using System;
using System.Data;
using System.Data.SqlClient;
using System.Threading.Tasks;

namespace NS
{
    class Program
    {
        static void Main(string[] args)
        {
            // 동시에 100개 쓰레드를 만들어 병렬 실행
            // CPU Core 갯수에 따라 자동 병렬 처리
            Parallel.For(0, 100, (i) => Run(i));
        }

        static void Run(int i)
        {
            var strConn = "Data Source=Test1;Initial Catalog=DB1;Integrated Security=true";

            using (var conn = new SqlConnection(strConn))
            {
                conn.Open();
                var cmd = new SqlCommand("sp_GetNext", conn);
                cmd.CommandType = CommandType.StoredProcedure;

                // Input param
                SqlParameter pInput = new SqlParameter("@in", SqlDbType.Int);
                pInput.Direction = ParameterDirection.Input;
                pInput.Value = 1;
                cmd.Parameters.Add(pInput);
                
                // Output param
                SqlParameter pOutput = new SqlParameter("@out", SqlDbType.Int);
                pOutput.Direction = ParameterDirection.Output;
                cmd.Parameters.Add(pOutput);

                cmd.ExecuteNonQuery();

                Console.WriteLine(pOutput.Value);
            }
        }
    }
}