Move WGraphicBufferProducer into libgui

So that client side omx codec code no longer need to
link to libstagefright_bufferqueue_helper (which we
want to link on server side only).

bug: 129272021

Change-Id: Id69854158b4083ff8f0280decd599d86f11db4f5

8 files changed, 2814 insertions, 2 deletions

diff --git a/libs/gui/Android.bp b/libs/gui/Android.bp
index 4c2e6532ff..fcbfba98af 100644
--- a/libs/gui/Android.bp
+++ b/libs/gui/Android.bp
@@ -83,8 +83,10 @@ cc_library_shared {
         "SyncFeatures.cpp",
         "view/Surface.cpp",
         "bufferqueue/1.0/B2HProducerListener.cpp",
+        "bufferqueue/1.0/Conversion.cpp",
         "bufferqueue/1.0/H2BGraphicBufferProducer.cpp",
         "bufferqueue/1.0/H2BProducerListener.cpp",
+        "bufferqueue/1.0/WProducerListener.cpp",
         "bufferqueue/2.0/B2HGraphicBufferProducer.cpp",
         "bufferqueue/2.0/B2HProducerListener.cpp",
         "bufferqueue/2.0/H2BGraphicBufferProducer.cpp",
diff --git a/libs/gui/bufferqueue/1.0/Conversion.cpp b/libs/gui/bufferqueue/1.0/Conversion.cpp
new file mode 100644
index 0000000000..5cb35933e9
--- /dev/null
+++ b/libs/gui/bufferqueue/1.0/Conversion.cpp
@@ -0,0 +1,1542 @@
+/*
+ * Copyright 2018, 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 <gui/bufferqueue/1.0/Conversion.h>
+
+namespace android {
+namespace conversion {
+
+// native_handle_t helper functions.
+
+/**
+ * \brief Take an fd and create a native handle containing only the given fd.
+ * The created handle will need to be deleted manually with
+ * `native_handle_delete()`.
+ *
+ * \param[in] fd The source file descriptor (of type `int`).
+ * \return The create `native_handle_t*` that contains the given \p fd. If the
+ * supplied \p fd is negative, the created native handle will contain no file
+ * descriptors.
+ *
+ * If the native handle cannot be created, the return value will be
+ * `nullptr`.
+ *
+ * This function does not duplicate the file descriptor.
+ */
+native_handle_t* native_handle_create_from_fd(int fd) {
+    if (fd < 2) {
+        return native_handle_create(0, 0);
+    }
+    native_handle_t* nh = native_handle_create(1, 0);
+    if (nh == nullptr) {
+        return nullptr;
+    }
+    nh->data[0] = fd;
+    return nh;
+}
+
+/**
+ * \brief Extract a file descriptor from a native handle.
+ *
+ * \param[in] nh The source `native_handle_t*`.
+ * \param[in] index The index of the file descriptor in \p nh to read from. This
+ * input has the default value of `0`.
+ * \return The `index`-th file descriptor in \p nh. If \p nh does not have
+ * enough file descriptors, the returned value will be `-1`.
+ *
+ * This function does not duplicate the file descriptor.
+ */
+int native_handle_read_fd(native_handle_t const* nh, int index) {
+    return ((nh == nullptr) || (nh->numFds == 0) ||
+            (nh->numFds <= index) || (index < 0)) ?
+            -1 : nh->data[index];
+}
+
+/**
+ * Conversion functions
+ * ====================
+ *
+ * There are two main directions of conversion:
+ * - `inTargetType(...)`: Create a wrapper whose lifetime depends on the
+ *   input. The wrapper has type `TargetType`.
+ * - `toTargetType(...)`: Create a standalone object of type `TargetType` that
+ *   corresponds to the input. The lifetime of the output does not depend on the
+ *   lifetime of the input.
+ * - `wrapIn(TargetType*, ...)`: Same as `inTargetType()`, but for `TargetType`
+ *   that cannot be copied and/or moved efficiently, or when there are multiple
+ *   output arguments.
+ * - `convertTo(TargetType*, ...)`: Same as `toTargetType()`, but for
+ *   `TargetType` that cannot be copied and/or moved efficiently, or when there
+ *   are multiple output arguments.
+ *
+ * `wrapIn()` and `convertTo()` functions will take output arguments before
+ * input arguments. Some of these functions might return a value to indicate
+ * success or error.
+ *
+ * In converting or wrapping something as a Treble type that contains a
+ * `hidl_handle`, `native_handle_t*` will need to be created and returned as
+ * an additional output argument, hence only `wrapIn()` or `convertTo()` would
+ * be available. The caller must call `native_handle_delete()` to deallocate the
+ * returned native handle when it is no longer needed.
+ *
+ * For types that contain file descriptors, `inTargetType()` and `wrapAs()` do
+ * not perform duplication of file descriptors, while `toTargetType()` and
+ * `convertTo()` do.
+ */
+
+/**
+ * \brief Convert `Return<void>` to `status_t`. This is for legacy binder calls.
+ *
+ * \param[in] t The source `Return<void>`.
+ * \return The corresponding `status_t`.
+ */
+// convert: Return<void> -> status_t
+status_t toStatusT(Return<void> const& t) {
+    return t.isOk() ? OK : (t.isDeadObject() ? DEAD_OBJECT : UNKNOWN_ERROR);
+}
+
+/**
+ * \brief Convert `Return<void>` to `binder::Status`.
+ *
+ * \param[in] t The source `Return<void>`.
+ * \return The corresponding `binder::Status`.
+ */
+// convert: Return<void> -> ::android::binder::Status
+::android::binder::Status toBinderStatus(
+        Return<void> const& t) {
+    return ::android::binder::Status::fromExceptionCode(
+            toStatusT(t),
+            t.description().c_str());
+}
+
+/**
+ * \brief Wrap `native_handle_t*` in `hidl_handle`.
+ *
+ * \param[in] nh The source `native_handle_t*`.
+ * \return The `hidl_handle` that points to \p nh.
+ */
+// wrap: native_handle_t* -> hidl_handle
+hidl_handle inHidlHandle(native_handle_t const* nh) {
+    return hidl_handle(nh);
+}
+
+/**
+ * \brief Convert `int32_t` to `Dataspace`.
+ *
+ * \param[in] l The source `int32_t`.
+ * \result The corresponding `Dataspace`.
+ */
+// convert: int32_t -> Dataspace
+Dataspace toHardwareDataspace(int32_t l) {
+    return static_cast<Dataspace>(l);
+}
+
+/**
+ * \brief Convert `Dataspace` to `int32_t`.
+ *
+ * \param[in] t The source `Dataspace`.
+ * \result The corresponding `int32_t`.
+ */
+// convert: Dataspace -> int32_t
+int32_t toRawDataspace(Dataspace const& t) {
+    return static_cast<int32_t>(t);
+}
+
+/**
+ * \brief Wrap an opaque buffer inside a `hidl_vec<uint8_t>`.
+ *
+ * \param[in] l The pointer to the beginning of the opaque buffer.
+ * \param[in] size The size of the buffer.
+ * \return A `hidl_vec<uint8_t>` that points to the buffer.
+ */
+// wrap: void*, size_t -> hidl_vec<uint8_t>
+hidl_vec<uint8_t> inHidlBytes(void const* l, size_t size) {
+    hidl_vec<uint8_t> t;
+    t.setToExternal(static_cast<uint8_t*>(const_cast<void*>(l)), size, false);
+    return t;
+}
+
+/**
+ * \brief Create a `hidl_vec<uint8_t>` that is a copy of an opaque buffer.
+ *
+ * \param[in] l The pointer to the beginning of the opaque buffer.
+ * \param[in] size The size of the buffer.
+ * \return A `hidl_vec<uint8_t>` that is a copy of the input buffer.
+ */
+// convert: void*, size_t -> hidl_vec<uint8_t>
+hidl_vec<uint8_t> toHidlBytes(void const* l, size_t size) {
+    hidl_vec<uint8_t> t;
+    t.resize(size);
+    uint8_t const* src = static_cast<uint8_t const*>(l);
+    std::copy(src, src + size, t.data());
+    return t;
+}
+
+/**
+ * \brief Wrap `GraphicBuffer` in `AnwBuffer`.
+ *
+ * \param[out] t The wrapper of type `AnwBuffer`.
+ * \param[in] l The source `GraphicBuffer`.
+ */
+// wrap: GraphicBuffer -> AnwBuffer
+void wrapAs(AnwBuffer* t, GraphicBuffer const& l) {
+    t->attr.width = l.getWidth();
+    t->attr.height = l.getHeight();
+    t->attr.stride = l.getStride();
+    t->attr.format = static_cast<PixelFormat>(l.getPixelFormat());
+    t->attr.layerCount = l.getLayerCount();
+    t->attr.usage = static_cast<uint32_t>(l.getUsage());
+    t->attr.id = l.getId();
+    t->attr.generationNumber = l.getGenerationNumber();
+    t->nativeHandle = hidl_handle(l.handle);
+}
+
+/**
+ * \brief Convert `AnwBuffer` to `GraphicBuffer`.
+ *
+ * \param[out] l The destination `GraphicBuffer`.
+ * \param[in] t The source `AnwBuffer`.
+ *
+ * This function will duplicate all file descriptors in \p t.
+ */
+// convert: AnwBuffer -> GraphicBuffer
+// Ref: frameworks/native/libs/ui/GraphicBuffer.cpp: GraphicBuffer::flatten
+bool convertTo(GraphicBuffer* l, AnwBuffer const& t) {
+    native_handle_t* handle = t.nativeHandle == nullptr ?
+            nullptr : native_handle_clone(t.nativeHandle);
+
+    size_t const numInts = 12 + static_cast<size_t>(handle ? handle->numInts : 0);
+    int32_t* ints = new int32_t[numInts];
+
+    size_t numFds = static_cast<size_t>(handle ? handle->numFds : 0);
+    int* fds = new int[numFds];
+
+    ints[0] = 'GBFR';
+    ints[1] = static_cast<int32_t>(t.attr.width);
+    ints[2] = static_cast<int32_t>(t.attr.height);
+    ints[3] = static_cast<int32_t>(t.attr.stride);
+    ints[4] = static_cast<int32_t>(t.attr.format);
+    ints[5] = static_cast<int32_t>(t.attr.layerCount);
+    ints[6] = static_cast<int32_t>(t.attr.usage);
+    ints[7] = static_cast<int32_t>(t.attr.id >> 32);
+    ints[8] = static_cast<int32_t>(t.attr.id & 0xFFFFFFFF);
+    ints[9] = static_cast<int32_t>(t.attr.generationNumber);
+    ints[10] = 0;
+    ints[11] = 0;
+    if (handle) {
+        ints[10] = static_cast<int32_t>(handle->numFds);
+        ints[11] = static_cast<int32_t>(handle->numInts);
+        int* intsStart = handle->data + handle->numFds;
+        std::copy(handle->data, intsStart, fds);
+        std::copy(intsStart, intsStart + handle->numInts, &ints[12]);
+    }
+
+    void const* constBuffer = static_cast<void const*>(ints);
+    size_t size = numInts * sizeof(int32_t);
+    int const* constFds = static_cast<int const*>(fds);
+    status_t status = l->unflatten(constBuffer, size, constFds, numFds);
+
+    delete [] fds;
+    delete [] ints;
+    native_handle_delete(handle);
+    return status == NO_ERROR;
+}
+
+/**
+ * Conversion functions for types outside media
+ * ============================================
+ *
+ * Some objects in libui and libgui that were made to go through binder calls do
+ * not expose ways to read or write their fields to the public. To pass an
+ * object of this kind through the HIDL boundary, translation functions need to
+ * work around the access restriction by using the publicly available
+ * `flatten()` and `unflatten()` functions.
+ *
+ * All `flatten()` and `unflatten()` overloads follow the same convention as
+ * follows:
+ *
+ *     status_t flatten(ObjectType const& object,
+ *                      [OtherType const& other, ...]
+ *                      void*& buffer, size_t& size,
+ *                      int*& fds, size_t& numFds)
+ *
+ *     status_t unflatten(ObjectType* object,
+ *                        [OtherType* other, ...,]
+ *                        void*& buffer, size_t& size,
+ *                        int*& fds, size_t& numFds)
+ *
+ * The number of `other` parameters varies depending on the `ObjectType`. For
+ * example, in the process of unflattening an object that contains
+ * `hidl_handle`, `other` is needed to hold `native_handle_t` objects that will
+ * be created.
+ *
+ * The last four parameters always work the same way in all overloads of
+ * `flatten()` and `unflatten()`:
+ * - For `flatten()`, `buffer` is the pointer to the non-fd buffer to be filled,
+ *   `size` is the size (in bytes) of the non-fd buffer pointed to by `buffer`,
+ *   `fds` is the pointer to the fd buffer to be filled, and `numFds` is the
+ *   size (in ints) of the fd buffer pointed to by `fds`.
+ * - For `unflatten()`, `buffer` is the pointer to the non-fd buffer to be read
+ *   from, `size` is the size (in bytes) of the non-fd buffer pointed to by
+ *   `buffer`, `fds` is the pointer to the fd buffer to be read from, and
+ *   `numFds` is the size (in ints) of the fd buffer pointed to by `fds`.
+ * - After a successful call to `flatten()` or `unflatten()`, `buffer` and `fds`
+ *   will be advanced, while `size` and `numFds` will be decreased to reflect
+ *   how much storage/data of the two buffers (fd and non-fd) have been used.
+ * - After an unsuccessful call, the values of `buffer`, `size`, `fds` and
+ *   `numFds` are invalid.
+ *
+ * The return value of a successful `flatten()` or `unflatten()` call will be
+ * `OK` (also aliased as `NO_ERROR`). Any other values indicate a failure.
+ *
+ * For each object type that supports flattening, there will be two accompanying
+ * functions: `getFlattenedSize()` and `getFdCount()`. `getFlattenedSize()` will
+ * return the size of the non-fd buffer that the object will need for
+ * flattening. `getFdCount()` will return the size of the fd buffer that the
+ * object will need for flattening.
+ *
+ * The set of these four functions, `getFlattenedSize()`, `getFdCount()`,
+ * `flatten()` and `unflatten()`, are similar to functions of the same name in
+ * the abstract class `Flattenable`. The only difference is that functions in
+ * this file are not member functions of the object type. For example, we write
+ *
+ *     flatten(x, buffer, size, fds, numFds)
+ *
+ * instead of
+ *
+ *     x.flatten(buffer, size, fds, numFds)
+ *
+ * because we cannot modify the type of `x`.
+ *
+ * There is one exception to the naming convention: `hidl_handle` that
+ * represents a fence. The four functions for this "Fence" type have the word
+ * "Fence" attched to their names because the object type, which is
+ * `hidl_handle`, does not carry the special meaning that the object itself can
+ * only contain zero or one file descriptor.
+ */
+
+// Ref: frameworks/native/libs/ui/Fence.cpp
+
+/**
+ * \brief Return the size of the non-fd buffer required to flatten a fence.
+ *
+ * \param[in] fence The input fence of type `hidl_handle`.
+ * \return The required size of the flat buffer.
+ *
+ * The current version of this function always returns 4, which is the number of
+ * bytes required to store the number of file descriptors contained in the fd
+ * part of the flat buffer.
+ */
+size_t getFenceFlattenedSize(hidl_handle const& /* fence */) {
+    return 4;
+};
+
+/**
+ * \brief Return the number of file descriptors contained in a fence.
+ *
+ * \param[in] fence The input fence of type `hidl_handle`.
+ * \return `0` if \p fence does not contain a valid file descriptor, or `1`
+ * otherwise.
+ */
+size_t getFenceFdCount(hidl_handle const& fence) {
+    return native_handle_read_fd(fence) == -1 ? 0 : 1;
+}
+
+/**
+ * \brief Unflatten `Fence` to `hidl_handle`.
+ *
+ * \param[out] fence The destination `hidl_handle`.
+ * \param[out] nh The underlying native handle.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * If the return value is `NO_ERROR`, \p nh will point to a newly created
+ * native handle, which needs to be deleted with `native_handle_delete()`
+ * afterwards.
+ */
+status_t unflattenFence(hidl_handle* fence, native_handle_t** nh,
+        void const*& buffer, size_t& size, int const*& fds, size_t& numFds) {
+    if (size < 4) {
+        return NO_MEMORY;
+    }
+
+    uint32_t numFdsInHandle;
+    FlattenableUtils::read(buffer, size, numFdsInHandle);
+
+    if (numFdsInHandle > 1) {
+        return BAD_VALUE;
+    }
+
+    if (numFds < numFdsInHandle) {
+        return NO_MEMORY;
+    }
+
+    if (numFdsInHandle) {
+        *nh = native_handle_create_from_fd(*fds);
+        if (*nh == nullptr) {
+            return NO_MEMORY;
+        }
+        *fence = *nh;
+        ++fds;
+        --numFds;
+    } else {
+        *nh = nullptr;
+        *fence = hidl_handle();
+    }
+
+    return NO_ERROR;
+}
+
+/**
+ * \brief Flatten `hidl_handle` as `Fence`.
+ *
+ * \param[in] t The source `hidl_handle`.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ */
+status_t flattenFence(hidl_handle const& fence,
+        void*& buffer, size_t& size, int*& fds, size_t& numFds) {
+    if (size < getFenceFlattenedSize(fence) ||
+            numFds < getFenceFdCount(fence)) {
+        return NO_MEMORY;
+    }
+    // Cast to uint32_t since the size of a size_t can vary between 32- and
+    // 64-bit processes
+    FlattenableUtils::write(buffer, size,
+            static_cast<uint32_t>(getFenceFdCount(fence)));
+    int fd = native_handle_read_fd(fence);
+    if (fd != -1) {
+        *fds = fd;
+        ++fds;
+        --numFds;
+    }
+    return NO_ERROR;
+}
+
+/**
+ * \brief Wrap `Fence` in `hidl_handle`.
+ *
+ * \param[out] t The wrapper of type `hidl_handle`.
+ * \param[out] nh The native handle pointed to by \p t.
+ * \param[in] l The source `Fence`.
+ *
+ * On success, \p nh will hold a newly created native handle, which must be
+ * deleted manually with `native_handle_delete()` afterwards.
+ */
+// wrap: Fence -> hidl_handle
+bool wrapAs(hidl_handle* t, native_handle_t** nh, Fence const& l) {
+    size_t const baseSize = l.getFlattenedSize();
+    std::unique_ptr<uint8_t[]> baseBuffer(
+            new (std::nothrow) uint8_t[baseSize]);
+    if (!baseBuffer) {
+        return false;
+    }
+
+    size_t const baseNumFds = l.getFdCount();
+    std::unique_ptr<int[]> baseFds(
+            new (std::nothrow) int[baseNumFds]);
+    if (!baseFds) {
+        return false;
+    }
+
+    void* buffer = static_cast<void*>(baseBuffer.get());
+    size_t size = baseSize;
+    int* fds = static_cast<int*>(baseFds.get());
+    size_t numFds = baseNumFds;
+    if (l.flatten(buffer, size, fds, numFds) != NO_ERROR) {
+        return false;
+    }
+
+    void const* constBuffer = static_cast<void const*>(baseBuffer.get());
+    size = baseSize;
+    int const* constFds = static_cast<int const*>(baseFds.get());
+    numFds = baseNumFds;
+    if (unflattenFence(t, nh, constBuffer, size, constFds, numFds)
+            != NO_ERROR) {
+        return false;
+    }
+
+    return true;
+}
+
+/**
+ * \brief Convert `hidl_handle` to `Fence`.
+ *
+ * \param[out] l The destination `Fence`. `l` must not have been used
+ * (`l->isValid()` must return `false`) before this function is called.
+ * \param[in] t The source `hidl_handle`.
+ *
+ * If \p t contains a valid file descriptor, it will be duplicated.
+ */
+// convert: hidl_handle -> Fence
+bool convertTo(Fence* l, hidl_handle const& t) {
+    int fd = native_handle_read_fd(t);
+    if (fd != -1) {
+        fd = dup(fd);
+        if (fd == -1) {
+            return false;
+        }
+    }
+    native_handle_t* nh = native_handle_create_from_fd(fd);
+    if (nh == nullptr) {
+        if (fd != -1) {
+            close(fd);
+        }
+        return false;
+    }
+
+    size_t const baseSize = getFenceFlattenedSize(t);
+    std::unique_ptr<uint8_t[]> baseBuffer(
+            new (std::nothrow) uint8_t[baseSize]);
+    if (!baseBuffer) {
+        native_handle_delete(nh);
+        return false;
+    }
+
+    size_t const baseNumFds = getFenceFdCount(t);
+    std::unique_ptr<int[]> baseFds(
+            new (std::nothrow) int[baseNumFds]);
+    if (!baseFds) {
+        native_handle_delete(nh);
+        return false;
+    }
+
+    void* buffer = static_cast<void*>(baseBuffer.get());
+    size_t size = baseSize;
+    int* fds = static_cast<int*>(baseFds.get());
+    size_t numFds = baseNumFds;
+    if (flattenFence(hidl_handle(nh), buffer, size, fds, numFds) != NO_ERROR) {
+        native_handle_delete(nh);
+        return false;
+    }
+    native_handle_delete(nh);
+
+    void const* constBuffer = static_cast<void const*>(baseBuffer.get());
+    size = baseSize;
+    int const* constFds = static_cast<int const*>(baseFds.get());
+    numFds = baseNumFds;
+    if (l->unflatten(constBuffer, size, constFds, numFds) != NO_ERROR) {
+        return false;
+    }
+
+    return true;
+}
+
+// Ref: frameworks/native/libs/ui/FenceTime.cpp: FenceTime::Snapshot
+
+/**
+ * \brief Return the size of the non-fd buffer required to flatten
+ * `FenceTimeSnapshot`.
+ *
+ * \param[in] t The input `FenceTimeSnapshot`.
+ * \return The required size of the flat buffer.
+ */
+size_t getFlattenedSize(
+        HGraphicBufferProducer::FenceTimeSnapshot const& t) {
+    constexpr size_t min = sizeof(t.state);
+    switch (t.state) {
+        case HGraphicBufferProducer::FenceTimeSnapshot::State::EMPTY:
+            return min;
+        case HGraphicBufferProducer::FenceTimeSnapshot::State::FENCE:
+            return min + getFenceFlattenedSize(t.fence);
+        case HGraphicBufferProducer::FenceTimeSnapshot::State::SIGNAL_TIME:
+            return min + sizeof(
+                    ::android::FenceTime::Snapshot::signalTime);
+    }
+    return 0;
+}
+
+/**
+ * \brief Return the number of file descriptors contained in
+ * `FenceTimeSnapshot`.
+ *
+ * \param[in] t The input `FenceTimeSnapshot`.
+ * \return The number of file descriptors contained in \p snapshot.
+ */
+size_t getFdCount(
+        HGraphicBufferProducer::FenceTimeSnapshot const& t) {
+    return t.state ==
+            HGraphicBufferProducer::FenceTimeSnapshot::State::FENCE ?
+            getFenceFdCount(t.fence) : 0;
+}
+
+/**
+ * \brief Flatten `FenceTimeSnapshot`.
+ *
+ * \param[in] t The source `FenceTimeSnapshot`.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * This function will duplicate the file descriptor in `t.fence` if `t.state ==
+ * FENCE`.
+ */
+status_t flatten(HGraphicBufferProducer::FenceTimeSnapshot const& t,
+        void*& buffer, size_t& size, int*& fds, size_t& numFds) {
+    if (size < getFlattenedSize(t)) {
+        return NO_MEMORY;
+    }
+
+    switch (t.state) {
+        case HGraphicBufferProducer::FenceTimeSnapshot::State::EMPTY:
+            FlattenableUtils::write(buffer, size,
+                    ::android::FenceTime::Snapshot::State::EMPTY);
+            return NO_ERROR;
+        case HGraphicBufferProducer::FenceTimeSnapshot::State::FENCE:
+            FlattenableUtils::write(buffer, size,
+                    ::android::FenceTime::Snapshot::State::FENCE);
+            return flattenFence(t.fence, buffer, size, fds, numFds);
+        case HGraphicBufferProducer::FenceTimeSnapshot::State::SIGNAL_TIME:
+            FlattenableUtils::write(buffer, size,
+                    ::android::FenceTime::Snapshot::State::SIGNAL_TIME);
+            FlattenableUtils::write(buffer, size, t.signalTimeNs);
+            return NO_ERROR;
+    }
+    return NO_ERROR;
+}
+
+/**
+ * \brief Unflatten `FenceTimeSnapshot`.
+ *
+ * \param[out] t The destination `FenceTimeSnapshot`.
+ * \param[out] nh The underlying native handle.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * If the return value is `NO_ERROR` and the constructed snapshot contains a
+ * file descriptor, \p nh will be created to hold that file descriptor. In this
+ * case, \p nh needs to be deleted with `native_handle_delete()` afterwards.
+ */
+status_t unflatten(
+        HGraphicBufferProducer::FenceTimeSnapshot* t, native_handle_t** nh,
+        void const*& buffer, size_t& size, int const*& fds, size_t& numFds) {
+    if (size < sizeof(t->state)) {
+        return NO_MEMORY;
+    }
+
+    *nh = nullptr;
+    ::android::FenceTime::Snapshot::State state;
+    FlattenableUtils::read(buffer, size, state);
+    switch (state) {
+        case ::android::FenceTime::Snapshot::State::EMPTY:
+            t->state = HGraphicBufferProducer::FenceTimeSnapshot::State::EMPTY;
+            return NO_ERROR;
+        case ::android::FenceTime::Snapshot::State::FENCE:
+            t->state = HGraphicBufferProducer::FenceTimeSnapshot::State::FENCE;
+            return unflattenFence(&t->fence, nh, buffer, size, fds, numFds);
+        case ::android::FenceTime::Snapshot::State::SIGNAL_TIME:
+            t->state = HGraphicBufferProducer::FenceTimeSnapshot::State::SIGNAL_TIME;
+            if (size < sizeof(t->signalTimeNs)) {
+                return NO_MEMORY;
+            }
+            FlattenableUtils::read(buffer, size, t->signalTimeNs);
+            return NO_ERROR;
+    }
+    return NO_ERROR;
+}
+
+// Ref: frameworks/native/libs/gui/FrameTimestamps.cpp: FrameEventsDelta
+
+/**
+ * \brief Return a lower bound on the size of the non-fd buffer required to
+ * flatten `FrameEventsDelta`.
+ *
+ * \param[in] t The input `FrameEventsDelta`.
+ * \return A lower bound on the size of the flat buffer.
+ */
+constexpr size_t minFlattenedSize(
+        HGraphicBufferProducer::FrameEventsDelta const& /* t */) {
+    return sizeof(uint64_t) + // mFrameNumber
+            sizeof(uint8_t) + // mIndex
+            sizeof(uint8_t) + // mAddPostCompositeCalled
+            sizeof(uint8_t) + // mAddRetireCalled
+            sizeof(uint8_t) + // mAddReleaseCalled
+            sizeof(nsecs_t) + // mPostedTime
+            sizeof(nsecs_t) + // mRequestedPresentTime
+            sizeof(nsecs_t) + // mLatchTime
+            sizeof(nsecs_t) + // mFirstRefreshStartTime
+            sizeof(nsecs_t); // mLastRefreshStartTime
+}
+
+/**
+ * \brief Return the size of the non-fd buffer required to flatten
+ * `FrameEventsDelta`.
+ *
+ * \param[in] t The input `FrameEventsDelta`.
+ * \return The required size of the flat buffer.
+ */
+size_t getFlattenedSize(
+        HGraphicBufferProducer::FrameEventsDelta const& t) {
+    return minFlattenedSize(t) +
+            getFlattenedSize(t.gpuCompositionDoneFence) +
+            getFlattenedSize(t.displayPresentFence) +
+            getFlattenedSize(t.displayRetireFence) +
+            getFlattenedSize(t.releaseFence);
+};
+
+/**
+ * \brief Return the number of file descriptors contained in
+ * `FrameEventsDelta`.
