Method check

psycopg_pool/psycopg_pool/pool.py:513–546

Verify the state of the connections currently in the pool. Test each connection: if it works return it to the pool, otherwise dispose of it and create a new one.

(self)

            self.run_task(AddConnection(self))

    def check(self) -> None:
        """Verify the state of the connections currently in the pool.

        Test each connection: if it works return it to the pool, otherwise
        dispose of it and create a new one.
        """
        with self._lock:
            conns = list(self._pool)
            self._pool.clear()

            # Give a chance to the pool to grow if it has no connection.
            # In case there are enough connection, or the pool is already
            # growing, this is a no-op.
            self._maybe_grow_pool()

        while conns:
            conn = conns.pop()

            # Check for expired connections
            if conn._expire_at <= monotonic():
                logger.info("discarding expired connection %s", conn)
                self._close_connection(conn)
                self.run_task(AddConnection(self))
                continue

            # Check for broken connections
            try:
                self.check_connection(conn)
            except CLIENT_EXCEPTIONS:
                self._stats[self._CONNECTIONS_LOST] += 1
                logger.warning("discarding broken connection: %s", conn)
                self.run_task(AddConnection(self))
            else:
                self._add_to_pool(conn)

    @staticmethod
    def check_connection(conn: CT) -> None: