Merge "graphics: add libhwc2on{1,fb}adapter"

graphics/composer/2.1/utils/hwc2on1adapter/Android.bp

@@ -0,0 +1,76 @@
+// Copyright 2010 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.
+
+cc_library_shared {
+    name: "libhwc2on1adapter",
+    vendor: true,
+
+    clang: true,
+    cflags: [
+        "-Wall",
+        "-Werror",
+        "-Wno-user-defined-warnings",
+    ],
+    cppflags: [
+        "-Weverything",
+        "-Wunused",
+        "-Wunreachable-code",
+
+        // The static constructors and destructors in this library have not been noted to
+        // introduce significant overheads
+        "-Wno-exit-time-destructors",
+        "-Wno-global-constructors",
+
+        // We only care about compiling as C++14
+        "-Wno-c++98-compat-pedantic",
+
+        // android/sensors.h uses nested anonymous unions and anonymous structs
+        "-Wno-nested-anon-types",
+        "-Wno-gnu-anonymous-struct",
+
+        // Don't warn about struct padding
+        "-Wno-padded",
+
+        // hwcomposer2.h features switch covering all cases.
+        "-Wno-covered-switch-default",
+
+        // hwcomposer.h features zero size array.
+        "-Wno-zero-length-array",
+
+        // Disabling warning specific to hwc2on1adapter code
+        "-Wno-double-promotion",
+        "-Wno-sign-conversion",
+        "-Wno-switch-enum",
+        "-Wno-float-equal",
+        "-Wno-shorten-64-to-32",
+        "-Wno-sign-compare",
+        "-Wno-missing-prototypes",
+    ],
+
+    srcs: [
+        "HWC2On1Adapter.cpp",
+        "MiniFence.cpp",
+    ],
+
+    shared_libs: [
+        "libutils",
+        "libcutils",
+        "liblog",
+        "libhardware",
+    ],
+
+    export_include_dirs: ["include"],
+
+    export_shared_lib_headers: ["libutils"],
+}

graphics/composer/2.1/utils/hwc2on1adapter/CleanSpec.mk

@@ -0,0 +1,52 @@
+# Copyright (C) 2017 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.
+#
+
+# If you don't need to do a full clean build but would like to touch
+# a file or delete some intermediate files, add a clean step to the end
+# of the list.  These steps will only be run once, if they haven't been
+# run before.
+#
+# E.g.:
+#     $(call add-clean-step, touch -c external/sqlite/sqlite3.h)
+#     $(call add-clean-step, rm -rf $(PRODUCT_OUT)/obj/STATIC_LIBRARIES/libz_intermediates)
+#
+# Always use "touch -c" and "rm -f" or "rm -rf" to gracefully deal with
+# files that are missing or have been moved.
+#
+# Use $(PRODUCT_OUT) to get to the "out/target/product/blah/" directory.
+# Use $(OUT_DIR) to refer to the "out" directory.
+#
+# If you need to re-do something that's already mentioned, just copy
+# the command and add it to the bottom of the list.  E.g., if a change
+# that you made last week required touching a file and a change you
+# made today requires touching the same file, just copy the old
+# touch step and add it to the end of the list.
+#
+# ************************************************
+# NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
+# ************************************************
+
+# For example:
+#$(call add-clean-step, rm -rf $(OUT_DIR)/target/common/obj/APPS/AndroidTests_intermediates)
+#$(call add-clean-step, rm -rf $(OUT_DIR)/target/common/obj/JAVA_LIBRARIES/core_intermediates)
+#$(call add-clean-step, find $(OUT_DIR) -type f -name "IGTalkSession*" -print0 | xargs -0 rm -f)
+#$(call add-clean-step, rm -rf $(PRODUCT_OUT)/data/*)
+
+# ************************************************
+# NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
+# ************************************************
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/obj/SHARED_LIBRARIES/libhwc2on1adapter_intermediates)
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/lib/libhwc2on1adapter.so)
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/lib64/libhwc2on1adapter.so)

graphics/composer/2.1/utils/hwc2on1adapter/MiniFence.cpp

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "hwc2on1adapter/MiniFence.h"
+
+#include <unistd.h>
+
+namespace android {
+
+const sp<MiniFence> MiniFence::NO_FENCE = sp<MiniFence>(new MiniFence);
+
+MiniFence::MiniFence() :
+    mFenceFd(-1) {
+}
+
+MiniFence::MiniFence(int fenceFd) :
+    mFenceFd(fenceFd) {
+}
+
+MiniFence::~MiniFence() {
+    if (mFenceFd != -1) {
+        close(mFenceFd);
+    }
+}
+
+int MiniFence::dup() const {
+    return ::dup(mFenceFd);
+}
+}

graphics/composer/2.1/utils/hwc2on1adapter/include/hwc2on1adapter/HWC2On1Adapter.h

