path: root/nn/runtime/VersionedInterfaces.cpp

/*
 * Copyright (C) 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.
 */

#define LOG_TAG "VersionedInterfaces"

#include "VersionedInterfaces.h"

#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/scopeguard.h>
#include <android-base/thread_annotations.h>

#include <chrono>
#include <functional>
#include <memory>
#include <string>
#include <tuple>
#include <type_traits>
#include <utility>
#include <vector>

#include "Callbacks.h"
#include "ExecutionBurstController.h"
#include "MetaModel.h"
#include "Tracing.h"
#include "Utils.h"

/*
 * Some notes about HIDL interface objects and lifetimes across processes:
 *
 * All HIDL interface objects inherit from IBase, which itself inherits from
 * ::android::RefBase. As such, all HIDL interface objects are reference counted
 * and must be owned through ::android::sp (or referenced through ::android::wp).
 * Allocating RefBase objects on the stack will log errors and may result in
 * crashes, and deleting a RefBase object through another means (e.g., "delete",
 * "free", or RAII-cleanup through std::unique_ptr or some equivalent) will
 * result in double-free and/or use-after-free undefined behavior.
 *
 * HIDL/Binder manages the reference count of HIDL interface objects
 * automatically across processes. If a process that references (but did not
 * create) the HIDL interface object dies, HIDL/Binder ensures any reference
 * count it held is properly released. (Caveat: it might be possible that
 * HIDL/Binder behave strangely with ::android::wp references.)
 *
 * If the process which created the HIDL interface object dies, any call on this
 * object from another process will result in a HIDL transport error with the
 * code DEAD_OBJECT.
 */

/*
 * Some notes about asynchronous calls across HIDL:
 *
 * For synchronous calls across HIDL, if an error occurs after the function was
 * called but before it returns, HIDL will return a transport error. For
 * example, if the message cannot be delivered to the server process or if the
 * server process dies before returning a result, HIDL will return from the
 * function with the appropriate transport error in the Return<> object which
 * can be queried with Return<>::isOk(), Return<>::isDeadObject(),
 * Return<>::description(), etc.
 *
 * However, HIDL offers no such error management in the case of asynchronous
 * calls. By default, if the client launches an asynchronous task and the server
 * fails to return a result through the callback, the client will be left
 * waiting indefinitely for a result it will never receive.
 *
 * In the NNAPI, IDevice::prepareModel* and IPreparedModel::execute* (but not
 * IPreparedModel::executeSynchronously) are asynchronous calls across HIDL.
 * Specifically, these asynchronous functions are called with a HIDL interface
 * callback object (IPrepareModelCallback for IDevice::prepareModel* and
 * IExecutionCallback for IPreparedModel::execute*) and are expected to quickly
 * return, and the results are returned at a later time through these callback
 * objects.
 *
 * To protect against the case when the server dies after the asynchronous task
 * was called successfully but before the results could be returned, HIDL
 * provides an object called a "hidl_death_recipient", which can be used to
 * detect when an interface object (and more generally, the server process) has
 * died. VersionedInterfaces uses hidl_death_recipients to detect when the
 * driver process has died, and VersionedInterfaces will unblock any thread
 * waiting on the results of a callback object that may otherwise not be
 * signaled.
 */

namespace android {
namespace nn {

// anonymous namespace
namespace {

using namespace hal;

const Timing kNoTiming = {.timeOnDevice = UINT64_MAX, .timeInDriver = UINT64_MAX};

void sendFailureMessage(const sp<IPreparedModelCallback>& cb) {
    cb->notify(ErrorStatus::GENERAL_FAILURE, nullptr);
}

void sendFailureMessage(const sp<PreparedModelCallback>& cb) {
    sendFailureMessage(static_cast<sp<IPreparedModelCallback>>(cb));
}

void sendFailureMessage(const sp<IExecutionCallback>& cb) {
    cb->notify(ErrorStatus::GENERAL_FAILURE);
}

// This class is thread safe
template <typename ICallback>
class DeathHandler : public hidl_death_recipient {
   public:
    void serviceDied(uint64_t /*cookie*/, const wp<hidl::base::V1_0::IBase>& /*who*/) override {
        LOG(ERROR) << "DeathHandler::serviceDied -- service unexpectedly died!";
        std::lock_guard<std::mutex> hold(mMutex);
        std::for_each(mCallbacks.begin(), mCallbacks.end(),
                      [](const auto& cb) { sendFailureMessage(cb); });
    }

    [[nodiscard]] base::ScopeGuard<std::function<void()>> protectCallback(
            const sp<ICallback>& callback) {
        registerCallback(callback);
        return ::android::base::make_scope_guard(
                [this, callback] { unregisterCallback(callback); });
    }

   private:
    void registerCallback(const sp<ICallback>& callback) {
        std::lock_guard<std::mutex> hold(mMutex);
        mCallbacks.push_back(callback);
    }

    void unregisterCallback(const sp<ICallback>& callback) {
        std::lock_guard<std::mutex> hold(mMutex);
        mCallbacks.erase(std::remove(mCallbacks.begin(), mCallbacks.end(), callback),
                         mCallbacks.end());
    }

    std::mutex mMutex;
    std::vector<sp<ICallback>> mCallbacks GUARDED_BY(mMutex);
};

