dapper_session_per_request.cs

     public interface IDbSession
	   {
	       IDbConnection Connection { get; }
	   }
	
	   	
	   public class SqlSession : IDbSession
	   {
	       private static readonly object @lock = new object();
	       private readonly string connectionString;
	       private bool isDisposed;
	       private IDbConnection cn;
	
	       public SqlSession(string connectionString)
	       {
	           this.connectionString = connectionString;
	       }
	
	       public virtual IDbConnection Connection
	       {
	           get
	           {
	               if (isDisposed)
	               {
	                   throw new InvalidOperationException("The connection has been disposed");
	               }
	
	               return GetConnection();
	           }
	       }
	
	       private IDbConnection GetConnection()
	       {
	           if (cn == null)
	           {
	               lock (@lock)
	               {
	                   if (cn == null)
	                   {
	                       cn = new SqlConnection(connectionString);
	                       cn.Open();
	                   }
	               }
	           }
	
	           return cn;
	       }
	
	       public void Dispose()
	       {
	           if (isDisposed)
	           {
	               if (cn != null)
	               {
	                   cn.Dispose();
	               }
	
	               isDisposed = true;
	           }
	       }
	   }