Function CheckConnection

src/bin/psql/common.c:294–342

CheckConnection * * Verify that we still have a good connection to the backend, and if not, * see if it can be restored. * * Returns true if either the connection was still there, or it could be * restored successfully; false otherwise. If, however, there was no * connection and the session is non-interactive, this will exit the program * with a code of EXIT_BADCONN. */

 * with a code of EXIT_BADCONN.
 */
static bool
CheckConnection(void)
{
	bool		OK;

	OK = ConnectionUp();
	if (!OK)
	{
		if (!pset.cur_cmd_interactive)
		{
			pg_log_fatal("connection to server was lost");
			exit(EXIT_BADCONN);
		}

		fprintf(stderr, _("The connection to the server was lost. Attempting reset: "));
		PQreset(pset.db);
		OK = ConnectionUp();
		if (!OK)
		{
			fprintf(stderr, _("Failed.\n"));

			/*
			 * Transition to having no connection; but stash away the failed
			 * connection so that we can still refer to its parameters in a
			 * later \connect attempt.  Keep the state cleanup here in sync
			 * with do_connect().
			 */
			if (pset.dead_conn)
				PQfinish(pset.dead_conn);
			pset.dead_conn = pset.db;
			pset.db = NULL;
			ResetCancelConn();
			UnsyncVariables();
		}
		else
		{
			fprintf(stderr, _("Succeeded.\n"));

			/*
			 * Re-sync, just in case anything changed.  Keep this in sync with
			 * do_connect().
			 */
			SyncVariables();
			connection_warnings(false); /* Must be after SyncVariables */
		}
	}

	return OK;
}