@@ -0,0 +1,738 @@
+/*
+ * Copyright 2015 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.
+ */
+
+#ifndef ANDROID_SF_HWC2_ON_1_ADAPTER_H
+#define ANDROID_SF_HWC2_ON_1_ADAPTER_H
+
+#define HWC2_INCLUDE_STRINGIFICATION
+#define HWC2_USE_CPP11
+#include <hardware/hwcomposer2.h>
+#undef HWC2_INCLUDE_STRINGIFICATION
+#undef HWC2_USE_CPP11
+
+#include "MiniFence.h"
+
+#include <atomic>
+#include <map>
+#include <mutex>
+#include <queue>
+#include <set>
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
+
+struct hwc_composer_device_1;
+struct hwc_display_contents_1;
+struct hwc_layer_1;
+
+namespace android {
+
+// For devices unable to provide an implementation of HWC2 (see hwcomposer2.h),
+// we provide an adapter able to talk to HWC1 (see hwcomposer.h). It translates
+// streamed function calls ala HWC2 model to batched array of structs calls ala
+// HWC1 model.
+class HWC2On1Adapter : public hwc2_device_t
+{
+public:
+    explicit HWC2On1Adapter(struct hwc_composer_device_1* hwc1Device);
+    ~HWC2On1Adapter();
+
+    struct hwc_composer_device_1* getHwc1Device() const { return mHwc1Device; }
+    uint8_t getHwc1MinorVersion() const { return mHwc1MinorVersion; }
+
+private:
+    static inline HWC2On1Adapter* getAdapter(hwc2_device_t* device) {
+        return static_cast<HWC2On1Adapter*>(device);
+    }
+
+    // getCapabilities
+
+    void doGetCapabilities(uint32_t* outCount,
+            int32_t* /*hwc2_capability_t*/ outCapabilities);
+    static void getCapabilitiesHook(hwc2_device_t* device, uint32_t* outCount,
+            int32_t* /*hwc2_capability_t*/ outCapabilities) {
+        getAdapter(device)->doGetCapabilities(outCount, outCapabilities);
+    }
+
+    bool supportsBackgroundColor() {
+        return mHwc1SupportsBackgroundColor;
+    }
+
+    // getFunction
+
+    hwc2_function_pointer_t doGetFunction(HWC2::FunctionDescriptor descriptor);
+    static hwc2_function_pointer_t getFunctionHook(hwc2_device_t* device,
+            int32_t intDesc) {
+        auto descriptor = static_cast<HWC2::FunctionDescriptor>(intDesc);
+        return getAdapter(device)->doGetFunction(descriptor);
+    }
+
+    // Device functions
+
+    HWC2::Error createVirtualDisplay(uint32_t width, uint32_t height,
+            hwc2_display_t* outDisplay);
+    static int32_t createVirtualDisplayHook(hwc2_device_t* device,
+            uint32_t width, uint32_t height, int32_t* /*format*/,
+            hwc2_display_t* outDisplay) {
+        // HWC1 implementations cannot override the buffer format requested by
+        // the consumer
+        auto error = getAdapter(device)->createVirtualDisplay(width, height,
+                outDisplay);
+        return static_cast<int32_t>(error);
+    }
+
+    HWC2::Error destroyVirtualDisplay(hwc2_display_t display);
+    static int32_t destroyVirtualDisplayHook(hwc2_device_t* device,
+            hwc2_display_t display) {
+        auto error = getAdapter(device)->destroyVirtualDisplay(display);
+        return static_cast<int32_t>(error);
+    }
+
+    std::string mDumpString;
+    void dump(uint32_t* outSize, char* outBuffer);
+    static void dumpHook(hwc2_device_t* device, uint32_t* outSize,
+            char* outBuffer) {
+        getAdapter(device)->dump(outSize, outBuffer);
+    }
+
+    uint32_t getMaxVirtualDisplayCount();
+    static uint32_t getMaxVirtualDisplayCountHook(hwc2_device_t* device) {
+        return getAdapter(device)->getMaxVirtualDisplayCount();
+    }
+
+    HWC2::Error registerCallback(HWC2::Callback descriptor,
+            hwc2_callback_data_t callbackData, hwc2_function_pointer_t pointer);
+    static int32_t registerCallbackHook(hwc2_device_t* device,
+            int32_t intDesc, hwc2_callback_data_t callbackData,
+            hwc2_function_pointer_t pointer) {
+        auto descriptor = static_cast<HWC2::Callback>(intDesc);
+        auto error = getAdapter(device)->registerCallback(descriptor,
+                callbackData, pointer);
+        return static_cast<int32_t>(error);
+    }
+
+    // Display functions
+
+    class Layer;
+
+    class SortLayersByZ {
+        public:
+            bool operator()(const std::shared_ptr<Layer>& lhs,
+                    const std::shared_ptr<Layer>& rhs);
+    };
+
+    // The semantics of the fences returned by the device differ between
+    // hwc1.set() and hwc2.present(). Read hwcomposer.h and hwcomposer2.h
+    // for more information.
+    //
+    // Release fences in hwc1 are obtained on set() for a frame n and signaled
+    // when the layer buffer is not needed for read operations anymore
+    // (typically on frame n+1). In HWC2, release fences are obtained with a
+    // special call after present() for frame n. These fences signal
+    // on frame n: More specifically, the fence for a given buffer provided in
+    // frame n will signal when the prior buffer is no longer required.
+    //
+    // A retire fence (HWC1) is signaled when a composition is replaced
+    // on the panel whereas a present fence (HWC2) is signaled when a
+    // composition starts to be displayed on a panel.
+    //
+    // The HWC2to1Adapter emulates the new fence semantics for a frame
+    // n by returning the fence from frame n-1. For frame 0, the adapter
+    // returns NO_FENCE.
+    class DeferredFence {
+        public:
+            DeferredFence()
+              : mFences({MiniFence::NO_FENCE, MiniFence::NO_FENCE}) {}
+
+            void add(int32_t fenceFd) {
+                mFences.emplace(new MiniFence(fenceFd));
+                mFences.pop();
+            }
+
+            const sp<MiniFence>& get() const {
+                return mFences.front();
+            }
+
+        private:
+            // There are always two fences in this queue.
+            std::queue<sp<MiniFence>> mFences;
+    };
+
+    class FencedBuffer {
+        public:
+            FencedBuffer() : mBuffer(nullptr), mFence(MiniFence::NO_FENCE) {}
+
+            void setBuffer(buffer_handle_t buffer) { mBuffer = buffer; }
+            void setFence(int fenceFd) { mFence = new MiniFence(fenceFd); }
+
+            buffer_handle_t getBuffer() const { return mBuffer; }
+            int getFence() const { return mFence->dup(); }
+
+        private:
+            buffer_handle_t mBuffer;
+            sp<MiniFence> mFence;
+    };
+
+    class Display {
+        public:
+            Display(HWC2On1Adapter& device, HWC2::DisplayType type);
+
+            hwc2_display_t getId() const { return mId; }
+            HWC2On1Adapter& getDevice() const { return mDevice; }
+
+            // Does not require locking because it is set before adding the
+            // Displays to the Adapter's list of displays
+            void setHwc1Id(int32_t id) { mHwc1Id = id; }
+            int32_t getHwc1Id() const { return mHwc1Id; }
+
+            // HWC2 Display functions
+            HWC2::Error acceptChanges();
+            HWC2::Error createLayer(hwc2_layer_t* outLayerId);
+            HWC2::Error destroyLayer(hwc2_layer_t layerId);
+            HWC2::Error getActiveConfig(hwc2_config_t* outConfigId);
+            HWC2::Error getAttribute(hwc2_config_t configId,
+                    HWC2::Attribute attribute, int32_t* outValue);
+            HWC2::Error getChangedCompositionTypes(uint32_t* outNumElements,
+                    hwc2_layer_t* outLayers, int32_t* outTypes);
+            HWC2::Error getColorModes(uint32_t* outNumModes, int32_t* outModes);
+            HWC2::Error getConfigs(uint32_t* outNumConfigs,
+                    hwc2_config_t* outConfigIds);
+            HWC2::Error getDozeSupport(int32_t* outSupport);
+            HWC2::Error getHdrCapabilities(uint32_t* outNumTypes,
+                    int32_t* outTypes, float* outMaxLuminance,
+                    float* outMaxAverageLuminance, float* outMinLuminance);
+            HWC2::Error getName(uint32_t* outSize, char* outName);
+            HWC2::Error getReleaseFences(uint32_t* outNumElements,
+                    hwc2_layer_t* outLayers, int32_t* outFences);
+            HWC2::Error getRequests(int32_t* outDisplayRequests,
+                    uint32_t* outNumElements, hwc2_layer_t* outLayers,
+                    int32_t* outLayerRequests);
+            HWC2::Error getType(int32_t* outType);
+
+            // Since HWC1 "presents" (called "set" in HWC1) all Displays
+            // at once, the first call to any Display::present will trigger
+            // present() on all Displays in the Device. Subsequent calls without
+            // first calling validate() are noop (except for duping/returning
+            // the retire fence).
+            HWC2::Error present(int32_t* outRetireFence);
+
+            HWC2::Error setActiveConfig(hwc2_config_t configId);
+            HWC2::Error setClientTarget(buffer_handle_t target,
+                    int32_t acquireFence, int32_t dataspace,
+                    hwc_region_t damage);
+            HWC2::Error setColorMode(android_color_mode_t mode);
+            HWC2::Error setColorTransform(android_color_transform_t hint);
+            HWC2::Error setOutputBuffer(buffer_handle_t buffer,
+                    int32_t releaseFence);
+            HWC2::Error setPowerMode(HWC2::PowerMode mode);
+            HWC2::Error setVsyncEnabled(HWC2::Vsync enabled);
+
+            // Since HWC1 "validates" (called "prepare" in HWC1) all Displays
+            // at once, the first call to any Display::validate() will trigger
+            // validate() on all other Displays in the Device.
+            HWC2::Error validate(uint32_t* outNumTypes,
+                    uint32_t* outNumRequests);
+
+            HWC2::Error updateLayerZ(hwc2_layer_t layerId, uint32_t z);
+
+            HWC2::Error getClientTargetSupport(uint32_t width, uint32_t height,
+                     int32_t format, int32_t dataspace);
+
+            // Read configs from HWC1 device
+            void populateConfigs();
+
+            // Set configs for a virtual display
+            void populateConfigs(uint32_t width, uint32_t height);
+
+            bool prepare();
+
+            // Called after hwc.prepare() with responses from the device.
+            void generateChanges();
+
+            bool hasChanges() const;
+            HWC2::Error set(hwc_display_contents_1& hwcContents);
+            void addRetireFence(int fenceFd);
+            void addReleaseFences(const hwc_display_contents_1& hwcContents);
+
+            bool hasColorTransform() const;
+
+            std::string dump() const;
+
+            // Return a rect from the pool allocated during validate()
+            hwc_rect_t* GetRects(size_t numRects);
+
+            hwc_display_contents_1* getDisplayContents();
+
+            void markGeometryChanged() { mGeometryChanged = true; }
+            void resetGeometryMarker() { mGeometryChanged = false;}
+        private:
+            class Config {
+                public:
+                    Config(Display& display)
+                      : mDisplay(display),
+                        mId(0),
+                        mAttributes() {}
+
+                    bool isOnDisplay(const Display& display) const {
+                        return display.getId() == mDisplay.getId();
+                    }
+
+                    void setAttribute(HWC2::Attribute attribute, int32_t value);
+                    int32_t getAttribute(HWC2::Attribute attribute) const;
+
+                    void setHwc1Id(uint32_t id);
+                    bool hasHwc1Id(uint32_t id) const;
+                    HWC2::Error getColorModeForHwc1Id(uint32_t id,
+                            android_color_mode_t *outMode) const;
+                    HWC2::Error getHwc1IdForColorMode(android_color_mode_t mode,
+                            uint32_t* outId) const;
+
+                    void setId(hwc2_config_t id) { mId = id; }
+                    hwc2_config_t getId() const { return mId; }
+
+                    // Attempts to merge two configs that differ only in color
+                    // mode. Returns whether the merge was successful
+                    bool merge(const Config& other);
+
+                    std::set<android_color_mode_t> getColorModes() const;
+
+                    // splitLine divides the output into two lines suitable for
+                    // dumpsys SurfaceFlinger
+                    std::string toString(bool splitLine = false) const;
+
+                private:
+                    Display& mDisplay;
+                    hwc2_config_t mId;
+                    std::unordered_map<HWC2::Attribute, int32_t> mAttributes;
+
+                    // Maps from color transform to HWC1 config ID
+                    std::unordered_map<android_color_mode_t, uint32_t> mHwc1Ids;
+            };
+
+            // Stores changes requested from the device upon calling prepare().
+            // Handles change request to:
+            //   - Layer composition type.
+            //   - Layer hints.
+            class Changes {
+                public:
+                    uint32_t getNumTypes() const {
+                        return static_cast<uint32_t>(mTypeChanges.size());
+                    }
+
+                    uint32_t getNumLayerRequests() const {
+                        return static_cast<uint32_t>(mLayerRequests.size());
+                    }
+
+                    const std::unordered_map<hwc2_layer_t, HWC2::Composition>&
+                            getTypeChanges() const {
+                        return mTypeChanges;
+                    }
+
+                    const std::unordered_map<hwc2_layer_t, HWC2::LayerRequest>&
+                            getLayerRequests() const {
+                        return mLayerRequests;
+                    }
+
+                    void addTypeChange(hwc2_layer_t layerId,
+                            HWC2::Composition type) {
+                        mTypeChanges.insert({layerId, type});
+                    }
+
+                    void clearTypeChanges() { mTypeChanges.clear(); }
+
+                    void addLayerRequest(hwc2_layer_t layerId,
+                            HWC2::LayerRequest request) {
+                        mLayerRequests.insert({layerId, request});
+                    }
+
+                private:
+                    std::unordered_map<hwc2_layer_t, HWC2::Composition>
+                            mTypeChanges;
+                    std::unordered_map<hwc2_layer_t, HWC2::LayerRequest>
+                            mLayerRequests;
+            };
+
+            std::shared_ptr<const Config>
+                    getConfig(hwc2_config_t configId) const;
+
+            void populateColorModes();
+            void initializeActiveConfig();
+
+            // Creates a bi-directional mapping between index in HWC1
+            // prepare/set array and Layer object. Stores mapping in
+            // mHwc1LayerMap and also updates Layer's attribute mHwc1Id.
+            void assignHwc1LayerIds();
+
+            // Called after a response to prepare() has been received:
