diff --git a/cmds/installd/dexopt.cpp b/cmds/installd/dexopt.cpp
index a639951..852aa79 100644
--- a/cmds/installd/dexopt.cpp
+++ b/cmds/installd/dexopt.cpp
@@ -1958,6 +1958,11 @@
         /* child -- drop privileges before continuing */
         drop_capabilities(uid);
 
+        // Clear BOOTCLASSPATH.
+        // Let dex2oat use the BCP from boot image, excluding updatable BCP
+        // modules for AOT to avoid app recompilation after their upgrades.
+        unsetenv("BOOTCLASSPATH");
+
         SetDex2OatScheduling(boot_complete);
         if (flock(out_oat_fd.get(), LOCK_EX | LOCK_NB) != 0) {
             PLOG(ERROR) << "flock(" << out_oat_path << ") failed";
diff --git a/libs/binder/ndk/Android.bp b/libs/binder/ndk/Android.bp
index 68011bb..a96c9a0 100644
--- a/libs/binder/ndk/Android.bp
+++ b/libs/binder/ndk/Android.bp
@@ -16,7 +16,7 @@
 
 cc_library {
     name: "libbinder_ndk",
-    vendor_available: false,
+    vendor_available: true,
 
     export_include_dirs: [
         "include_ndk",
@@ -50,6 +50,13 @@
         "libandroid_runtime",
     ],
 
+    header_libs: [
+        "jni_headers",
+    ],
+    export_header_lib_headers: [
+        "jni_headers",
+    ],
+
     version_script: "libbinder_ndk.map.txt",
     stubs: {
         symbol_file: "libbinder_ndk.map.txt",
diff --git a/libs/graphicsenv/GraphicsEnv.cpp b/libs/graphicsenv/GraphicsEnv.cpp
index 9a28ec7..75fe2d3 100644
--- a/libs/graphicsenv/GraphicsEnv.cpp
+++ b/libs/graphicsenv/GraphicsEnv.cpp
@@ -316,28 +316,28 @@
         return false;
     }
 
-    return mUseAngle;
+    return (mUseAngle == YES) ? true : false;
 }
 
 void GraphicsEnv::updateUseAngle() {
-    mUseAngle = false;
+    mUseAngle = NO;
 
     const char* ANGLE_PREFER_ANGLE = "angle";
     const char* ANGLE_PREFER_NATIVE = "native";
 
     if (mAngleDeveloperOptIn == ANGLE_PREFER_ANGLE) {
         ALOGV("User set \"Developer Options\" to force the use of ANGLE");
-        mUseAngle = true;
+        mUseAngle = YES;
     } else if (mAngleDeveloperOptIn == ANGLE_PREFER_NATIVE) {
         ALOGV("User set \"Developer Options\" to force the use of Native");
-        mUseAngle = false;
+        mUseAngle = NO;
     } else {
         // The "Developer Options" value wasn't set to force the use of ANGLE.  Need to temporarily
         // load ANGLE and call the updatable opt-in/out logic:
         void* featureSo = loadLibrary("feature_support");
         if (featureSo) {
             ALOGV("loaded ANGLE's opt-in/out logic from namespace");
-            mUseAngle = checkAngleRules(featureSo);
+            mUseAngle = checkAngleRules(featureSo) ? YES : NO;
             dlclose(featureSo);
             featureSo = nullptr;
         } else {
@@ -349,6 +349,13 @@
 void GraphicsEnv::setAngleInfo(const std::string path, const std::string appName,
                                const std::string developerOptIn, const int rulesFd,
                                const long rulesOffset, const long rulesLength) {
+    if (mUseAngle != UNKNOWN) {
+        // We've already figured out an answer for this app, so just return.
+        ALOGV("Already evaluated the rules file for '%s': use ANGLE = %s", appName.c_str(),
+              (mUseAngle == YES) ? "true" : "false");
+        return;
+    }
+
     ALOGV("setting ANGLE path to '%s'", path.c_str());
     mAnglePath = path;
     ALOGV("setting ANGLE app name to '%s'", appName.c_str());
diff --git a/libs/graphicsenv/include/graphicsenv/GraphicsEnv.h b/libs/graphicsenv/include/graphicsenv/GraphicsEnv.h
index f48d887..c4482b7 100644
--- a/libs/graphicsenv/include/graphicsenv/GraphicsEnv.h
+++ b/libs/graphicsenv/include/graphicsenv/GraphicsEnv.h
@@ -74,6 +74,8 @@
     const std::string& getDebugLayersGLES();
 
 private:
+    enum UseAngle { UNKNOWN, YES, NO };
+
     void* loadLibrary(std::string name);
     bool checkAngleRules(void* so);
     void updateUseAngle();
@@ -85,7 +87,7 @@
     std::string mAngleAppName;
     std::string mAngleDeveloperOptIn;
     std::vector<char> mRulesBuffer;
-    bool mUseAngle;
+    UseAngle mUseAngle = UNKNOWN;
     std::string mDebugLayers;
     std::string mDebugLayersGLES;
     std::string mLayerPaths;
diff --git a/libs/gui/Android.bp b/libs/gui/Android.bp
index f40eb6c..0510492 100644
--- a/libs/gui/Android.bp
+++ b/libs/gui/Android.bp
@@ -104,6 +104,7 @@
         "IGraphicBufferConsumer.cpp",
         "IGraphicBufferProducer.cpp",
         "IProducerListener.cpp",
+        "IRegionSamplingListener.cpp",
         "ISurfaceComposer.cpp",
         "ISurfaceComposerClient.cpp",
         "ITransactionCompletedListener.cpp",
diff --git a/libs/gui/IRegionSamplingListener.cpp b/libs/gui/IRegionSamplingListener.cpp
new file mode 100644
index 0000000..40cbfce
--- /dev/null
+++ b/libs/gui/IRegionSamplingListener.cpp
@@ -0,0 +1,64 @@
+/*
+ * 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.
+ */
+
+#define LOG_TAG "IRegionSamplingListener"
+//#define LOG_NDEBUG 0
+
+#include <gui/IRegionSamplingListener.h>
+
+namespace android {
+
+namespace { // Anonymous
+
+enum class Tag : uint32_t {
+    ON_SAMPLE_COLLECTED = IBinder::FIRST_CALL_TRANSACTION,
+    LAST = ON_SAMPLE_COLLECTED,
+};
+
+} // Anonymous namespace
+
+class BpRegionSamplingListener : public SafeBpInterface<IRegionSamplingListener> {
+public:
+    explicit BpRegionSamplingListener(const sp<IBinder>& impl)
+          : SafeBpInterface<IRegionSamplingListener>(impl, "BpRegionSamplingListener") {}
+
+    ~BpRegionSamplingListener() override;
+
+    void onSampleCollected(float medianLuma) override {
+        callRemoteAsync<decltype(
+                &IRegionSamplingListener::onSampleCollected)>(Tag::ON_SAMPLE_COLLECTED, medianLuma);
+    }
+};
+
+// Out-of-line virtual method definitions to trigger vtable emission in this translation unit (see
+// clang warning -Wweak-vtables)
+BpRegionSamplingListener::~BpRegionSamplingListener() = default;
+
+IMPLEMENT_META_INTERFACE(RegionSamplingListener, "android.gui.IRegionSamplingListener");
+
+status_t BnRegionSamplingListener::onTransact(uint32_t code, const Parcel& data, Parcel* reply,
+                                              uint32_t flags) {
+    if (code < IBinder::FIRST_CALL_TRANSACTION || code > static_cast<uint32_t>(Tag::LAST)) {
+        return BBinder::onTransact(code, data, reply, flags);
+    }
+    auto tag = static_cast<Tag>(code);
+    switch (tag) {
+        case Tag::ON_SAMPLE_COLLECTED:
+            return callLocalAsync(data, reply, &IRegionSamplingListener::onSampleCollected);
+    }
+}
+
+} // namespace android
diff --git a/libs/gui/ISurfaceComposer.cpp b/libs/gui/ISurfaceComposer.cpp
index fc9185d..f77eeb2 100644
--- a/libs/gui/ISurfaceComposer.cpp
+++ b/libs/gui/ISurfaceComposer.cpp
@@ -26,6 +26,7 @@
 
 #include <gui/IDisplayEventConnection.h>
 #include <gui/IGraphicBufferProducer.h>
+#include <gui/IRegionSamplingListener.h>
 #include <gui/ISurfaceComposer.h>
 #include <gui/ISurfaceComposerClient.h>
 #include <gui/LayerDebugInfo.h>
@@ -754,6 +755,57 @@
         error = reply.readBool(outIsWideColorDisplay);
         return error;
     }
+
+    virtual status_t addRegionSamplingListener(const Rect& samplingArea,
+                                               const sp<IBinder>& stopLayerHandle,
+                                               const sp<IRegionSamplingListener>& listener) {
+        Parcel data, reply;
+        status_t error = data.writeInterfaceToken(ISurfaceComposer::getInterfaceDescriptor());
+        if (error != NO_ERROR) {
+            ALOGE("addRegionSamplingListener: Failed to write interface token");
+            return error;
+        }
+        error = data.write(samplingArea);
+        if (error != NO_ERROR) {
+            ALOGE("addRegionSamplingListener: Failed to write sampling area");
+            return error;
+        }
+        error = data.writeStrongBinder(stopLayerHandle);
+        if (error != NO_ERROR) {
+            ALOGE("addRegionSamplingListener: Failed to write stop layer handle");
+            return error;
+        }
+        error = data.writeStrongBinder(IInterface::asBinder(listener));
+        if (error != NO_ERROR) {
+            ALOGE("addRegionSamplingListener: Failed to write listener");
+            return error;
+        }
+        error = remote()->transact(BnSurfaceComposer::ADD_REGION_SAMPLING_LISTENER, data, &reply);
+        if (error != NO_ERROR) {
+            ALOGE("addRegionSamplingListener: Failed to transact");
+        }
+        return error;
+    }
+
+    virtual status_t removeRegionSamplingListener(const sp<IRegionSamplingListener>& listener) {
+        Parcel data, reply;
+        status_t error = data.writeInterfaceToken(ISurfaceComposer::getInterfaceDescriptor());
+        if (error != NO_ERROR) {
+            ALOGE("addRegionSamplingListener: Failed to write interface token");
+            return error;
+        }
+        error = data.writeStrongBinder(IInterface::asBinder(listener));
+        if (error != NO_ERROR) {
+            ALOGE("addRegionSamplingListener: Failed to write listener");
+            return error;
+        }
+        error = remote()->transact(BnSurfaceComposer::REMOVE_REGION_SAMPLING_LISTENER, data,
+                                   &reply);
+        if (error != NO_ERROR) {
+            ALOGE("addRegionSamplingListener: Failed to transact");
+        }
+        return error;
+    }
 };
 
 // Out-of-line virtual method definition to trigger vtable emission in this
@@ -1233,6 +1285,38 @@
             CHECK_INTERFACE(ISurfaceComposer, data, reply);
             return reply->writeUint64Vector(getPhysicalDisplayIds());
         }
+        case ADD_REGION_SAMPLING_LISTENER: {
+            CHECK_INTERFACE(ISurfaceComposer, data, reply);
+            Rect samplingArea;
+            status_t result = data.read(samplingArea);
+            if (result != NO_ERROR) {
+                ALOGE("addRegionSamplingListener: Failed to read sampling area");
+                return result;
+            }
+            sp<IBinder> stopLayerHandle;
+            result = data.readNullableStrongBinder(&stopLayerHandle);
+            if (result != NO_ERROR) {
+                ALOGE("addRegionSamplingListener: Failed to read stop layer handle");
+                return result;
+            }
+            sp<IRegionSamplingListener> listener;
+            result = data.readNullableStrongBinder(&listener);
+            if (result != NO_ERROR) {
+                ALOGE("addRegionSamplingListener: Failed to read listener");
+                return result;
+            }
+            return addRegionSamplingListener(samplingArea, stopLayerHandle, listener);
+        }
+        case REMOVE_REGION_SAMPLING_LISTENER: {
+            CHECK_INTERFACE(ISurfaceComposer, data, reply);
+            sp<IRegionSamplingListener> listener;
+            status_t result = data.readNullableStrongBinder(&listener);
+            if (result != NO_ERROR) {
+                ALOGE("removeRegionSamplingListener: Failed to read listener");
+                return result;
+            }
+            return removeRegionSamplingListener(listener);
+        }
         default: {
             return BBinder::onTransact(code, data, reply, flags);
         }
diff --git a/libs/gui/include/gui/IRegionSamplingListener.h b/libs/gui/include/gui/IRegionSamplingListener.h
new file mode 100644
index 0000000..1803d9a
--- /dev/null
+++ b/libs/gui/include/gui/IRegionSamplingListener.h
@@ -0,0 +1,43 @@
+/*
+ * 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 <cstdint>
+#include <vector>
+
+#include <binder/IInterface.h>
+#include <binder/SafeInterface.h>
+
+namespace android {
+
+class IRegionSamplingListener : public IInterface {
+public:
+    DECLARE_META_INTERFACE(RegionSamplingListener)
+
+    virtual void onSampleCollected(float medianLuma) = 0;
+};
+
+class BnRegionSamplingListener : public SafeBnInterface<IRegionSamplingListener> {
+public:
+    BnRegionSamplingListener()
+          : SafeBnInterface<IRegionSamplingListener>("BnRegionSamplingListener") {}
+
+    status_t onTransact(uint32_t code, const Parcel& data, Parcel* reply,
+                        uint32_t flags = 0) override;
+};
+
+} // namespace android
diff --git a/libs/gui/include/gui/ISurfaceComposer.h b/libs/gui/include/gui/ISurfaceComposer.h
index a2db7bc..1a0b6bb 100644
--- a/libs/gui/include/gui/ISurfaceComposer.h
+++ b/libs/gui/include/gui/ISurfaceComposer.h
@@ -50,6 +50,7 @@
 class IDisplayEventConnection;
 class IGraphicBufferProducer;
 class ISurfaceComposerClient;
+class IRegionSamplingListener;
 class Rect;
 enum class FrameEvent;
 
@@ -338,6 +339,26 @@
      */
     virtual status_t isWideColorDisplay(const sp<IBinder>& token,
                                         bool* outIsWideColorDisplay) const = 0;
+
+    /* Registers a listener to stream median luma updates from SurfaceFlinger.
+     *
+     * The sampling area is bounded by both samplingArea and the given stopLayerHandle
+     * (i.e., only layers behind the stop layer will be captured and sampled).
+     *
+     * Multiple listeners may be provided so long as they have independent listeners.
+     * If multiple listeners are provided, the effective sampling region for each listener will
+     * be bounded by whichever stop layer has a lower Z value.
+     *
+     * Requires the same permissions as captureLayers and captureScreen.
+     */
+    virtual status_t addRegionSamplingListener(const Rect& samplingArea,
+                                               const sp<IBinder>& stopLayerHandle,
+                                               const sp<IRegionSamplingListener>& listener) = 0;
+
+    /*
+     * Removes a listener that was streaming median luma updates from SurfaceFlinger.
+     */
+    virtual status_t removeRegionSamplingListener(const sp<IRegionSamplingListener>& listener) = 0;
 };
 
