in reply to Wait for the response of API

Are you talking about the "fetchrow_array()" statement of the DBI API ?

If so - that is a well tested path, and will block (not return) until data is available.

At what line do you think data was expected and not found ?

What diagnostic method did you use ?

What diagnostic or error message supports your claim ? Have you tried to reproduce the issue with a minimal perl script, to test your claim ?

Oh yes - Seasons Greetings !

             "By three methods we may learn wisdom: First, by reflection, which is noblest; Second, by imitation, which is easiest; and third by experience, which is the bitterest."           -Confucius