/**
* An event is to be sent down the stack. The layer may want to examine its type and perform some
* action on it, depending on the event's type. If the event is a message MSG, then the layer may
* need to add a header to it (or do nothing at all) before sending it down the stack using <code>
* PassDown</code>. In case of a GET_ADDRESS event (which tries to retrieve the stack's address
* from one of the bottom layers), the layer may need to send a new response event back up the
* stack using <code>up_prot.up()</code>. The PING protocol is interested in several different
* down events, Event.FIND_INITIAL_MBRS - sent by the GMS layer and expecting a GET_MBRS_OK
* Event.TMP_VIEW and Event.VIEW_CHANGE - a view change event Event.BECOME_SERVER - called after
* client has joined and is fully working group member Event.CONNECT, Event.DISCONNECT.
*/
@SuppressWarnings("unchecked")
public Object down(Event evt) {
switch (evt.getType()) {
case Event.FIND_INITIAL_MBRS: // sent by GMS layer
case Event.FIND_ALL_VIEWS:
// sends the GET_MBRS_REQ to all members, waits 'timeout' ms or until 'num_initial_members'
// have been retrieved
long start = System.currentTimeMillis();
boolean find_all_views = evt.getType() == Event.FIND_ALL_VIEWS;
Promise<JoinRsp> promise = (Promise<JoinRsp>) evt.getArg();
List<PingData> rsps = find_all_views ? findAllViews(promise) : findInitialMembers(promise);
long diff = System.currentTimeMillis() - start;
if (log.isTraceEnabled())
log.trace("discovery took " + diff + " ms: responses: " + Util.printPingData(rsps));
return rsps;
case Event.TMP_VIEW:
case Event.VIEW_CHANGE:
List<Address> tmp;
view = (View) evt.getArg();
if ((tmp = view.getMembers()) != null) {
synchronized (members) {
members.clear();
members.addAll(tmp);
}
}
current_coord = !members.isEmpty() ? members.get(0) : null;
is_coord = current_coord != null && local_addr != null && current_coord.equals(local_addr);
return down_prot.down(evt);
case Event.BECOME_SERVER: // called after client has joined and is fully working group member
down_prot.down(evt);
is_server = true;
return null;
case Event.SET_LOCAL_ADDRESS:
local_addr = (Address) evt.getArg();
return down_prot.down(evt);
case Event.CONNECT:
case Event.CONNECT_WITH_STATE_TRANSFER:
case Event.CONNECT_USE_FLUSH:
case Event.CONNECT_WITH_STATE_TRANSFER_USE_FLUSH:
is_leaving = false;
group_addr = (String) evt.getArg();
Object ret = down_prot.down(evt);
handleConnect();
return ret;
case Event.DISCONNECT:
is_leaving = true;
handleDisconnect();
return down_prot.down(evt);
default:
return down_prot.down(evt); // Pass on to the layer below us
}
}
protected void handleViewChange(View v) {
Address old_coord;
List<Address> new_members = v.getMembers();
boolean send_up_exception = false;
this.view = v;
synchronized (members) {
old_coord = (!members.isEmpty() ? members.get(0) : null);
members.clear();
members.addAll(new_members);
// this handles the case where a coord dies during a state transfer; prevents clients from
// hanging forever
// Note this only takes a coordinator crash into account, a getState(target, timeout), where
// target is not
// null is not handled ! (Usually we get the state from the coordinator)
// http://jira.jboss.com/jira/browse/JGRP-148
if (waiting_for_state_response && old_coord != null && !members.contains(old_coord))
send_up_exception = true;
}
if (send_up_exception) {
log.warn("%s: discovered that the state provider (%s) left", local_addr, old_coord);
waiting_for_state_response = false;
Exception ex = new EOFException("state provider " + old_coord + " left");
up_prot.up(new Event(Event.GET_STATE_OK, new StateTransferResult(ex)));
openBarrierAndResumeStable();
}
// remove non members from list of members requesting state
state_requesters.retainAll(new_members);
}
public void run() {
long end_time, wait_time;
List<Request> requests = new LinkedList<Request>();
while (Thread.currentThread().equals(thread) && !suspended) {
try {
boolean keepGoing = false;
end_time = System.currentTimeMillis() + max_bundling_time;
do {
Request firstRequest =
(Request)
queue.remove(INTERVAL); // throws a TimeoutException if it runs into timeout
requests.add(firstRequest);
if (!view_bundling) break;
if (queue.size() > 0) {
Request nextReq = (Request) queue.peek();
keepGoing = view_bundling && firstRequest.canBeProcessedTogether(nextReq);
} else {
wait_time = end_time - System.currentTimeMillis();
if (wait_time > 0)
queue.waitUntilClosed(
wait_time); // misnomer: waits until element has been added or q closed
keepGoing =
queue.size() > 0 && firstRequest.canBeProcessedTogether((Request) queue.peek());
}
} while (keepGoing && System.currentTimeMillis() < end_time);