 // ----------------------------------------------------------------------------
@@ -383,6 +404,8 @@
         IS_WIDE_COLOR_DISPLAY,
         GET_DISPLAY_NATIVE_PRIMARIES,
         GET_PHYSICAL_DISPLAY_IDS,
+        ADD_REGION_SAMPLING_LISTENER,
+        REMOVE_REGION_SAMPLING_LISTENER,
         // Always append new enum to the end.
     };
 
diff --git a/libs/gui/tests/Surface_test.cpp b/libs/gui/tests/Surface_test.cpp
index bec9299..f127853 100644
--- a/libs/gui/tests/Surface_test.cpp
+++ b/libs/gui/tests/Surface_test.cpp
@@ -669,6 +669,16 @@
 
     status_t isWideColorDisplay(const sp<IBinder>&, bool*) const override { return NO_ERROR; }
 
+    status_t addRegionSamplingListener(const Rect& /*samplingArea*/,
+                                       const sp<IBinder>& /*stopLayerHandle*/,
+                                       const sp<IRegionSamplingListener>& /*listener*/) override {
+        return NO_ERROR;
+    }
+    status_t removeRegionSamplingListener(
+            const sp<IRegionSamplingListener>& /*listener*/) override {
+        return NO_ERROR;
+    }
+
 protected:
     IBinder* onAsBinder() override { return nullptr; }
 
diff --git a/libs/ui/BufferHubBuffer.cpp b/libs/ui/BufferHubBuffer.cpp
index cce35fd..405bcb6 100644
--- a/libs/ui/BufferHubBuffer.cpp
+++ b/libs/ui/BufferHubBuffer.cpp
@@ -47,8 +47,8 @@
     return buffer->isValid() ? std::move(buffer) : nullptr;
 }
 
-std::unique_ptr<BufferHubBuffer> BufferHubBuffer::import(const native_handle_t* token) {
-    if (token == nullptr) {
+std::unique_ptr<BufferHubBuffer> BufferHubBuffer::import(const sp<NativeHandle>& token) {
+    if (token == nullptr || token.get() == nullptr) {
         ALOGE("%s: token cannot be nullptr!", __FUNCTION__);
         return nullptr;
     }
@@ -105,7 +105,7 @@
     mBufferClient = std::move(client);
 }
 
-BufferHubBuffer::BufferHubBuffer(const native_handle_t* token) {
+BufferHubBuffer::BufferHubBuffer(const sp<NativeHandle>& token) {
     sp<IBufferHub> bufferhub = IBufferHub::getService();
     if (bufferhub.get() == nullptr) {
         ALOGE("%s: BufferHub service not found!", __FUNCTION__);
@@ -124,7 +124,7 @@
 
     // hidl_handle(native_handle_t*) simply creates a raw pointer reference withouth ownership
     // transfer.
-    if (!bufferhub->importBuffer(hidl_handle(token), import_cb).isOk()) {
+    if (!bufferhub->importBuffer(hidl_handle(token.get()->handle()), import_cb).isOk()) {
         ALOGE("%s: importBuffer transaction failed!", __FUNCTION__);
         return;
     } else if (ret != BufferHubStatus::NO_ERROR) {
@@ -328,7 +328,7 @@
             mEventFd.get() >= 0 && mMetadata.isValid() && mBufferClient != nullptr;
 }
 
-native_handle_t* BufferHubBuffer::duplicate() {
+sp<NativeHandle> BufferHubBuffer::duplicate() {
     if (mBufferClient == nullptr) {
         ALOGE("%s: missing BufferClient!", __FUNCTION__);
         return nullptr;
@@ -352,7 +352,7 @@
         return nullptr;
     }
 
-    return native_handle_clone(token.getNativeHandle());
+    return NativeHandle::create(native_handle_clone(token.getNativeHandle()), /*ownsHandle=*/true);
 }
 
 } // namespace android
diff --git a/libs/ui/include/ui/BufferHubBuffer.h b/libs/ui/include/ui/BufferHubBuffer.h
index eac8c84..5c09032 100644
--- a/libs/ui/include/ui/BufferHubBuffer.h
+++ b/libs/ui/include/ui/BufferHubBuffer.h
@@ -23,6 +23,7 @@
 #include <ui/BufferHubDefs.h>
 #include <ui/BufferHubEventFd.h>
 #include <ui/BufferHubMetadata.h>
+#include <utils/NativeHandle.h>
 
 namespace android {
 
@@ -33,10 +34,8 @@
                                                    uint32_t layerCount, uint32_t format,
                                                    uint64_t usage, size_t userMetadataSize);
 
-    // Imports the given token to a BufferHubBuffer. Not taking ownership of the token. Caller
-    // should close and destroy the token after calling this function regardless of output.
-    // TODO(b/122543147): use a movable wrapper for token
-    static std::unique_ptr<BufferHubBuffer> import(const native_handle_t* token);
+    // Imports the given token to a BufferHubBuffer. Not taking ownership of the token.
+    static std::unique_ptr<BufferHubBuffer> import(const sp<NativeHandle>& token);
 
     BufferHubBuffer(const BufferHubBuffer&) = delete;
     void operator=(const BufferHubBuffer&) = delete;
@@ -100,17 +99,15 @@
 
     // Creates a token that stands for this BufferHubBuffer client and could be used for Import to
     // create another BufferHubBuffer. The new BufferHubBuffer will share the same underlying
-    // gralloc buffer and ashmem region for metadata. Note that the caller owns the token and
-    // should free it after use.
+    // gralloc buffer and ashmem region for metadata. Not taking ownership of the token.
     // Returns a valid token on success, nullptr on failure.
-    // TODO(b/122543147): use a movable wrapper for token
-    native_handle_t* duplicate();
+    sp<NativeHandle> duplicate();
 
 private:
     BufferHubBuffer(uint32_t width, uint32_t height, uint32_t layerCount, uint32_t format,
                     uint64_t usage, size_t userMetadataSize);
 
-    BufferHubBuffer(const native_handle_t* token);
+    BufferHubBuffer(const sp<NativeHandle>& token);
 
     int initWithBufferTraits(const frameworks::bufferhub::V1_0::BufferTraits& bufferTraits);
 
diff --git a/libs/ui/tests/BufferHubBuffer_test.cpp b/libs/ui/tests/BufferHubBuffer_test.cpp
index 3087a90..634bce1 100644
--- a/libs/ui/tests/BufferHubBuffer_test.cpp
+++ b/libs/ui/tests/BufferHubBuffer_test.cpp
@@ -86,13 +86,10 @@
     b1ClientMask = b1->clientStateMask();
     ASSERT_NE(b1ClientMask, 0U);
 
-    native_handle_t* token = b1->duplicate();
+    sp<NativeHandle> token = b1->duplicate();
     ASSERT_THAT(token, NotNull());
 
