        getHwComposer().setActiveConfigWithConstraints(*displayId, allowedConfigs[0], constraints,
+                                                       &timeline);
+        if (timeline.refreshRequired) {
+            repaintEverythingForHWC();
+        }
+
+        auto configId = HwcConfigIndexType(allowedConfigs[0]);
+        display->setActiveConfig(configId);
+        mScheduler->onConfigChanged(mAppConnectionHandle, display->getId()->value, configId);
         return;
     }
 
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index ae3f2d7..53b8908 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -176,7 +176,7 @@
                        public ClientCache::ErasedRecipient,
                        private IBinder::DeathRecipient,
                        private HWC2::ComposerCallback,
-                       private Scheduler::ISchedulerCallback {
+                       private ISchedulerCallback {
 public:
     SurfaceFlingerBE& getBE() { return mBE; }
     const SurfaceFlingerBE& getBE() const { return mBE; }
@@ -273,9 +273,6 @@
     // force full composition on all displays
     void repaintEverything();
 
-    // force full composition on all displays without resetting the scheduler idle timer.
-    void repaintEverythingForHWC();
-
     surfaceflinger::Factory& getFactory() { return mFactory; }
 
     // The CompositionEngine encapsulates all composition related interfaces and actions.
@@ -519,9 +516,11 @@
             const hwc_vsync_period_change_timeline_t& updatedTimeline) override;
 
     /* ------------------------------------------------------------------------
-     * Scheduler::ISchedulerCallback
+     * ISchedulerCallback
      */
     void changeRefreshRate(const Scheduler::RefreshRate&, Scheduler::ConfigEvent) override;
+    // force full composition on all displays without resetting the scheduler idle timer.
+    void repaintEverythingForHWC() override;
     /* ------------------------------------------------------------------------
      * Message handling
      */
diff --git a/services/surfaceflinger/SurfaceFlingerDefaultFactory.cpp b/services/surfaceflinger/SurfaceFlingerDefaultFactory.cpp
index 4f439da..bd4cdba 100644
--- a/services/surfaceflinger/SurfaceFlingerDefaultFactory.cpp
+++ b/services/surfaceflinger/SurfaceFlingerDefaultFactory.cpp
@@ -64,8 +64,9 @@
 }
 
 std::unique_ptr<Scheduler> DefaultFactory::createScheduler(
-        SetVSyncEnabled setVSyncEnabled, const scheduler::RefreshRateConfigs& configs) {
-    return std::make_unique<Scheduler>(std::move(setVSyncEnabled), configs);
+        SetVSyncEnabled setVSyncEnabled, const scheduler::RefreshRateConfigs& configs,
+        ISchedulerCallback& schedulerCallback) {
+    return std::make_unique<Scheduler>(std::move(setVSyncEnabled), configs, schedulerCallback);
 }
 
 std::unique_ptr<SurfaceInterceptor> DefaultFactory::createSurfaceInterceptor(
diff --git a/services/surfaceflinger/SurfaceFlingerDefaultFactory.h b/services/surfaceflinger/SurfaceFlingerDefaultFactory.h
index 42bb177..1a24448 100644
--- a/services/surfaceflinger/SurfaceFlingerDefaultFactory.h
+++ b/services/surfaceflinger/SurfaceFlingerDefaultFactory.h
@@ -32,7 +32,8 @@
     std::unique_ptr<MessageQueue> createMessageQueue() override;
     std::unique_ptr<scheduler::PhaseOffsets> createPhaseOffsets() override;
     std::unique_ptr<Scheduler> createScheduler(SetVSyncEnabled,
-                                               const scheduler::RefreshRateConfigs&) override;
+                                               const scheduler::RefreshRateConfigs&,
+                                               ISchedulerCallback&) override;
     std::unique_ptr<SurfaceInterceptor> createSurfaceInterceptor(SurfaceFlinger*) override;
     sp<StartPropertySetThread> createStartPropertySetThread(bool timestampPropertyValue) override;
     sp<DisplayDevice> createDisplayDevice(DisplayDeviceCreationArgs&&) override;
diff --git a/services/surfaceflinger/SurfaceFlingerFactory.h b/services/surfaceflinger/SurfaceFlingerFactory.h
index 20784d2..0db941d 100644
--- a/services/surfaceflinger/SurfaceFlingerFactory.h
+++ b/services/surfaceflinger/SurfaceFlingerFactory.h
@@ -40,6 +40,7 @@
 class HWComposer;
 class IGraphicBufferConsumer;
 class IGraphicBufferProducer;
+class ISchedulerCallback;
 class Layer;
 class MessageQueue;
 class Scheduler;
@@ -75,7 +76,8 @@
     virtual std::unique_ptr<MessageQueue> createMessageQueue() = 0;
     virtual std::unique_ptr<scheduler::PhaseOffsets> createPhaseOffsets() = 0;
     virtual std::unique_ptr<Scheduler> createScheduler(SetVSyncEnabled,
-                                                       const scheduler::RefreshRateConfigs&) = 0;
+                                                       const scheduler::RefreshRateConfigs&,
+                                                       ISchedulerCallback&) = 0;
     virtual std::unique_ptr<SurfaceInterceptor> createSurfaceInterceptor(SurfaceFlinger*) = 0;
 
     virtual sp<StartPropertySetThread> createStartPropertySetThread(
diff --git a/services/surfaceflinger/tests/unittests/TestableScheduler.h b/services/surfaceflinger/tests/unittests/TestableScheduler.h
index 40c00c4..fa095aa 100644
--- a/services/surfaceflinger/tests/unittests/TestableScheduler.h
+++ b/services/surfaceflinger/tests/unittests/TestableScheduler.h
@@ -26,17 +26,17 @@
 
 namespace android {
 
-class TestableScheduler : public Scheduler {
+class TestableScheduler : public Scheduler, private ISchedulerCallback {
 public:
     explicit TestableScheduler(const scheduler::RefreshRateConfigs& configs)
-          : Scheduler([](bool) {}, configs) {
+          : Scheduler([](bool) {}, configs, *this) {
         mLayerHistory.emplace();
     }
 
     TestableScheduler(std::unique_ptr<DispSync> primaryDispSync,
                       std::unique_ptr<EventControlThread> eventControlThread,
                       const scheduler::RefreshRateConfigs& configs)
-          : Scheduler(std::move(primaryDispSync), std::move(eventControlThread), configs) {
+          : Scheduler(std::move(primaryDispSync), std::move(eventControlThread), configs, *this) {
         mLayerHistory.emplace();
     }
 
@@ -68,6 +68,10 @@
         mutablePrimaryDispSync().reset();
         mConnections.clear();
     }
+
+private:
+    void changeRefreshRate(const RefreshRate&, ConfigEvent) override {}
+    void repaintEverythingForHWC() override {}
 };
 
 } // namespace android
diff --git a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
index b2210ec..facf142 100644
--- a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
+++ b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
@@ -84,7 +84,8 @@
     }
 
     std::unique_ptr<Scheduler> createScheduler(std::function<void(bool)>,
-                                               const scheduler::RefreshRateConfigs&) override {
+                                               const scheduler::RefreshRateConfigs&,
+                                               ISchedulerCallback&) override {
         return nullptr;
     }
 
diff --git a/services/surfaceflinger/tests/unittests/VSyncPredictorTest.cpp b/services/surfaceflinger/tests/unittests/VSyncPredictorTest.cpp
index d0c8090..4cb6a38 100644
--- a/services/surfaceflinger/tests/unittests/VSyncPredictorTest.cpp
+++ b/services/surfaceflinger/tests/unittests/VSyncPredictorTest.cpp
@@ -319,4 +319,36 @@
     }
 }
 
+// See b/145667109, and comment in prod code under test.
+TEST_F(VSyncPredictorTest, doesNotPredictBeforeTimePointWithHigherIntercept) {
+    std::vector<nsecs_t> const simulatedVsyncs{
+            158929578733000,
+            158929306806205, // oldest TS in ringbuffer
+            158929650879052,
+            158929661969209,
+            158929684198847,
+            158929695268171,
+            158929706370359,
+    };
+    auto const idealPeriod = 11111111;
+    auto const expectedPeriod = 11113500;
+    auto const expectedIntercept = -395335;
+
+    tracker.setPeriod(idealPeriod);
+    for (auto const& timestamp : simulatedVsyncs) {
+        tracker.addVsyncTimestamp(timestamp);
+    }
+
+    auto [slope, intercept] = tracker.getVSyncPredictionModel();
+    EXPECT_THAT(slope, IsCloseTo(expectedPeriod, mMaxRoundingError));
+    EXPECT_THAT(intercept, IsCloseTo(expectedIntercept, mMaxRoundingError));
+
+    // (timePoint - oldestTS) % expectedPeriod works out to be: 395334
+    // (timePoint - oldestTS) / expectedPeriod works out to be: 38.96
+    // so failure to account for the offset will floor the ordinal to 38, which was in the past.
+    auto const timePoint = 158929728723871;
+    auto const prediction = tracker.nextAnticipatedVSyncTimeFrom(timePoint);
+    EXPECT_THAT(prediction, Ge(timePoint));
+}
+
 } // namespace android::scheduler