+            // Ingest composition type changes requested by the device.
+            void updateTypeChanges(const struct hwc_layer_1& hwc1Layer,
+                    const Layer& layer);
+
+            // Called after a response to prepare() has been received:
+            // Ingest layer hint changes requested by the device.
+            void updateLayerRequests(const struct hwc_layer_1& hwc1Layer,
+                    const Layer& layer);
+
+            // Set all fields in HWC1 comm array for layer containing the
+            // HWC_FRAMEBUFFER_TARGET (always the last layer).
+            void prepareFramebufferTarget();
+
+            // Display ID generator.
+            static std::atomic<hwc2_display_t> sNextId;
+            const hwc2_display_t mId;
+
+
+            HWC2On1Adapter& mDevice;
+
+            // The state of this display should only be modified from
+            // SurfaceFlinger's main loop, with the exception of when dump is
+            // called. To prevent a bad state from crashing us during a dump
+            // call, all public calls into Display must acquire this mutex.
+            //
+            // It is recursive because we don't want to deadlock in validate
+            // (or present) when we call HWC2On1Adapter::prepareAllDisplays
+            // (or setAllDisplays), which calls back into Display functions
+            // which require locking.
+            mutable std::recursive_mutex mStateMutex;
+
+            // Allocate RAM able to store all layers and rects used for
+            // communication with HWC1. Place allocated RAM in variable
+            // mHwc1RequestedContents.
+            void allocateRequestedContents();
+
+            // Array of structs exchanged between client and hwc1 device.
+            // Sent to device upon calling prepare().
+            std::unique_ptr<hwc_display_contents_1> mHwc1RequestedContents;
+    private:
+            DeferredFence mRetireFence;
+
+            // Will only be non-null after the Display has been validated and
+            // before it has been presented
+            std::unique_ptr<Changes> mChanges;
+
+            int32_t mHwc1Id;
+
+            std::vector<std::shared_ptr<Config>> mConfigs;
+            std::shared_ptr<const Config> mActiveConfig;
+            std::set<android_color_mode_t> mColorModes;
+            android_color_mode_t mActiveColorMode;
+            std::string mName;
+            HWC2::DisplayType mType;
+            HWC2::PowerMode mPowerMode;
+            HWC2::Vsync mVsyncEnabled;
+
+            // Used to populate HWC1 HWC_FRAMEBUFFER_TARGET layer
+            FencedBuffer mClientTarget;
+
+
+            FencedBuffer mOutputBuffer;
+
+            bool mHasColorTransform;
+
+            // All layers this Display is aware of.
+            std::multiset<std::shared_ptr<Layer>, SortLayersByZ> mLayers;
+
+            // Mapping between layer index in array of hwc_display_contents_1*
+            // passed to HWC1 during validate/set and Layer object.
+            std::unordered_map<size_t, std::shared_ptr<Layer>> mHwc1LayerMap;
+
+            // All communication with HWC1 via prepare/set is done with one
+            // alloc. This pointer is pointing to a pool of hwc_rect_t.
+            size_t mNumAvailableRects;
+            hwc_rect_t* mNextAvailableRect;
+
+            // True if any of the Layers contained in this Display have been
+            // updated with anything other than a buffer since last call to
+            // Display::set()
+            bool mGeometryChanged;
+    };
+
+    // Utility template calling a Display object method directly based on the
+    // hwc2_display_t displayId parameter.
+    template <typename ...Args>
+    static int32_t callDisplayFunction(hwc2_device_t* device,
+            hwc2_display_t displayId, HWC2::Error (Display::*member)(Args...),
+            Args... args) {
+        auto display = getAdapter(device)->getDisplay(displayId);
+        if (!display) {
+            return static_cast<int32_t>(HWC2::Error::BadDisplay);
+        }
+        auto error = ((*display).*member)(std::forward<Args>(args)...);
+        return static_cast<int32_t>(error);
+    }
+
+    template <typename MF, MF memFunc, typename ...Args>
+    static int32_t displayHook(hwc2_device_t* device, hwc2_display_t displayId,
+            Args... args) {
+        return HWC2On1Adapter::callDisplayFunction(device, displayId, memFunc,
+                std::forward<Args>(args)...);
+    }
+
+    static int32_t getDisplayAttributeHook(hwc2_device_t* device,
+            hwc2_display_t display, hwc2_config_t config,
+            int32_t intAttribute, int32_t* outValue) {
+        auto attribute = static_cast<HWC2::Attribute>(intAttribute);
+        return callDisplayFunction(device, display, &Display::getAttribute,
+                config, attribute, outValue);
+    }
+
+    static int32_t setColorTransformHook(hwc2_device_t* device,
+            hwc2_display_t display, const float* /*matrix*/,
+            int32_t /*android_color_transform_t*/ intHint) {
+        // We intentionally throw away the matrix, because if the hint is
+        // anything other than IDENTITY, we have to fall back to client
+        // composition anyway
+        auto hint = static_cast<android_color_transform_t>(intHint);
+        return callDisplayFunction(device, display, &Display::setColorTransform,
+                hint);
+    }
+
+    static int32_t setColorModeHook(hwc2_device_t* device,
+            hwc2_display_t display, int32_t /*android_color_mode_t*/ intMode) {
+        auto mode = static_cast<android_color_mode_t>(intMode);
+        return callDisplayFunction(device, display, &Display::setColorMode,
+                mode);
+    }
+
+    static int32_t setPowerModeHook(hwc2_device_t* device,
+            hwc2_display_t display, int32_t intMode) {
+        auto mode = static_cast<HWC2::PowerMode>(intMode);
+        return callDisplayFunction(device, display, &Display::setPowerMode,
+                mode);
+    }
+
+    static int32_t setVsyncEnabledHook(hwc2_device_t* device,
+            hwc2_display_t display, int32_t intEnabled) {
+        auto enabled = static_cast<HWC2::Vsync>(intEnabled);
+        return callDisplayFunction(device, display, &Display::setVsyncEnabled,
+                enabled);
+    }
+
+    class Layer {
+        public:
+            explicit Layer(Display& display);
+
+            bool operator==(const Layer& other) { return mId == other.mId; }
+            bool operator!=(const Layer& other) { return !(*this == other); }
+
+            hwc2_layer_t getId() const { return mId; }
+            Display& getDisplay() const { return mDisplay; }
+
+            // HWC2 Layer functions
+            HWC2::Error setBuffer(buffer_handle_t buffer, int32_t acquireFence);
+            HWC2::Error setCursorPosition(int32_t x, int32_t y);
+            HWC2::Error setSurfaceDamage(hwc_region_t damage);
+
+            // HWC2 Layer state functions
+            HWC2::Error setBlendMode(HWC2::BlendMode mode);
+            HWC2::Error setColor(hwc_color_t color);
+            HWC2::Error setCompositionType(HWC2::Composition type);
+            HWC2::Error setDataspace(android_dataspace_t dataspace);
+            HWC2::Error setDisplayFrame(hwc_rect_t frame);
+            HWC2::Error setPlaneAlpha(float alpha);
+            HWC2::Error setSidebandStream(const native_handle_t* stream);
+            HWC2::Error setSourceCrop(hwc_frect_t crop);
+            HWC2::Error setTransform(HWC2::Transform transform);
+            HWC2::Error setVisibleRegion(hwc_region_t visible);
+            HWC2::Error setZ(uint32_t z);
+
+            HWC2::Composition getCompositionType() const {
+                return mCompositionType;
+            }
+            uint32_t getZ() const { return mZ; }
+
+            void addReleaseFence(int fenceFd);
+            const sp<MiniFence>& getReleaseFence() const;
+
+            void setHwc1Id(size_t id) { mHwc1Id = id; }
+            size_t getHwc1Id() const { return mHwc1Id; }
+
+            // Write state to HWC1 communication struct.
+            void applyState(struct hwc_layer_1& hwc1Layer);
+
+            std::string dump() const;
+
+            std::size_t getNumVisibleRegions() { return mVisibleRegion.size(); }
+
+            std::size_t getNumSurfaceDamages() { return mSurfaceDamage.size(); }
+
+            // True if a layer cannot be properly rendered by the device due
+            // to usage of SolidColor (a.k.a BackgroundColor in HWC1).
+            bool hasUnsupportedBackgroundColor() {
+                return (mCompositionType == HWC2::Composition::SolidColor &&
+                        !mDisplay.getDevice().supportsBackgroundColor());
+            }
+        private:
+            void applyCommonState(struct hwc_layer_1& hwc1Layer);
+            void applySolidColorState(struct hwc_layer_1& hwc1Layer);
+            void applySidebandState(struct hwc_layer_1& hwc1Layer);
+            void applyBufferState(struct hwc_layer_1& hwc1Layer);
+            void applyCompositionType(struct hwc_layer_1& hwc1Layer);
+
+            static std::atomic<hwc2_layer_t> sNextId;
+            const hwc2_layer_t mId;
+            Display& mDisplay;
+
+            FencedBuffer mBuffer;
+            std::vector<hwc_rect_t> mSurfaceDamage;
+
+            HWC2::BlendMode mBlendMode;
+            hwc_color_t mColor;
+            HWC2::Composition mCompositionType;
+            hwc_rect_t mDisplayFrame;
+            float mPlaneAlpha;
+            const native_handle_t* mSidebandStream;
+            hwc_frect_t mSourceCrop;
+            HWC2::Transform mTransform;
+            std::vector<hwc_rect_t> mVisibleRegion;
+
+            uint32_t mZ;
+
+            DeferredFence mReleaseFence;
+
+            size_t mHwc1Id;
+            bool mHasUnsupportedPlaneAlpha;
+    };
+
+    // Utility tempate calling a Layer object method based on ID parameters:
+    // hwc2_display_t displayId
+    // and
+    // hwc2_layer_t layerId
+    template <typename ...Args>
+    static int32_t callLayerFunction(hwc2_device_t* device,
+            hwc2_display_t displayId, hwc2_layer_t layerId,
+            HWC2::Error (Layer::*member)(Args...), Args... args) {
+        auto result = getAdapter(device)->getLayer(displayId, layerId);
+        auto error = std::get<HWC2::Error>(result);
+        if (error == HWC2::Error::None) {
+            auto layer = std::get<Layer*>(result);
+            error = ((*layer).*member)(std::forward<Args>(args)...);
+        }
+        return static_cast<int32_t>(error);
+    }
+
+    template <typename MF, MF memFunc, typename ...Args>
+    static int32_t layerHook(hwc2_device_t* device, hwc2_display_t displayId,
+            hwc2_layer_t layerId, Args... args) {
+        return HWC2On1Adapter::callLayerFunction(device, displayId, layerId,
+                memFunc, std::forward<Args>(args)...);
+    }
+
+    // Layer state functions
+
+    static int32_t setLayerBlendModeHook(hwc2_device_t* device,
+            hwc2_display_t display, hwc2_layer_t layer, int32_t intMode) {
+        auto mode = static_cast<HWC2::BlendMode>(intMode);
+        return callLayerFunction(device, display, layer,
+                &Layer::setBlendMode, mode);
+    }
+
+    static int32_t setLayerCompositionTypeHook(hwc2_device_t* device,
+            hwc2_display_t display, hwc2_layer_t layer, int32_t intType) {
+        auto type = static_cast<HWC2::Composition>(intType);
+        return callLayerFunction(device, display, layer,
+                &Layer::setCompositionType, type);
+    }
+
+    static int32_t setLayerDataspaceHook(hwc2_device_t* device,
+            hwc2_display_t display, hwc2_layer_t layer, int32_t intDataspace) {
+        auto dataspace = static_cast<android_dataspace_t>(intDataspace);
+        return callLayerFunction(device, display, layer, &Layer::setDataspace,
+                dataspace);
+    }
+
+    static int32_t setLayerTransformHook(hwc2_device_t* device,
+            hwc2_display_t display, hwc2_layer_t layer, int32_t intTransform) {
+        auto transform = static_cast<HWC2::Transform>(intTransform);
+        return callLayerFunction(device, display, layer, &Layer::setTransform,
+                transform);
+    }
+
+    static int32_t setLayerZOrderHook(hwc2_device_t* device,
+            hwc2_display_t display, hwc2_layer_t layer, uint32_t z) {
+        return callDisplayFunction(device, display, &Display::updateLayerZ,
+                layer, z);
+    }
+
+    // Adapter internals
+
+    void populateCapabilities();
+    Display* getDisplay(hwc2_display_t id);
+    std::tuple<Layer*, HWC2::Error> getLayer(hwc2_display_t displayId,
+            hwc2_layer_t layerId);
+    void populatePrimary();
+
+    bool prepareAllDisplays();
+    std::vector<struct hwc_display_contents_1*> mHwc1Contents;
+    HWC2::Error setAllDisplays();
+
+    // Callbacks
+    void hwc1Invalidate();
+    void hwc1Vsync(int hwc1DisplayId, int64_t timestamp);
+    void hwc1Hotplug(int hwc1DisplayId, int connected);
+
+    // These are set in the constructor and before any asynchronous events are
+    // possible
+
+    struct hwc_composer_device_1* const mHwc1Device;
+    const uint8_t mHwc1MinorVersion;
+    bool mHwc1SupportsVirtualDisplays;
+    bool mHwc1SupportsBackgroundColor;
+
+    class Callbacks;
+    const std::unique_ptr<Callbacks> mHwc1Callbacks;
+
+    std::unordered_set<HWC2::Capability> mCapabilities;
+
+    // These are only accessed from the main SurfaceFlinger thread (not from
+    // callbacks or dump
+
+    std::map<hwc2_layer_t, std::shared_ptr<Layer>> mLayers;
+
+    // A HWC1 supports only one virtual display.
+    std::shared_ptr<Display> mHwc1VirtualDisplay;
+
+    // These are potentially accessed from multiple threads, and are protected
+    // by this mutex. This needs to be recursive, since the HWC1 implementation
+    // can call back into the invalidate callback on the same thread that is
+    // calling prepare.
+    std::recursive_timed_mutex mStateMutex;
+
+    struct CallbackInfo {
+        hwc2_callback_data_t data;
+        hwc2_function_pointer_t pointer;
+    };
+    std::unordered_map<HWC2::Callback, CallbackInfo> mCallbacks;
+    bool mHasPendingInvalidate;
+
+    // There is a small gap between the time the HWC1 module is started and
+    // when the callbacks for vsync and hotplugs are registered by the
+    // HWC2on1Adapter. To prevent losing events they are stored in these arrays
+    // and fed to the callback as soon as possible.
+    std::vector<std::pair<int, int64_t>> mPendingVsyncs;
+    std::vector<std::pair<int, int>> mPendingHotplugs;
+
+    // Mapping between HWC1 display id and Display objects.
+    std::map<hwc2_display_t, std::shared_ptr<Display>> mDisplays;
+
+    // Map HWC1 display type (HWC_DISPLAY_PRIMARY, HWC_DISPLAY_EXTERNAL,
+    // HWC_DISPLAY_VIRTUAL) to Display IDs generated by HWC2on1Adapter objects.
+    std::unordered_map<int, hwc2_display_t> mHwc1DisplayMap;
+};
+
+} // namespace android
+
+#endif

