// We check against 8 = 2 * 4 because we need to wait for at
// least two complete heartbeat setting intervals before
// complaining, and we've set the socket timeout to a quarter
// of the heartbeat setting in setHeartbeat above.
if (++_missedHeartbeats > (2 * 4)) {
throw new MissedHeartbeatException("Heartbeat missing with heartbeat = " +
_heartbeat + " seconds");
}
}