}  // anonymous namespace

class IDeviceDeathHandler : public DeathHandler<IPreparedModelCallback> {};
class IPreparedModelDeathHandler : public DeathHandler<IExecutionCallback> {};

static std::shared_ptr<VersionedIPreparedModel> makeVersionedIPreparedModel(
        sp<V1_0::IPreparedModel> preparedModel) {
    // verify input
    if (preparedModel == nullptr) {
        LOG(ERROR) << "makeVersionedIPreparedModel passed invalid preparedModel object.";
        return nullptr;
    }

    // create death handler object
    sp<IPreparedModelDeathHandler> deathHandler = new IPreparedModelDeathHandler();

    // linkToDeath registers a callback that will be invoked on service death to
    // proactively handle service crashes. If the linkToDeath call fails,
    // asynchronous calls are susceptible to hangs if the service crashes before
    // providing the response.
    const Return<bool> ret = preparedModel->linkToDeath(deathHandler, 0);
    if (!ret.isOk() || ret != true) {
        LOG(ERROR) << "makeVersionedIPreparedModel failed to register a death recipient for the "
                      "IPreparedModel object.";
        return nullptr;
    }

    // return a valid VersionedIPreparedModel object
    return std::make_shared<VersionedIPreparedModel>(std::move(preparedModel),
                                                     std::move(deathHandler));
}

VersionedIPreparedModel::VersionedIPreparedModel(sp<V1_0::IPreparedModel> preparedModel,
                                                 sp<IPreparedModelDeathHandler> deathHandler)
    : mPreparedModelV1_0(std::move(preparedModel)),
      mPreparedModelV1_2(V1_2::IPreparedModel::castFrom(mPreparedModelV1_0).withDefault(nullptr)),
      mDeathHandler(std::move(deathHandler)) {}

VersionedIPreparedModel::~VersionedIPreparedModel() {
    // It is safe to ignore any errors resulting from this unlinkToDeath call
    // because the VersionedIPreparedModel object is already being destroyed and
    // its underlying IPreparedModel object is no longer being used by the NN
    // runtime.
    mPreparedModelV1_0->unlinkToDeath(mDeathHandler).isOk();
}

std::tuple<int, std::vector<OutputShape>, Timing> VersionedIPreparedModel::executeAsynchronously(
        const Request& request, MeasureTiming measure) const {
    const auto failWithStatus = [](ErrorStatus status) {
        return getExecutionResult(status, {}, kNoTiming);
    };
    const auto getResults = [](const ExecutionCallback& cb) {
        return getExecutionResult(cb.getStatus(), cb.getOutputShapes(), cb.getTiming());
    };

    const sp<ExecutionCallback> callback = new ExecutionCallback();
    const auto scoped = mDeathHandler->protectCallback(callback);

    // version 1.2+ HAL
    if (mPreparedModelV1_2 != nullptr) {
        Return<ErrorStatus> ret = mPreparedModelV1_2->execute_1_2(request, measure, callback);
        if (!ret.isOk()) {
            LOG(ERROR) << "execute_1_2 failure: " << ret.description();
            return failWithStatus(ErrorStatus::GENERAL_FAILURE);
        }
        if (ret != ErrorStatus::NONE) {
            LOG(ERROR) << "execute_1_2 returned " << toString(static_cast<ErrorStatus>(ret));
            return failWithStatus(ret);
        }
        callback->wait();
        return getResults(*callback);
    }

    // version 1.0+ HAL
    if (mPreparedModelV1_0 != nullptr) {
        Return<ErrorStatus> ret = mPreparedModelV1_0->execute(request, callback);
        if (!ret.isOk()) {
            LOG(ERROR) << "execute failure: " << ret.description();
            return failWithStatus(ErrorStatus::GENERAL_FAILURE);
        }
        if (ret != ErrorStatus::NONE) {
            LOG(ERROR) << "execute returned " << toString(static_cast<ErrorStatus>(ret));
            return failWithStatus(ret);
        }
        callback->wait();
        return getResults(*callback);
    }

    // No prepared model available
    LOG(ERROR) << "executeAsynchronously called with no preparedModel";
    return failWithStatus(ErrorStatus::GENERAL_FAILURE);
}

std::tuple<int, std::vector<OutputShape>, Timing> VersionedIPreparedModel::executeSynchronously(
        const Request& request, MeasureTiming measure) const {
    const auto kFailure = getExecutionResult(ErrorStatus::GENERAL_FAILURE, {}, kNoTiming);

    // version 1.2+ HAL
    if (mPreparedModelV1_2 != nullptr) {
        std::tuple<int, std::vector<OutputShape>, Timing> result;
        Return<void> ret = mPreparedModelV1_2->executeSynchronously(
                request, measure,
                [&result](ErrorStatus error, const hidl_vec<OutputShape>& outputShapes,
                          const Timing& timing) {
                    result = getExecutionResult(error, outputShapes, timing);
                });
        if (!ret.isOk()) {
            LOG(ERROR) << "executeSynchronously failure: " << ret.description();
            return kFailure;
        }
        return result;
    }

    // Fallback to asynchronous execution.
    return executeAsynchronously(request, measure);
}

std::tuple<int, std::vector<OutputShape>, Timing> VersionedIPreparedModel::execute(
        const Request& request, MeasureTiming measure, bool preferSynchronous) const {
    if (preferSynchronous) {
        VLOG(EXECUTION) << "Before executeSynchronously() " << SHOW_IF_DEBUG(toString(request));
        return executeSynchronously(request, measure);
    }

    VLOG(EXECUTION) << "Before executeAsynchronously() " << SHOW_IF_DEBUG(toString(request));
    return executeAsynchronously(request, measure);
}