-    // TODO(b/122543147): use a movalbe wrapper for token
     b2 = BufferHubBuffer::import(token);
-    native_handle_close(token);
-    native_handle_delete(token);
     ASSERT_THAT(b2, NotNull());
 
     b2ClientMask = b2->clientStateMask();
@@ -137,16 +134,14 @@
     ASSERT_THAT(b1, NotNull());
     EXPECT_TRUE(b1->isValid());
 
-    native_handle_t* token = b1->duplicate();
-    EXPECT_TRUE(token);
+    sp<NativeHandle> token = b1->duplicate();
+    ASSERT_THAT(token, NotNull());
 
     // The detached buffer should still be valid.
     EXPECT_TRUE(b1->isConnected());
     EXPECT_TRUE(b1->isValid());
 
     std::unique_ptr<BufferHubBuffer> b2 = BufferHubBuffer::import(token);
-    native_handle_close(token);
-    native_handle_delete(token);
 
     ASSERT_THAT(b2, NotNull());
     EXPECT_TRUE(b2->isValid());
@@ -197,16 +192,13 @@
     ASSERT_THAT(b1, NotNull());
     EXPECT_TRUE(b1->isValid());
 
-    native_handle_t* token = b1->duplicate();
-    EXPECT_TRUE(token);
+    sp<NativeHandle> token = b1->duplicate();
+    ASSERT_THAT(token, NotNull());
 
     // Explicitly destroy b1. Backend buffer should be freed and token becomes invalid
     b1.reset();
 
-    // TODO(b/122543147): use a movalbe wrapper for token
     std::unique_ptr<BufferHubBuffer> b2 = BufferHubBuffer::import(token);
-    native_handle_close(token);
-    native_handle_delete(token);
 
     // Import should fail with INVALID_TOKEN
     EXPECT_THAT(b2, IsNull());
@@ -222,7 +214,7 @@
     native_handle_t* token = native_handle_create(/*numFds=*/0, /*numInts=*/1);
     token->data[0] = 0;
 
-    auto b1 = BufferHubBuffer::import(token);
+    auto b1 = BufferHubBuffer::import(NativeHandle::create(token, /*ownHandle=*/true));
     native_handle_delete(token);
 
     EXPECT_THAT(b1, IsNull());
@@ -425,13 +417,10 @@
 
     // Create a consumer of the buffer and test if the consumer can acquire the
     // buffer if producer posts.
-    // TODO(b/122543147): use a movalbe wrapper for token
-    native_handle_t* token = b1->duplicate();
-    ASSERT_TRUE(token);
+    sp<NativeHandle> token = b1->duplicate();
+    ASSERT_THAT(token, NotNull());
 
     std::unique_ptr<BufferHubBuffer> b2 = BufferHubBuffer::import(token);
-    native_handle_close(token);
-    native_handle_delete(token);
 
     ASSERT_THAT(b2, NotNull());
     ASSERT_NE(b1->clientStateMask(), b2->clientStateMask());
@@ -450,13 +439,10 @@
 
     // Create a consumer of the buffer and test if the consumer can acquire the
     // buffer if producer posts.
-    // TODO(b/122543147): use a movalbe wrapper for token
-    native_handle_t* token = b1->duplicate();
-    ASSERT_TRUE(token);
+    sp<NativeHandle> token = b1->duplicate();
+    ASSERT_THAT(token, NotNull());
 
     std::unique_ptr<BufferHubBuffer> b2 = BufferHubBuffer::import(token);
-    native_handle_close(token);
-    native_handle_delete(token);
 
     ASSERT_THAT(b2, NotNull());
     ASSERT_NE(b1->clientStateMask(), b2->clientStateMask());
diff --git a/services/surfaceflinger/Scheduler/IdleTimer.cpp b/services/surfaceflinger/Scheduler/IdleTimer.cpp
index e975e65..b28b1aa 100644
--- a/services/surfaceflinger/Scheduler/IdleTimer.cpp
+++ b/services/surfaceflinger/Scheduler/IdleTimer.cpp
@@ -22,8 +22,9 @@
 namespace android {
 namespace scheduler {
 
-IdleTimer::IdleTimer(const Interval& interval, const TimeoutCallback& timeoutCallback)
-      : mInterval(interval), mTimeoutCallback(timeoutCallback) {}
+IdleTimer::IdleTimer(const Interval& interval, const ResetCallback& resetCallback,
+                     const TimeoutCallback& timeoutCallback)
+      : mInterval(interval), mResetCallback(resetCallback), mTimeoutCallback(timeoutCallback) {}
 
 IdleTimer::~IdleTimer() {
     stop();
@@ -49,11 +50,34 @@
 }
 
 void IdleTimer::loop() {
-    std::lock_guard<std::mutex> lock(mMutex);
-    while (mState != TimerState::STOPPED) {
-        if (mState == TimerState::IDLE) {
-            mCondition.wait(mMutex);
-        } else if (mState == TimerState::RESET) {
+    while (true) {
+        bool triggerReset = false;
+        bool triggerTimeout = false;
+        {
+            std::lock_guard<std::mutex> lock(mMutex);
+            if (mState == TimerState::STOPPED) {
+                break;
+            }
+
+            if (mState == TimerState::IDLE) {
+                mCondition.wait(mMutex);
+                continue;
+            }
+
+            if (mState == TimerState::RESET) {
+                triggerReset = true;
+            }
+        }
+        if (triggerReset && mResetCallback) {
+            mResetCallback();
+        }
+
+        { // lock the mutex again. someone might have called stop meanwhile
+            std::lock_guard<std::mutex> lock(mMutex);
+            if (mState == TimerState::STOPPED) {
+                break;
+            }
+
             auto triggerTime = std::chrono::steady_clock::now() + mInterval;
             mState = TimerState::WAITING;
             while (mState == TimerState::WAITING) {
@@ -62,14 +86,14 @@
                 if (waitTime > zero) mCondition.wait_for(mMutex, waitTime);
                 if (mState == TimerState::WAITING &&
                     (triggerTime - std::chrono::steady_clock::now()) <= zero) {
-                    if (mTimeoutCallback) {
-                        mTimeoutCallback();
-                    }
-
+                    triggerTimeout = true;
                     mState = TimerState::IDLE;
                 }
             }
         }
+        if (triggerTimeout && mTimeoutCallback) {
+            mTimeoutCallback();
+        }
     }
 } // namespace scheduler
 
diff --git a/services/surfaceflinger/Scheduler/IdleTimer.h b/services/surfaceflinger/Scheduler/IdleTimer.h
index aee3fa3..19f1267 100644
--- a/services/surfaceflinger/Scheduler/IdleTimer.h
+++ b/services/surfaceflinger/Scheduler/IdleTimer.h
@@ -32,9 +32,11 @@
 class IdleTimer {
 public:
     using Interval = std::chrono::milliseconds;
+    using ResetCallback = std::function<void()>;
     using TimeoutCallback = std::function<void()>;
 
-    IdleTimer(const Interval& interval, const TimeoutCallback& timeoutCallback);
+    IdleTimer(const Interval& interval, const ResetCallback& resetCallback,
+              const TimeoutCallback& timeoutCallback);
     ~IdleTimer();
 
     void start();
@@ -62,6 +64,9 @@
     // Interval after which timer expires.
     const Interval mInterval;
 
+    // Callback that happens when timer resets.
+    const ResetCallback mResetCallback;
+
     // Callback that happens when timer expires.
     const TimeoutCallback mTimeoutCallback;
 };
diff --git a/services/surfaceflinger/Scheduler/Scheduler.cpp b/services/surfaceflinger/Scheduler/Scheduler.cpp
index 5268c8c..af439f7 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -75,6 +75,7 @@
     if (mSetIdleTimerMs > 0) {
         mIdleTimer =
                 std::make_unique<scheduler::IdleTimer>(std::chrono::milliseconds(mSetIdleTimerMs),
+                                                       [this] { resetTimerCallback(); },
                                                        [this] { expiredTimerCallback(); });
         mIdleTimer->start();
     }
@@ -87,7 +88,6 @@
 
 sp<Scheduler::ConnectionHandle> Scheduler::createConnection(
         const char* connectionName, int64_t phaseOffsetNs, ResyncCallback resyncCallback,
-        ResetIdleTimerCallback resetIdleTimerCallback,
         impl::EventThread::InterceptVSyncsCallback interceptCallback) {
     const int64_t id = sNextId++;
     ALOGV("Creating a connection handle with ID: %" PRId64 "\n", id);
@@ -97,8 +97,7 @@
                             std::move(interceptCallback));
 
     auto eventThreadConnection =
-            createConnectionInternal(eventThread.get(), std::move(resyncCallback),
-                                     std::move(resetIdleTimerCallback));
+            createConnectionInternal(eventThread.get(), std::move(resyncCallback));
     mConnections.emplace(id,
                          std::make_unique<Connection>(new ConnectionHandle(id),
                                                       eventThreadConnection,
@@ -115,26 +114,17 @@
                                                std::move(interceptCallback), connectionName);
 }
 
-sp<EventThreadConnection> Scheduler::createConnectionInternal(
-        EventThread* eventThread, ResyncCallback&& resyncCallback,
-        ResetIdleTimerCallback&& resetIdleTimerCallback) {
+sp<EventThreadConnection> Scheduler::createConnectionInternal(EventThread* eventThread,
+                                                              ResyncCallback&& resyncCallback) {
     return eventThread->createEventConnection(std::move(resyncCallback),
-                                              [this,
-                                               resetIdleTimerCallback =
-                                                       std::move(resetIdleTimerCallback)] {
-                                                  resetIdleTimer();
-                                                  if (resetIdleTimerCallback) {
-                                                      resetIdleTimerCallback();
-                                                  }
-                                              });
+                                              [this] { resetIdleTimer(); });
 }
 
 sp<IDisplayEventConnection> Scheduler::createDisplayEventConnection(
-        const sp<Scheduler::ConnectionHandle>& handle, ResyncCallback resyncCallback,
-        ResetIdleTimerCallback resetIdleTimerCallback) {
+        const sp<Scheduler::ConnectionHandle>& handle, ResyncCallback resyncCallback) {
     RETURN_VALUE_IF_INVALID(nullptr);
     return createConnectionInternal(mConnections[handle->id]->thread.get(),
-                                    std::move(resyncCallback), std::move(resetIdleTimerCallback));
+                                    std::move(resyncCallback));
 }
 
 EventThread* Scheduler::getEventThread(const sp<Scheduler::ConnectionHandle>& handle) {
@@ -200,9 +190,15 @@
 }
 
 void Scheduler::setVsyncPeriod(const nsecs_t period) {
+    std::lock_guard<std::mutex> lock(mHWVsyncLock);
     mPrimaryDispSync->reset();
     mPrimaryDispSync->setPeriod(period);
-    enableHardwareVsync();
+
+    if (!mPrimaryHWVsyncEnabled) {
+        mPrimaryDispSync->beginResync();
+        mEventControlThread->setVsyncEnabled(true);
+        mPrimaryHWVsyncEnabled = true;
+    }
 }
 
 void Scheduler::addResyncSample(const nsecs_t timestamp) {
@@ -238,10 +234,19 @@
     mHWVsyncAvailable = makeAvailable;
 }
 
+bool Scheduler::getHWSyncAvailable() {
+    std::lock_guard<std::mutex> lock(mHWVsyncLock);
+    return mHWVsyncAvailable;
+}
+
 nsecs_t Scheduler::expectedPresentTime() {
     return mPrimaryDispSync->expectedPresentTime();
 }
 
+void Scheduler::dumpPrimaryDispSync(std::string& result) const {
+    mPrimaryDispSync->dump(result);
+}
+
 void Scheduler::addFramePresentTimeForLayer(const nsecs_t framePresentTime, bool isAutoTimestamp,
                                             const std::string layerName) {
     // This is V1 logic. It calculates the average FPS based on the timestamp frequency
@@ -263,6 +268,11 @@
     mExpiredTimerCallback = expiredTimerCallback;
 }
 
+void Scheduler::setResetIdleTimerCallback(const ResetIdleTimerCallback& resetTimerCallback) {
+    std::lock_guard<std::mutex> lock(mCallbackLock);
+    mResetTimerCallback = resetTimerCallback;
+}
+
 void Scheduler::updateFrameSkipping(const int64_t skipCount) {
     ATRACE_INT("FrameSkipCount", skipCount);
     if (mSkipCount != skipCount) {
@@ -351,6 +361,13 @@
 void Scheduler::resetIdleTimer() {
     if (mIdleTimer) {
         mIdleTimer->reset();
+    }
+}
+
+void Scheduler::resetTimerCallback() {
+    std::lock_guard<std::mutex> lock(mCallbackLock);
+    if (mResetTimerCallback) {
+        mResetTimerCallback();
         ATRACE_INT("ExpiredIdleTimer", 0);
     }
 }
diff --git a/services/surfaceflinger/Scheduler/Scheduler.h b/services/surfaceflinger/Scheduler/Scheduler.h
index 089d579..d628e40 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.h
+++ b/services/surfaceflinger/Scheduler/Scheduler.h
@@ -37,6 +37,7 @@
 class Scheduler {
 public:
     using ExpiredIdleTimerCallback = std::function<void()>;
+    using ResetIdleTimerCallback = std::function<void()>;
 
     // Enum to indicate whether to start the transaction early, or at vsync time.
     enum class TransactionStart { EARLY, NORMAL };
@@ -72,12 +73,11 @@
 
     /** Creates an EventThread connection. */
     sp<ConnectionHandle> createConnection(const char* connectionName, int64_t phaseOffsetNs,
-                                          ResyncCallback, ResetIdleTimerCallback,
+                                          ResyncCallback,
                                           impl::EventThread::InterceptVSyncsCallback);
 
     sp<IDisplayEventConnection> createDisplayEventConnection(const sp<ConnectionHandle>& handle,
-                                                             ResyncCallback,
-                                                             ResetIdleTimerCallback);
+                                                             ResyncCallback);
 
     // Getter methods.
     EventThread* getEventThread(const sp<ConnectionHandle>& handle);
@@ -109,6 +109,8 @@
     void addPresentFence(const std::shared_ptr<FenceTime>& fenceTime);
     void setIgnorePresentFences(bool ignore);
     void makeHWSyncAvailable(bool makeAvailable);
+    // returns HWSyncAvailable flag to SF would enable HW vsync based on this
+    bool getHWSyncAvailable();
     nsecs_t expectedPresentTime();
     // Adds the present time for given layer to the history of present times.
     void addFramePresentTimeForLayer(const nsecs_t framePresentTime, bool isAutoTimestamp,
@@ -117,9 +119,14 @@
     void incrementFrameCounter();
     // Callback that gets invoked once the idle timer expires.
     void setExpiredIdleTimerCallback(const ExpiredIdleTimerCallback& expiredTimerCallback);
+    // Callback that gets invoked once the idle timer is reset.
+    void setResetIdleTimerCallback(const ResetIdleTimerCallback& resetTimerCallback);
     // Returns relevant information about Scheduler for dumpsys purposes.
     std::string doDump();
 
+    // calls DispSync::dump() on primary disp sync
+    void dumpPrimaryDispSync(std::string& result) const;
+
 protected:
     virtual std::unique_ptr<EventThread> makeEventThread(
             const char* connectionName, DispSync* dispSync, int64_t phaseOffsetNs,
@@ -127,8 +134,7 @@
 
 private:
     // Creates a connection on the given EventThread and forwards the given callbacks.
-    sp<EventThreadConnection> createConnectionInternal(EventThread*, ResyncCallback&&,
-                                                       ResetIdleTimerCallback&&);
+    sp<EventThreadConnection> createConnectionInternal(EventThread*, ResyncCallback&&);
 
     nsecs_t calculateAverage() const;
     void updateFrameSkipping(const int64_t skipCount);
@@ -140,10 +146,11 @@
     void determineTimestampAverage(bool isAutoTimestamp, const nsecs_t framePresentTime);
     // Function that resets the idle timer.
     void resetIdleTimer();
+    // Function that is called when the timer resets.
+    void resetTimerCallback();
     // Function that is called when the timer expires.
     void expiredTimerCallback();
 
-
     // If fences from sync Framework are supported.
     const bool mHasSyncFramework;
 
@@ -184,6 +191,7 @@
 
     std::mutex mCallbackLock;
     ExpiredIdleTimerCallback mExpiredTimerCallback GUARDED_BY(mCallbackLock);
+    ExpiredIdleTimerCallback mResetTimerCallback GUARDED_BY(mCallbackLock);
 };
 
 } // namespace android
diff --git a/services/surfaceflinger/Scheduler/VSyncModulator.h b/services/surfaceflinger/Scheduler/VSyncModulator.h
index d7ec733..0bf3ceb 100644
--- a/services/surfaceflinger/Scheduler/VSyncModulator.h
+++ b/services/surfaceflinger/Scheduler/VSyncModulator.h
@@ -124,7 +124,7 @@
             changed = true;
         }
         if (desired.app != current.app) {
-            if (mSfConnectionHandle != nullptr) {
+            if (mAppConnectionHandle != nullptr) {
                 mScheduler->setPhaseOffset(mAppConnectionHandle, desired.app);
             } else {
                 mAppEventThread->setPhaseOffset(desired.app);
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index f9000b5..a999b27 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -635,17 +635,13 @@
         mPhaseOffsets->setRefreshRateType(
                 scheduler::RefreshRateConfigs::RefreshRateType::PERFORMANCE);
 
-        auto resetIdleTimerCallback =
-                std::bind(&SurfaceFlinger::setRefreshRateTo, this, RefreshRateType::PERFORMANCE);
-
         mAppConnectionHandle =
-                mScheduler->createConnection("appConnection", mPhaseOffsets->getCurrentAppOffset(),
-                                             resyncCallback, resetIdleTimerCallback,
+                mScheduler->createConnection("app", mPhaseOffsets->getCurrentAppOffset(),
+                                             resyncCallback,
                                              impl::EventThread::InterceptVSyncsCallback());
         mSfConnectionHandle =
-                mScheduler->createConnection("sfConnection", mPhaseOffsets->getCurrentSfOffset(),
-                                             resyncCallback, resetIdleTimerCallback,
-                                             [this](nsecs_t timestamp) {
+                mScheduler->createConnection("sf", mPhaseOffsets->getCurrentSfOffset(),
+                                             resyncCallback, [this](nsecs_t timestamp) {
                                                  mInterceptor->saveVSyncEvent(timestamp);
                                              });
 
@@ -749,6 +745,10 @@
             Mutex::Autolock lock(mStateLock);
             setRefreshRateTo(RefreshRateType::DEFAULT);
         });
+        mScheduler->setResetIdleTimerCallback([this] {
+            Mutex::Autolock lock(mStateLock);
+            setRefreshRateTo(RefreshRateType::PERFORMANCE);
+        });
 
         mRefreshRateStats =
                 std::make_unique<scheduler::RefreshRateStats>(getHwComposer().getConfigs(
@@ -1324,6 +1324,17 @@
     return NO_ERROR;
 }
 
+status_t SurfaceFlinger::addRegionSamplingListener(
+        const Rect& /*samplingArea*/, const sp<IBinder>& /*stopLayerHandle*/,
+        const sp<IRegionSamplingListener>& /*listener*/) {
+    return NO_ERROR;
+}
+
+status_t SurfaceFlinger::removeRegionSamplingListener(
+        const sp<IRegionSamplingListener>& /*listener*/) {
+    return NO_ERROR;
+}
+
 // ----------------------------------------------------------------------------
 
 sp<IDisplayEventConnection> SurfaceFlinger::createDisplayEventConnection(
@@ -1334,16 +1345,10 @@
     });
 
     if (mUseScheduler) {
-        auto resetIdleTimerCallback = [this] {
-            Mutex::Autolock lock(mStateLock);
-            setRefreshRateTo(RefreshRateType::PERFORMANCE);
-        };
-
         const auto& handle = vsyncSource == eVsyncSourceSurfaceFlinger ? mSfConnectionHandle
                                                                        : mAppConnectionHandle;
 
-        return mScheduler->createDisplayEventConnection(handle, std::move(resyncCallback),
-                                                        std::move(resetIdleTimerCallback));
+        return mScheduler->createDisplayEventConnection(handle, std::move(resyncCallback));
     } else {
         if (vsyncSource == eVsyncSourceSurfaceFlinger) {
             return mSFEventThread->createEventConnection(resyncCallback, ResetIdleTimerCallback());
@@ -1414,17 +1419,23 @@
 
 void SurfaceFlinger::resyncToHardwareVsync(bool makeAvailable, nsecs_t period) {
     Mutex::Autolock _l(mHWVsyncLock);
-
-    if (makeAvailable) {
-        mHWVsyncAvailable = true;
-        // TODO(b/113612090): This is silly, but necessary evil until we turn on the flag for good.
-        if (mUseScheduler) {
+    // TODO(b/113612090): This is silly, but necessary evil until we turn on the flag for good.
+    if (mUseScheduler) {
+        if (makeAvailable) {
             mScheduler->makeHWSyncAvailable(true);
+        } else if (!mScheduler->getHWSyncAvailable()) {
+            // Hardware vsync is not currently available, so abort the resync
+            // attempt for now
+            return;
         }
-    } else if (!mHWVsyncAvailable) {
-        // Hardware vsync is not currently available, so abort the resync
-        // attempt for now
-        return;
+    } else {
+        if (makeAvailable) {
+            mHWVsyncAvailable = true;
+        } else if (!mHWVsyncAvailable) {
+            // Hardware vsync is not currently available, so abort the resync
+            // attempt for now
+            return;
+        }
     }
 
