/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve.

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 "paddle/platform/device_context_manager.h"

namespace paddle {
namespace platform {

DeviceContextManager::DeviceContextManager() {
#ifndef PADDLE_ONLY_CPU
  device_count_ = GetDeviceCount();
  cuda_contexts_.reserve(device_count_);
  for (int i = 0; i < device_count_; i++) {
    cuda_contexts_[i] = nullptr;
  }
#endif
}

template <>
CPUDeviceContext* DeviceContextManager::GetDeviceContext<
    CPUPlace, CPUDeviceContext>(const CPUPlace& place) {
  if (!cpu_context_) {
    cpu_context_ = new CPUDeviceContext(place);
  }
  return cpu_context_;
}

#ifndef PADDLE_ONLY_CPU
template <>
CUDADeviceContext* DeviceContextManager::GetDeviceContext<
    GPUPlace, CUDADeviceContext>(const GPUPlace& place) {
  int gpu_id = place.device;
  PADDLE_ENFORCE(gpu_id < device_count_,
                 "GPU device id must less than device count");
  SetDeviceId(gpu_id);
  if (!cuda_contexts_[gpu_id]) {
    cuda_contexts_[gpu_id] = new CUDADeviceContext(place);
  }
  return cuda_contexts_[gpu_id];
}
#endif

DeviceContextManager::~DeviceContextManager() {
  if (cpu_context_) {
    delete cpu_context_;
  }
#ifndef PADDLE_ONLY_CPU
  for (int i = 0; i < device_count_; i++) {
    if (cuda_contexts_[i]) {
      delete cuda_contexts_[i];
    }
  }
#endif
}

}  // namespace platform
}  // namespace paddle