+ *
+ * \param[in] t The input `FrameEventsDelta`.
+ * \return The number of file descriptors contained in \p t.
+ */
+size_t getFdCount(
+        HGraphicBufferProducer::FrameEventsDelta const& t) {
+    return getFdCount(t.gpuCompositionDoneFence) +
+            getFdCount(t.displayPresentFence) +
+            getFdCount(t.displayRetireFence) +
+            getFdCount(t.releaseFence);
+};
+
+/**
+ * \brief Unflatten `FrameEventsDelta`.
+ *
+ * \param[out] t The destination `FrameEventsDelta`.
+ * \param[out] nh The underlying array of native handles.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * If the return value is `NO_ERROR`, \p nh will have length 4, and it will be
+ * populated with `nullptr` or newly created handles. Each non-null slot in \p
+ * nh will need to be deleted manually with `native_handle_delete()`.
+ */
+status_t unflatten(HGraphicBufferProducer::FrameEventsDelta* t,
+        std::vector<native_handle_t*>* nh,
+        void const*& buffer, size_t& size, int const*& fds, size_t& numFds) {
+    if (size < minFlattenedSize(*t)) {
+        return NO_MEMORY;
+    }
+    FlattenableUtils::read(buffer, size, t->frameNumber);
+
+    // These were written as uint8_t for alignment.
+    uint8_t temp = 0;
+    FlattenableUtils::read(buffer, size, temp);
+    size_t index = static_cast<size_t>(temp);
+    if (index >= ::android::FrameEventHistory::MAX_FRAME_HISTORY) {
+        return BAD_VALUE;
+    }
+    t->index = static_cast<uint32_t>(index);
+
+    FlattenableUtils::read(buffer, size, temp);
+    t->addPostCompositeCalled = static_cast<bool>(temp);
+    FlattenableUtils::read(buffer, size, temp);
+    t->addRetireCalled = static_cast<bool>(temp);
+    FlattenableUtils::read(buffer, size, temp);
+    t->addReleaseCalled = static_cast<bool>(temp);
+
+    FlattenableUtils::read(buffer, size, t->postedTimeNs);
+    FlattenableUtils::read(buffer, size, t->requestedPresentTimeNs);
+    FlattenableUtils::read(buffer, size, t->latchTimeNs);
+    FlattenableUtils::read(buffer, size, t->firstRefreshStartTimeNs);
+    FlattenableUtils::read(buffer, size, t->lastRefreshStartTimeNs);
+    FlattenableUtils::read(buffer, size, t->dequeueReadyTime);
+
+    // Fences
+    HGraphicBufferProducer::FenceTimeSnapshot* tSnapshot[4];
+    tSnapshot[0] = &t->gpuCompositionDoneFence;
+    tSnapshot[1] = &t->displayPresentFence;
+    tSnapshot[2] = &t->displayRetireFence;
+    tSnapshot[3] = &t->releaseFence;
+    nh->resize(4);
+    for (size_t snapshotIndex = 0; snapshotIndex < 4; ++snapshotIndex) {
+        status_t status = unflatten(
+                tSnapshot[snapshotIndex], &((*nh)[snapshotIndex]),
+                buffer, size, fds, numFds);
+        if (status != NO_ERROR) {
+            while (snapshotIndex > 0) {
+                --snapshotIndex;
+                if ((*nh)[snapshotIndex] != nullptr) {
+                    native_handle_delete((*nh)[snapshotIndex]);
+                }
+            }
+            return status;
+        }
+    }
+    return NO_ERROR;
+}
+
+/**
+ * \brief Flatten `FrameEventsDelta`.
+ *
+ * \param[in] t The source `FrameEventsDelta`.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * This function will duplicate file descriptors contained in \p t.
+ */
+// Ref: frameworks/native/libs/gui/FrameTimestamp.cpp:
+//      FrameEventsDelta::flatten
+status_t flatten(HGraphicBufferProducer::FrameEventsDelta const& t,
+        void*& buffer, size_t& size, int*& fds, size_t numFds) {
+    // Check that t.index is within a valid range.
+    if (t.index >= static_cast<uint32_t>(FrameEventHistory::MAX_FRAME_HISTORY)
+            || t.index > std::numeric_limits<uint8_t>::max()) {
+        return BAD_VALUE;
+    }
+
+    FlattenableUtils::write(buffer, size, t.frameNumber);
+
+    // These are static_cast to uint8_t for alignment.
+    FlattenableUtils::write(buffer, size, static_cast<uint8_t>(t.index));
+    FlattenableUtils::write(
+            buffer, size, static_cast<uint8_t>(t.addPostCompositeCalled));
+    FlattenableUtils::write(
+            buffer, size, static_cast<uint8_t>(t.addRetireCalled));
+    FlattenableUtils::write(
+            buffer, size, static_cast<uint8_t>(t.addReleaseCalled));
+
+    FlattenableUtils::write(buffer, size, t.postedTimeNs);
+    FlattenableUtils::write(buffer, size, t.requestedPresentTimeNs);
+    FlattenableUtils::write(buffer, size, t.latchTimeNs);
+    FlattenableUtils::write(buffer, size, t.firstRefreshStartTimeNs);
+    FlattenableUtils::write(buffer, size, t.lastRefreshStartTimeNs);
+    FlattenableUtils::write(buffer, size, t.dequeueReadyTime);
+
+    // Fences
+    HGraphicBufferProducer::FenceTimeSnapshot const* tSnapshot[4];
+    tSnapshot[0] = &t.gpuCompositionDoneFence;
+    tSnapshot[1] = &t.displayPresentFence;
+    tSnapshot[2] = &t.displayRetireFence;
+    tSnapshot[3] = &t.releaseFence;
+    for (size_t snapshotIndex = 0; snapshotIndex < 4; ++snapshotIndex) {
+        status_t status = flatten(
+                *(tSnapshot[snapshotIndex]), buffer, size, fds, numFds);
+        if (status != NO_ERROR) {
+            return status;
+        }
+    }
+    return NO_ERROR;
+}
+
+// Ref: frameworks/native/libs/gui/FrameTimestamps.cpp: FrameEventHistoryDelta
+
+/**
+ * \brief Return the size of the non-fd buffer required to flatten
+ * `HGraphicBufferProducer::FrameEventHistoryDelta`.
+ *
+ * \param[in] t The input `HGraphicBufferProducer::FrameEventHistoryDelta`.
+ * \return The required size of the flat buffer.
+ */
+size_t getFlattenedSize(
+        HGraphicBufferProducer::FrameEventHistoryDelta const& t) {
+    size_t size = 4 + // mDeltas.size()
+            sizeof(t.compositorTiming);
+    for (size_t i = 0; i < t.deltas.size(); ++i) {
+        size += getFlattenedSize(t.deltas[i]);
+    }
+    return size;
+}
+
+/**
+ * \brief Return the number of file descriptors contained in
+ * `HGraphicBufferProducer::FrameEventHistoryDelta`.
+ *
+ * \param[in] t The input `HGraphicBufferProducer::FrameEventHistoryDelta`.
+ * \return The number of file descriptors contained in \p t.
+ */
+size_t getFdCount(
+        HGraphicBufferProducer::FrameEventHistoryDelta const& t) {
+    size_t numFds = 0;
+    for (size_t i = 0; i < t.deltas.size(); ++i) {
+        numFds += getFdCount(t.deltas[i]);
+    }
+    return numFds;
+}
+
+/**
+ * \brief Unflatten `FrameEventHistoryDelta`.
+ *
+ * \param[out] t The destination `FrameEventHistoryDelta`.
+ * \param[out] nh The underlying array of arrays of native handles.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * If the return value is `NO_ERROR`, \p nh will be populated with `nullptr` or
+ * newly created handles. The second dimension of \p nh will be 4. Each non-null
+ * slot in \p nh will need to be deleted manually with `native_handle_delete()`.
+ */
+status_t unflatten(
+        HGraphicBufferProducer::FrameEventHistoryDelta* t,
+        std::vector<std::vector<native_handle_t*> >* nh,
+        void const*& buffer, size_t& size, int const*& fds, size_t& numFds) {
+    if (size < 4) {
+        return NO_MEMORY;
+    }
+
+    FlattenableUtils::read(buffer, size, t->compositorTiming);
+
+    uint32_t deltaCount = 0;
+    FlattenableUtils::read(buffer, size, deltaCount);
+    if (static_cast<size_t>(deltaCount) >
+            ::android::FrameEventHistory::MAX_FRAME_HISTORY) {
+        return BAD_VALUE;
+    }
+    t->deltas.resize(deltaCount);
+    nh->resize(deltaCount);
+    for (size_t deltaIndex = 0; deltaIndex < deltaCount; ++deltaIndex) {
+        status_t status = unflatten(
+                &(t->deltas[deltaIndex]), &((*nh)[deltaIndex]),
+                buffer, size, fds, numFds);
+        if (status != NO_ERROR) {
+            return status;
+        }
+    }
+    return NO_ERROR;
+}
+
+/**
+ * \brief Flatten `FrameEventHistoryDelta`.
+ *
+ * \param[in] t The source `FrameEventHistoryDelta`.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * This function will duplicate file descriptors contained in \p t.
+ */
+status_t flatten(
+        HGraphicBufferProducer::FrameEventHistoryDelta const& t,
+        void*& buffer, size_t& size, int*& fds, size_t& numFds) {
+    if (t.deltas.size() > ::android::FrameEventHistory::MAX_FRAME_HISTORY) {
+        return BAD_VALUE;
+    }
+    if (size < getFlattenedSize(t)) {
+        return NO_MEMORY;
+    }
+
+    FlattenableUtils::write(buffer, size, t.compositorTiming);
+
+    FlattenableUtils::write(buffer, size, static_cast<uint32_t>(t.deltas.size()));
+    for (size_t deltaIndex = 0; deltaIndex < t.deltas.size(); ++deltaIndex) {
+        status_t status = flatten(t.deltas[deltaIndex], buffer, size, fds, numFds);
+        if (status != NO_ERROR) {
+            return status;
+        }
+    }
+    return NO_ERROR;
+}
+
+/**
+ * \brief Wrap `::android::FrameEventHistoryData` in
+ * `HGraphicBufferProducer::FrameEventHistoryDelta`.
+ *
+ * \param[out] t The wrapper of type
+ * `HGraphicBufferProducer::FrameEventHistoryDelta`.
+ * \param[out] nh The array of array of native handles that are referred to by
+ * members of \p t.
+ * \param[in] l The source `::android::FrameEventHistoryDelta`.
+ *
+ * On success, each member of \p nh will be either `nullptr` or a newly created
+ * native handle. All the non-`nullptr` elements must be deleted individually
+ * with `native_handle_delete()`.
+ */
+bool wrapAs(HGraphicBufferProducer::FrameEventHistoryDelta* t,
+        std::vector<std::vector<native_handle_t*> >* nh,
+        ::android::FrameEventHistoryDelta const& l) {
+
+    size_t const baseSize = l.getFlattenedSize();
+    std::unique_ptr<uint8_t[]> baseBuffer(
+            new (std::nothrow) uint8_t[baseSize]);
+    if (!baseBuffer) {
+        return false;
+    }
+
+    size_t const baseNumFds = l.getFdCount();
+    std::unique_ptr<int[]> baseFds(
+            new (std::nothrow) int[baseNumFds]);
+    if (!baseFds) {
+        return false;
+    }
+
+    void* buffer = static_cast<void*>(baseBuffer.get());
+    size_t size = baseSize;
+    int* fds = baseFds.get();
+    size_t numFds = baseNumFds;
+    if (l.flatten(buffer, size, fds, numFds) != NO_ERROR) {
+        return false;
+    }
+
+    void const* constBuffer = static_cast<void const*>(baseBuffer.get());
+    size = baseSize;
+    int const* constFds = static_cast<int const*>(baseFds.get());
+    numFds = baseNumFds;
+    if (unflatten(t, nh, constBuffer, size, constFds, numFds) != NO_ERROR) {
+        return false;
+    }
+
+    return true;
+}
+
+/**
+ * \brief Convert `HGraphicBufferProducer::FrameEventHistoryDelta` to
+ * `::android::FrameEventHistoryDelta`.
+ *
+ * \param[out] l The destination `::android::FrameEventHistoryDelta`.
+ * \param[in] t The source `HGraphicBufferProducer::FrameEventHistoryDelta`.
+ *
+ * This function will duplicate all file descriptors contained in \p t.
+ */
+bool convertTo(
+        ::android::FrameEventHistoryDelta* l,
+        HGraphicBufferProducer::FrameEventHistoryDelta const& t) {
+
+    size_t const baseSize = getFlattenedSize(t);
+    std::unique_ptr<uint8_t[]> baseBuffer(
+            new (std::nothrow) uint8_t[baseSize]);
+    if (!baseBuffer) {
+        return false;
+    }
+
+    size_t const baseNumFds = getFdCount(t);
+    std::unique_ptr<int[]> baseFds(
+            new (std::nothrow) int[baseNumFds]);
+    if (!baseFds) {
+        return false;
+    }
+
+    void* buffer = static_cast<void*>(baseBuffer.get());
+    size_t size = baseSize;
+    int* fds = static_cast<int*>(baseFds.get());
+    size_t numFds = baseNumFds;
+    if (flatten(t, buffer, size, fds, numFds) != NO_ERROR) {
+        return false;
+    }
+
+    void const* constBuffer = static_cast<void const*>(baseBuffer.get());
+    size = baseSize;
+    int const* constFds = static_cast<int const*>(baseFds.get());
+    numFds = baseNumFds;
+    if (l->unflatten(constBuffer, size, constFds, numFds) != NO_ERROR) {
+        return false;
+    }
+
+    return true;
+}
+
+// Ref: frameworks/native/libs/ui/Region.cpp
+
+/**
+ * \brief Return the size of the buffer required to flatten `Region`.
+ *
+ * \param[in] t The input `Region`.
+ * \return The required size of the flat buffer.
+ */
+size_t getFlattenedSize(Region const& t) {
+    return sizeof(uint32_t) + t.size() * sizeof(::android::Rect);
+}
+
+/**
+ * \brief Unflatten `Region`.