graphics/composer/2.1/utils/hwc2on1adapter/include/hwc2on1adapter/MiniFence.h

@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+#ifndef MINIFENCE_H
+#define MINIFENCE_H
+
+#include <utils/RefBase.h>
+
+namespace android {
+
+/* MiniFence is a minimal re-implementation of Fence from libui. It exists to
+ * avoid linking the HWC2on1Adapter to libui and satisfy Treble requirements.
+ */
+class MiniFence : public LightRefBase<MiniFence> {
+public:
+    static const sp<MiniFence> NO_FENCE;
+
+    // Construct a new MiniFence object with an invalid file descriptor.
+    MiniFence();
+
+    // Construct a new MiniFence object to manage a given fence file descriptor.
+    // When the new MiniFence object is destructed the file descriptor will be
+    // closed.
+    explicit MiniFence(int fenceFd);
+
+    // Not copyable or movable.
+    MiniFence(const MiniFence& rhs) = delete;
+    MiniFence& operator=(const MiniFence& rhs) = delete;
+    MiniFence(MiniFence&& rhs) = delete;
+    MiniFence& operator=(MiniFence&& rhs) = delete;
+
+    // Return a duplicate of the fence file descriptor. The caller is
+    // responsible for closing the returned file descriptor. On error, -1 will
+    // be returned and errno will indicate the problem.
+    int dup() const;
+
+private:
+    // Only allow instantiation using ref counting.
+    friend class LightRefBase<MiniFence>;
+    ~MiniFence();
+
+    int mFenceFd;
+
+};
+}
+#endif //MINIFENCE_H

graphics/composer/2.1/utils/hwc2onfbadapter/Android.bp

@@ -0,0 +1,33 @@
+// Copyright 2010 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.
+
+cc_library_shared {
+    name: "libhwc2onfbadapter",
+    vendor: true,
+
+    clang: true,
+    cflags: [
+        "-Wall",
+        "-Wextra",
+        "-Werror",
+    ],
+
+    srcs: [
+        "HWC2OnFbAdapter.cpp",
+    ],
+
+    header_libs: ["libhardware_headers"],
+    shared_libs: ["liblog", "libsync"],
+    export_include_dirs: ["include"],
+}

