}
};

typedef TracingContext* (*FactoryFunction)(const char* fn_name, TF_Status*);
absl::Status SetDefaultTracingEngine(const char* name);
void RegisterTracingEngineFactory(const ::tensorflow::string& name,
                                  FactoryFunction factory);
}  // namespace tracing

DEFINE_CONVERSION_FUNCTIONS(AbstractContext, TF_ExecutionContext)

static FactoriesMap& GetFactories() {
  static FactoriesMap* factories = new FactoriesMap;
  return *factories;
}

static tracing::FactoryFunction default_factory;

void RegisterTracingEngineFactory(const string& name, FactoryFunction factory) {
  assert((!GetFactories().count(name)) ||
         (GetFactories()[name] == factory) &&
             "Duplicate tracing factory registration");

  return new GraphContext(name);
}

// Register the tracing implemented in this file as the default tracing engine.
static bool register_tracing = [] {
  RegisterTracingEngineFactory("graphdef", GraphTracingFactory);
  SetDefaultTracingEngine("graphdef").IgnoreError();
  return true;
}();

}  // namespace graph
}  // namespace tracing