+ *
+ * \param[out] t The destination `Region`.
+ * \param[in,out] buffer The pointer to the flat buffer.
+ * \param[in,out] size The size of the flat buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ */
+status_t unflatten(Region* t, void const*& buffer, size_t& size) {
+    if (size < sizeof(uint32_t)) {
+        return NO_MEMORY;
+    }
+
+    uint32_t numRects = 0;
+    FlattenableUtils::read(buffer, size, numRects);
+    if (size < numRects * sizeof(Rect)) {
+        return NO_MEMORY;
+    }
+    if (numRects > (UINT32_MAX / sizeof(Rect))) {
+        return NO_MEMORY;
+    }
+
+    t->resize(numRects);
+    for (size_t r = 0; r < numRects; ++r) {
+        ::android::Rect rect(::android::Rect::EMPTY_RECT);
+        status_t status = rect.unflatten(buffer, size);
+        if (status != NO_ERROR) {
+            return status;
+        }
+        FlattenableUtils::advance(buffer, size, sizeof(rect));
+        (*t)[r] = Rect{
+                static_cast<int32_t>(rect.left),
+                static_cast<int32_t>(rect.top),
+                static_cast<int32_t>(rect.right),
+                static_cast<int32_t>(rect.bottom)};
+    }
+    return NO_ERROR;
+}
+
+/**
+ * \brief Flatten `Region`.
+ *
+ * \param[in] t The source `Region`.
+ * \param[in,out] buffer The pointer to the flat buffer.
+ * \param[in,out] size The size of the flat buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ */
+status_t flatten(Region const& t, void*& buffer, size_t& size) {
+    if (size < getFlattenedSize(t)) {
+        return NO_MEMORY;
+    }
+
+    FlattenableUtils::write(buffer, size, static_cast<uint32_t>(t.size()));
+    for (size_t r = 0; r < t.size(); ++r) {
+        ::android::Rect rect(
+                static_cast<int32_t>(t[r].left),
+                static_cast<int32_t>(t[r].top),
+                static_cast<int32_t>(t[r].right),
+                static_cast<int32_t>(t[r].bottom));
+        status_t status = rect.flatten(buffer, size);
+        if (status != NO_ERROR) {
+            return status;
+        }
+        FlattenableUtils::advance(buffer, size, sizeof(rect));
+    }
+    return NO_ERROR;
+}
+
+/**
+ * \brief Convert `::android::Region` to `Region`.
+ *
+ * \param[out] t The destination `Region`.
+ * \param[in] l The source `::android::Region`.
+ */
+// convert: ::android::Region -> Region
+bool convertTo(Region* t, ::android::Region const& l) {
+    size_t const baseSize = l.getFlattenedSize();
+    std::unique_ptr<uint8_t[]> baseBuffer(
+            new (std::nothrow) uint8_t[baseSize]);
+    if (!baseBuffer) {
+        return false;
+    }
+
+    void* buffer = static_cast<void*>(baseBuffer.get());
+    size_t size = baseSize;
+    if (l.flatten(buffer, size) != NO_ERROR) {
+        return false;
+    }
+
+    void const* constBuffer = static_cast<void const*>(baseBuffer.get());
+    size = baseSize;
+    if (unflatten(t, constBuffer, size) != NO_ERROR) {
+        return false;
+    }
+
+    return true;
+}
+
+/**
+ * \brief Convert `Region` to `::android::Region`.
+ *
+ * \param[out] l The destination `::android::Region`.
+ * \param[in] t The source `Region`.
+ */
+// convert: Region -> ::android::Region
+bool convertTo(::android::Region* l, Region const& t) {
+    size_t const baseSize = getFlattenedSize(t);
+    std::unique_ptr<uint8_t[]> baseBuffer(
+            new (std::nothrow) uint8_t[baseSize]);
+    if (!baseBuffer) {
+        return false;
+    }
+
+    void* buffer = static_cast<void*>(baseBuffer.get());
+    size_t size = baseSize;
+    if (flatten(t, buffer, size) != NO_ERROR) {
+        return false;
+    }
+
+    void const* constBuffer = static_cast<void const*>(baseBuffer.get());
+    size = baseSize;
+    if (l->unflatten(constBuffer, size) != NO_ERROR) {
+        return false;
+    }
+
+    return true;
+}
+
+// Ref: frameworks/native/libs/gui/BGraphicBufferProducer.cpp:
+//      BGraphicBufferProducer::QueueBufferInput
+
+/**
+ * \brief Return a lower bound on the size of the buffer required to flatten
+ * `HGraphicBufferProducer::QueueBufferInput`.
+ *
+ * \param[in] t The input `HGraphicBufferProducer::QueueBufferInput`.
+ * \return A lower bound on the size of the flat buffer.
+ */
+constexpr size_t minFlattenedSize(
+        HGraphicBufferProducer::QueueBufferInput const& /* t */) {
+    return sizeof(int64_t) + // timestamp
+            sizeof(int) + // isAutoTimestamp
+            sizeof(android_dataspace) + // dataSpace
+            sizeof(::android::Rect) + // crop
+            sizeof(int) + // scalingMode
+            sizeof(uint32_t) + // transform
+            sizeof(uint32_t) + // stickyTransform
+            sizeof(bool); // getFrameTimestamps
+}
+
+/**
+ * \brief Return the size of the buffer required to flatten
+ * `HGraphicBufferProducer::QueueBufferInput`.
+ *
+ * \param[in] t The input `HGraphicBufferProducer::QueueBufferInput`.
+ * \return The required size of the flat buffer.
+ */
+size_t getFlattenedSize(HGraphicBufferProducer::QueueBufferInput const& t) {
+    return minFlattenedSize(t) +
+            getFenceFlattenedSize(t.fence) +
+            getFlattenedSize(t.surfaceDamage) +
+            sizeof(HdrMetadata::validTypes);
+}
+
+/**
+ * \brief Return the number of file descriptors contained in
+ * `HGraphicBufferProducer::QueueBufferInput`.
+ *
+ * \param[in] t The input `HGraphicBufferProducer::QueueBufferInput`.
+ * \return The number of file descriptors contained in \p t.
+ */
+size_t getFdCount(
+        HGraphicBufferProducer::QueueBufferInput const& t) {
+    return getFenceFdCount(t.fence);
+}
+
+/**
+ * \brief Flatten `HGraphicBufferProducer::QueueBufferInput`.
+ *
+ * \param[in] t The source `HGraphicBufferProducer::QueueBufferInput`.
+ * \param[out] nh The native handle cloned from `t.fence`.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * This function will duplicate the file descriptor in `t.fence`. */
+status_t flatten(HGraphicBufferProducer::QueueBufferInput const& t,
+        native_handle_t** nh,
+        void*& buffer, size_t& size, int*& fds, size_t& numFds) {
+    if (size < getFlattenedSize(t)) {
+        return NO_MEMORY;
+    }
+
+    FlattenableUtils::write(buffer, size, t.timestamp);
+    FlattenableUtils::write(buffer, size, static_cast<int>(t.isAutoTimestamp));
+    FlattenableUtils::write(buffer, size,
+            static_cast<android_dataspace_t>(t.dataSpace));
+    FlattenableUtils::write(buffer, size, ::android::Rect(
+            static_cast<int32_t>(t.crop.left),
+            static_cast<int32_t>(t.crop.top),
+            static_cast<int32_t>(t.crop.right),
+            static_cast<int32_t>(t.crop.bottom)));
+    FlattenableUtils::write(buffer, size, static_cast<int>(t.scalingMode));
+    FlattenableUtils::write(buffer, size, t.transform);
+    FlattenableUtils::write(buffer, size, t.stickyTransform);
+    FlattenableUtils::write(buffer, size, t.getFrameTimestamps);
+
+    *nh = t.fence.getNativeHandle() == nullptr ?
+            nullptr : native_handle_clone(t.fence);
+    status_t status = flattenFence(hidl_handle(*nh), buffer, size, fds, numFds);
+    if (status != NO_ERROR) {
+        return status;
+    }
+    status = flatten(t.surfaceDamage, buffer, size);
+    if (status != NO_ERROR) {
+        return status;
+    }
+    FlattenableUtils::write(buffer, size, decltype(HdrMetadata::validTypes)(0));
+    return NO_ERROR;
+}
+
+/**
+ * \brief Unflatten `HGraphicBufferProducer::QueueBufferInput`.
+ *
+ * \param[out] t The destination `HGraphicBufferProducer::QueueBufferInput`.
+ * \param[out] nh The underlying native handle for `t->fence`.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * If the return value is `NO_ERROR` and `t->fence` contains a valid file
+ * descriptor, \p nh will be a newly created native handle holding that file
+ * descriptor. \p nh needs to be deleted with `native_handle_delete()`
+ * afterwards.
+ */
+status_t unflatten(
+        HGraphicBufferProducer::QueueBufferInput* t, native_handle_t** nh,
+        void const*& buffer, size_t& size, int const*& fds, size_t& numFds) {
+    if (size < minFlattenedSize(*t)) {
+        return NO_MEMORY;
+    }
+
+    FlattenableUtils::read(buffer, size, t->timestamp);
+    int lIsAutoTimestamp;
+    FlattenableUtils::read(buffer, size, lIsAutoTimestamp);
+    t->isAutoTimestamp = static_cast<int32_t>(lIsAutoTimestamp);
+    android_dataspace_t lDataSpace;
+    FlattenableUtils::read(buffer, size, lDataSpace);
+    t->dataSpace = static_cast<Dataspace>(lDataSpace);
+    Rect lCrop;
+    FlattenableUtils::read(buffer, size, lCrop);
+    t->crop = Rect{
+            static_cast<int32_t>(lCrop.left),
+            static_cast<int32_t>(lCrop.top),
+            static_cast<int32_t>(lCrop.right),
+            static_cast<int32_t>(lCrop.bottom)};
+    int lScalingMode;
+    FlattenableUtils::read(buffer, size, lScalingMode);
+    t->scalingMode = static_cast<int32_t>(lScalingMode);
+    FlattenableUtils::read(buffer, size, t->transform);
+    FlattenableUtils::read(buffer, size, t->stickyTransform);
+    FlattenableUtils::read(buffer, size, t->getFrameTimestamps);
+
+    status_t status = unflattenFence(&(t->fence), nh,
+            buffer, size, fds, numFds);
+    if (status != NO_ERROR) {
+        return status;
+    }
+    // HdrMetadata ignored
+    return unflatten(&(t->surfaceDamage), buffer, size);
+}
+
+/**
+ * \brief Wrap `BGraphicBufferProducer::QueueBufferInput` in
+ * `HGraphicBufferProducer::QueueBufferInput`.
+ *
+ * \param[out] t The wrapper of type
+ * `HGraphicBufferProducer::QueueBufferInput`.
+ * \param[out] nh The underlying native handle for `t->fence`.
+ * \param[in] l The source `BGraphicBufferProducer::QueueBufferInput`.
+ *
+ * If the return value is `true` and `t->fence` contains a valid file
+ * descriptor, \p nh will be a newly created native handle holding that file
+ * descriptor. \p nh needs to be deleted with `native_handle_delete()`
+ * afterwards.
+ */
+bool wrapAs(
+        HGraphicBufferProducer::QueueBufferInput* t,
+        native_handle_t** nh,
+        BGraphicBufferProducer::QueueBufferInput const& l) {
+
+    size_t const baseSize = l.getFlattenedSize();
+    std::unique_ptr<uint8_t[]> baseBuffer(
+            new (std::nothrow) uint8_t[baseSize]);
+    if (!baseBuffer) {
+        return false;
+    }
+
+    size_t const baseNumFds = l.getFdCount();
+    std::unique_ptr<int[]> baseFds(
+            new (std::nothrow) int[baseNumFds]);
+    if (!baseFds) {
+        return false;
+    }
+
+    void* buffer = static_cast<void*>(baseBuffer.get());
+    size_t size = baseSize;
+    int* fds = baseFds.get();
+    size_t numFds = baseNumFds;
+    if (l.flatten(buffer, size, fds, numFds) != NO_ERROR) {
+        return false;
+    }
+
+    void const* constBuffer = static_cast<void const*>(baseBuffer.get());
+    size = baseSize;
+    int const* constFds = static_cast<int const*>(baseFds.get());
+    numFds = baseNumFds;
+    if (unflatten(t, nh, constBuffer, size, constFds, numFds) != NO_ERROR) {
+        return false;
+    }
+
+    return true;
+}
+
+/**
+ * \brief Convert `HGraphicBufferProducer::QueueBufferInput` to
+ * `BGraphicBufferProducer::QueueBufferInput`.
+ *
+ * \param[out] l The destination `BGraphicBufferProducer::QueueBufferInput`.
+ * \param[in] t The source `HGraphicBufferProducer::QueueBufferInput`.
+ *
+ * If `t.fence` has a valid file descriptor, it will be duplicated.
+ */
+bool convertTo(
+        BGraphicBufferProducer::QueueBufferInput* l,
+        HGraphicBufferProducer::QueueBufferInput const& t) {
+
+    size_t const baseSize = getFlattenedSize(t);
+    std::unique_ptr<uint8_t[]> baseBuffer(
+            new (std::nothrow) uint8_t[baseSize]);
+    if (!baseBuffer) {
+        return false;
+    }
+
+    size_t const baseNumFds = getFdCount(t);
+    std::unique_ptr<int[]> baseFds(
+            new (std::nothrow) int[baseNumFds]);
+    if (!baseFds) {
+        return false;
+    }
+
+    void* buffer = static_cast<void*>(baseBuffer.get());
+    size_t size = baseSize;
+    int* fds = baseFds.get();
+    size_t numFds = baseNumFds;
+    native_handle_t* nh;
+    if (flatten(t, &nh, buffer, size, fds, numFds) != NO_ERROR) {
+        return false;
+    }
+
+    void const* constBuffer = static_cast<void const*>(baseBuffer.get());
+    size = baseSize;
+    int const* constFds = static_cast<int const*>(baseFds.get());
+    numFds = baseNumFds;
+    if (l->unflatten(constBuffer, size, constFds, numFds) != NO_ERROR) {
+        if (nh != nullptr) {
+            native_handle_close(nh);
+            native_handle_delete(nh);
+        }
+        return false;
+    }
+
+    native_handle_delete(nh);
+    return true;
+}
+
+// Ref: frameworks/native/libs/gui/BGraphicBufferProducer.cpp:
+//      BGraphicBufferProducer::QueueBufferOutput
+
+/**
+ * \brief Wrap `BGraphicBufferProducer::QueueBufferOutput` in
+ * `HGraphicBufferProducer::QueueBufferOutput`.