graphics/composer/2.1/utils/hwc2onfbadapter/HWC2OnFbAdapter.cpp

@@ -0,0 +1,887 @@
+/*
+ * Copyright 2017 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 "HWC2OnFbAdapter"
+
+//#define LOG_NDEBUG 0
+
+#include "hwc2onfbadapter/HWC2OnFbAdapter.h"
+
+#include <algorithm>
+#include <type_traits>
+
+#include <inttypes.h>
+#include <time.h>
+#include <sys/prctl.h>
+#include <unistd.h> // for close
+
+#include <hardware/fb.h>
+#include <log/log.h>
+#include <sync/sync.h>
+
+namespace android {
+
+namespace {
+
+void dumpHook(hwc2_device_t* device, uint32_t* outSize, char* outBuffer) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (outBuffer) {
+        *outSize = adapter.getDebugString().copy(outBuffer, *outSize);
+    } else {
+        adapter.updateDebugString();
+        *outSize = adapter.getDebugString().size();
+    }
+}
+
+int32_t registerCallbackHook(hwc2_device_t* device, int32_t descriptor,
+                             hwc2_callback_data_t callbackData, hwc2_function_pointer_t pointer) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    switch (descriptor) {
+        case HWC2_CALLBACK_HOTPLUG:
+            if (pointer) {
+                reinterpret_cast<HWC2_PFN_HOTPLUG>(pointer)(callbackData, adapter.getDisplayId(),
+                                                            HWC2_CONNECTION_CONNECTED);
+            }
+            break;
+        case HWC2_CALLBACK_REFRESH:
+            break;
+        case HWC2_CALLBACK_VSYNC:
+            adapter.setVsyncCallback(reinterpret_cast<HWC2_PFN_VSYNC>(pointer), callbackData);
+            break;
+        default:
+            return HWC2_ERROR_BAD_PARAMETER;
+    }
+
+    return HWC2_ERROR_NONE;
+}
+
+uint32_t getMaxVirtualDisplayCountHook(hwc2_device_t* /*device*/) {
+    return 0;
+}
+
+int32_t createVirtualDisplayHook(hwc2_device_t* /*device*/, uint32_t /*width*/, uint32_t /*height*/,
+                                 int32_t* /*format*/, hwc2_display_t* /*outDisplay*/) {
+    return HWC2_ERROR_NO_RESOURCES;
+}
+
+int32_t destroyVirtualDisplayHook(hwc2_device_t* /*device*/, hwc2_display_t /*display*/) {
+    return HWC2_ERROR_BAD_DISPLAY;
+}
+
+int32_t setOutputBufferHook(hwc2_device_t* /*device*/, hwc2_display_t /*display*/,
+                            buffer_handle_t /*buffer*/, int32_t /*releaseFence*/) {
+    return HWC2_ERROR_BAD_DISPLAY;
+}
+
+int32_t getDisplayNameHook(hwc2_device_t* device, hwc2_display_t display, uint32_t* outSize,
+                           char* outName) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+
+    const auto& info = adapter.getInfo();
+    if (outName) {
+        *outSize = info.name.copy(outName, *outSize);
+    } else {
+        *outSize = info.name.size();
+    }
+
+    return HWC2_ERROR_NONE;
+}
+
+int32_t getDisplayTypeHook(hwc2_device_t* device, hwc2_display_t display, int32_t* outType) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+
+    *outType = HWC2_DISPLAY_TYPE_PHYSICAL;
+    return HWC2_ERROR_NONE;
+}
+
+int32_t getDozeSupportHook(hwc2_device_t* device, hwc2_display_t display, int32_t* outSupport) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+
+    *outSupport = 0;
+    return HWC2_ERROR_NONE;
+}
+
+int32_t getHdrCapabilitiesHook(hwc2_device_t* device, hwc2_display_t display, uint32_t* outNumTypes,
+                               int32_t* /*outTypes*/, float* /*outMaxLuminance*/,
+                               float* /*outMaxAverageLuminance*/, float* /*outMinLuminance*/) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+
+    *outNumTypes = 0;
+    return HWC2_ERROR_NONE;
+}
+
+int32_t setPowerModeHook(hwc2_device_t* device, hwc2_display_t display, int32_t /*mode*/) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+
+    // pretend that it works
+    return HWC2_ERROR_NONE;
+}
+
+int32_t setVsyncEnabledHook(hwc2_device_t* device, hwc2_display_t display, int32_t enabled) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+
+    adapter.enableVsync(enabled == HWC2_VSYNC_ENABLE);
+    return HWC2_ERROR_NONE;
+}
+
+int32_t getColorModesHook(hwc2_device_t* device, hwc2_display_t display, uint32_t* outNumModes,
+                          int32_t* outModes) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+
+    if (outModes) {
+        if (*outNumModes > 0) {
+            outModes[0] = HAL_COLOR_MODE_NATIVE;
+            *outNumModes = 1;
+        }
+    } else {
+        *outNumModes = 1;
+    }
+
+    return HWC2_ERROR_NONE;
+}
+
+int32_t setColorModeHook(hwc2_device_t* device, hwc2_display_t display, int32_t mode) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+    if (mode != HAL_COLOR_MODE_NATIVE) {
+        return HWC2_ERROR_BAD_PARAMETER;
+    }
+
+    return HWC2_ERROR_NONE;
+}
+
+int32_t setColorTransformHook(hwc2_device_t* device, hwc2_display_t display,
+                              const float* /*matrix*/, int32_t /*hint*/) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+
+    // we always force client composition
+    adapter.setState(HWC2OnFbAdapter::State::MODIFIED);
+    return HWC2_ERROR_NONE;
+}
+
+int32_t getClientTargetSupportHook(hwc2_device_t* device, hwc2_display_t display, uint32_t width,
+                                   uint32_t height, int32_t format, int32_t dataspace) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+    if (dataspace != HAL_DATASPACE_UNKNOWN) {
+        return HWC2_ERROR_UNSUPPORTED;
+    }
+
+    const auto& info = adapter.getInfo();
+    return (info.width == width && info.height == height && info.format == format)
+            ? HWC2_ERROR_NONE
+            : HWC2_ERROR_UNSUPPORTED;
+}
+
+int32_t setClientTargetHook(hwc2_device_t* device, hwc2_display_t display, buffer_handle_t target,
+                            int32_t acquireFence, int32_t dataspace, hwc_region_t /*damage*/) {
+    if (acquireFence >= 0) {
+        sync_wait(acquireFence, -1);
+        close(acquireFence);
+    }
+
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+    if (dataspace != HAL_DATASPACE_UNKNOWN) {
+        return HWC2_ERROR_BAD_PARAMETER;
+    }
+
+    // no state change
+    adapter.setBuffer(target);
+    return HWC2_ERROR_NONE;
+}
+
+int32_t getDisplayConfigsHook(hwc2_device_t* device, hwc2_display_t display,
+                              uint32_t* outNumConfigs, hwc2_config_t* outConfigs) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+
+    if (outConfigs) {
+        if (*outNumConfigs > 0) {
+            outConfigs[0] = adapter.getConfigId();
+            *outNumConfigs = 1;
+        }
+    } else {
+        *outNumConfigs = 1;
+    }
+
+    return HWC2_ERROR_NONE;
+}
+
+int32_t getDisplayAttributeHook(hwc2_device_t* device, hwc2_display_t display, hwc2_config_t config,
+                                int32_t attribute, int32_t* outValue) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+    if (adapter.getConfigId() != config) {
+        return HWC2_ERROR_BAD_CONFIG;
+    }
+
+    const auto& info = adapter.getInfo();
+    switch (attribute) {
+        case HWC2_ATTRIBUTE_WIDTH:
+            *outValue = int32_t(info.width);
+            break;
+        case HWC2_ATTRIBUTE_HEIGHT:
+            *outValue = int32_t(info.height);
+            break;
+        case HWC2_ATTRIBUTE_VSYNC_PERIOD:
+            *outValue = int32_t(info.vsync_period_ns);
+            break;
+        case HWC2_ATTRIBUTE_DPI_X:
+            *outValue = int32_t(info.xdpi_scaled);
+            break;
+        case HWC2_ATTRIBUTE_DPI_Y:
+            *outValue = int32_t(info.ydpi_scaled);
+            break;
+        default:
+            return HWC2_ERROR_BAD_PARAMETER;
+    }
+
+    return HWC2_ERROR_NONE;
+}
+
+int32_t getActiveConfigHook(hwc2_device_t* device, hwc2_display_t display,
+                            hwc2_config_t* outConfig) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+
+    *outConfig = adapter.getConfigId();
+    return HWC2_ERROR_NONE;
+}
+
+int32_t setActiveConfigHook(hwc2_device_t* device, hwc2_display_t display, hwc2_config_t config) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+    if (adapter.getConfigId() != config) {
+        return HWC2_ERROR_BAD_CONFIG;
+    }
+
+    return HWC2_ERROR_NONE;
+}
+
+int32_t validateDisplayHook(hwc2_device_t* device, hwc2_display_t display, uint32_t* outNumTypes,
+                            uint32_t* outNumRequests) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+
+    const auto& dirtyLayers = adapter.getDirtyLayers();
+    *outNumTypes = dirtyLayers.size();
+    *outNumRequests = 0;
+
+    if (*outNumTypes > 0) {
+        adapter.setState(HWC2OnFbAdapter::State::VALIDATED_WITH_CHANGES);
+        return HWC2_ERROR_HAS_CHANGES;
+    } else {
+        adapter.setState(HWC2OnFbAdapter::State::VALIDATED);
+        return HWC2_ERROR_NONE;
+    }
+}
+
+int32_t getChangedCompositionTypesHook(hwc2_device_t* device, hwc2_display_t display,
+                                       uint32_t* outNumElements, hwc2_layer_t* outLayers,
+                                       int32_t* outTypes) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+    if (adapter.getState() == HWC2OnFbAdapter::State::MODIFIED) {