try {
process(requests);
} finally {
requests.clear();
}
} catch (QueueClosedException e) {
break;
} catch (TimeoutException e) {
break;
} catch (Throwable catchall) {
Util.sleep(50);
}
}
}
public Object down(Event evt) {
switch (evt.getType()) {
case Event.MSG: // Add UnicastHeader, add to AckSenderWindow and pass down
Message msg = (Message) evt.getArg();
Address dst = msg.getDest();
/* only handle unicast messages */
if (dst == null || msg.isFlagSet(Message.NO_RELIABILITY)) break;
if (!started) {
if (log.isTraceEnabled())
log.trace("discarded message as start() has not yet been called, message: " + msg);
return null;
}
SenderEntry entry = send_table.get(dst);
if (entry == null) {
entry = new SenderEntry(getNewConnectionId());
SenderEntry existing = send_table.putIfAbsent(dst, entry);
if (existing != null) entry = existing;
else {
if (log.isTraceEnabled())
log.trace(
local_addr
+ ": created connection to "
+ dst
+ " (conn_id="
+ entry.send_conn_id
+ ")");
if (cache != null && !members.contains(dst)) cache.add(dst);
}
}
long seqno = -2;
short send_conn_id = -1;
Unicast2Header hdr;
entry.lock(); // threads will only sync if they access the same entry
try {
seqno = entry.sent_msgs_seqno;
send_conn_id = entry.send_conn_id;
hdr = Unicast2Header.createDataHeader(seqno, send_conn_id, seqno == DEFAULT_FIRST_SEQNO);
msg.putHeader(this.id, hdr);
entry.sent_msgs.addToMessages(
seqno, msg); // add *including* UnicastHeader, adds to retransmitter
entry.sent_msgs_seqno++;
entry.update();
} finally {
entry.unlock();
}
if (log.isTraceEnabled()) {
StringBuilder sb = new StringBuilder();
sb.append(local_addr)
.append(" --> DATA(")
.append(dst)
.append(": #")
.append(seqno)
.append(", conn_id=")
.append(send_conn_id);
if (hdr.first) sb.append(", first");
sb.append(')');
log.trace(sb);
}
try {
down_prot.down(evt);
num_msgs_sent++;
num_bytes_sent += msg.getLength();
} catch (Throwable t) {
log.warn("failed sending the message", t);
}
return null; // we already passed the msg down
case Event.VIEW_CHANGE: // remove connections to peers that are not members anymore !
View view = (View) evt.getArg();
List<Address> new_members = view.getMembers();
Set<Address> non_members = new HashSet<Address>(send_table.keySet());
non_members.addAll(recv_table.keySet());
synchronized (members) {
members.clear();
if (new_members != null) members.addAll(new_members);
non_members.removeAll(members);
if (cache != null) {
cache.removeAll(members);
}
}
if (!non_members.isEmpty()) {
if (log.isTraceEnabled()) log.trace("removing non members " + non_members);
for (Address non_mbr : non_members) removeConnection(non_mbr);
}
break;
case Event.SET_LOCAL_ADDRESS:
local_addr = (Address) evt.getArg();
break;
}
return down_prot.down(evt); // Pass on to the layer below us
}
@SuppressWarnings("unchecked")
public Object down(Event evt) {
switch (evt.getType()) {
case Event.FIND_INITIAL_MBRS: // sent by GMS layer
return findMembers(null, true, false); // triggered by JOIN process (ClientGmsImpl)
case Event.FIND_MBRS:
return findMembers(
(List<Address>) evt.getArg(), false, false); // triggered by MERGE2/MERGE3
// case Event.TMP_VIEW:
case Event.VIEW_CHANGE:
List<Address> tmp;
View old_view = view;
view = (View) evt.getArg();
if ((tmp = view.getMembers()) != null) {
synchronized (members) {
members.clear();
members.addAll(tmp);
}
}
current_coord = !members.isEmpty() ? members.get(0) : null;
is_coord = current_coord != null && local_addr != null && current_coord.equals(local_addr);
Object retval = down_prot.down(evt);
if (send_cache_on_join && !isDynamic() && is_coord) {
List<Address> curr_mbrs, left_mbrs, new_mbrs;
synchronized (members) {
curr_mbrs = new ArrayList<>(members);
left_mbrs = old_view != null ? Util.leftMembers(old_view.getMembers(), members) : null;
new_mbrs = old_view != null ? Util.newMembers(old_view.getMembers(), members) : null;
}
startCacheDissemination(curr_mbrs, left_mbrs, new_mbrs); // separate task
}
return retval;
case Event.BECOME_SERVER: // called after client has joined and is fully working group member
down_prot.down(evt);
is_server = true;
return null;
case Event.SET_LOCAL_ADDRESS:
local_addr = (Address) evt.getArg();
return down_prot.down(evt);
case Event.CONNECT:
case Event.CONNECT_WITH_STATE_TRANSFER:
case Event.CONNECT_USE_FLUSH:
case Event.CONNECT_WITH_STATE_TRANSFER_USE_FLUSH:
is_leaving = false;
cluster_name = (String) evt.getArg();
Object ret = down_prot.down(evt);
handleConnect();
return ret;
case Event.DISCONNECT:
is_leaving = true;
handleDisconnect();
return down_prot.down(evt);
default:
return down_prot.down(evt); // Pass on to the layer below us
}
}