+ *
+ * \param[out] t The wrapper of type
+ * `HGraphicBufferProducer::QueueBufferOutput`.
+ * \param[out] nh The array of array of native handles that are referred to by
+ * members of \p t.
+ * \param[in] l The source `BGraphicBufferProducer::QueueBufferOutput`.
+ *
+ * On success, each member of \p nh will be either `nullptr` or a newly created
+ * native handle. All the non-`nullptr` elements must be deleted individually
+ * with `native_handle_delete()`.
+ */
+// wrap: BGraphicBufferProducer::QueueBufferOutput ->
+// HGraphicBufferProducer::QueueBufferOutput
+bool wrapAs(HGraphicBufferProducer::QueueBufferOutput* t,
+        std::vector<std::vector<native_handle_t*> >* nh,
+        BGraphicBufferProducer::QueueBufferOutput const& l) {
+    if (!wrapAs(&(t->frameTimestamps), nh, l.frameTimestamps)) {
+        return false;
+    }
+    t->width = l.width;
+    t->height = l.height;
+    t->transformHint = l.transformHint;
+    t->numPendingBuffers = l.numPendingBuffers;
+    t->nextFrameNumber = l.nextFrameNumber;
+    t->bufferReplaced = l.bufferReplaced;
+    return true;
+}
+
+/**
+ * \brief Convert `HGraphicBufferProducer::QueueBufferOutput` to
+ * `BGraphicBufferProducer::QueueBufferOutput`.
+ *
+ * \param[out] l The destination `BGraphicBufferProducer::QueueBufferOutput`.
+ * \param[in] t The source `HGraphicBufferProducer::QueueBufferOutput`.
+ *
+ * This function will duplicate all file descriptors contained in \p t.
+ */
+// convert: HGraphicBufferProducer::QueueBufferOutput ->
+// BGraphicBufferProducer::QueueBufferOutput
+bool convertTo(
+        BGraphicBufferProducer::QueueBufferOutput* l,
+        HGraphicBufferProducer::QueueBufferOutput const& t) {
+    if (!convertTo(&(l->frameTimestamps), t.frameTimestamps)) {
+        return false;
+    }
+    l->width = t.width;
+    l->height = t.height;
+    l->transformHint = t.transformHint;
+    l->numPendingBuffers = t.numPendingBuffers;
+    l->nextFrameNumber = t.nextFrameNumber;
+    l->bufferReplaced = t.bufferReplaced;
+    return true;
+}
+
+/**
+ * \brief Convert `BGraphicBufferProducer::DisconnectMode` to
+ * `HGraphicBufferProducer::DisconnectMode`.
+ *
+ * \param[in] l The source `BGraphicBufferProducer::DisconnectMode`.
+ * \return The corresponding `HGraphicBufferProducer::DisconnectMode`.
+ */
+HGraphicBufferProducer::DisconnectMode toHidlDisconnectMode(
+        BGraphicBufferProducer::DisconnectMode l) {
+    switch (l) {
+        case BGraphicBufferProducer::DisconnectMode::Api:
+            return HGraphicBufferProducer::DisconnectMode::API;
+        case BGraphicBufferProducer::DisconnectMode::AllLocal:
+            return HGraphicBufferProducer::DisconnectMode::ALL_LOCAL;
+    }
+    return HGraphicBufferProducer::DisconnectMode::API;
+}
+
+/**
+ * \brief Convert `HGraphicBufferProducer::DisconnectMode` to
+ * `BGraphicBufferProducer::DisconnectMode`.
+ *
+ * \param[in] l The source `HGraphicBufferProducer::DisconnectMode`.
+ * \return The corresponding `BGraphicBufferProducer::DisconnectMode`.
+ */
+BGraphicBufferProducer::DisconnectMode toGuiDisconnectMode(
+        HGraphicBufferProducer::DisconnectMode t) {
+    switch (t) {
+        case HGraphicBufferProducer::DisconnectMode::API:
+            return BGraphicBufferProducer::DisconnectMode::Api;
+        case HGraphicBufferProducer::DisconnectMode::ALL_LOCAL:
+            return BGraphicBufferProducer::DisconnectMode::AllLocal;
+    }
+    return BGraphicBufferProducer::DisconnectMode::Api;
+}
+
+}  // namespace conversion
+}  // namespace android
+
diff --git a/libs/gui/bufferqueue/1.0/WProducerListener.cpp b/libs/gui/bufferqueue/1.0/WProducerListener.cpp
new file mode 100644
index 0000000000..78dc4e8b18
--- /dev/null
+++ b/libs/gui/bufferqueue/1.0/WProducerListener.cpp
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2016, 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 <gui/bufferqueue/1.0/WProducerListener.h>
+
+namespace android {
+
+// TWProducerListener
+TWProducerListener::TWProducerListener(
+        sp<BProducerListener> const& base):
+    mBase(base) {
+}
+
+Return<void> TWProducerListener::onBufferReleased() {
+    mBase->onBufferReleased();
+    return Void();
+}
+
+Return<bool> TWProducerListener::needsReleaseNotify() {
+    return mBase->needsReleaseNotify();
+}
+
+// LWProducerListener
+LWProducerListener::LWProducerListener(
+        sp<HProducerListener> const& base):
+    mBase(base) {
+}
+
+void LWProducerListener::onBufferReleased() {
+    mBase->onBufferReleased();
+}
+
+bool LWProducerListener::needsReleaseNotify() {
+    return static_cast<bool>(mBase->needsReleaseNotify());
+}
+
+}  // namespace android
diff --git a/libs/gui/include/gui/IGraphicBufferProducer.h b/libs/gui/include/gui/IGraphicBufferProducer.h
index 2f538adebc..9f7e22bac5 100644
--- a/libs/gui/include/gui/IGraphicBufferProducer.h
+++ b/libs/gui/include/gui/IGraphicBufferProducer.h
@@ -25,6 +25,7 @@
 
 #include <binder/IInterface.h>
 
+#include <ui/BufferQueueDefs.h>
 #include <ui/Fence.h>
 #include <ui/GraphicBuffer.h>
 #include <ui/Rect.h>
@@ -75,10 +76,10 @@ public:
     enum {
         // A flag returned by dequeueBuffer when the client needs to call
         // requestBuffer immediately thereafter.
-        BUFFER_NEEDS_REALLOCATION = 0x1,
+        BUFFER_NEEDS_REALLOCATION = BufferQueueDefs::BUFFER_NEEDS_REALLOCATION,
         // A flag returned by dequeueBuffer when all mirrored slots should be
         // released by the client. This flag should always be processed first.
-        RELEASE_ALL_BUFFERS       = 0x2,
+        RELEASE_ALL_BUFFERS       = BufferQueueDefs::RELEASE_ALL_BUFFERS,
     };
 
     enum {
diff --git a/libs/gui/include/gui/bufferqueue/1.0/Conversion.h b/libs/gui/include/gui/bufferqueue/1.0/Conversion.h
new file mode 100644
index 0000000000..627845c0ea
--- /dev/null
+++ b/libs/gui/include/gui/bufferqueue/1.0/Conversion.h
@@ -0,0 +1,765 @@
+/*
+ * Copyright 2016, 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_HARDWARE_GRAPHICS_BUFFERQUEUE_V1_0_CONVERSION_H_
+#define ANDROID_HARDWARE_GRAPHICS_BUFFERQUEUE_V1_0_CONVERSION_H_
+
+#include <vector>
+#include <list>
+
+#include <unistd.h>
+
+#include <hidl/MQDescriptor.h>
+#include <hidl/Status.h>
+
+#include <binder/Binder.h>
+#include <binder/Status.h>
+#include <ui/FenceTime.h>
+#include <cutils/native_handle.h>
+#include <gui/IGraphicBufferProducer.h>
+
+#include <android/hardware/graphics/bufferqueue/1.0/IProducerListener.h>
+
+namespace android {
+namespace conversion {
+
+using ::android::hardware::hidl_array;
+using ::android::hardware::hidl_string;
+using ::android::hardware::hidl_vec;
+using ::android::hardware::hidl_handle;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+using ::android::sp;
+using ::android::status_t;
+
+using ::android::String8;
+
+using ::android::hardware::media::V1_0::Rect;
+using ::android::hardware::media::V1_0::Region;
+
+using ::android::hardware::graphics::common::V1_0::Dataspace;
+
+using ::android::hardware::graphics::common::V1_0::PixelFormat;
+
+using ::android::hardware::media::V1_0::AnwBuffer;
+using ::android::GraphicBuffer;
+
+typedef ::android::hardware::graphics::bufferqueue::V1_0::IGraphicBufferProducer
+        HGraphicBufferProducer;
+typedef ::android::IGraphicBufferProducer
+        BGraphicBufferProducer;
+
+// native_handle_t helper functions.
+
+/**
+ * \brief Take an fd and create a native handle containing only the given fd.
+ * The created handle will need to be deleted manually with
+ * `native_handle_delete()`.
+ *
+ * \param[in] fd The source file descriptor (of type `int`).
+ * \return The create `native_handle_t*` that contains the given \p fd. If the
+ * supplied \p fd is negative, the created native handle will contain no file
+ * descriptors.
+ *
+ * If the native handle cannot be created, the return value will be
+ * `nullptr`.
+ *
+ * This function does not duplicate the file descriptor.
+ */
+native_handle_t* native_handle_create_from_fd(int fd);
+
+/**
+ * \brief Extract a file descriptor from a native handle.
+ *
+ * \param[in] nh The source `native_handle_t*`.
+ * \param[in] index The index of the file descriptor in \p nh to read from. This
+ * input has the default value of `0`.
+ * \return The `index`-th file descriptor in \p nh. If \p nh does not have
+ * enough file descriptors, the returned value will be `-1`.
+ *
+ * This function does not duplicate the file descriptor.
+ */
+int native_handle_read_fd(native_handle_t const* nh, int index = 0);
+
+/**
+ * Conversion functions
+ * ====================
+ *
+ * There are two main directions of conversion:
+ * - `inTargetType(...)`: Create a wrapper whose lifetime depends on the
+ *   input. The wrapper has type `TargetType`.
+ * - `toTargetType(...)`: Create a standalone object of type `TargetType` that
+ *   corresponds to the input. The lifetime of the output does not depend on the
+ *   lifetime of the input.
+ * - `wrapIn(TargetType*, ...)`: Same as `inTargetType()`, but for `TargetType`
+ *   that cannot be copied and/or moved efficiently, or when there are multiple
+ *   output arguments.
+ * - `convertTo(TargetType*, ...)`: Same as `toTargetType()`, but for
+ *   `TargetType` that cannot be copied and/or moved efficiently, or when there
+ *   are multiple output arguments.
+ *
+ * `wrapIn()` and `convertTo()` functions will take output arguments before
+ * input arguments. Some of these functions might return a value to indicate
+ * success or error.
+ *
+ * In converting or wrapping something as a Treble type that contains a
+ * `hidl_handle`, `native_handle_t*` will need to be created and returned as
+ * an additional output argument, hence only `wrapIn()` or `convertTo()` would
+ * be available. The caller must call `native_handle_delete()` to deallocate the
+ * returned native handle when it is no longer needed.
+ *
+ * For types that contain file descriptors, `inTargetType()` and `wrapAs()` do
+ * not perform duplication of file descriptors, while `toTargetType()` and
+ * `convertTo()` do.
+ */
+
+/**
+ * \brief Convert `Return<void>` to `binder::Status`.
+ *
+ * \param[in] t The source `Return<void>`.
+ * \return The corresponding `binder::Status`.
+ */
+// convert: Return<void> -> ::android::binder::Status
+::android::binder::Status toBinderStatus(Return<void> const& t);
+
+/**
+ * \brief Convert `Return<void>` to `status_t`. This is for legacy binder calls.
+ *
+ * \param[in] t The source `Return<void>`.
+ * \return The corresponding `status_t`.
+ */
+// convert: Return<void> -> status_t
+status_t toStatusT(Return<void> const& t);
+
+/**
+ * \brief Wrap `native_handle_t*` in `hidl_handle`.
+ *
+ * \param[in] nh The source `native_handle_t*`.
+ * \return The `hidl_handle` that points to \p nh.
+ */
+// wrap: native_handle_t* -> hidl_handle
+hidl_handle inHidlHandle(native_handle_t const* nh);
+
+/**
+ * \brief Convert `int32_t` to `Dataspace`.
+ *
+ * \param[in] l The source `int32_t`.
+ * \result The corresponding `Dataspace`.
+ */
+// convert: int32_t -> Dataspace
+Dataspace toHardwareDataspace(int32_t l);
+
+/**
+ * \brief Convert `Dataspace` to `int32_t`.
+ *
+ * \param[in] t The source `Dataspace`.
+ * \result The corresponding `int32_t`.
+ */
+// convert: Dataspace -> int32_t
+int32_t toRawDataspace(Dataspace const& t);
+
+/**
+ * \brief Wrap an opaque buffer inside a `hidl_vec<uint8_t>`.
+ *
+ * \param[in] l The pointer to the beginning of the opaque buffer.
+ * \param[in] size The size of the buffer.
+ * \return A `hidl_vec<uint8_t>` that points to the buffer.
+ */
+// wrap: void*, size_t -> hidl_vec<uint8_t>
+hidl_vec<uint8_t> inHidlBytes(void const* l, size_t size);
+
+/**
+ * \brief Create a `hidl_vec<uint8_t>` that is a copy of an opaque buffer.
+ *
+ * \param[in] l The pointer to the beginning of the opaque buffer.
+ * \param[in] size The size of the buffer.