+        return HWC2_ERROR_NOT_VALIDATED;
+    }
+
+    // request client composition for all layers
+    const auto& dirtyLayers = adapter.getDirtyLayers();
+    if (outLayers && outTypes) {
+        *outNumElements = std::min(*outNumElements, uint32_t(dirtyLayers.size()));
+        auto iter = dirtyLayers.cbegin();
+        for (uint32_t i = 0; i < *outNumElements; i++) {
+            outLayers[i] = *iter++;
+            outTypes[i] = HWC2_COMPOSITION_CLIENT;
+        }
+    } else {
+        *outNumElements = dirtyLayers.size();
+    }
+
+    return HWC2_ERROR_NONE;
+}
+
+int32_t getDisplayRequestsHook(hwc2_device_t* device, hwc2_display_t display,
+                               int32_t* outDisplayRequests, uint32_t* outNumElements,
+                               hwc2_layer_t* /*outLayers*/, int32_t* /*outLayerRequests*/) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+    if (adapter.getState() == HWC2OnFbAdapter::State::MODIFIED) {
+        return HWC2_ERROR_NOT_VALIDATED;
+    }
+
+    *outDisplayRequests = 0;
+    *outNumElements = 0;
+    return HWC2_ERROR_NONE;
+}
+
+int32_t acceptDisplayChangesHook(hwc2_device_t* device, hwc2_display_t display) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+    if (adapter.getState() == HWC2OnFbAdapter::State::MODIFIED) {
+        return HWC2_ERROR_NOT_VALIDATED;
+    }
+
+    adapter.clearDirtyLayers();
+    adapter.setState(HWC2OnFbAdapter::State::VALIDATED);
+    return HWC2_ERROR_NONE;
+}
+
+int32_t presentDisplayHook(hwc2_device_t* device, hwc2_display_t display,
+                           int32_t* outPresentFence) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+    if (adapter.getState() != HWC2OnFbAdapter::State::VALIDATED) {
+        return HWC2_ERROR_NOT_VALIDATED;
+    }
+
+    adapter.postBuffer();
+    *outPresentFence = -1;
+
+    return HWC2_ERROR_NONE;
+}
+
+int32_t getReleaseFencesHook(hwc2_device_t* device, hwc2_display_t display,
+                             uint32_t* outNumElements, hwc2_layer_t* /*outLayers*/,
+                             int32_t* /*outFences*/) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+
+    *outNumElements = 0;
+    return HWC2_ERROR_NONE;
+}
+
+int32_t createLayerHook(hwc2_device_t* device, hwc2_display_t display, hwc2_layer_t* outLayer) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+
+    *outLayer = adapter.addLayer();
+    adapter.setState(HWC2OnFbAdapter::State::MODIFIED);
+    return HWC2_ERROR_NONE;
+}
+
+int32_t destroyLayerHook(hwc2_device_t* device, hwc2_display_t display, hwc2_layer_t layer) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+
+    if (adapter.removeLayer(layer)) {
+        adapter.setState(HWC2OnFbAdapter::State::MODIFIED);
+        return HWC2_ERROR_NONE;
+    } else {
+        return HWC2_ERROR_BAD_LAYER;
+    }
+}
+
+int32_t setCursorPositionHook(hwc2_device_t* device, hwc2_display_t display, hwc2_layer_t /*layer*/,
+                              int32_t /*x*/, int32_t /*y*/) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+
+    // always an error
+    return HWC2_ERROR_BAD_LAYER;
+}
+
+int32_t setLayerBufferHook(hwc2_device_t* device, hwc2_display_t display, hwc2_layer_t layer,
+                           buffer_handle_t /*buffer*/, int32_t acquireFence) {
+    if (acquireFence >= 0) {
+        sync_wait(acquireFence, -1);
+        close(acquireFence);
+    }
+
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+    if (!adapter.hasLayer(layer)) {
+        return HWC2_ERROR_BAD_LAYER;
+    }
+
+    // no state change
+    return HWC2_ERROR_NONE;
+}
+
+int32_t setLayerSurfaceDamageHook(hwc2_device_t* device, hwc2_display_t display, hwc2_layer_t layer,
+                                  hwc_region_t /*damage*/) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+    if (!adapter.hasLayer(layer)) {
+        return HWC2_ERROR_BAD_LAYER;
+    }
+
+    // no state change
+    return HWC2_ERROR_NONE;
+}
+
+int32_t setLayerCompositionTypeHook(hwc2_device_t* device, hwc2_display_t display,
+                                    hwc2_layer_t layer, int32_t type) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+    if (!adapter.markLayerDirty(layer, type != HWC2_COMPOSITION_CLIENT)) {
+        return HWC2_ERROR_BAD_LAYER;
+    }
+
+    adapter.setState(HWC2OnFbAdapter::State::MODIFIED);
+    return HWC2_ERROR_NONE;
+}
+
+template <typename... Args>
+int32_t setLayerStateHook(hwc2_device_t* device, hwc2_display_t display, hwc2_layer_t layer,
+                          Args... /*args*/) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    if (adapter.getDisplayId() != display) {
+        return HWC2_ERROR_BAD_DISPLAY;
+    }
+    if (!adapter.hasLayer(layer)) {
+        return HWC2_ERROR_BAD_LAYER;
+    }
+
+    adapter.setState(HWC2OnFbAdapter::State::MODIFIED);
+    return HWC2_ERROR_NONE;
+}
+
+template <typename PFN, typename T>
+static hwc2_function_pointer_t asFP(T function) {
+    static_assert(std::is_same<PFN, T>::value, "Incompatible function pointer");
+    return reinterpret_cast<hwc2_function_pointer_t>(function);
+}
+
+hwc2_function_pointer_t getFunctionHook(hwc2_device_t* /*device*/, int32_t descriptor) {
+    switch (descriptor) {
+        // global functions
+        case HWC2_FUNCTION_DUMP:
+            return asFP<HWC2_PFN_DUMP>(dumpHook);
+        case HWC2_FUNCTION_REGISTER_CALLBACK:
+            return asFP<HWC2_PFN_REGISTER_CALLBACK>(registerCallbackHook);
+
+        // virtual display functions
+        case HWC2_FUNCTION_GET_MAX_VIRTUAL_DISPLAY_COUNT:
+            return asFP<HWC2_PFN_GET_MAX_VIRTUAL_DISPLAY_COUNT>(getMaxVirtualDisplayCountHook);
+        case HWC2_FUNCTION_CREATE_VIRTUAL_DISPLAY:
+            return asFP<HWC2_PFN_CREATE_VIRTUAL_DISPLAY>(createVirtualDisplayHook);
+        case HWC2_FUNCTION_DESTROY_VIRTUAL_DISPLAY:
+            return asFP<HWC2_PFN_DESTROY_VIRTUAL_DISPLAY>(destroyVirtualDisplayHook);
+        case HWC2_FUNCTION_SET_OUTPUT_BUFFER:
+            return asFP<HWC2_PFN_SET_OUTPUT_BUFFER>(setOutputBufferHook);
+
+        // display functions
+        case HWC2_FUNCTION_GET_DISPLAY_NAME:
+            return asFP<HWC2_PFN_GET_DISPLAY_NAME>(getDisplayNameHook);
+        case HWC2_FUNCTION_GET_DISPLAY_TYPE:
+            return asFP<HWC2_PFN_GET_DISPLAY_TYPE>(getDisplayTypeHook);
+        case HWC2_FUNCTION_GET_DOZE_SUPPORT:
+            return asFP<HWC2_PFN_GET_DOZE_SUPPORT>(getDozeSupportHook);
+        case HWC2_FUNCTION_GET_HDR_CAPABILITIES:
+            return asFP<HWC2_PFN_GET_HDR_CAPABILITIES>(getHdrCapabilitiesHook);
+        case HWC2_FUNCTION_SET_POWER_MODE:
+            return asFP<HWC2_PFN_SET_POWER_MODE>(setPowerModeHook);
+        case HWC2_FUNCTION_SET_VSYNC_ENABLED:
+            return asFP<HWC2_PFN_SET_VSYNC_ENABLED>(setVsyncEnabledHook);
+        case HWC2_FUNCTION_GET_COLOR_MODES:
+            return asFP<HWC2_PFN_GET_COLOR_MODES>(getColorModesHook);
+        case HWC2_FUNCTION_SET_COLOR_MODE:
+            return asFP<HWC2_PFN_SET_COLOR_MODE>(setColorModeHook);
+        case HWC2_FUNCTION_SET_COLOR_TRANSFORM:
+            return asFP<HWC2_PFN_SET_COLOR_TRANSFORM>(setColorTransformHook);
+        case HWC2_FUNCTION_GET_CLIENT_TARGET_SUPPORT:
+            return asFP<HWC2_PFN_GET_CLIENT_TARGET_SUPPORT>(getClientTargetSupportHook);
+        case HWC2_FUNCTION_SET_CLIENT_TARGET:
+            return asFP<HWC2_PFN_SET_CLIENT_TARGET>(setClientTargetHook);
+
+        // config functions
+        case HWC2_FUNCTION_GET_DISPLAY_CONFIGS:
+            return asFP<HWC2_PFN_GET_DISPLAY_CONFIGS>(getDisplayConfigsHook);
+        case HWC2_FUNCTION_GET_DISPLAY_ATTRIBUTE:
+            return asFP<HWC2_PFN_GET_DISPLAY_ATTRIBUTE>(getDisplayAttributeHook);
+        case HWC2_FUNCTION_GET_ACTIVE_CONFIG:
+            return asFP<HWC2_PFN_GET_ACTIVE_CONFIG>(getActiveConfigHook);
+        case HWC2_FUNCTION_SET_ACTIVE_CONFIG:
+            return asFP<HWC2_PFN_SET_ACTIVE_CONFIG>(setActiveConfigHook);
+
+        // validate/present functions
+        case HWC2_FUNCTION_VALIDATE_DISPLAY:
+            return asFP<HWC2_PFN_VALIDATE_DISPLAY>(validateDisplayHook);
+        case HWC2_FUNCTION_GET_CHANGED_COMPOSITION_TYPES:
+            return asFP<HWC2_PFN_GET_CHANGED_COMPOSITION_TYPES>(getChangedCompositionTypesHook);
+        case HWC2_FUNCTION_GET_DISPLAY_REQUESTS:
+            return asFP<HWC2_PFN_GET_DISPLAY_REQUESTS>(getDisplayRequestsHook);
+        case HWC2_FUNCTION_ACCEPT_DISPLAY_CHANGES:
+            return asFP<HWC2_PFN_ACCEPT_DISPLAY_CHANGES>(acceptDisplayChangesHook);
+        case HWC2_FUNCTION_PRESENT_DISPLAY:
+            return asFP<HWC2_PFN_PRESENT_DISPLAY>(presentDisplayHook);
+        case HWC2_FUNCTION_GET_RELEASE_FENCES:
+            return asFP<HWC2_PFN_GET_RELEASE_FENCES>(getReleaseFencesHook);
+
+        // layer create/destroy
+        case HWC2_FUNCTION_CREATE_LAYER:
+            return asFP<HWC2_PFN_CREATE_LAYER>(createLayerHook);
+        case HWC2_FUNCTION_DESTROY_LAYER:
+            return asFP<HWC2_PFN_DESTROY_LAYER>(destroyLayerHook);
+
+        // layer functions; validateDisplay not required
+        case HWC2_FUNCTION_SET_CURSOR_POSITION:
+            return asFP<HWC2_PFN_SET_CURSOR_POSITION>(setCursorPositionHook);
+        case HWC2_FUNCTION_SET_LAYER_BUFFER:
+            return asFP<HWC2_PFN_SET_LAYER_BUFFER>(setLayerBufferHook);
+        case HWC2_FUNCTION_SET_LAYER_SURFACE_DAMAGE:
+            return asFP<HWC2_PFN_SET_LAYER_SURFACE_DAMAGE>(setLayerSurfaceDamageHook);
+
+        // layer state functions; validateDisplay required
+        case HWC2_FUNCTION_SET_LAYER_COMPOSITION_TYPE:
+            return asFP<HWC2_PFN_SET_LAYER_COMPOSITION_TYPE>(setLayerCompositionTypeHook);
+        case HWC2_FUNCTION_SET_LAYER_BLEND_MODE:
+            return asFP<HWC2_PFN_SET_LAYER_BLEND_MODE>(setLayerStateHook<int32_t>);
+        case HWC2_FUNCTION_SET_LAYER_COLOR:
+            return asFP<HWC2_PFN_SET_LAYER_COLOR>(setLayerStateHook<hwc_color_t>);
+        case HWC2_FUNCTION_SET_LAYER_DATASPACE:
+            return asFP<HWC2_PFN_SET_LAYER_DATASPACE>(setLayerStateHook<int32_t>);
+        case HWC2_FUNCTION_SET_LAYER_DISPLAY_FRAME:
+            return asFP<HWC2_PFN_SET_LAYER_DISPLAY_FRAME>(setLayerStateHook<hwc_rect_t>);
+        case HWC2_FUNCTION_SET_LAYER_PLANE_ALPHA:
+            return asFP<HWC2_PFN_SET_LAYER_PLANE_ALPHA>(setLayerStateHook<float>);
+        case HWC2_FUNCTION_SET_LAYER_SIDEBAND_STREAM:
+            return asFP<HWC2_PFN_SET_LAYER_SIDEBAND_STREAM>(setLayerStateHook<buffer_handle_t>);
+        case HWC2_FUNCTION_SET_LAYER_SOURCE_CROP:
+            return asFP<HWC2_PFN_SET_LAYER_SOURCE_CROP>(setLayerStateHook<hwc_frect_t>);
+        case HWC2_FUNCTION_SET_LAYER_TRANSFORM:
+            return asFP<HWC2_PFN_SET_LAYER_TRANSFORM>(setLayerStateHook<int32_t>);
+        case HWC2_FUNCTION_SET_LAYER_VISIBLE_REGION:
+            return asFP<HWC2_PFN_SET_LAYER_VISIBLE_REGION>(setLayerStateHook<hwc_region_t>);
+        case HWC2_FUNCTION_SET_LAYER_Z_ORDER:
+            return asFP<HWC2_PFN_SET_LAYER_Z_ORDER>(setLayerStateHook<uint32_t>);
+
+        default:
+            ALOGE("unknown function descriptor %d", descriptor);
+            return nullptr;
+    }
+}
+
+void getCapabilitiesHook(hwc2_device_t* /*device*/, uint32_t* outCount,
+                         int32_t* /*outCapabilities*/) {
+    *outCount = 0;
+}
+
+int closeHook(hw_device_t* device) {
+    auto& adapter = HWC2OnFbAdapter::cast(device);
+    adapter.close();
+    return 0;
+}
+
+} // anonymous namespace
+
+HWC2OnFbAdapter::HWC2OnFbAdapter(framebuffer_device_t* fbDevice)
+      : hwc2_device_t(), mFbDevice(fbDevice) {
+    common.close = closeHook;
+    hwc2_device::getCapabilities = getCapabilitiesHook;
+    hwc2_device::getFunction = getFunctionHook;
+
+    mFbInfo.name = "fbdev";
+    mFbInfo.width = mFbDevice->width;
+    mFbInfo.height = mFbDevice->height;
+    mFbInfo.format = mFbDevice->format;
+    mFbInfo.vsync_period_ns = int(1e9 / mFbDevice->fps);
+    mFbInfo.xdpi_scaled = int(mFbDevice->xdpi * 1000.0f);
+    mFbInfo.ydpi_scaled = int(mFbDevice->ydpi * 1000.0f);
+
+    mVsyncThread.start(0, mFbInfo.vsync_period_ns);
+}
+
+HWC2OnFbAdapter& HWC2OnFbAdapter::cast(hw_device_t* device) {
+    return *reinterpret_cast<HWC2OnFbAdapter*>(device);
+}
+
+HWC2OnFbAdapter& HWC2OnFbAdapter::cast(hwc2_device_t* device) {
+    return *reinterpret_cast<HWC2OnFbAdapter*>(device);
+}
+
+hwc2_display_t HWC2OnFbAdapter::getDisplayId() {
+    return 0;
+}
+
+hwc2_config_t HWC2OnFbAdapter::getConfigId() {
+    return 0;
+}
+
+void HWC2OnFbAdapter::close() {
+    mVsyncThread.stop();
+    framebuffer_close(mFbDevice);
+}
+
+const HWC2OnFbAdapter::Info& HWC2OnFbAdapter::getInfo() const {
+    return mFbInfo;
+}
+
+void HWC2OnFbAdapter::updateDebugString() {
+    if (mFbDevice->common.version >= 1 && mFbDevice->dump) {
+        char buffer[4096];
+        mFbDevice->dump(mFbDevice, buffer, sizeof(buffer));
+        buffer[sizeof(buffer) - 1] = '\0';
+
+        mDebugString = buffer;
+    }
+}
+
+const std::string& HWC2OnFbAdapter::getDebugString() const {
+    return mDebugString;
+}
+
+void HWC2OnFbAdapter::setState(State state) {
+    mState = state;
+}
+
+HWC2OnFbAdapter::State HWC2OnFbAdapter::getState() const {
+    return mState;
+}
+
+hwc2_layer_t HWC2OnFbAdapter::addLayer() {
+    hwc2_layer_t id = ++mNextLayerId;
+
+    mLayers.insert(id);
+    mDirtyLayers.insert(id);
+
+    return id;
+}
+
+bool HWC2OnFbAdapter::removeLayer(hwc2_layer_t layer) {
+    mDirtyLayers.erase(layer);
+    return mLayers.erase(layer);
+}
+
+bool HWC2OnFbAdapter::hasLayer(hwc2_layer_t layer) const {
+    return mLayers.count(layer) > 0;
+}
+
+bool HWC2OnFbAdapter::markLayerDirty(hwc2_layer_t layer, bool dirty) {
+    if (mLayers.count(layer) == 0) {
+        return false;
+    }
+
+    if (dirty) {
+        mDirtyLayers.insert(layer);
+    } else {
+        mDirtyLayers.erase(layer);
+    }
+
+    return true;
+}
+
+const std::unordered_set<hwc2_layer_t>& HWC2OnFbAdapter::getDirtyLayers() const {
+    return mDirtyLayers;
+}
+
+void HWC2OnFbAdapter::clearDirtyLayers() {
+    mDirtyLayers.clear();
+}
+
+/*
+ * For each frame, SurfaceFlinger
+ *
+ *  - peforms GLES composition
+ *  - calls eglSwapBuffers
+ *  - calls setClientTarget, which maps to setBuffer below
+ *  - calls presentDisplay, which maps to postBuffer below
+ *
+ * setBuffer should be a good place to call compositionComplete.
+ *
+ * As for post, it
+ *
+ *  - schedules the buffer for presentation on the next vsync
+ *  - locks the buffer and blocks all other users trying to lock it
+ *
+ * It does not give us a way to return a present fence, and we need to live
+ * with that.  The implication is that, when we are double-buffered,
+ * SurfaceFlinger assumes the front buffer is available for rendering again
+ * immediately after the back buffer is posted.  The locking semantics
+ * hopefully are strong enough that the rendering will be blocked.
+ */
+void HWC2OnFbAdapter::setBuffer(buffer_handle_t buffer) {
+    if (mFbDevice->compositionComplete) {
+        mFbDevice->compositionComplete(mFbDevice);
+    }
+    mBuffer = buffer;
+}
+
+bool HWC2OnFbAdapter::postBuffer() {
+    int error = 0;
+    if (mBuffer) {
+        error = mFbDevice->post(mFbDevice, mBuffer);
+    }
+
+    return error == 0;
+}
+
+void HWC2OnFbAdapter::setVsyncCallback(HWC2_PFN_VSYNC callback, hwc2_callback_data_t data) {
+    mVsyncThread.setCallback(callback, data);
+}
+
+void HWC2OnFbAdapter::enableVsync(bool enable) {
+    mVsyncThread.enableCallback(enable);
+}
+
+int64_t HWC2OnFbAdapter::VsyncThread::now() {
+    struct timespec ts;
+    clock_gettime(CLOCK_MONOTONIC, &ts);
+
+    return int64_t(ts.tv_sec) * 1'000'000'000 + ts.tv_nsec;
+}
+
+bool HWC2OnFbAdapter::VsyncThread::sleepUntil(int64_t t) {
+    struct timespec ts;
+    ts.tv_sec = t / 1'000'000'000;
+    ts.tv_nsec = t % 1'000'000'000;
+
+    while (true) {
+        int error = clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &ts, nullptr);
+        if (error) {
+            if (error == EINTR) {
+                continue;
+            }
+            return false;
+        } else {
+            return true;
+        }
+    }
+}
+
+void HWC2OnFbAdapter::VsyncThread::start(int64_t firstVsync, int64_t period) {
+    mNextVsync = firstVsync;
+    mPeriod = period;
+    mStarted = true;
+    mThread = std::thread(&VsyncThread::vsyncLoop, this);
+}
+
+void HWC2OnFbAdapter::VsyncThread::stop() {
+    {
+        std::lock_guard<std::mutex> lock(mMutex);
+        mStarted = false;
+    }
+    mCondition.notify_all();
+    mThread.join();
+}
+
+void HWC2OnFbAdapter::VsyncThread::setCallback(HWC2_PFN_VSYNC callback, hwc2_callback_data_t data) {
+    std::lock_guard<std::mutex> lock(mMutex);
+    mCallback = callback;
+    mCallbackData = data;
+}
+
+void HWC2OnFbAdapter::VsyncThread::enableCallback(bool enable) {
+    {
+        std::lock_guard<std::mutex> lock(mMutex);
+        mCallbackEnabled = enable;
+    }
+    mCondition.notify_all();
+}
+
+void HWC2OnFbAdapter::VsyncThread::vsyncLoop() {
+    prctl(PR_SET_NAME, "VsyncThread", 0, 0, 0);
+
+    std::unique_lock<std::mutex> lock(mMutex);
+    if (!mStarted) {
+        return;
+    }
+
+    while (true) {
+        if (!mCallbackEnabled) {
+            mCondition.wait(lock, [this] { return mCallbackEnabled || !mStarted; });
+            if (!mStarted) {
+                break;
+            }
+        }
+
+        lock.unlock();
+
+        // adjust mNextVsync if necessary
+        int64_t t = now();
+        if (mNextVsync < t) {
+            int64_t n = (t - mNextVsync + mPeriod - 1) / mPeriod;
+            mNextVsync += mPeriod * n;
+        }
+        bool fire = sleepUntil(mNextVsync);
+
+        lock.lock();
+
+        if (fire) {
+            ALOGV("VsyncThread(%" PRId64 ")", mNextVsync);
+            if (mCallback) {
+                mCallback(mCallbackData, getDisplayId(), mNextVsync);
+            }
+            mNextVsync += mPeriod;
+        }
+    }
+}
+
+} // namespace android

