/**
* 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
}
}
private void handleViewChange(View view) {
List<Address> new_mbrs = view.getMembers();
List<Address> left_mbrs = Util.determineLeftMembers(members, new_mbrs);
members.clear();
members.addAll(new_mbrs);
for (Address mbr : left_mbrs) {
// the new view doesn't contain the sender, it must have left,
// hence we will clear all of itsfragmentation tables
fragment_list.remove(mbr);
if (log.isTraceEnabled())
log.trace("[VIEW_CHANGE] removed " + mbr + " from fragmentation table");
}
}
@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
}
}