Function executor

cpp/src/arrow/acero/query_context.h:47–47

  const QueryOptions& options() const { return options_; }
  MemoryPool* memory_pool() const { return exec_context_.memory_pool(); }
  ::arrow::internal::Executor* executor() const { return exec_context_.executor(); }
  ExecContext* exec_context() { return &exec_context_; }
  IOContext* io_context() { return &io_context_; }
  TaskScheduler* scheduler() { return task_scheduler_.get(); }