// This is the amount of time the ExecutionBurstController should spend polling
// the FMQ to see if it has data available before it should fall back to
// waiting on the futex.
static std::chrono::microseconds getPollingTimeWindow() {
    constexpr int32_t defaultPollingTimeWindow = 50;
#ifdef NN_DEBUGGABLE
    constexpr int32_t minPollingTimeWindow = 0;
    const int32_t selectedPollingTimeWindow =
            base::GetIntProperty("debug.nn.burst-conrtoller-polling-window",
                                 defaultPollingTimeWindow, minPollingTimeWindow);
    return std::chrono::microseconds{selectedPollingTimeWindow};
#else
    return std::chrono::microseconds{defaultPollingTimeWindow};
#endif  // NN_DEBUGGABLE
}

std::shared_ptr<ExecutionBurstController> VersionedIPreparedModel::configureExecutionBurst(
        bool preferPowerOverLatency) const {
    if (mPreparedModelV1_2 == nullptr) {
        return nullptr;
    }
    const auto pollingTimeWindow =
            (preferPowerOverLatency ? std::chrono::microseconds{0} : getPollingTimeWindow());
    return ExecutionBurstController::create(mPreparedModelV1_2, pollingTimeWindow);
}

std::shared_ptr<VersionedIDevice> VersionedIDevice::create(std::string serviceName,
                                                           sp<V1_0::IDevice> device) {
    auto core = Core::create(std::move(device));
    if (!core.has_value()) {
        LOG(ERROR) << "VersionedIDevice::create failed to create Core.";
        return nullptr;
    }

    // return a valid VersionedIDevice object
    return std::make_shared<VersionedIDevice>(std::move(serviceName), std::move(core.value()));
}

VersionedIDevice::VersionedIDevice(std::string serviceName, Core core)
    : mServiceName(std::move(serviceName)), mCore(std::move(core)) {}

std::optional<VersionedIDevice::Core> VersionedIDevice::Core::create(sp<V1_0::IDevice> device) {
    // verify input
    CHECK(device != nullptr) << "VersionedIDevice::Core::create passed invalid device object.";

    // create death handler object
    sp<IDeviceDeathHandler> deathHandler = new IDeviceDeathHandler();

    // linkToDeath registers a callback that will be invoked on service death to
    // proactively handle service crashes. If the linkToDeath call fails,
    // asynchronous calls are susceptible to hangs if the service crashes before
    // providing the response.
    const Return<bool> ret = device->linkToDeath(deathHandler, 0);
    if (!ret.isOk() || ret != true) {
        LOG(ERROR) << "VersionedIDevice::Core::create failed to register a death recipient for the "
                      "IDevice object.";
        return {};
    }

    // return a valid Core object
    return Core(std::move(device), std::move(deathHandler));
}

// HIDL guarantees all V1_1 interfaces inherit from their corresponding V1_0 interfaces.
VersionedIDevice::Core::Core(sp<V1_0::IDevice> device, sp<IDeviceDeathHandler> deathHandler)
    : mDeviceV1_0(std::move(device)),
      mDeviceV1_1(V1_1::IDevice::castFrom(mDeviceV1_0).withDefault(nullptr)),
      mDeviceV1_2(V1_2::IDevice::castFrom(mDeviceV1_0).withDefault(nullptr)),
      mDeviceV1_3(V1_3::IDevice::castFrom(mDeviceV1_0).withDefault(nullptr)),
      mDeathHandler(std::move(deathHandler)) {}

VersionedIDevice::Core::~Core() {
    if (mDeathHandler != nullptr) {
        CHECK(mDeviceV1_0 != nullptr);
        // It is safe to ignore any errors resulting from this unlinkToDeath call
        // because the VersionedIDevice::Core object is already being destroyed and
        // its underlying IDevice object is no longer being used by the NN runtime.
        mDeviceV1_0->unlinkToDeath(mDeathHandler).isOk();
    }
}

VersionedIDevice::Core::Core(Core&& other) noexcept
    : mDeviceV1_0(std::move(other.mDeviceV1_0)),
      mDeviceV1_1(std::move(other.mDeviceV1_1)),
      mDeviceV1_2(std::move(other.mDeviceV1_2)),
      mDeviceV1_3(std::move(other.mDeviceV1_3)),
      mDeathHandler(std::move(other.mDeathHandler)) {
    other.mDeathHandler = nullptr;
}

VersionedIDevice::Core& VersionedIDevice::Core::operator=(Core&& other) noexcept {
    if (this != &other) {
        mDeviceV1_0 = std::move(other.mDeviceV1_0);
        mDeviceV1_1 = std::move(other.mDeviceV1_1);
        mDeviceV1_2 = std::move(other.mDeviceV1_2);
        mDeviceV1_3 = std::move(other.mDeviceV1_3);
        mDeathHandler = std::move(other.mDeathHandler);
        other.mDeathHandler = nullptr;
    }
    return *this;
}

template <typename T_IDevice>
std::pair<sp<T_IDevice>, sp<IDeviceDeathHandler>> VersionedIDevice::Core::getDeviceAndDeathHandler()
        const {
    return {getDevice<T_IDevice>(), mDeathHandler};
}

template <typename T_IDevice, typename T_Callback>
Return<ErrorStatus> callProtected(
        const char* context, const std::function<Return<ErrorStatus>(const sp<T_IDevice>&)>& fn,
        const sp<T_IDevice>& device, const sp<T_Callback>& callback,
        const sp<IDeviceDeathHandler>& deathHandler) {
    const auto scoped = deathHandler->protectCallback(callback);
    Return<ErrorStatus> ret = fn(device);
    // Suppose there was a transport error.  We have the following cases:
    // 1. Either not due to a dead device, or due to a device that was
    //    already dead at the time of the call to protectCallback().  In
    //    this case, the callback was never signalled.
    // 2. Due to a device that died after the call to protectCallback() but
    //    before fn() completed.  In this case, the callback was (or will
    //    be) signalled by the deathHandler.
    // Furthermore, what if there was no transport error, but the ErrorStatus is
    // other than NONE?  We'll conservatively signal the callback anyway, just in
    // case the driver was sloppy and failed to do so.
    if (!ret.isOk() || ret != ErrorStatus::NONE) {
        // What if the deathHandler has signalled or will signal the callback?
        // This is fine -- we're permitted to signal multiple times; and we're
        // sending the same signal that the deathHandler does.
        //
        // What if the driver signalled the callback?  Then this signal is
        // ignored.

        if (ret.isOk()) {
            LOG(ERROR) << context << " returned " << toString(static_cast<ErrorStatus>(ret));
        } else {
            LOG(ERROR) << context << " failure: " << ret.description();
        }
        sendFailureMessage(callback);
    }
    callback->wait();
    return ret;
}
template <typename T_Return, typename T_IDevice>
Return<T_Return> callProtected(const char*,
                               const std::function<Return<T_Return>(const sp<T_IDevice>&)>& fn,
                               const sp<T_IDevice>& device, const std::nullptr_t&,
                               const sp<IDeviceDeathHandler>&) {
    return fn(device);
}

template <typename T_Return, typename T_IDevice, typename T_Callback>
Return<T_Return> VersionedIDevice::recoverable(
        const char* context, const std::function<Return<T_Return>(const sp<T_IDevice>&)>& fn,
        const T_Callback& callback) const EXCLUDES(mMutex) {
    CHECK_EQ(callback == nullptr, (std::is_same_v<T_Callback, std::nullptr_t>));

    sp<T_IDevice> device;
    sp<IDeviceDeathHandler> deathHandler;
    std::tie(device, deathHandler) = getDeviceAndDeathHandler<T_IDevice>();

    Return<T_Return> ret = callProtected(context, fn, device, callback, deathHandler);

    if (ret.isDeadObject()) {
        {
            std::unique_lock lock(mMutex);
            // It's possible that another device has already done the recovery.
            // It's harmless but wasteful for us to do so in this case.
            auto pingReturn = mCore.getDevice<T_IDevice>()->ping();
            if (pingReturn.isDeadObject()) {
                VLOG(DRIVER) << "VersionedIDevice::recoverable(" << context << ") -- Recovering "
                             << mServiceName;
                sp<V1_0::IDevice> recoveredDevice = V1_0::IDevice::tryGetService(mServiceName);
                if (recoveredDevice == nullptr) {
                    VLOG(DRIVER) << "VersionedIDevice::recoverable got a null IDEVICE for "
                                 << mServiceName;
                    return ret;
                }

                auto core = Core::create(std::move(recoveredDevice));
                if (!core.has_value()) {
                    LOG(ERROR) << "VersionedIDevice::recoverable failed to create Core.";
                    return ret;
                }

                mCore = std::move(core.value());
            } else {
                VLOG(DRIVER) << "VersionedIDevice::recoverable(" << context
                             << ") -- Someone else recovered " << mServiceName;
                // Might still have a transport error, which we need to check
                // before pingReturn goes out of scope.
                (void)pingReturn.isOk();
            }
            std::tie(device, deathHandler) = mCore.getDeviceAndDeathHandler<T_IDevice>();
        }
        ret = callProtected(context, fn, device, callback, deathHandler);
        // It's possible that the device died again, but we're only going to
        // attempt recovery once per call to recoverable().
    }
    return ret;
}

std::pair<ErrorStatus, Capabilities> VersionedIDevice::getCapabilities() const {
    const std::pair<ErrorStatus, Capabilities> kFailure = {ErrorStatus::GENERAL_FAILURE, {}};
    std::pair<ErrorStatus, Capabilities> result;

    // version 1.3+ HAL
    if (getDevice<V1_3::IDevice>() != nullptr) {
        NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_INITIALIZATION, "getCapabilities_1_3");
        Return<void> ret = recoverable<void, V1_3::IDevice>(
                __FUNCTION__, [&result](const sp<V1_3::IDevice>& device) {
                    return device->getCapabilities_1_3(
                            [&result](ErrorStatus error, const Capabilities& capabilities) {
                                result = std::make_pair(error, capabilities);
                            });
                });
        if (!ret.isOk()) {
            LOG(ERROR) << "getCapabilities_1_3 failure: " << ret.description();
            return {ErrorStatus::GENERAL_FAILURE, {}};
        }
        return result;
    }

    // version 1.2 HAL
    if (getDevice<V1_2::IDevice>() != nullptr) {
        NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_INITIALIZATION, "getCapabilities_1_2");
        Return<void> ret = recoverable<void, V1_2::IDevice>(
                __FUNCTION__, [&result](const sp<V1_2::IDevice>& device) {
                    return device->getCapabilities_1_2(
                            [&result](ErrorStatus error, const V1_2::Capabilities& capabilities) {
                                result = std::make_pair(error, convertToV1_3(capabilities));
                            });
                });
        if (!ret.isOk()) {
            LOG(ERROR) << "getCapabilities_1_2 failure: " << ret.description();
            return {ErrorStatus::GENERAL_FAILURE, {}};
        }
        return result;
    }