graphics/composer/2.1/utils/hwc2onfbadapter/include/hwc2onfbadapter/HWC2OnFbAdapter.h

@@ -0,0 +1,123 @@
+/*
+ * Copyright 2017 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.
+ */
+
+#ifndef ANDROID_SF_HWC2_ON_FB_ADAPTER_H
+#define ANDROID_SF_HWC2_ON_FB_ADAPTER_H
+
+#include <condition_variable>
+#include <mutex>
+#include <string>
+#include <thread>
+#include <unordered_set>
+
+#include <hardware/hwcomposer2.h>
+
+struct framebuffer_device_t;
+
+namespace android {
+
+class HWC2OnFbAdapter : public hwc2_device_t {
+public:
+    HWC2OnFbAdapter(framebuffer_device_t* fbDevice);
+
+    static HWC2OnFbAdapter& cast(hw_device_t* device);
+    static HWC2OnFbAdapter& cast(hwc2_device_t* device);
+
+    static hwc2_display_t getDisplayId();
+    static hwc2_config_t getConfigId();
+
+    void close();
+
+    struct Info {
+        std::string name;
+        uint32_t width;
+        uint32_t height;
+        int format;
+        int vsync_period_ns;
+        int xdpi_scaled;
+        int ydpi_scaled;
+    };
+    const Info& getInfo() const;
+
+    void updateDebugString();
+    const std::string& getDebugString() const;
+
+    enum class State {
+        MODIFIED,
+        VALIDATED_WITH_CHANGES,
+        VALIDATED,
+    };
+    void setState(State state);
+    State getState() const;
+
+    hwc2_layer_t addLayer();
+    bool removeLayer(hwc2_layer_t layer);
+    bool hasLayer(hwc2_layer_t layer) const;
+    bool markLayerDirty(hwc2_layer_t layer, bool dirty);
+    const std::unordered_set<hwc2_layer_t>& getDirtyLayers() const;
+    void clearDirtyLayers();
+
+    void setBuffer(buffer_handle_t buffer);
+    bool postBuffer();
+
+    void setVsyncCallback(HWC2_PFN_VSYNC callback, hwc2_callback_data_t data);
+    void enableVsync(bool enable);
+
+private:
+    framebuffer_device_t* mFbDevice{nullptr};
+    Info mFbInfo{};
+
+    std::string mDebugString;
+
+    State mState{State::MODIFIED};
+
+    uint64_t mNextLayerId{0};
+    std::unordered_set<hwc2_layer_t> mLayers;
+    std::unordered_set<hwc2_layer_t> mDirtyLayers;
+
+    buffer_handle_t mBuffer{nullptr};
+
+    class VsyncThread {
+    public:
+        static int64_t now();
+        static bool sleepUntil(int64_t t);
+
+        void start(int64_t first, int64_t period);
+        void stop();
+        void setCallback(HWC2_PFN_VSYNC callback, hwc2_callback_data_t data);
+        void enableCallback(bool enable);
+
+    private:
+        void vsyncLoop();
+        bool waitUntilNextVsync();
+
+        std::thread mThread;
+        int64_t mNextVsync{0};
+        int64_t mPeriod{0};
+
+        std::mutex mMutex;
+        std::condition_variable mCondition;
+        bool mStarted{false};
+        HWC2_PFN_VSYNC mCallback{nullptr};
+        hwc2_callback_data_t mCallbackData{nullptr};
+        bool mCallbackEnabled{false};
+    };
+    VsyncThread mVsyncThread;
+};
+
+} // namespace android
+
+#endif // ANDROID_SF_HWC2_ON_FB_ADAPTER_H