/*
 * Copyright (C) 2020 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_INTERFACES_NEURALNETWORKS_UTILS_COMMON_RESILIENT_BURST_H
#define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_UTILS_COMMON_RESILIENT_BURST_H

#include <android-base/thread_annotations.h>
#include <nnapi/IBurst.h>
#include <nnapi/Result.h>
#include <nnapi/Types.h>

#include <functional>
#include <memory>
#include <mutex>
#include <optional>
#include <utility>

namespace android::hardware::neuralnetworks::utils {

class ResilientBurst final : public nn::IBurst,
                             public std::enable_shared_from_this<ResilientBurst> {
    struct PrivateConstructorTag {};

  public:
    using Factory = std::function<nn::GeneralResult<nn::SharedBurst>()>;

    static nn::GeneralResult<std::shared_ptr<const ResilientBurst>> create(Factory makeBurst);

    ResilientBurst(PrivateConstructorTag tag, Factory makeBurst, nn::SharedBurst burst);

    nn::SharedBurst getBurst() const;
    nn::GeneralResult<nn::SharedBurst> recover(const nn::IBurst* failingBurst) const;

    OptionalCacheHold cacheMemory(const nn::SharedMemory& memory) const override;

    nn::ExecutionResult<std::pair<std::vector<nn::OutputShape>, nn::Timing>> execute(
            const nn::Request& request, nn::MeasureTiming measure,
            const nn::OptionalTimePoint& deadline,
            const nn::OptionalDuration& loopTimeoutDuration) const override;

    nn::GeneralResult<nn::SharedExecution> createReusableExecution(
            const nn::Request& request, nn::MeasureTiming measure,
            const nn::OptionalDuration& loopTimeoutDuration) const override;

  private:
    bool isValidInternal() const EXCLUDES(mMutex);
    nn::GeneralResult<nn::SharedExecution> createReusableExecutionInternal(
            const nn::Request& request, nn::MeasureTiming measure,
            const nn::OptionalDuration& loopTimeoutDuration) const;

    const Factory kMakeBurst;
    mutable std::mutex mMutex;
    mutable nn::SharedBurst mBurst GUARDED_BY(mMutex);
};

}  // namespace android::hardware::neuralnetworks::utils

#endif  // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_UTILS_COMMON_RESILIENT_BURST_H