    // version 1.1 HAL
    if (getDevice<V1_1::IDevice>() != nullptr) {
        NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_INITIALIZATION, "getCapabilities_1_1");
        Return<void> ret = recoverable<void, V1_1::IDevice>(
                __FUNCTION__, [&result](const sp<V1_1::IDevice>& device) {
                    return device->getCapabilities_1_1(
                            [&result](ErrorStatus error, const V1_1::Capabilities& capabilities) {
                                // Time taken to convert capabilities is trivial
                                result = std::make_pair(error, convertToV1_3(capabilities));
                            });
                });
        if (!ret.isOk()) {
            LOG(ERROR) << "getCapabilities_1_1 failure: " << ret.description();
            return kFailure;
        }
        return result;
    }

    // version 1.0 HAL
    if (getDevice<V1_0::IDevice>() != nullptr) {
        NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_INITIALIZATION, "getCapabilities");
        Return<void> ret = recoverable<void, V1_0::IDevice>(
                __FUNCTION__, [&result](const sp<V1_0::IDevice>& device) {
                    return device->getCapabilities(
                            [&result](ErrorStatus error, const V1_0::Capabilities& capabilities) {
                                // Time taken to convert capabilities is trivial
                                result = std::make_pair(error, convertToV1_3(capabilities));
                            });
                });
        if (!ret.isOk()) {
            LOG(ERROR) << "getCapabilities failure: " << ret.description();
            return kFailure;
        }
        return result;
    }

    // No device available
    LOG(ERROR) << "Device not available!";
    return {ErrorStatus::DEVICE_UNAVAILABLE, {}};
}

std::pair<ErrorStatus, hidl_vec<Extension>> VersionedIDevice::getSupportedExtensions() const {
    const std::pair<ErrorStatus, hidl_vec<Extension>> kFailure = {ErrorStatus::GENERAL_FAILURE, {}};

    // version 1.2+ HAL
    if (getDevice<V1_2::IDevice>() != nullptr) {
        NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_INITIALIZATION, "getSupportedExtensions");
        std::pair<ErrorStatus, hidl_vec<Extension>> result;
        Return<void> ret = recoverable<void, V1_2::IDevice>(
                __FUNCTION__, [&result](const sp<V1_2::IDevice>& device) {
                    return device->getSupportedExtensions(
                            [&result](ErrorStatus error, const hidl_vec<Extension>& extensions) {
                                result = std::make_pair(error, extensions);
                            });
                });
        if (!ret.isOk()) {
            LOG(ERROR) << "getSupportedExtensions failure: " << ret.description();
            return kFailure;
        }
        return result;
    }

    // version too low
    if (getDevice<V1_0::IDevice>() != nullptr) {
        return {ErrorStatus::NONE, {/* No extensions. */}};
    }

    // No device available
    LOG(ERROR) << "Device not available!";
    return {ErrorStatus::DEVICE_UNAVAILABLE, {}};
}

std::pair<ErrorStatus, hidl_vec<bool>> VersionedIDevice::getSupportedOperations(
        const MetaModel& metaModel) const {
    const std::pair<ErrorStatus, hidl_vec<bool>> kFailure = {ErrorStatus::GENERAL_FAILURE, {}};
    std::pair<ErrorStatus, hidl_vec<bool>> result;

    const Model& model = metaModel.getModel();

    auto noneSupported = [&model] {
        hidl_vec<bool> supported(model.operations.size());
        std::fill(supported.begin(), supported.end(), false);
        return std::make_pair(ErrorStatus::NONE, std::move(supported));
    };

    auto remappedResult = [&model](const std::pair<ErrorStatus, hidl_vec<bool>>& result,
                                   const std::function<uint32_t(uint32_t)>&
                                           submodelOperationIndexToModelOperationIndex) {
        const ErrorStatus status = result.first;
        const hidl_vec<bool>& supported = result.second;
        hidl_vec<bool> remappedSupported(model.operations.size());
        std::fill(remappedSupported.begin(), remappedSupported.end(), false);
        for (size_t i = 0; i < supported.size(); ++i) {
            if (supported[i]) {
                remappedSupported[submodelOperationIndexToModelOperationIndex(i)] = true;
            }
        }
        return std::make_pair(status, std::move(remappedSupported));
    };

    // version 1.3+ HAL
    if (getDevice<V1_3::IDevice>() != nullptr) {
        NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_COMPILATION, "getSupportedOperations_1_3");
        Return<void> ret = recoverable<void, V1_3::IDevice>(
                __FUNCTION__, [&model, &result](const sp<V1_3::IDevice>& device) {
                    return device->getSupportedOperations_1_3(
                            model, [&result](ErrorStatus error, const hidl_vec<bool>& supported) {
                                result = std::make_pair(error, supported);
                            });
                });
        if (!ret.isOk()) {
            LOG(ERROR) << "getSupportedOperations_1_3 failure: " << ret.description();
            return kFailure;
        }
        return result;
    }

