keepalive problem with libpg connection

Hi,

I am writing my own connection pool for libpq's connection.

My goal is to try to reduce the amount of time spent in opening and closing
socket. However, I see that Postgres would close my connection after every
so often.

What is the best solution for that? Should I regularly send some "Select 1"
to keep the connection alive or is there a better way to write a connection
pool for libpq?

Any suggestion will be greatly appreciated.

JB