private void checkDrainCondition() {
// Don't ever go backwards once the drain decision is made.
if (m_mustDrain) {
return;
}
// if we've got things to sequence, check to if we're blocked
if (!m_replayEntries.isEmpty()) {
ReplayEntry head = m_replayEntries.firstEntry().getValue();
if (!head.isReady()) {
// if we're blocked, see if we have a sentinel or a fragment.
// we know we have one or the other but not both. Neither
// means we wouldn't exist, and both would make us ready.
// if it's the sentinel, see if the MPI's command log is done
if (head.hasSentinel() && m_mpiEOLReached) {
m_mustDrain = true;
}
}
}
}
// Offer a new message. Return false if the offered message can be run immediately.
public boolean offer(long inTxnId, TransactionInfoBaseMessage in) {
ReplayEntry found = m_replayEntries.get(inTxnId);
if (in instanceof Iv2EndOfLogMessage) {
m_mpiEOLReached = true;
return true;
}
if (in instanceof MultiPartitionParticipantMessage) {
/*
* DR sends multiple @LoadMultipartitionTable proc calls with the
* same txnId, which is the snapshot txnId. For each partition,
* there is a sentinel paired with the @LoadMultipartitionTable
* call. Dedupe the sentinels the same way as we dedupe fragments,
* so that there won't be sentinels end up in the sequencer where
* matching fragments are deduped.
*/
if (inTxnId <= m_lastPolledFragmentTxnId) {
return true;
}
if (found == null) {
ReplayEntry newEntry = new ReplayEntry();
newEntry.m_sentinalTxnId = inTxnId;
m_replayEntries.put(inTxnId, newEntry);
} else {
found.m_sentinalTxnId = inTxnId;
assert (found.isReady());
}
} else if (in instanceof FragmentTaskMessage) {
// already sequenced
if (inTxnId <= m_lastPolledFragmentTxnId) {
return false;
}
FragmentTaskMessage ftm = (FragmentTaskMessage) in;
if (found == null) {
ReplayEntry newEntry = new ReplayEntry();
newEntry.m_firstFragment = ftm;
m_replayEntries.put(inTxnId, newEntry);
} else if (found.m_firstFragment == null) {
found.m_firstFragment = ftm;
assert (found.isReady());
} else {
found.addFragmentMessage(ftm);
}
} else if (in instanceof CompleteTransactionMessage) {
CompleteTransactionMessage ctm = (CompleteTransactionMessage) in;
// already sequenced
if (inTxnId <= m_lastPolledFragmentTxnId) {
if (found != null && found.m_firstFragment != null) {
found.markLastFragment(ctm);
}
return false;
}
if (found != null && found.m_firstFragment != null) {
found.addCompletedMessage(ctm);
} else {
// Always expect to see the fragment first, but there are places in the protocol
// where CompleteTransactionMessages may arrive for transactions that this site hasn't
// done/won't do, e.g. txn restart, so just tell the caller that we can't do
// anything with it and hope the right thing happens.
return false;
}
} else {
if (dedupe(inTxnId, in) != null) {
// Ignore an already seen txn
return true;
}
updateLastSeenTxnId(inTxnId, in);
if (m_replayEntries.isEmpty() || !m_replayEntries.lastEntry().getValue().hasSentinel()) {
// not-blocked work; rejected and not queued.
return false;
} else {
// blocked work queues with the newest replayEntry
m_replayEntries.lastEntry().getValue().addBlockedMessage(in);
}
}
return true;
}