    // version 1.2 HAL
    if (getDevice<V1_2::IDevice>() != nullptr) {
        const bool compliant = compliantWithV1_2(model);
        V1_2::Model model12;
        std::function<uint32_t(uint32_t)> submodelOperationIndexToModelOperationIndex;
        if (compliant) {
            model12 = convertToV1_2(model);
        } else {
            const auto slice12 = metaModel.getSliceV1_2();
            if (!slice12.has_value()) {
                return noneSupported();
            }
            std::tie(model12, submodelOperationIndexToModelOperationIndex) = *slice12;
        }
        NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_COMPILATION, "getSupportedOperations_1_2");
        Return<void> ret = recoverable<void, V1_2::IDevice>(
                __FUNCTION__, [&model12, &result](const sp<V1_2::IDevice>& device) {
                    return device->getSupportedOperations_1_2(
                            model12, [&result](ErrorStatus error, const hidl_vec<bool>& supported) {
                                result = std::make_pair(error, supported);
                            });
                });
        if (!ret.isOk()) {
            LOG(ERROR) << "getSupportedOperations_1_2 failure: " << ret.description();
            return kFailure;
        }
        if (!compliant) {
            return remappedResult(result, submodelOperationIndexToModelOperationIndex);
        }
        return result;
    }

    // version 1.1 HAL
    if (getDevice<V1_1::IDevice>() != nullptr) {
        const bool compliant = compliantWithV1_1(model);
        V1_1::Model model11;
        std::function<uint32_t(uint32_t)> submodelOperationIndexToModelOperationIndex;
        if (compliant) {
            model11 = convertToV1_1(model);
        } else {
            const auto slice11 = metaModel.getSliceV1_1();
            if (!slice11.has_value()) {
                return noneSupported();
            }
            std::tie(model11, submodelOperationIndexToModelOperationIndex) = *slice11;
        }
        NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_COMPILATION, "getSupportedOperations_1_1");
        Return<void> ret = recoverable<void, V1_1::IDevice>(
                __FUNCTION__, [&model11, &result](const sp<V1_1::IDevice>& device) {
                    return device->getSupportedOperations_1_1(
                            model11, [&result](ErrorStatus error, const hidl_vec<bool>& supported) {
                                result = std::make_pair(error, supported);
                            });
                });
        if (!ret.isOk()) {
            LOG(ERROR) << "getSupportedOperations_1_1 failure: " << ret.description();
            return kFailure;
        }
        if (!compliant) {
            return remappedResult(result, submodelOperationIndexToModelOperationIndex);
        }
        return result;
    }

    // version 1.0 HAL
    if (getDevice<V1_0::IDevice>() != nullptr) {
        const bool compliant = compliantWithV1_0(model);
        V1_0::Model model10;
        std::function<uint32_t(uint32_t)> submodelOperationIndexToModelOperationIndex;
        if (compliant) {
            model10 = convertToV1_0(model);
        } else {
            const auto slice10 = metaModel.getSliceV1_0();
            if (!slice10.has_value()) {
                return noneSupported();
            }
            std::tie(model10, submodelOperationIndexToModelOperationIndex) = *slice10;
        }
        NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_COMPILATION, "getSupportedOperations");
        Return<void> ret = recoverable<void, V1_0::IDevice>(
                __FUNCTION__, [&model10, &result](const sp<V1_0::IDevice>& device) {
                    return device->getSupportedOperations(
                            model10, [&result](ErrorStatus error, const hidl_vec<bool>& supported) {
                                result = std::make_pair(error, supported);
                            });
                });
        if (!ret.isOk()) {
            LOG(ERROR) << "getSupportedOperations failure: " << ret.description();
            return kFailure;
        }
        if (!compliant) {
            return remappedResult(result, submodelOperationIndexToModelOperationIndex);
        }
        return result;
    }

    // No device available
    LOG(ERROR) << "Device not available!";
    return kFailure;
}

std::pair<ErrorStatus, std::shared_ptr<VersionedIPreparedModel>> VersionedIDevice::prepareModel(
        const Model& model, ExecutionPreference preference, const hidl_vec<hidl_handle>& modelCache,
        const hidl_vec<hidl_handle>& dataCache, const CacheToken& token) const {
    const std::pair<ErrorStatus, std::shared_ptr<VersionedIPreparedModel>> kFailure = {
            ErrorStatus::GENERAL_FAILURE, nullptr};

    const sp<PreparedModelCallback> callback = new PreparedModelCallback();

    // If 1.3 device, try preparing model
    if (getDevice<V1_3::IDevice>() != nullptr) {
        const Return<ErrorStatus> ret = recoverable<ErrorStatus, V1_3::IDevice>(
                __FUNCTION__,
                [&model, &preference, &modelCache, &dataCache, &token,
                 &callback](const sp<V1_3::IDevice>& device) {
                    return device->prepareModel_1_3(model, preference, modelCache, dataCache, token,
                                                    callback);
                },
                callback);
        if (!ret.isOk()) {
            LOG(ERROR) << "prepareModel_1_3 failure: " << ret.description();
            return kFailure;
        }
        if (ret != ErrorStatus::NONE) {
            LOG(ERROR) << "prepareModel_1_3 returned " << toString(static_cast<ErrorStatus>(ret));
            return kFailure;
        }
        callback->wait();
        return {callback->getStatus(), makeVersionedIPreparedModel(callback->getPreparedModel())};
    }

