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#pragma once

#include <functional>
#include <queue>

#include "infer_response.h"
#include "pb_preferred_memory.h"

namespace triton { namespace backend { namespace python {

struct ResponseAllocatorUserp {
  ResponseAllocatorUserp(
      void* shm_pool, const PreferredMemory& preferred_memory)
      : shm_pool(shm_pool), preferred_memory(preferred_memory)
  {
  }
  void* shm_pool;
  PreferredMemory preferred_memory;
};

class InferPayload : public std::enable_shared_from_this<InferPayload> {
 public:
  InferPayload(
      const bool is_decouple,
      std::function<void(std::unique_ptr<InferResponse>)> callback);

  /// GetPtr should be only called when the InferPayload object is constructed
  /// using a shared pointer. Calling this function in any other circumstance
  /// is undefined behaviour until C++17.
  std::shared_ptr<InferPayload> GetPtr() { return shared_from_this(); }
  void SetValue(std::unique_ptr<InferResponse> infer_response);
  void SetFuture(std::future<std::unique_ptr<InferResponse>>& response_future);
  bool IsDecoupled();
  bool IsPromiseSet();
  void Callback(std::unique_ptr<InferResponse> infer_response);
  void SetResponseAllocUserp(
      const ResponseAllocatorUserp& response_alloc_userp);
  std::shared_ptr<ResponseAllocatorUserp> ResponseAllocUserp();

 private:
  std::unique_ptr<std::promise<std::unique_ptr<InferResponse>>> promise_;
  bool is_decoupled_;
  std::mutex mutex_;
  bool is_promise_set_;
  std::function<void(std::unique_ptr<InferResponse>)> callback_;
  std::shared_ptr<ResponseAllocatorUserp> response_alloc_userp_;
};

}}}  // namespace triton::backend::python