+ * \return A `hidl_vec<uint8_t>` that is a copy of the input buffer.
+ */
+// convert: void*, size_t -> hidl_vec<uint8_t>
+hidl_vec<uint8_t> toHidlBytes(void const* l, size_t size);
+
+/**
+ * \brief Wrap `GraphicBuffer` in `AnwBuffer`.
+ *
+ * \param[out] t The wrapper of type `AnwBuffer`.
+ * \param[in] l The source `GraphicBuffer`.
+ */
+// wrap: GraphicBuffer -> AnwBuffer
+void wrapAs(AnwBuffer* t, GraphicBuffer const& l);
+
+/**
+ * \brief Convert `AnwBuffer` to `GraphicBuffer`.
+ *
+ * \param[out] l The destination `GraphicBuffer`.
+ * \param[in] t The source `AnwBuffer`.
+ *
+ * This function will duplicate all file descriptors in \p t.
+ */
+// convert: AnwBuffer -> GraphicBuffer
+// Ref: frameworks/native/libs/ui/GraphicBuffer.cpp: GraphicBuffer::flatten
+bool convertTo(GraphicBuffer* l, AnwBuffer const& t);
+
+/**
+ * Conversion functions for types outside media
+ * ============================================
+ *
+ * Some objects in libui and libgui that were made to go through binder calls do
+ * not expose ways to read or write their fields to the public. To pass an
+ * object of this kind through the HIDL boundary, translation functions need to
+ * work around the access restriction by using the publicly available
+ * `flatten()` and `unflatten()` functions.
+ *
+ * All `flatten()` and `unflatten()` overloads follow the same convention as
+ * follows:
+ *
+ *     status_t flatten(ObjectType const& object,
+ *                      [OtherType const& other, ...]
+ *                      void*& buffer, size_t& size,
+ *                      int*& fds, size_t& numFds)
+ *
+ *     status_t unflatten(ObjectType* object,
+ *                        [OtherType* other, ...,]
+ *                        void*& buffer, size_t& size,
+ *                        int*& fds, size_t& numFds)
+ *
+ * The number of `other` parameters varies depending on the `ObjectType`. For
+ * example, in the process of unflattening an object that contains
+ * `hidl_handle`, `other` is needed to hold `native_handle_t` objects that will
+ * be created.
+ *
+ * The last four parameters always work the same way in all overloads of
+ * `flatten()` and `unflatten()`:
+ * - For `flatten()`, `buffer` is the pointer to the non-fd buffer to be filled,
+ *   `size` is the size (in bytes) of the non-fd buffer pointed to by `buffer`,
+ *   `fds` is the pointer to the fd buffer to be filled, and `numFds` is the
+ *   size (in ints) of the fd buffer pointed to by `fds`.
+ * - For `unflatten()`, `buffer` is the pointer to the non-fd buffer to be read
+ *   from, `size` is the size (in bytes) of the non-fd buffer pointed to by
+ *   `buffer`, `fds` is the pointer to the fd buffer to be read from, and
+ *   `numFds` is the size (in ints) of the fd buffer pointed to by `fds`.
+ * - After a successful call to `flatten()` or `unflatten()`, `buffer` and `fds`
+ *   will be advanced, while `size` and `numFds` will be decreased to reflect
+ *   how much storage/data of the two buffers (fd and non-fd) have been used.
+ * - After an unsuccessful call, the values of `buffer`, `size`, `fds` and
+ *   `numFds` are invalid.
+ *
+ * The return value of a successful `flatten()` or `unflatten()` call will be
+ * `OK` (also aliased as `NO_ERROR`). Any other values indicate a failure.
+ *
+ * For each object type that supports flattening, there will be two accompanying
+ * functions: `getFlattenedSize()` and `getFdCount()`. `getFlattenedSize()` will
+ * return the size of the non-fd buffer that the object will need for
+ * flattening. `getFdCount()` will return the size of the fd buffer that the
+ * object will need for flattening.
+ *
+ * The set of these four functions, `getFlattenedSize()`, `getFdCount()`,
+ * `flatten()` and `unflatten()`, are similar to functions of the same name in
+ * the abstract class `Flattenable`. The only difference is that functions in
+ * this file are not member functions of the object type. For example, we write
+ *
+ *     flatten(x, buffer, size, fds, numFds)
+ *
+ * instead of
+ *
+ *     x.flatten(buffer, size, fds, numFds)
+ *
+ * because we cannot modify the type of `x`.
+ *
+ * There is one exception to the naming convention: `hidl_handle` that
+ * represents a fence. The four functions for this "Fence" type have the word
+ * "Fence" attched to their names because the object type, which is
+ * `hidl_handle`, does not carry the special meaning that the object itself can
+ * only contain zero or one file descriptor.
+ */
+
+// Ref: frameworks/native/libs/ui/Fence.cpp
+
+/**
+ * \brief Return the size of the non-fd buffer required to flatten a fence.
+ *
+ * \param[in] fence The input fence of type `hidl_handle`.
+ * \return The required size of the flat buffer.
+ *
+ * The current version of this function always returns 4, which is the number of
+ * bytes required to store the number of file descriptors contained in the fd
+ * part of the flat buffer.
+ */
+size_t getFenceFlattenedSize(hidl_handle const& fence);
+
+/**
+ * \brief Return the number of file descriptors contained in a fence.
+ *
+ * \param[in] fence The input fence of type `hidl_handle`.
+ * \return `0` if \p fence does not contain a valid file descriptor, or `1`
+ * otherwise.
+ */
+size_t getFenceFdCount(hidl_handle const& fence);
+
+/**
+ * \brief Unflatten `Fence` to `hidl_handle`.
+ *
+ * \param[out] fence The destination `hidl_handle`.
+ * \param[out] nh The underlying native handle.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * If the return value is `NO_ERROR`, \p nh will point to a newly created
+ * native handle, which needs to be deleted with `native_handle_delete()`
+ * afterwards.
+ */
+status_t unflattenFence(hidl_handle* fence, native_handle_t** nh,
+        void const*& buffer, size_t& size, int const*& fds, size_t& numFds);
+
+/**
+ * \brief Flatten `hidl_handle` as `Fence`.
+ *
+ * \param[in] t The source `hidl_handle`.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ */
+status_t flattenFence(hidl_handle const& fence,
+        void*& buffer, size_t& size, int*& fds, size_t& numFds);
+
+/**
+ * \brief Wrap `Fence` in `hidl_handle`.
+ *
+ * \param[out] t The wrapper of type `hidl_handle`.
+ * \param[out] nh The native handle pointed to by \p t.
+ * \param[in] l The source `Fence`.
+ *
+ * On success, \p nh will hold a newly created native handle, which must be
+ * deleted manually with `native_handle_delete()` afterwards.
+ */
+// wrap: Fence -> hidl_handle
+bool wrapAs(hidl_handle* t, native_handle_t** nh, Fence const& l);
+
+/**
+ * \brief Convert `hidl_handle` to `Fence`.
+ *
+ * \param[out] l The destination `Fence`. `l` must not have been used
+ * (`l->isValid()` must return `false`) before this function is called.
+ * \param[in] t The source `hidl_handle`.
+ *
+ * If \p t contains a valid file descriptor, it will be duplicated.
+ */
+// convert: hidl_handle -> Fence
+bool convertTo(Fence* l, hidl_handle const& t);
+
+// Ref: frameworks/native/libs/ui/FenceTime.cpp: FenceTime::Snapshot
+
+/**
+ * \brief Return the size of the non-fd buffer required to flatten
+ * `FenceTimeSnapshot`.
+ *
+ * \param[in] t The input `FenceTimeSnapshot`.
+ * \return The required size of the flat buffer.
+ */
+size_t getFlattenedSize(HGraphicBufferProducer::FenceTimeSnapshot const& t);
+
+/**
+ * \brief Return the number of file descriptors contained in
+ * `FenceTimeSnapshot`.
+ *
+ * \param[in] t The input `FenceTimeSnapshot`.
+ * \return The number of file descriptors contained in \p snapshot.
+ */
+size_t getFdCount(HGraphicBufferProducer::FenceTimeSnapshot const& t);
+
+/**
+ * \brief Flatten `FenceTimeSnapshot`.
+ *
+ * \param[in] t The source `FenceTimeSnapshot`.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * This function will duplicate the file descriptor in `t.fence` if `t.state ==
+ * FENCE`.
+ */
+status_t flatten(HGraphicBufferProducer::FenceTimeSnapshot const& t,
+        void*& buffer, size_t& size, int*& fds, size_t& numFds);
+
+/**
+ * \brief Unflatten `FenceTimeSnapshot`.
+ *
+ * \param[out] t The destination `FenceTimeSnapshot`.
+ * \param[out] nh The underlying native handle.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * If the return value is `NO_ERROR` and the constructed snapshot contains a
+ * file descriptor, \p nh will be created to hold that file descriptor. In this
+ * case, \p nh needs to be deleted with `native_handle_delete()` afterwards.
+ */
+status_t unflatten(
+        HGraphicBufferProducer::FenceTimeSnapshot* t, native_handle_t** nh,
+        void const*& buffer, size_t& size, int const*& fds, size_t& numFds);
+
+// Ref: frameworks/native/libs/gui/FrameTimestamps.cpp: FrameEventsDelta
+
+/**
+ * \brief Return the size of the non-fd buffer required to flatten
+ * `FrameEventsDelta`.
+ *
+ * \param[in] t The input `FrameEventsDelta`.
+ * \return The required size of the flat buffer.
+ */
+size_t getFlattenedSize(HGraphicBufferProducer::FrameEventsDelta const& t);
+
+/**
+ * \brief Return the number of file descriptors contained in
+ * `FrameEventsDelta`.
+ *
+ * \param[in] t The input `FrameEventsDelta`.
+ * \return The number of file descriptors contained in \p t.
+ */
+size_t getFdCount(HGraphicBufferProducer::FrameEventsDelta const& t);
+
+/**
+ * \brief Unflatten `FrameEventsDelta`.
+ *
+ * \param[out] t The destination `FrameEventsDelta`.
+ * \param[out] nh The underlying array of native handles.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * If the return value is `NO_ERROR`, \p nh will have length 4, and it will be
+ * populated with `nullptr` or newly created handles. Each non-null slot in \p
+ * nh will need to be deleted manually with `native_handle_delete()`.
+ */
+status_t unflatten(HGraphicBufferProducer::FrameEventsDelta* t,
+        std::vector<native_handle_t*>* nh,
+        void const*& buffer, size_t& size, int const*& fds, size_t& numFds);
+
+/**
+ * \brief Flatten `FrameEventsDelta`.
+ *
+ * \param[in] t The source `FrameEventsDelta`.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * This function will duplicate file descriptors contained in \p t.
+ */
+// Ref: frameworks/native/libs/gui/FrameTimestamp.cpp:
+//      FrameEventsDelta::flatten
+status_t flatten(HGraphicBufferProducer::FrameEventsDelta const& t,
+        void*& buffer, size_t& size, int*& fds, size_t numFds);
+
+// Ref: frameworks/native/libs/gui/FrameTimestamps.cpp: FrameEventHistoryDelta
+
+/**
+ * \brief Return the size of the non-fd buffer required to flatten
+ * `HGraphicBufferProducer::FrameEventHistoryDelta`.
+ *
+ * \param[in] t The input `HGraphicBufferProducer::FrameEventHistoryDelta`.
+ * \return The required size of the flat buffer.
+ */
+size_t getFlattenedSize(
+        HGraphicBufferProducer::FrameEventHistoryDelta const& t);
+
+/**
+ * \brief Return the number of file descriptors contained in
+ * `HGraphicBufferProducer::FrameEventHistoryDelta`.
+ *
+ * \param[in] t The input `HGraphicBufferProducer::FrameEventHistoryDelta`.
+ * \return The number of file descriptors contained in \p t.
+ */
+size_t getFdCount(
+        HGraphicBufferProducer::FrameEventHistoryDelta const& t);
+
+/**
+ * \brief Unflatten `FrameEventHistoryDelta`.
+ *
+ * \param[out] t The destination `FrameEventHistoryDelta`.
+ * \param[out] nh The underlying array of arrays of native handles.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * If the return value is `NO_ERROR`, \p nh will be populated with `nullptr` or
+ * newly created handles. The second dimension of \p nh will be 4. Each non-null
+ * slot in \p nh will need to be deleted manually with `native_handle_delete()`.
+ */
+status_t unflatten(
+        HGraphicBufferProducer::FrameEventHistoryDelta* t,
+        std::vector<std::vector<native_handle_t*> >* nh,
+        void const*& buffer, size_t& size, int const*& fds, size_t& numFds);
+
+/**
+ * \brief Flatten `FrameEventHistoryDelta`.
+ *
+ * \param[in] t The source `FrameEventHistoryDelta`.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * This function will duplicate file descriptors contained in \p t.
+ */
+status_t flatten(
+        HGraphicBufferProducer::FrameEventHistoryDelta const& t,
+        void*& buffer, size_t& size, int*& fds, size_t& numFds);
+
+/**
+ * \brief Wrap `::android::FrameEventHistoryData` in
+ * `HGraphicBufferProducer::FrameEventHistoryDelta`.
+ *
+ * \param[out] t The wrapper of type
+ * `HGraphicBufferProducer::FrameEventHistoryDelta`.
+ * \param[out] nh The array of array of native handles that are referred to by
+ * members of \p t.
+ * \param[in] l The source `::android::FrameEventHistoryDelta`.
+ *
+ * On success, each member of \p nh will be either `nullptr` or a newly created
+ * native handle. All the non-`nullptr` elements must be deleted individually
+ * with `native_handle_delete()`.
+ */
+bool wrapAs(HGraphicBufferProducer::FrameEventHistoryDelta* t,
+        std::vector<std::vector<native_handle_t*> >* nh,
+        ::android::FrameEventHistoryDelta const& l);
+
+/**
+ * \brief Convert `HGraphicBufferProducer::FrameEventHistoryDelta` to
+ * `::android::FrameEventHistoryDelta`.
+ *
+ * \param[out] l The destination `::android::FrameEventHistoryDelta`.
