/* Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License. */

#pragma once

#include <cstdint>
#include <memory>

#include "paddle/fluid/platform/gpu_info.h"
#include "paddle/fluid/platform/macros.h"
#include "paddle/fluid/platform/place.h"
#include "paddle/fluid/platform/stream_callback_manager.h"

namespace paddle {
namespace platform {
namespace stream {

#if defined(PADDLE_WITH_CUDA) || defined(PADDLE_WITH_HIP)

enum class Priority : uint8_t {
  kNull = 0x0,
  kHigh = 0x1,
  kNormal = 0x2,
};

class CUDAStream final {
 public:
  CUDAStream() = default;
  explicit CUDAStream(const Place& place,
                      const Priority& priority = Priority::kNormal) {
    Init(place, priority);
  }
  virtual ~CUDAStream() { Destroy(); }

  bool Init(const Place& place, const Priority& priority = Priority::kNormal);

  template <typename Callback>
  void AddCallback(Callback&& callback) const {
    callback_manager_->AddCallback(callback);
  }

  template <typename Callback>
#ifdef PADDLE_WITH_HIP
  void RecordEvent(hipEvent_t ev, Callback callback) const {
    callback();
    PADDLE_ENFORCE_CUDA_SUCCESS(hipEventRecord(ev, stream_));
  }
#else
  void RecordEvent(cudaEvent_t ev, Callback callback) const {
    callback();
    PADDLE_ENFORCE_CUDA_SUCCESS(cudaEventRecord(ev, stream_));
  }
#endif

#ifdef PADDLE_WITH_HIP
  void RecordEvent(hipEvent_t ev) const {
    PADDLE_ENFORCE_CUDA_SUCCESS(hipEventRecord(ev, stream_));
  }
#else
  void RecordEvent(cudaEvent_t ev) const {
    PADDLE_ENFORCE_CUDA_SUCCESS(cudaEventRecord(ev, stream_));
  }
#endif

#ifdef PADDLE_WITH_HIP
  void WaitEvent(hipEvent_t ev) const {
    PADDLE_ENFORCE_CUDA_SUCCESS(hipStreamWaitEvent(stream_, ev, 0));
  }
#else
  void WaitEvent(cudaEvent_t ev) const {
    PADDLE_ENFORCE_CUDA_SUCCESS(cudaStreamWaitEvent(stream_, ev, 0));
  }
#endif

  void Wait() const;
  void WaitCallback() const { callback_manager_->Wait(); }

#ifdef PADDLE_WITH_HIP
  const hipStream_t& raw_stream() const { return stream_; }
#else
  const cudaStream_t& raw_stream() const { return stream_; }
#endif
  void Destroy();

 private:
  Place place_;
#ifdef PADDLE_WITH_HIP
  hipStream_t stream_{nullptr};
#else
  cudaStream_t stream_{nullptr};
#endif
  Priority priority_{Priority::kNormal};
  std::unique_ptr<StreamCallbackManager<gpuStream_t>> callback_manager_;

  DISABLE_COPY_AND_ASSIGN(CUDAStream);
};

#endif

}  // namespace stream
}  // namespace platform
}  // namespace paddle