/// <summary>
/// Stops any awaiting stability multicasts, passes STABLE Event up the stack.
/// </summary>
/// <param name="d">Stable Digest</param>
private void handleStabilityMessage(Digest d)
{
if (d == null)
{
if (Trace.trace)
{
Trace.error("STABLE.handleStabilityMessage()", "stability vector is null");
}
return;
}
if (Trace.trace)
{
Trace.info("STABLE.handleStabilityMessage()", "stability vector is " + d.printHighSeqnos());
}
lock (stability_mutex)
{
if (stability_task != null)
{
if (Trace.trace)
{
Trace.info("STABLE.handleStabilityMessage()", "cancelling stability task (running=" + !stability_task.cancelled() + ")");
}
stability_task.stop();
stability_task = null;
}
}
// pass STABLE event up the stack, so NAKACK can garbage collect old messages
passUp(new Event(Event.STABLE, d));
}
/// <remarks>
/// The reason for waiting a random amount of time is that, in the worst case, all members receive a
/// STABLE_GOSSIP message from the last outstanding member at the same time and would therefore mcast the
/// STABILITY message at the same time too. To avoid this, each member waits random N msecs. If, before N
/// elapses, some other member sent the STABILITY message, we just cancel our own message. If, during
/// waiting for N msecs to send STABILITY message S1, another STABILITY message S2 is to be sent, we just
/// discard S2.
/// </remarks>
/// <summary>
/// Schedules a stability message to be mcast after a random number of milliseconds.
/// </summary>
/// <param name="tmp">Stable Digest</param>
private void sendStabilityMessage(Digest tmp)
{
long delay;
if (timer == null)
{
if (Trace.trace)
{
Trace.error("STABLE.sendStabilityMessage()", "timer is null, cannot schedule " + "stability message to be sent");
}
timer = stack != null ? stack.timer : null;
return;
}
// give other members a chance to mcast STABILITY message. if we receive STABILITY by the end of
// our random sleep, we will not send the STABILITY msg. this prevents that all mbrs mcast a
// STABILITY msg at the same time
delay = random.Next((int)stability_delay);
if (Trace.trace)
{
Trace.info("STABLE.sendStabilityMessage()", "stability_task=" + stability_task + ", delay is " + delay);
}
lock (stability_mutex)
{
if (stability_task != null && !stability_task.cancelled()) // schedule only if not yet running
{
return;
}
stability_task = new StabilitySendTask(this, tmp, delay);
timer.add(stability_task, true); // run it 1x after delay msecs. use fixed-rate scheduling
}
}
/// <remarks>
/// The reason for waiting a random amount of time is that, in the worst case, all members receive a
/// STABLE_GOSSIP message from the last outstanding member at the same time and would therefore mcast the
/// STABILITY message at the same time too. To avoid this, each member waits random N msecs. If, before N
/// elapses, some other member sent the STABILITY message, we just cancel our own message. If, during
/// waiting for N msecs to send STABILITY message S1, another STABILITY message S2 is to be sent, we just
/// discard S2.
/// </remarks>
/// <summary>
/// Schedules a stability message to be mcast after a random number of milliseconds.
/// </summary>
/// <param name="tmp">Stable Digest</param>
private void sendStabilityMessage(Digest tmp)
{
long delay;
if(timer == null)
{
if(Trace.trace)
Trace.error("STABLE.sendStabilityMessage()", "timer is null, cannot schedule " + "stability message to be sent");
timer=stack != null ? stack.timer : null;
return;
}
// give other members a chance to mcast STABILITY message. if we receive STABILITY by the end of
// our random sleep, we will not send the STABILITY msg. this prevents that all mbrs mcast a
// STABILITY msg at the same time
delay=random.Next((int)stability_delay);
if(Trace.trace)
Trace.info("STABLE.sendStabilityMessage()", "stability_task=" + stability_task + ", delay is " + delay);
lock(stability_mutex)
{
if(stability_task != null && !stability_task.cancelled()) // schedule only if not yet running
return;
stability_task =new StabilitySendTask(this, tmp, delay);
timer.add(stability_task, true); // run it 1x after delay msecs. use fixed-rate scheduling
}
}
/// <summary>
/// Stops any awaiting stability multicasts, passes STABLE Event up the stack.
/// </summary>
/// <param name="d">Stable Digest</param>
private void handleStabilityMessage(Digest d)
{
if(d == null)
{
if(Trace.trace)
Trace.error("STABLE.handleStabilityMessage()", "stability vector is null");
return;
}
if(Trace.trace)
Trace.info("STABLE.handleStabilityMessage()", "stability vector is " + d.printHighSeqnos());
lock(stability_mutex)
{
if(stability_task != null)
{
if(Trace.trace)
Trace.info("STABLE.handleStabilityMessage()", "cancelling stability task (running=" + !stability_task.cancelled() + ")");
stability_task.stop();
stability_task=null;
}
}
// pass STABLE event up the stack, so NAKACK can garbage collect old messages
passUp(new Event(Event.STABLE, d));
}
