GET DIAGNOSTICS Mysql how to catch the variable

Question

I'm writing one update statement in my procedure but there are chances that CommandTimeout(30 sec for testing my code) may expire. So I was looking for a solution.

Then I came to know that in mysql Diagnostic is available. So i tried that. It is working fine in my workbench. It is returning the variable with message that after which count it is failing.

To execute the procedure failure I putted a condition that if it is true then say signal error

I'm executing this line of code in c#

object Result = _DBCommand.ExecuteScalar();

And after this when timeout is happening mysql error in coming.

I'm wondering how can i catch the variable that I'm throwing from Procedure.

DROP PROCEDURE IF EXISTS udsp_Test;
DELIMITER //

CREATE PROCEDURE udsp_Test(
    -- paramters...
)
BEGIN

    -- --------------------------------------------------------------------------
    -- 00 Declaration
    -- --------------------------------------------------------------------------

        DECLARE error_InvalidInputs      CONDITION FOR SQLSTATE 'HY000'; 



       DECLARE EXIT HANDLER FOR SQLEXCEPTION
        BEGIN
            ROLLBACK;
            GET DIAGNOSTICS CONDITION 1 @var_SqlState = RETURNED_SQLSTATE, @var_MessageText = MESSAGE_TEXT, @var_MySqlErrorNo = MYSQL_ERRNO, @var_SchemaName = SCHEMA_NAME, @var_TableName = TABLE_NAME;

            SET @var_FullError = CONCAT("ERROR: ", @var_MySqlErrorNo, " (", @var_SqlState, "): ", @var_MessageText, "Scheman Name: ", @var_SchemaName, "Table Name: ",@var_TableName);

            SET @var_ErrorMessage = CONCAT(@var_ErrorMessage,';;;;;', @var_FullError);
            SELECT @var_ErrorMessage;
            RESIGNAL ;
        END;


        SET @var_ErrorMessage = '';

        SET @var_ErrorMessage = CONCAT(@var_ErrorMessage,'Error message: = Now; ');

        -- update statement here

        SET @var_ErrorMessage = CONCAT(@var_ErrorMessage,'Error message: = Now; ');


    SELECT 1 as UpdatedSuccessfully;
END//
DELIMITER ;