text: /*
   * Copyright (c) 2018 Samsung Electronics Co., Ltd. All Rights Reserved
   * Copyright (C) 2017 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 __EXECUTOR_H__
  #define __EXECUTOR_H__
  
  #include "Model.h"
  
  #include "Shape.h"
  #include "Request.h"
  
  #include <vector>
  
  // Information we maintain about each operand during execution that
  // may change during execution.
  struct RunTimeOperandInfo
  {
    // TODO Storing the type here is redundant, as it won't change during execution.
    OperandType type;
  
    // The type and dimensions of the operand.  The dimensions can
    // change at runtime.  We include the type because it's useful
    // to pass together with the dimension to the functions implementing
    // the operators.
    //
    // Q: Is it possible??
    std::vector<uint32_t> dimensions;
    float scale;
    int32_t zeroPoint;
  
    // Where the operand's data is stored.  Check the corresponding
    // location information in the model to figure out if this points
    // to memory we have allocated for an temporary operand.
    uint8_t *buffer;
    // The length of the buffer.
    uint32_t length;
  
    // Whether this is a temporary variable, a model input, a constant, etc.
    OperandLifeTime lifetime;
  
    // Keeps track of how many operations have yet to make use
    // of this temporary variable.  When the count is decremented to 0,
    // we free the buffer.  For non-temporary variables, this count is
    // always 0.
    uint32_t numberOfUsesLeft;
  
    Shape shape() const
    {
      return Shape{.type = type, .dimensions = dimensions, .scale = scale, .offset = zeroPoint};
    }
  };
  
  // Used to keep a pointer to each of the memory pools
  struct RunTimePoolInfo
  {
    uint8_t *buffer;
  
    bool set(uint8_t *m)
    {
      buffer = m;
      return true;
    }
  };
  
  // This class is used to execute a model on the CPU.
  class Executor
  {
  public:
    // Executes the model. The results will be stored at the locations
    // specified in the constructor.
    // The model must outlive the executor.  We prevent it from being modified
    // while this is executing.
    int run(const Model &model, const Request &request,
            const std::vector<RunTimePoolInfo> &modelPoolInfos,
            const std::vector<RunTimePoolInfo> &requestPoolInfos);
  
  private:
    bool initializeRunTimeInfo(const std::vector<RunTimePoolInfo> &modelPoolInfos,
                               const std::vector<RunTimePoolInfo> &requestPoolInfos);
    // Runs one operation of the graph.
    int executeOperation(const Operation &entry);
    // Decrement the usage count for the operands listed.  Frees the memory
    // allocated for any temporary variable with a count of zero.
    void freeNoLongerUsedOperands(const std::vector<uint32_t> &inputs);
  
    // The model and the request that we'll execute. Only valid while run()
    // is being executed.
    const Model *mModel = nullptr;
    const Request *mRequest = nullptr;
  
    // We're copying the list of all the dimensions from the model, as
    // these may be modified when we run the operatins.  Since we're
    // making a full copy, the indexes used in the operand description
    // stay valid.
    //    std::vector<uint32_t> mDimensions;
    // Runtime information about all the operands.
    std::vector<RunTimeOperandInfo> mOperands;
  };
  
  #endif // __CPU_EXECUTOR_H__
  