     if (period <= 0) {
@@ -4540,7 +4551,13 @@
                 {"--clear-layer-stats"s, dumper([this](std::string&) { mLayerStats.clear(); })},
                 {"--disable-layer-stats"s, dumper([this](std::string&) { mLayerStats.disable(); })},
                 {"--display-id"s, dumper(&SurfaceFlinger::dumpDisplayIdentificationData)},
-                {"--dispsync"s, dumper([this](std::string& s) { mPrimaryDispSync->dump(s); })},
+                {"--dispsync"s, dumper([this](std::string& s) {
+                     if (mUseScheduler) {
+                         mScheduler->dumpPrimaryDispSync(s);
+                     } else {
+                         mPrimaryDispSync->dump(s);
+                     }
+                 })},
                 {"--dump-layer-stats"s, dumper([this](std::string& s) { mLayerStats.dump(s); })},
                 {"--enable-layer-stats"s, dumper([this](std::string&) { mLayerStats.enable(); })},
                 {"--frame-composition"s, dumper(&SurfaceFlinger::dumpFrameCompositionInfo)},
@@ -5121,7 +5138,9 @@
             return OK;
         }
         case CAPTURE_LAYERS:
-        case CAPTURE_SCREEN: {
+        case CAPTURE_SCREEN:
+        case ADD_REGION_SAMPLING_LISTENER:
+        case REMOVE_REGION_SAMPLING_LISTENER: {
             // codes that require permission check
             IPCThreadState* ipc = IPCThreadState::self();
             const int pid = ipc->getCallingPid();
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 060fc7a..669d3a1 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -476,7 +476,9 @@
     status_t getProtectedContentSupport(bool* outSupported) const override;
     status_t isWideColorDisplay(const sp<IBinder>& displayToken,
                                 bool* outIsWideColorDisplay) const override;
-
+    status_t addRegionSamplingListener(const Rect& samplingArea, const sp<IBinder>& stopLayerHandle,
+                                       const sp<IRegionSamplingListener>& listener) override;
+    status_t removeRegionSamplingListener(const sp<IRegionSamplingListener>& listener) override;
     /* ------------------------------------------------------------------------
      * DeathRecipient interface
      */
diff --git a/services/surfaceflinger/tests/unittests/IdleTimerTest.cpp b/services/surfaceflinger/tests/unittests/IdleTimerTest.cpp
index dc63260..5e82225 100644
--- a/services/surfaceflinger/tests/unittests/IdleTimerTest.cpp
+++ b/services/surfaceflinger/tests/unittests/IdleTimerTest.cpp
@@ -13,7 +13,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 #undef LOG_TAG
 #define LOG_TAG "SchedulerUnittests"
 
@@ -44,6 +43,7 @@
     // Note that there can be false-negatives if the callback happens later.
     static constexpr auto waitTimeForUnexpected3msCallback = 6ms;
 
+    AsyncCallRecorder<void (*)()> mResetTimerCallback;
     AsyncCallRecorder<void (*)()> mExpiredTimerCallback;
 
     std::unique_ptr<IdleTimer> mIdleTimer;
@@ -56,31 +56,39 @@
 
 namespace {
 TEST_F(IdleTimerTest, createAndDestroyTest) {
-    mIdleTimer = std::make_unique<scheduler::IdleTimer>(3ms, [] {});
+    mIdleTimer = std::make_unique<scheduler::IdleTimer>(3ms, [] {}, [] {});
 }
 
 TEST_F(IdleTimerTest, startStopTest) {
-    mIdleTimer = std::make_unique<scheduler::IdleTimer>(30ms, mExpiredTimerCallback.getInvocable());
+    mIdleTimer = std::make_unique<scheduler::IdleTimer>(30ms, mResetTimerCallback.getInvocable(),
+                                                        mExpiredTimerCallback.getInvocable());
     auto startTime = std::chrono::steady_clock::now();
     mIdleTimer->start();
+    EXPECT_TRUE(mResetTimerCallback.waitForCall().has_value());
     // The idle timer fires after 30ms, so there should be no callback within
-    // 25ms (waiting for a ballback for the full 30ms would be problematic).
+    // 25ms (waiting for a callback for the full 30ms would be problematic).
     bool callbackCalled = mExpiredTimerCallback.waitForCall(25ms).has_value();
     // Under ideal conditions there should be no event. But occasionally
     // it is possible that the wait just prior takes more than 30ms, and
     // a callback is observed. We check the elapsed time since before the IdleTimer
     // thread was started as a sanity check to not have a flakey test.
     EXPECT_FALSE(callbackCalled && std::chrono::steady_clock::now() - startTime < 30ms);
+
+    std::this_thread::sleep_for(std::chrono::milliseconds(25));
+    EXPECT_FALSE(mResetTimerCallback.waitForCall().has_value());
     mIdleTimer->stop();
 }
 
 TEST_F(IdleTimerTest, resetTest) {
-    mIdleTimer = std::make_unique<scheduler::IdleTimer>(30ms, mExpiredTimerCallback.getInvocable());
+    mIdleTimer = std::make_unique<scheduler::IdleTimer>(20ms, mResetTimerCallback.getInvocable(),
+                                                        mExpiredTimerCallback.getInvocable());
     mIdleTimer->start();
+    EXPECT_TRUE(mResetTimerCallback.waitForCall().has_value());
     // Observe any event that happens in about 25ms. We don't care if one was
     // observed or not.
     mExpiredTimerCallback.waitForCall(25ms).has_value();
     mIdleTimer->reset();
+    EXPECT_TRUE(mResetTimerCallback.waitForCall().has_value());
     // There may have been a race with the reset. Clear any callbacks we
     // received right afterwards.
     clearPendingCallbacks();
@@ -93,60 +101,110 @@
     mIdleTimer->stop();
     // Final quick check that no more callback were observed.
     EXPECT_FALSE(mExpiredTimerCallback.waitForCall(0ms).has_value());
+    EXPECT_FALSE(mResetTimerCallback.waitForCall(0ms).has_value());
 }
 
-TEST_F(IdleTimerTest, startNotCalledTest) {
-    mIdleTimer = std::make_unique<scheduler::IdleTimer>(3ms, mExpiredTimerCallback.getInvocable());
-    // The start hasn't happened, so the callback does not happen.
+TEST_F(IdleTimerTest, resetBackToBackTest) {
+    mIdleTimer = std::make_unique<scheduler::IdleTimer>(20ms, mResetTimerCallback.getInvocable(),
+                                                        mExpiredTimerCallback.getInvocable());
+    mIdleTimer->start();
+    EXPECT_TRUE(mResetTimerCallback.waitForCall().has_value());
+
+    mIdleTimer->reset();
+    EXPECT_TRUE(mResetTimerCallback.waitForCall().has_value());
     EXPECT_FALSE(mExpiredTimerCallback.waitForCall(waitTimeForUnexpected3msCallback).has_value());
+
+    mIdleTimer->reset();
+    EXPECT_TRUE(mResetTimerCallback.waitForCall().has_value());
+    EXPECT_FALSE(mExpiredTimerCallback.waitForCall(waitTimeForUnexpected3msCallback).has_value());
+
+    mIdleTimer->reset();
+    EXPECT_TRUE(mResetTimerCallback.waitForCall().has_value());
+    EXPECT_FALSE(mExpiredTimerCallback.waitForCall(waitTimeForUnexpected3msCallback).has_value());
+
+    mIdleTimer->reset();
+    EXPECT_TRUE(mResetTimerCallback.waitForCall().has_value());
+    EXPECT_FALSE(mExpiredTimerCallback.waitForCall(waitTimeForUnexpected3msCallback).has_value());
+
+    // A single callback should be generated after 30ms
+    EXPECT_TRUE(
+            mExpiredTimerCallback.waitForCall(waitTimeForExpected3msCallback + 30ms).has_value());
     mIdleTimer->stop();
     // Final quick check that no more callback were observed.
     EXPECT_FALSE(mExpiredTimerCallback.waitForCall(0ms).has_value());
+    EXPECT_FALSE(mResetTimerCallback.waitForCall(0ms).has_value());
+}
+
+TEST_F(IdleTimerTest, startNotCalledTest) {
+    mIdleTimer = std::make_unique<scheduler::IdleTimer>(3ms, mResetTimerCallback.getInvocable(),
+                                                        mExpiredTimerCallback.getInvocable());
+    // The start hasn't happened, so the callback does not happen.
+    EXPECT_FALSE(mExpiredTimerCallback.waitForCall(waitTimeForUnexpected3msCallback).has_value());
+    EXPECT_FALSE(mResetTimerCallback.waitForCall(1us).has_value());
+    mIdleTimer->stop();
+    // Final quick check that no more callback were observed.
+    EXPECT_FALSE(mExpiredTimerCallback.waitForCall(0ms).has_value());
+    EXPECT_FALSE(mResetTimerCallback.waitForCall(0ms).has_value());
 }
 
