Really I personally use the next sentence continue reading another question within this page:

SELECT UPDATE_TIME
FROM   information_schema.tables
WHERE  TABLE_SCHEMA = 'dbname'
   AND TABLE_NAME = 'tabname'

However I think that it's using lots of process time, it will likely be less complicated if mysql-server transmits us a signal once the table is up-to-date in order to hold back until my program picks up that signal.

Is possible? I am programming in C.

Thanks greatly.

Use a trigger coupled with a UDF progammed in C(++) to complete the notification.
Here's dummy code.

DELIMITER $$

CREATE TRIGGER ai_table1_each AFTER INSERT ON table1 FOR EACH ROW
BEGIN
  CALL ChangeNotification('table1', 'insert', NEW.id);
END $$

DELIMITER ;

You will need to perform a trigger for place/remove increase. 3x per table.
You can't give a trigger somewhere tables IIRC, since these are actually sights and never actual tables.

You will need to write a UDF in C(++) known as changenotification that does the notification for you personally.

Links:
http://dev.mysql.com/doc/refman/5.0/en/adding-udf.html
http://www.mysqludf.org/
http://dev.mysql.com/doc/refman/5.0/en/triggers.html
http://dev.mysql.com/doc/refman/5.0/en/getting-unique-id.html