public static void testPickNext() {
List<Integer> list = new ArrayList<>(10);
for (int i = 0; i < 10; i++) list.add(i);
Integer num = Util.pickNext(list, 5);
System.out.println("number next to 5: " + num);
assert num != null;
assert num.equals(6);
num = Util.pickNext(list, 9);
System.out.println("number next to 9: " + num);
assert num != null;
assert num.equals(0);
num = Util.pickNext(list, 11);
assert num == null;
}
protected void handleView(View view) {
view_size = view.size();
Address tmp = Util.pickNext(view.getMembers(), local_addr);
if (tmp != null && !tmp.equals(local_addr)) {
next = tmp;
if (log.isDebugEnabled()) log.debug("next=" + next);
}
}
public static void testPickNextN() {
List<Integer> list = Arrays.asList(1, 2, 3, 4);
List<Integer> result = Util.pickNext(list, 0, 1);
assert result.isEmpty();
result = Util.pickNext(list, 1, 1);
System.out.println("result = " + result);
assert result.size() == 1;
assert result.contains(2);
result = Util.pickNext(list, 3, 2);
System.out.println("result = " + result);
assert result.size() == 2;
assert result.contains(4) && result.contains(1);
result = Util.pickNext(list, 4, 5);
System.out.println("result = " + result);
assert result.size() == 3;
assert result.contains(1) && result.contains(2) && result.contains(3);
}
public void handleView(View view) {
Address oldCoord = coord;
if (view.size() > 0) {
coord = view.getMembers().iterator().next();
is_coord = coord.equals(local_addr);
if (log.isDebugEnabled())
log.debug("local_addr=" + local_addr + ", coord=" + coord + ", is_coord=" + is_coord);
}
// If we got a new coordinator we have to send all the requests for
// tasks and consumers again just incase they were missed when
// coordinator went down
// We are okay with duplicates since we don't add multiple times.
// We also have a problem that if a task/consumer was picked up as the
// consumer is changing we may have duplicates. But this is technically
// okay in that an extra consumer will reject and an extra task will just
// be ran and return nowhere, but at least we won't lose data.
if (oldCoord != coord) {
for (Long requests : _requestId.values()) {
sendToCoordinator(Type.RUN_REQUEST, requests, local_addr);
}
for (Long requests : _consumerId.keySet()) {
sendToCoordinator(Type.CONSUMER_READY, requests, local_addr);
}
}
if (num_backups > 0) {
if (is_coord) {
List<Address> new_backups = Util.pickNext(view.getMembers(), local_addr, num_backups);
List<Address> new_members = null;
synchronized (backups) {
if (!backups.equals(new_backups)) {
new_members = new ArrayList<Address>(new_backups);
new_members.removeAll(backups);
backups.clear();
backups.addAll(new_backups);
}
}
if (new_members != null && !new_members.isEmpty()) copyQueueTo(new_members);
}
// We keep what backups we have ourselves, so that when we become
// the coordinator we don't update them again. Technically we can
// send multiple requests but don't if to prevent more message being
// sent.
else {
List<Address> possiblebackups = Util.pickNext(view.getMembers(), coord, num_backups);
boolean foundMyself = false;
List<Address> myBackups = new ArrayList<Address>();
for (Address backup : possiblebackups) {
if (foundMyself) {
myBackups.add(backup);
} else if (backup.equals(local_addr)) {
foundMyself = true;
}
}
synchronized (backups) {
backups.clear();
backups.addAll(myBackups);
}
}
}
// Need to run this last so the backups are updated
super.handleView(view);
}