 TEST_F(IdleTimerTest, idleTimerIdlesTest) {
-    mIdleTimer = std::make_unique<scheduler::IdleTimer>(3ms, mExpiredTimerCallback.getInvocable());
+    mIdleTimer = std::make_unique<scheduler::IdleTimer>(3ms, mResetTimerCallback.getInvocable(),
+                                                        mExpiredTimerCallback.getInvocable());
     mIdleTimer->start();
+    EXPECT_TRUE(mResetTimerCallback.waitForCall().has_value());
+
     // A callback should be generated after 3ms
     EXPECT_TRUE(mExpiredTimerCallback.waitForCall(waitTimeForExpected3msCallback).has_value());
     // After one event, it should be idle, and not generate another.
     EXPECT_FALSE(mExpiredTimerCallback.waitForCall(waitTimeForUnexpected3msCallback).has_value());
     // Once reset, it should generate another
     mIdleTimer->reset();
+    EXPECT_TRUE(mResetTimerCallback.waitForCall(1ms).has_value());
     EXPECT_TRUE(mExpiredTimerCallback.waitForCall(waitTimeForExpected3msCallback).has_value());
     mIdleTimer->stop();
     // Final quick check that no more callback were observed.
     EXPECT_FALSE(mExpiredTimerCallback.waitForCall(0ms).has_value());
+    EXPECT_FALSE(mResetTimerCallback.waitForCall(0ms).has_value());
 }
 
 TEST_F(IdleTimerTest, timeoutCallbackExecutionTest) {
-    mIdleTimer = std::make_unique<scheduler::IdleTimer>(3ms, mExpiredTimerCallback.getInvocable());
-
+    mIdleTimer = std::make_unique<scheduler::IdleTimer>(3ms, mResetTimerCallback.getInvocable(),
+                                                        mExpiredTimerCallback.getInvocable());
     mIdleTimer->start();
+    EXPECT_TRUE(mResetTimerCallback.waitForCall(1us).has_value());
     EXPECT_TRUE(mExpiredTimerCallback.waitForCall(waitTimeForExpected3msCallback).has_value());
     mIdleTimer->stop();
 }
 
 TEST_F(IdleTimerTest, noCallbacksAfterStopAndResetTest) {
-    mIdleTimer = std::make_unique<scheduler::IdleTimer>(3ms, mExpiredTimerCallback.getInvocable());
+    mIdleTimer = std::make_unique<scheduler::IdleTimer>(3ms, mResetTimerCallback.getInvocable(),
+                                                        mExpiredTimerCallback.getInvocable());
     mIdleTimer->start();
+    EXPECT_TRUE(mResetTimerCallback.waitForCall(1ms).has_value());
     EXPECT_TRUE(mExpiredTimerCallback.waitForCall(waitTimeForExpected3msCallback).has_value());
+
     mIdleTimer->stop();
     clearPendingCallbacks();
     mIdleTimer->reset();
     EXPECT_FALSE(mExpiredTimerCallback.waitForCall(waitTimeForUnexpected3msCallback).has_value());
+    EXPECT_FALSE(mResetTimerCallback.waitForCall(1ms).has_value());
 }
 
 TEST_F(IdleTimerTest, noCallbacksAfterStopTest) {
-    mIdleTimer = std::make_unique<scheduler::IdleTimer>(3ms, mExpiredTimerCallback.getInvocable());
+    mIdleTimer = std::make_unique<scheduler::IdleTimer>(3ms, mResetTimerCallback.getInvocable(),
+                                                        mExpiredTimerCallback.getInvocable());
     mIdleTimer->start();
+    EXPECT_TRUE(mResetTimerCallback.waitForCall(1ms).has_value());
+
     mIdleTimer->stop();
     clearPendingCallbacks();
     mIdleTimer->reset();
+
     // No more idle events should be observed
     EXPECT_FALSE(mExpiredTimerCallback.waitForCall(waitTimeForUnexpected3msCallback).has_value());
+    EXPECT_FALSE(mResetTimerCallback.waitForCall(1ms).has_value());
 }
 
 } // namespace
 } // namespace scheduler
-} // namespace android
\ No newline at end of file
+} // namespace android
diff --git a/services/surfaceflinger/tests/unittests/SchedulerTest.cpp b/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
index 26b6d0c..ec76538 100644
--- a/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
+++ b/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
@@ -82,7 +82,6 @@
             .WillRepeatedly(Return(mEventThreadConnection));
 
     mConnectionHandle = mScheduler->createConnection("appConnection", 16, ResyncCallback(),
-                                                     ResetIdleTimerCallback(),
                                                      impl::EventThread::InterceptVSyncsCallback());
     EXPECT_TRUE(mConnectionHandle != nullptr);
 }
@@ -103,8 +102,7 @@
     // exceptions, just gracefully continues.
     sp<IDisplayEventConnection> returnedValue;
     ASSERT_NO_FATAL_FAILURE(
-            returnedValue = mScheduler->createDisplayEventConnection(nullptr, ResyncCallback(),
-                                                                     ResetIdleTimerCallback()));
+            returnedValue = mScheduler->createDisplayEventConnection(nullptr, ResyncCallback()));
     EXPECT_TRUE(returnedValue == nullptr);
     EXPECT_TRUE(mScheduler->getEventThread(nullptr) == nullptr);
     EXPECT_TRUE(mScheduler->getEventConnection(nullptr) == nullptr);
@@ -125,8 +123,7 @@
     sp<IDisplayEventConnection> returnedValue;
     ASSERT_NO_FATAL_FAILURE(
             returnedValue =
-                    mScheduler->createDisplayEventConnection(connectionHandle, ResyncCallback(),
-                                                             ResetIdleTimerCallback()));
+                    mScheduler->createDisplayEventConnection(connectionHandle, ResyncCallback()));
     EXPECT_TRUE(returnedValue == nullptr);
     EXPECT_TRUE(mScheduler->getEventThread(connectionHandle) == nullptr);
     EXPECT_TRUE(mScheduler->getEventConnection(connectionHandle) == nullptr);
@@ -155,8 +152,7 @@
     sp<IDisplayEventConnection> returnedValue;
     ASSERT_NO_FATAL_FAILURE(
             returnedValue =
-                    mScheduler->createDisplayEventConnection(mConnectionHandle, ResyncCallback(),
-                                                             ResetIdleTimerCallback()));
+                    mScheduler->createDisplayEventConnection(mConnectionHandle, ResyncCallback()));
     EXPECT_TRUE(returnedValue != nullptr);
     ASSERT_EQ(returnedValue, mEventThreadConnection);