+ * \param[in] t The source `HGraphicBufferProducer::FrameEventHistoryDelta`.
+ *
+ * This function will duplicate all file descriptors contained in \p t.
+ */
+bool convertTo(
+        ::android::FrameEventHistoryDelta* l,
+        HGraphicBufferProducer::FrameEventHistoryDelta const& t);
+
+// Ref: frameworks/native/libs/ui/Region.cpp
+
+/**
+ * \brief Return the size of the buffer required to flatten `Region`.
+ *
+ * \param[in] t The input `Region`.
+ * \return The required size of the flat buffer.
+ */
+size_t getFlattenedSize(Region const& t);
+
+/**
+ * \brief Unflatten `Region`.
+ *
+ * \param[out] t The destination `Region`.
+ * \param[in,out] buffer The pointer to the flat buffer.
+ * \param[in,out] size The size of the flat buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ */
+status_t unflatten(Region* t, void const*& buffer, size_t& size);
+
+/**
+ * \brief Flatten `Region`.
+ *
+ * \param[in] t The source `Region`.
+ * \param[in,out] buffer The pointer to the flat buffer.
+ * \param[in,out] size The size of the flat buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ */
+status_t flatten(Region const& t, void*& buffer, size_t& size);
+
+/**
+ * \brief Convert `::android::Region` to `Region`.
+ *
+ * \param[out] t The destination `Region`.
+ * \param[in] l The source `::android::Region`.
+ */
+// convert: ::android::Region -> Region
+bool convertTo(Region* t, ::android::Region const& l);
+
+/**
+ * \brief Convert `Region` to `::android::Region`.
+ *
+ * \param[out] l The destination `::android::Region`.
+ * \param[in] t The source `Region`.
+ */
+// convert: Region -> ::android::Region
+bool convertTo(::android::Region* l, Region const& t);
+
+// Ref: frameworks/native/libs/gui/BGraphicBufferProducer.cpp:
+//      BGraphicBufferProducer::QueueBufferInput
+
+/**
+ * \brief Return the size of the buffer required to flatten
+ * `HGraphicBufferProducer::QueueBufferInput`.
+ *
+ * \param[in] t The input `HGraphicBufferProducer::QueueBufferInput`.
+ * \return The required size of the flat buffer.
+ */
+size_t getFlattenedSize(HGraphicBufferProducer::QueueBufferInput const& t);
+
+/**
+ * \brief Return the number of file descriptors contained in
+ * `HGraphicBufferProducer::QueueBufferInput`.
+ *
+ * \param[in] t The input `HGraphicBufferProducer::QueueBufferInput`.
+ * \return The number of file descriptors contained in \p t.
+ */
+size_t getFdCount(
+        HGraphicBufferProducer::QueueBufferInput const& t);
+/**
+ * \brief Flatten `HGraphicBufferProducer::QueueBufferInput`.
+ *
+ * \param[in] t The source `HGraphicBufferProducer::QueueBufferInput`.
+ * \param[out] nh The native handle cloned from `t.fence`.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * This function will duplicate the file descriptor in `t.fence`. */
+status_t flatten(HGraphicBufferProducer::QueueBufferInput const& t,
+        native_handle_t** nh,
+        void*& buffer, size_t& size, int*& fds, size_t& numFds);
+
+/**
+ * \brief Unflatten `HGraphicBufferProducer::QueueBufferInput`.
+ *
+ * \param[out] t The destination `HGraphicBufferProducer::QueueBufferInput`.
+ * \param[out] nh The underlying native handle for `t->fence`.
+ * \param[in,out] buffer The pointer to the flat non-fd buffer.
+ * \param[in,out] size The size of the flat non-fd buffer.
+ * \param[in,out] fds The pointer to the flat fd buffer.
+ * \param[in,out] numFds The size of the flat fd buffer.
+ * \return `NO_ERROR` on success; other value on failure.
+ *
+ * If the return value is `NO_ERROR` and `t->fence` contains a valid file
+ * descriptor, \p nh will be a newly created native handle holding that file
+ * descriptor. \p nh needs to be deleted with `native_handle_delete()`
+ * afterwards.
+ */
+status_t unflatten(
+        HGraphicBufferProducer::QueueBufferInput* t, native_handle_t** nh,
+        void const*& buffer, size_t& size, int const*& fds, size_t& numFds);
+
+/**
+ * \brief Wrap `BGraphicBufferProducer::QueueBufferInput` in
+ * `HGraphicBufferProducer::QueueBufferInput`.
+ *
+ * \param[out] t The wrapper of type
+ * `HGraphicBufferProducer::QueueBufferInput`.
+ * \param[out] nh The underlying native handle for `t->fence`.
+ * \param[in] l The source `BGraphicBufferProducer::QueueBufferInput`.
+ *
+ * If the return value is `true` and `t->fence` contains a valid file
+ * descriptor, \p nh will be a newly created native handle holding that file
+ * descriptor. \p nh needs to be deleted with `native_handle_delete()`
+ * afterwards.
+ */
+bool wrapAs(
+        HGraphicBufferProducer::QueueBufferInput* t,
+        native_handle_t** nh,
+        BGraphicBufferProducer::QueueBufferInput const& l);
+
+/**
+ * \brief Convert `HGraphicBufferProducer::QueueBufferInput` to
+ * `BGraphicBufferProducer::QueueBufferInput`.
+ *
+ * \param[out] l The destination `BGraphicBufferProducer::QueueBufferInput`.
+ * \param[in] t The source `HGraphicBufferProducer::QueueBufferInput`.
+ *
+ * If `t.fence` has a valid file descriptor, it will be duplicated.
+ */
+bool convertTo(
+        BGraphicBufferProducer::QueueBufferInput* l,
+        HGraphicBufferProducer::QueueBufferInput const& t);
+
+// Ref: frameworks/native/libs/gui/BGraphicBufferProducer.cpp:
+//      BGraphicBufferProducer::QueueBufferOutput
+
+/**
+ * \brief Wrap `BGraphicBufferProducer::QueueBufferOutput` in
+ * `HGraphicBufferProducer::QueueBufferOutput`.
+ *
+ * \param[out] t The wrapper of type
+ * `HGraphicBufferProducer::QueueBufferOutput`.
+ * \param[out] nh The array of array of native handles that are referred to by
+ * members of \p t.
+ * \param[in] l The source `BGraphicBufferProducer::QueueBufferOutput`.
+ *
+ * On success, each member of \p nh will be either `nullptr` or a newly created
+ * native handle. All the non-`nullptr` elements must be deleted individually
+ * with `native_handle_delete()`.
+ */
+// wrap: BGraphicBufferProducer::QueueBufferOutput ->
+// HGraphicBufferProducer::QueueBufferOutput
+bool wrapAs(HGraphicBufferProducer::QueueBufferOutput* t,
+        std::vector<std::vector<native_handle_t*> >* nh,
+        BGraphicBufferProducer::QueueBufferOutput const& l);
+
+/**
+ * \brief Convert `HGraphicBufferProducer::QueueBufferOutput` to
+ * `BGraphicBufferProducer::QueueBufferOutput`.
+ *
+ * \param[out] l The destination `BGraphicBufferProducer::QueueBufferOutput`.
+ * \param[in] t The source `HGraphicBufferProducer::QueueBufferOutput`.
+ *
+ * This function will duplicate all file descriptors contained in \p t.
+ */
+// convert: HGraphicBufferProducer::QueueBufferOutput ->
+// BGraphicBufferProducer::QueueBufferOutput
+bool convertTo(
+        BGraphicBufferProducer::QueueBufferOutput* l,
+        HGraphicBufferProducer::QueueBufferOutput const& t);
+
+/**
+ * \brief Convert `BGraphicBufferProducer::DisconnectMode` to
+ * `HGraphicBufferProducer::DisconnectMode`.
+ *
+ * \param[in] l The source `BGraphicBufferProducer::DisconnectMode`.
+ * \return The corresponding `HGraphicBufferProducer::DisconnectMode`.
+ */
+HGraphicBufferProducer::DisconnectMode toHidlDisconnectMode(
+        BGraphicBufferProducer::DisconnectMode l);
+
+/**
+ * \brief Convert `HGraphicBufferProducer::DisconnectMode` to
+ * `BGraphicBufferProducer::DisconnectMode`.
+ *
+ * \param[in] l The source `HGraphicBufferProducer::DisconnectMode`.
+ * \return The corresponding `BGraphicBufferProducer::DisconnectMode`.
+ */
+BGraphicBufferProducer::DisconnectMode toGuiDisconnectMode(
+        HGraphicBufferProducer::DisconnectMode t);
+
+}  // namespace conversion
+}  // namespace android
+
+#endif  // ANDROID_HARDWARE_GRAPHICS_BUFFERQUEUE_V1_0_CONVERSION_H_
diff --git a/libs/gui/include/gui/bufferqueue/1.0/WGraphicBufferProducer.h b/libs/gui/include/gui/bufferqueue/1.0/WGraphicBufferProducer.h
new file mode 100644
index 0000000000..0e57f208f8
--- /dev/null
+++ b/libs/gui/include/gui/bufferqueue/1.0/WGraphicBufferProducer.h
@@ -0,0 +1,380 @@
+/*
+ * Copyright 2016, 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_HARDWARE_GRAPHICS_BUFFERQUEUE_V1_0_WGRAPHICBUFFERPRODUCER_H_
+#define ANDROID_HARDWARE_GRAPHICS_BUFFERQUEUE_V1_0_WGRAPHICBUFFERPRODUCER_H_
+
+#include <hidl/MQDescriptor.h>
+#include <hidl/Status.h>
+
+#include <binder/Binder.h>
+#include <gui/IGraphicBufferProducer.h>
+#include <gui/IProducerListener.h>
+#include <gui/bufferqueue/1.0/Conversion.h>
+#include <gui/bufferqueue/1.0/WProducerListener.h>
+#include <system/window.h>
+
+#include <android/hardware/graphics/bufferqueue/1.0/IGraphicBufferProducer.h>
+
+namespace android {
+
+using ::android::hardware::media::V1_0::AnwBuffer;
+using ::android::hidl::base::V1_0::IBase;
+using ::android::hardware::hidl_array;
+using ::android::hardware::hidl_handle;
+using ::android::hardware::hidl_memory;
+using ::android::hardware::hidl_string;
+using ::android::hardware::hidl_vec;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+using ::android::sp;
+
+typedef ::android::hardware::graphics::bufferqueue::V1_0::
+        IGraphicBufferProducer HGraphicBufferProducer;
+typedef ::android::hardware::graphics::bufferqueue::V1_0::
+        IProducerListener HProducerListener;
+
+typedef ::android::IGraphicBufferProducer BGraphicBufferProducer;
+typedef ::android::IProducerListener BProducerListener;
+using ::android::BnGraphicBufferProducer;
+
+#ifndef LOG
+struct LOG_dummy {
+    template <typename T>
+    LOG_dummy& operator<< (const T&) { return *this; }
+};
+
+#define LOG(x)  LOG_dummy()
+#endif
+
+// Instantiate only if HGraphicBufferProducer is base of BASE.
