+
+/*********************************************************************
+ *
+ * Function : close_unusable_connections
+ *
+ * Description : Closes remembered connections that have timed
+ * out or have been closed on the other side.
+ *
+ * Parameters : none
+ *
+ * Returns : void
+ *
+ *********************************************************************/
+static void close_unusable_connections(void)
+{
+ unsigned int slot = 0;
+
+ for (slot = 0; slot < SZ(reusable_connection); slot++)
+ {
+ if (!reusable_connection[slot].in_use
+ && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
+ {
+ time_t time_open = time(NULL) - reusable_connection[slot].timestamp;
+
+ if (keep_alive_timeout < time_open)
+ {
+ log_error(LOG_LEVEL_CONNECT,
+ "The connection to %s:%d in slot %d timed out. "
+ "Closing socket %d. Timeout is: %d.",
+ reusable_connection[slot].host,
+ reusable_connection[slot].port, slot,
+ reusable_connection[slot].sfd, keep_alive_timeout);
+ close_socket(reusable_connection[slot].sfd);
+ mark_connection_closed(&reusable_connection[slot]);
+ continue;
+ }
+
+ if (!socket_is_still_usable(reusable_connection[slot].sfd))
+ {
+ log_error(LOG_LEVEL_CONNECT,
+ "The connection to %s:%d in slot %d is no longer usable. "
+ "Closing socket %d.", reusable_connection[slot].host,
+ reusable_connection[slot].port, slot,
+ reusable_connection[slot].sfd);
+ close_socket(reusable_connection[slot].sfd);
+ mark_connection_closed(&reusable_connection[slot]);
+ continue;
+ }
+ }
+ }
+}
+
+
+/*********************************************************************
+ *
+ * Function : socket_is_still_usable
+ *
+ * Description : Decides whether or not an open socket is still usable.
+ *
+ * Parameters :
+ * 1 : sfd = The socket to check.
+ *
+ * Returns : TRUE for yes, otherwise FALSE.
+ *
+ *********************************************************************/
+static int socket_is_still_usable(jb_socket sfd)
+{
+#ifdef HAVE_POLL
+ int poll_result;
+ struct pollfd poll_fd[1];
+
+ memset(poll_fd, 0, sizeof(poll_fd));
+ poll_fd[0].fd = sfd;
+ poll_fd[0].events = POLLIN;
+
+ poll_result = poll(poll_fd, 1, 0);
+
+ if (-1 != poll_result)
+ {
+ return !(poll_fd[0].revents & POLLIN);
+ }
+ else
+ {
+ log_error(LOG_LEVEL_CONNECT, "Polling socket %d failed.", sfd);
+ return FALSE;
+ }
+#else
+ fd_set readable_fds;
+ struct timeval timeout;
+ int ret;
+ int socket_is_alive = 0;
+
+ memset(&timeout, '\0', sizeof(timeout));
+ FD_ZERO(&readable_fds);
+ FD_SET(sfd, &readable_fds);
+
+ ret = select((int)sfd+1, &readable_fds, NULL, NULL, &timeout);
+ if (ret < 0)
+ {
+ log_error(LOG_LEVEL_ERROR, "select() failed!: %E");
+ }
+
+ /*
+ * XXX: I'm not sure why !FD_ISSET() works,
+ * but apparently it does.
+ */
+ socket_is_alive = !FD_ISSET(sfd, &readable_fds);
+
+ return socket_is_alive;
+#endif /* def HAVE_POLL */
+}
+
+