    // If 1.2 device, try preparing model (requires conversion)
    if (getDevice<V1_2::IDevice>() != nullptr) {
        bool compliant = false;
        V1_2::Model model12;
        {
            // Attribute time spent in model inspection and conversion to
            // Runtime, as the time may be substantial (0.03ms for mobilenet,
            // but could be larger for other models).
            NNTRACE_FULL_SUBTRACT(NNTRACE_LAYER_RUNTIME, NNTRACE_PHASE_COMPILATION,
                                  "VersionedIDevice::prepareModel_1_2");
            compliant = compliantWithV1_2(model);
            if (compliant) {
                model12 = convertToV1_2(model);  // copy is elided
            }
        }
        if (compliant) {
            const Return<ErrorStatus> ret = recoverable<ErrorStatus, V1_2::IDevice>(
                    __FUNCTION__,
                    [&model12, &preference, &modelCache, &dataCache, &token,
                     &callback](const sp<V1_2::IDevice>& device) {
                        return device->prepareModel_1_2(model12, preference, modelCache, dataCache,
                                                        token, callback);
                    },
                    callback);
            if (!ret.isOk()) {
                LOG(ERROR) << "prepareModel_1_2 failure: " << ret.description();
                return kFailure;
            }
            if (ret != ErrorStatus::NONE) {
                LOG(ERROR) << "prepareModel_1_2 returned "
                           << toString(static_cast<ErrorStatus>(ret));
                return kFailure;
            }
            callback->wait();
            return {callback->getStatus(),
                    makeVersionedIPreparedModel(callback->getPreparedModel())};
        }

        LOG(ERROR) << "Could not handle prepareModel_1_2!";
        return kFailure;
    }

    // If 1.1 device, try preparing model (requires conversion)
    if (getDevice<V1_1::IDevice>() != nullptr) {
        bool compliant = false;
        V1_1::Model model11;
        {
            // Attribute time spent in model inspection and conversion to
            // Runtime, as the time may be substantial (0.03ms for mobilenet,
            // but could be larger for other models).
            NNTRACE_FULL_SUBTRACT(NNTRACE_LAYER_RUNTIME, NNTRACE_PHASE_COMPILATION,
                                  "VersionedIDevice::prepareModel_1_1");
            compliant = compliantWithV1_1(model);
            if (compliant) {
                model11 = convertToV1_1(model);  // copy is elided
            }
        }
        if (compliant) {
            const Return<ErrorStatus> ret = recoverable<ErrorStatus, V1_1::IDevice>(
                    __FUNCTION__,
                    [&model11, &preference, &callback](const sp<V1_1::IDevice>& device) {
                        return device->prepareModel_1_1(model11, preference, callback);
                    },
                    callback);
            if (!ret.isOk()) {
                LOG(ERROR) << "prepareModel_1_1 failure: " << ret.description();
                return kFailure;
            }
            if (ret != ErrorStatus::NONE) {
                LOG(ERROR) << "prepareModel_1_1 returned "
                           << toString(static_cast<ErrorStatus>(ret));
                return kFailure;
            }
            callback->wait();
            return {callback->getStatus(),
                    makeVersionedIPreparedModel(callback->getPreparedModel())};
        }

        LOG(ERROR) << "Could not handle prepareModel_1_1!";
        return kFailure;
    }

    // If 1.0 device, try preparing model (requires conversion)
    if (getDevice<V1_0::IDevice>() != nullptr) {
        bool compliant = false;
        V1_0::Model model10;
        {
            // Attribute time spent in model inspection and conversion to
            // Runtime, as the time may be substantial (0.03ms for mobilenet,
            // but could be larger for other models).
            NNTRACE_FULL_SUBTRACT(NNTRACE_LAYER_RUNTIME, NNTRACE_PHASE_COMPILATION,
                                  "VersionedIDevice::prepareModel");
            compliant = compliantWithV1_0(model);
            if (compliant) {
                model10 = convertToV1_0(model);  // copy is elided
            }
        }
        if (compliant) {
            const Return<ErrorStatus> ret = recoverable<ErrorStatus, V1_0::IDevice>(
                    __FUNCTION__,
                    [&model10, &callback](const sp<V1_0::IDevice>& device) {
                        return device->prepareModel(model10, callback);
                    },
                    callback);
            if (!ret.isOk()) {
                LOG(ERROR) << "prepareModel failure: " << ret.description();
                return kFailure;
            }
            if (ret != ErrorStatus::NONE) {
                LOG(ERROR) << "prepareModel returned " << toString(static_cast<ErrorStatus>(ret));
                return kFailure;
            }
            callback->wait();
            return {callback->getStatus(),
                    makeVersionedIPreparedModel(callback->getPreparedModel())};
        }

        LOG(ERROR) << "Could not handle prepareModel!";
        return kFailure;
    }

    // Return error because there is no valid device
    LOG(ERROR) << "prepareModel called with no device";
    return kFailure;
}

std::pair<ErrorStatus, std::shared_ptr<VersionedIPreparedModel>>
VersionedIDevice::prepareModelFromCache(const hidl_vec<hidl_handle>& modelCache,
                                        const hidl_vec<hidl_handle>& dataCache,
                                        const CacheToken& token) const {
    const std::pair<ErrorStatus, std::shared_ptr<VersionedIPreparedModel>> kFailure = {
            ErrorStatus::GENERAL_FAILURE, nullptr};

    // version 1.2+ HAL
    if (getDevice<V1_2::IDevice>() != nullptr) {
        const sp<PreparedModelCallback> callback = new PreparedModelCallback();
        const Return<ErrorStatus> ret = recoverable<ErrorStatus, V1_2::IDevice>(
                __FUNCTION__,
                [&modelCache, &dataCache, &token, &callback](const sp<V1_2::IDevice>& device) {
                    return device->prepareModelFromCache(modelCache, dataCache, token, callback);
                },
                callback);
        if (!ret.isOk()) {
            LOG(ERROR) << "prepareModelFromCache failure: " << ret.description();
            return kFailure;
        }
        if (ret != ErrorStatus::NONE) {
            LOG(ERROR) << "prepareModelFromCache returned "
                       << toString(static_cast<ErrorStatus>(ret));
            return kFailure;
        }
        callback->wait();
        return {callback->getStatus(), makeVersionedIPreparedModel(callback->getPreparedModel())};
    }

    // version too low
    if (getDevice<V1_0::IDevice>() != nullptr) {
        LOG(ERROR) << "prepareModelFromCache called on V1_1 or V1_0 device";
        return kFailure;
    }

    // No device available
    LOG(ERROR) << "prepareModelFromCache called with no device";
    return kFailure;
}

DeviceStatus VersionedIDevice::getStatus() const {
    // version 1.0+ HAL
    if (getDevice<V1_0::IDevice>() != nullptr) {
        Return<DeviceStatus> ret = recoverable<DeviceStatus, V1_0::IDevice>(
                __FUNCTION__, [](const sp<V1_0::IDevice>& device) { return device->getStatus(); });

        if (!ret.isOk()) {
            LOG(ERROR) << "getStatus failure: " << ret.description();
            return DeviceStatus::UNKNOWN;
        }
        return static_cast<DeviceStatus>(ret);
    }

    // No device available
    LOG(ERROR) << "Device not available!";
    return DeviceStatus::UNKNOWN;
}

int64_t VersionedIDevice::getFeatureLevel() const {
    constexpr int64_t kFailure = -1;

    if (getDevice<V1_3::IDevice>() != nullptr) {
        return __ANDROID_API_R__;
    } else if (getDevice<V1_2::IDevice>() != nullptr) {
        return __ANDROID_API_Q__;
    } else if (getDevice<V1_1::IDevice>() != nullptr) {
        return __ANDROID_API_P__;
    } else if (getDevice<V1_0::IDevice>() != nullptr) {
        return __ANDROID_API_O_MR1__;
    } else {
        LOG(ERROR) << "Device not available!";
        return kFailure;
    }
}

int32_t VersionedIDevice::getType() const {
    constexpr int32_t kFailure = -1;

    // version 1.2+ HAL
    if (getDevice<V1_2::IDevice>() != nullptr) {
        int32_t result = kFailure;
        Return<void> ret = recoverable<void, V1_2::IDevice>(
                __FUNCTION__, [&result](const sp<V1_2::IDevice>& device) {
                    return device->getType([&result](ErrorStatus error, DeviceType deviceType) {
                        if (error == ErrorStatus::NONE) {
                            result = static_cast<int32_t>(deviceType);
                        }
                    });
                });
        if (!ret.isOk()) {
            LOG(ERROR) << "getType failure: " << ret.description();
            return kFailure;
        }
        return result;
    }

    // version too low or no device available
    LOG(INFO) << "Unknown NNAPI device type.";
    return ANEURALNETWORKS_DEVICE_UNKNOWN;
}

std::pair<ErrorStatus, hidl_string> VersionedIDevice::getVersionString() const {
    const std::pair<ErrorStatus, hidl_string> kFailure = {ErrorStatus::GENERAL_FAILURE, ""};

    // version 1.2+ HAL
    if (getDevice<V1_2::IDevice>() != nullptr) {
        std::pair<ErrorStatus, hidl_string> result;
        Return<void> ret = recoverable<void, V1_2::IDevice>(
                __FUNCTION__, [&result](const sp<V1_2::IDevice>& device) {
                    return device->getVersionString(
                            [&result](ErrorStatus error, const hidl_string& version) {
                                result = std::make_pair(error, version);
                            });
                });
        if (!ret.isOk()) {
            LOG(ERROR) << "getVersion failure: " << ret.description();
            return kFailure;
        }
        return result;
    }

    // version too low
    if (getDevice<V1_0::IDevice>() != nullptr) {
        return {ErrorStatus::NONE, "UNKNOWN"};
    }

    // No device available
    LOG(ERROR) << "Could not handle getVersionString";
    return kFailure;
}

std::tuple<ErrorStatus, uint32_t, uint32_t> VersionedIDevice::getNumberOfCacheFilesNeeded() const {
    constexpr std::tuple<ErrorStatus, uint32_t, uint32_t> kFailure = {ErrorStatus::GENERAL_FAILURE,
                                                                      0, 0};

    // version 1.2+ HAL
    if (getDevice<V1_2::IDevice>() != nullptr) {
        std::tuple<ErrorStatus, uint32_t, uint32_t> result;
        Return<void> ret = recoverable<void, V1_2::IDevice>(
                __FUNCTION__, [&result](const sp<V1_2::IDevice>& device) {
                    return device->getNumberOfCacheFilesNeeded([&result](ErrorStatus error,
                                                                         uint32_t numModelCache,
                                                                         uint32_t numDataCache) {
                        result = {error, numModelCache, numDataCache};
                    });
                });
        if (!ret.isOk()) {
            LOG(ERROR) << "getNumberOfCacheFilesNeeded failure: " << ret.description();
            return kFailure;
        }
        return result;
    }

    // version too low
    if (getDevice<V1_0::IDevice>() != nullptr) {
        return {ErrorStatus::NONE, 0, 0};
    }

    // No device available
    LOG(ERROR) << "Could not handle getNumberOfCacheFilesNeeded";
    return kFailure;
}

}  // namespace nn
}  // namespace android