+template <typename BASE,
+          typename = typename std::enable_if<std::is_base_of<HGraphicBufferProducer, BASE>::value>::type>
+struct TWGraphicBufferProducer : public BASE {
+    TWGraphicBufferProducer(sp<BGraphicBufferProducer> const& base) : mBase(base) {}
+    Return<void> requestBuffer(int32_t slot, HGraphicBufferProducer::requestBuffer_cb _hidl_cb) override {
+        sp<GraphicBuffer> buf;
+        status_t status = mBase->requestBuffer(slot, &buf);
+        AnwBuffer anwBuffer;
+        if (buf != nullptr) {
+            ::android::conversion::wrapAs(&anwBuffer, *buf);
+        }
+        _hidl_cb(static_cast<int32_t>(status), anwBuffer);
+        return Void();
+    }
+
+    Return<int32_t> setMaxDequeuedBufferCount(int32_t maxDequeuedBuffers) override {
+        return static_cast<int32_t>(mBase->setMaxDequeuedBufferCount(
+                static_cast<int>(maxDequeuedBuffers)));
+    }
+
+    Return<int32_t> setAsyncMode(bool async) override {
+        return static_cast<int32_t>(mBase->setAsyncMode(async));
+    }
+
+    Return<void> dequeueBuffer(
+            uint32_t width, uint32_t height,
+            ::android::hardware::graphics::common::V1_0::PixelFormat format, uint32_t usage,
+            bool getFrameTimestamps, HGraphicBufferProducer::dequeueBuffer_cb _hidl_cb) override {
+        int slot;
+        sp<Fence> fence;
+        ::android::FrameEventHistoryDelta outTimestamps;
+        status_t status = mBase->dequeueBuffer(
+            &slot, &fence, width, height,
+            static_cast<::android::PixelFormat>(format), usage, nullptr,
+            getFrameTimestamps ? &outTimestamps : nullptr);
+        hidl_handle tFence;
+        HGraphicBufferProducer::FrameEventHistoryDelta tOutTimestamps;
+
+        native_handle_t* nh = nullptr;
+        if ((fence == nullptr) || !::android::conversion::wrapAs(&tFence, &nh, *fence)) {
+            LOG(ERROR) << "TWGraphicBufferProducer::dequeueBuffer - "
+                    "Invalid output fence";
+            _hidl_cb(static_cast<int32_t>(status),
+                     static_cast<int32_t>(slot),
+                     tFence,
+                     tOutTimestamps);
+            return Void();
+        }
+        std::vector<std::vector<native_handle_t*> > nhAA;
+        if (getFrameTimestamps && !::android::conversion::wrapAs(&tOutTimestamps, &nhAA, outTimestamps)) {
+            LOG(ERROR) << "TWGraphicBufferProducer::dequeueBuffer - "
+                    "Invalid output timestamps";
+            _hidl_cb(static_cast<int32_t>(status),
+                     static_cast<int32_t>(slot),
+                     tFence,
+                     tOutTimestamps);
+            native_handle_delete(nh);
+            return Void();
+        }
+
+        _hidl_cb(static_cast<int32_t>(status),
+                static_cast<int32_t>(slot),
+                tFence,
+                tOutTimestamps);
+        native_handle_delete(nh);
+        if (getFrameTimestamps) {
+            for (auto& nhA : nhAA) {
+                for (auto& handle : nhA) {
+                    native_handle_delete(handle);
+                }
+            }
+        }
+        return Void();
+    }
+
+    Return<int32_t> detachBuffer(int32_t slot) override {
+        return static_cast<int32_t>(mBase->detachBuffer(slot));
+    }
+
+    Return<void> detachNextBuffer(HGraphicBufferProducer::detachNextBuffer_cb _hidl_cb) override {
+        sp<GraphicBuffer> outBuffer;
+        sp<Fence> outFence;
+        status_t status = mBase->detachNextBuffer(&outBuffer, &outFence);
+        AnwBuffer tBuffer;
+        hidl_handle tFence;
+
+        if (outBuffer == nullptr) {
+            LOG(ERROR) << "TWGraphicBufferProducer::detachNextBuffer - "
+                    "Invalid output buffer";
+            _hidl_cb(static_cast<int32_t>(status), tBuffer, tFence);
+            return Void();
+        }
+        ::android::conversion::wrapAs(&tBuffer, *outBuffer);
+        native_handle_t* nh = nullptr;
+        if ((outFence != nullptr) && !::android::conversion::wrapAs(&tFence, &nh, *outFence)) {
+            LOG(ERROR) << "TWGraphicBufferProducer::detachNextBuffer - "
+                    "Invalid output fence";
+            _hidl_cb(static_cast<int32_t>(status), tBuffer, tFence);
+            return Void();
+        }
+
+        _hidl_cb(static_cast<int32_t>(status), tBuffer, tFence);
+        native_handle_delete(nh);
+        return Void();
+    }
+
+    Return<void> attachBuffer(const AnwBuffer& buffer, HGraphicBufferProducer::attachBuffer_cb _hidl_cb) override {
+        int outSlot;
+        sp<GraphicBuffer> lBuffer = new GraphicBuffer();
+        if (!::android::conversion::convertTo(lBuffer.get(), buffer)) {
+            LOG(ERROR) << "TWGraphicBufferProducer::attachBuffer - "
+                    "Invalid input native window buffer";
+            _hidl_cb(static_cast<int32_t>(BAD_VALUE), -1);
+            return Void();
+        }
+        status_t status = mBase->attachBuffer(&outSlot, lBuffer);
+
+        _hidl_cb(static_cast<int32_t>(status), static_cast<int32_t>(outSlot));
+        return Void();
+    }
+
+    Return<void> queueBuffer(
+            int32_t slot, const HGraphicBufferProducer::QueueBufferInput& input,
+            HGraphicBufferProducer::queueBuffer_cb _hidl_cb) override {
+        HGraphicBufferProducer::QueueBufferOutput tOutput;
+        BGraphicBufferProducer::QueueBufferInput lInput(
+                0, false, HAL_DATASPACE_UNKNOWN,
+                ::android::Rect(0, 0, 1, 1),
+                NATIVE_WINDOW_SCALING_MODE_FREEZE,
+                0, ::android::Fence::NO_FENCE);
+        if (!::android::conversion::convertTo(&lInput, input)) {
+            LOG(ERROR) << "TWGraphicBufferProducer::queueBuffer - "
+                    "Invalid input";
+            _hidl_cb(static_cast<int32_t>(BAD_VALUE), tOutput);
+            return Void();
+        }
+        BGraphicBufferProducer::QueueBufferOutput lOutput;
+        status_t status = mBase->queueBuffer(
+                static_cast<int>(slot), lInput, &lOutput);
+
+        std::vector<std::vector<native_handle_t*> > nhAA;
+        if (!::android::conversion::wrapAs(&tOutput, &nhAA, lOutput)) {
+            LOG(ERROR) << "TWGraphicBufferProducer::queueBuffer - "
+                    "Invalid output";
+            _hidl_cb(static_cast<int32_t>(BAD_VALUE), tOutput);
+            return Void();
+        }
+
+        _hidl_cb(static_cast<int32_t>(status), tOutput);
+        for (auto& nhA : nhAA) {
+            for (auto& nh : nhA) {
+                native_handle_delete(nh);
+            }
+        }
+        return Void();
+    }
+
+    Return<int32_t> cancelBuffer(int32_t slot, const hidl_handle& fence) override {
+        sp<Fence> lFence = new Fence();
+        if (!::android::conversion::convertTo(lFence.get(), fence)) {
+            LOG(ERROR) << "TWGraphicBufferProducer::cancelBuffer - "
+                    "Invalid input fence";
+            return static_cast<int32_t>(BAD_VALUE);
+        }
+        return static_cast<int32_t>(mBase->cancelBuffer(static_cast<int>(slot), lFence));
+    }
+
+    Return<void> query(int32_t what, HGraphicBufferProducer::query_cb _hidl_cb) override {
+        int lValue;
+        int lReturn = mBase->query(static_cast<int>(what), &lValue);
+        _hidl_cb(static_cast<int32_t>(lReturn), static_cast<int32_t>(lValue));
+        return Void();
+    }
+
+    Return<void> connect(const sp<HProducerListener>& listener,
+            int32_t api, bool producerControlledByApp,
+            HGraphicBufferProducer::connect_cb _hidl_cb) override {
+        sp<BProducerListener> lListener = listener == nullptr ?
+                nullptr : new LWProducerListener(listener);
+        BGraphicBufferProducer::QueueBufferOutput lOutput;
+        status_t status = mBase->connect(lListener,
+                static_cast<int>(api),
+                producerControlledByApp,
+                &lOutput);
+
+        HGraphicBufferProducer::QueueBufferOutput tOutput;
+        std::vector<std::vector<native_handle_t*> > nhAA;
+        if (!::android::conversion::wrapAs(&tOutput, &nhAA, lOutput)) {
+            LOG(ERROR) << "TWGraphicBufferProducer::connect - "
+                    "Invalid output";
+            _hidl_cb(static_cast<int32_t>(status), tOutput);
+            return Void();
+        }
+
+        _hidl_cb(static_cast<int32_t>(status), tOutput);
+        for (auto& nhA : nhAA) {
+            for (auto& nh : nhA) {
+                native_handle_delete(nh);
+            }
+        }
+        return Void();
+    }
+
+    Return<int32_t> disconnect(
+            int32_t api,
+            HGraphicBufferProducer::DisconnectMode mode) override {
+        return static_cast<int32_t>(mBase->disconnect(
+                static_cast<int>(api),
+                ::android::conversion::toGuiDisconnectMode(mode)));
+    }
+
+    Return<int32_t> setSidebandStream(const hidl_handle& stream) override {
+        return static_cast<int32_t>(mBase->setSidebandStream(NativeHandle::create(
+                stream ? native_handle_clone(stream) : NULL, true)));
+    }
+
+    Return<void> allocateBuffers(
+            uint32_t width, uint32_t height,
+            ::android::hardware::graphics::common::V1_0::PixelFormat format,
+            uint32_t usage) override {
+        mBase->allocateBuffers(
+                width, height,
+                static_cast<::android::PixelFormat>(format),
+                usage);
+        return Void();
+    }
+
+    Return<int32_t> allowAllocation(bool allow) override {
+        return static_cast<int32_t>(mBase->allowAllocation(allow));
+    }
+
+    Return<int32_t> setGenerationNumber(uint32_t generationNumber) override {
+        return static_cast<int32_t>(mBase->setGenerationNumber(generationNumber));
+    }
+
+    Return<void> getConsumerName(HGraphicBufferProducer::getConsumerName_cb _hidl_cb) override {
+        _hidl_cb(mBase->getConsumerName().string());
+        return Void();
+    }
+
+    Return<int32_t> setSharedBufferMode(bool sharedBufferMode) override {
+        return static_cast<int32_t>(mBase->setSharedBufferMode(sharedBufferMode));
+    }
+
+    Return<int32_t> setAutoRefresh(bool autoRefresh) override {
+        return static_cast<int32_t>(mBase->setAutoRefresh(autoRefresh));
+    }
+
+    Return<int32_t> setDequeueTimeout(int64_t timeoutNs) override {
+        return static_cast<int32_t>(mBase->setDequeueTimeout(timeoutNs));
+    }
+
+    Return<void> getLastQueuedBuffer(HGraphicBufferProducer::getLastQueuedBuffer_cb _hidl_cb) override {
+        sp<GraphicBuffer> lOutBuffer = new GraphicBuffer();
+        sp<Fence> lOutFence = new Fence();
+        float lOutTransformMatrix[16];
+        status_t status = mBase->getLastQueuedBuffer(
+                &lOutBuffer, &lOutFence, lOutTransformMatrix);
+
+        AnwBuffer tOutBuffer;
+        if (lOutBuffer != nullptr) {
+            ::android::conversion::wrapAs(&tOutBuffer, *lOutBuffer);
+        }
+        hidl_handle tOutFence;
+        native_handle_t* nh = nullptr;
+        if ((lOutFence == nullptr) || !::android::conversion::wrapAs(&tOutFence, &nh, *lOutFence)) {
+            LOG(ERROR) << "TWGraphicBufferProducer::getLastQueuedBuffer - "
+                    "Invalid output fence";
+            _hidl_cb(static_cast<int32_t>(status),
+                    tOutBuffer,
+                    tOutFence,
+                    hidl_array<float, 16>());
+            return Void();
+        }
+        hidl_array<float, 16> tOutTransformMatrix(lOutTransformMatrix);
+
+        _hidl_cb(static_cast<int32_t>(status), tOutBuffer, tOutFence, tOutTransformMatrix);
+        native_handle_delete(nh);
+        return Void();
+    }
+
+    Return<void> getFrameTimestamps(HGraphicBufferProducer::getFrameTimestamps_cb _hidl_cb) override {
+        ::android::FrameEventHistoryDelta lDelta;
+        mBase->getFrameTimestamps(&lDelta);
+
+        HGraphicBufferProducer::FrameEventHistoryDelta tDelta;
+        std::vector<std::vector<native_handle_t*> > nhAA;
+        if (!::android::conversion::wrapAs(&tDelta, &nhAA, lDelta)) {
+            LOG(ERROR) << "TWGraphicBufferProducer::getFrameTimestamps - "
+                    "Invalid output frame timestamps";
+            _hidl_cb(tDelta);
+            return Void();
+        }
+
+        _hidl_cb(tDelta);
+        for (auto& nhA : nhAA) {
+            for (auto& nh : nhA) {
+                native_handle_delete(nh);
+            }
+        }
+        return Void();
+    }
+
+    Return<void> getUniqueId(HGraphicBufferProducer::getUniqueId_cb _hidl_cb) override {
+        uint64_t outId;
+        status_t status = mBase->getUniqueId(&outId);
+        _hidl_cb(static_cast<int32_t>(status), outId);
+        return Void();
+    }
+
+private:
+    sp<BGraphicBufferProducer> mBase;
+};
+
+}  // namespace android
+
+#endif  // ANDROID_HARDWARE_GRAPHICS_BUFFERQUEUE_V1_0_WGRAPHICBUFFERPRODUCER_H_
diff --git a/libs/gui/include/gui/bufferqueue/1.0/WProducerListener.h b/libs/gui/include/gui/bufferqueue/1.0/WProducerListener.h
new file mode 100644
index 0000000000..51dff5b8be
--- /dev/null
+++ b/libs/gui/include/gui/bufferqueue/1.0/WProducerListener.h
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2016, 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_HARDWARE_GRAPHICS_BUFFERQUEUE_V1_0_WPRODUCERLISTENER_H_
+#define ANDROID_HARDWARE_GRAPHICS_BUFFERQUEUE_V1_0_WPRODUCERLISTENER_H_
+
+#include <hidl/MQDescriptor.h>
+#include <hidl/Status.h>
+
+#include <binder/IBinder.h>
+#include <gui/IProducerListener.h>
+
+#include <android/hardware/graphics/bufferqueue/1.0/IProducerListener.h>
+
+namespace android {
+
+using ::android::hidl::base::V1_0::IBase;
+using ::android::hardware::hidl_array;
+using ::android::hardware::hidl_memory;
+using ::android::hardware::hidl_string;
+using ::android::hardware::hidl_vec;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+using ::android::sp;
+
+typedef ::android::hardware::graphics::bufferqueue::V1_0::IProducerListener
+        HProducerListener;
+typedef ::android::IProducerListener
+        BProducerListener;
+using ::android::BnProducerListener;
+
+struct TWProducerListener : public HProducerListener {
+    sp<BProducerListener> mBase;
+    TWProducerListener(sp<BProducerListener> const& base);
+    Return<void> onBufferReleased() override;
+    Return<bool> needsReleaseNotify() override;
+};
+
+class LWProducerListener : public BnProducerListener {
+public:
+    sp<HProducerListener> mBase;
+    LWProducerListener(sp<HProducerListener> const& base);
+    void onBufferReleased() override;
+    bool needsReleaseNotify() override;
+};
+
+}  // namespace android
+
+#endif  // ANDROID_HARDWARE_GRAPHICS_BUFFERQUEUE_V1_0_WPRODUCERLISTENER_H_
diff --git a/libs/ui/include/ui/BufferQueueDefs.h b/libs/ui/include/ui/BufferQueueDefs.h
index 56de181bca..0fecda9cf1 100644
--- a/libs/ui/include/ui/BufferQueueDefs.h
+++ b/libs/ui/include/ui/BufferQueueDefs.h
@@ -23,6 +23,16 @@ namespace android {
         // Attempts at runtime to increase the number of buffers past this
         // will fail.
         static constexpr int NUM_BUFFER_SLOTS = 64;
+
+        enum {
+            // A flag returned by dequeueBuffer when the client needs to call
+            // requestBuffer immediately thereafter.
+            BUFFER_NEEDS_REALLOCATION = 0x1,
+            // A flag returned by dequeueBuffer when all mirrored slots should be
+            // released by the client. This flag should always be processed first.
+            RELEASE_ALL_BUFFERS       = 0x2,
+        };
+
     } // namespace BufferQueueDefs
 } // namespace android