/* 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/framework/op_registry.h"
#include "paddle/platform/place.h"

namespace paddle {
namespace operators {

class GetPlacesOp : public framework::OperatorBase {
 public:
  GetPlacesOp(const std::string &type, const framework::VariableNameMap &inputs,
              const framework::VariableNameMap &outputs,
              const framework::AttributeMap &attrs)
      : OperatorBase(type, inputs, outputs, attrs) {}
  void Run(const framework::Scope &scope,
           const platform::DeviceContext &dev_ctx) const override {
    auto use_gpu = Attr<bool>("use_gpu");
    auto trainer_count = Attr<int>("trainer_count");

    auto out_var_name = Output("Out");
    auto *out_var = scope.FindVar(out_var_name);
    PADDLE_ENFORCE(out_var != nullptr, "Output variable %s cannot be found",
                   out_var_name);

    auto &places = *(out_var->GetMutable<std::vector<platform::Place>>());
    places.reserve(trainer_count);
    if (use_gpu) {
      for (int i = 0; i < trainer_count; i++) {
        places.emplace_back(platform::GPUPlace(i));
      }
    } else {
      for (int i = 0; i < trainer_count; i++) {
        places.emplace_back(platform::CPUPlace());
      }
    }
  }
};

class GetPlacesOpProtoMaker : public framework::OpProtoAndCheckerMaker {
 public:
  GetPlacesOpProtoMaker(framework::OpProto *proto,
                        framework::OpAttrChecker *op_checker)
      : OpProtoAndCheckerMaker(proto, op_checker) {
    AddOutput("Out", "vector of Place");
    AddAttr<int>("trainer_count", "(int)trainer count").SetDefault(1);
    AddAttr<bool>("use_gpu", "(bool)use gpu").SetDefault(false);
    AddComment(R"DOC(
GetPlaces Operator.

)DOC");
  }
};
}  // namespace operators
}  // namespace paddle
namespace ops = paddle::operators;

REGISTER_OPERATOR(get_places, ops::GetPlacesOp, ops::GetPlacesOpProtoMaker);