void
MulticastSession::send_synack()
{
size_t len = sizeof(this->remote_peer_);
Message_Block_Ptr data(new ACE_Message_Block(len));
Serializer serializer(data.get());
serializer << this->remote_peer_;
VDBG_LVL((LM_DEBUG, "(%P|%t) MulticastSession[%C]::send_synack "
"local %#08x%08x remote %#08x%08x active %d\n",
this->link()->config()->name().c_str(),
(unsigned int)(this->link()->local_peer() >> 32),
(unsigned int) this->link()->local_peer(),
(unsigned int)(this->remote_peer_ >> 32),
(unsigned int) this->remote_peer_,
this->active_ ? 1 : 0), 2);
// Send control sample to remote peer:
send_control(MULTICAST_SYNACK, move(data));
// Send naks before sending synack to
// reduce wait time for resends from remote.
send_naks();
}
void
ReliableSession::send_naks()
{
// Could get data samples before syn control message.
// No use nak'ing until syn control message is received and session is acked.
if (!this->acked()) return;
if (DCPS_debug_level > 5) {
ACE_DEBUG((LM_DEBUG, ACE_TEXT("(%P|%t) ReliableSession::send_naks local %d ")
ACE_TEXT("remote %d nak request size %d \n"),
this->link_->local_peer(), this->remote_peer_, this->nak_requests_.size()));
}
if (!this->nak_sequence_.disjoint()) return; // nothing to send
ACE_Time_Value now(ACE_OS::gettimeofday());
// Record high-water mark for this interval; this value will
// be used to reset the low-water mark in the event the remote
// peer becomes unresponsive:
this->nak_requests_[now] = this->nak_sequence_.high();
typedef std::vector<SequenceRange> RangeVector;
RangeVector ignored;
/// The range first - second will be skiped (no naks sent for it).
SequenceNumber first;
SequenceNumber second;
NakRequestMap::reverse_iterator itr(this->nak_requests_.rbegin());
if (this->nak_requests_.size() > 1) {
// The sequences between rbegin - 1 and rbegin will not be ignored for naking.
++itr;
size_t nak_delay_intervals = this->link()->config()->nak_delay_intervals_;
size_t nak_max = this->link()->config()->nak_max_;
size_t sz = this->nak_requests_.size();
// Image i is the index of element in nak_requests_ in reverse order.
// index 0 sequence is most recent high water mark.
// e.g index , 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0
// 0 (rbegin) is always skipped because missing sample between 1 and 0 interval
// should always be naked.,
// if nak_delay_intervals=4, nak_max=3, any sequence between 5 - 1, 10 - 6, 15 - 11
// are skipped for naking due to nak_delay_intervals and 20 - 16 are skipped for
// naking due to nak_max.
for (size_t i = 1; i < sz; ++i) {
if ((i * 1.0) / (nak_delay_intervals + 1) > nak_max) {
if (first != SequenceNumber()) {
first = this->nak_requests_.begin()->second;
}
else {
ignored.push_back(std::make_pair(this->nak_requests_.begin()->second, itr->second));
}
break;
}
if (i % (nak_delay_intervals + 1) == 1) {
second = itr->second;
}
if (second != SequenceNumber()) {
first = itr->second;
}
if (i % (nak_delay_intervals + 1) == 0) {
first = itr->second;
if (first != SequenceNumber() && second != SequenceNumber()) {
ignored.push_back(std::make_pair(first, second));
first = SequenceNumber();
second = SequenceNumber();
}
}
++itr;
}
if (first != SequenceNumber() && second != SequenceNumber() && first != second) {
ignored.push_back(std::make_pair(first, second));
}
}
// Take a copy to facilitate temporary suppression:
DisjointSequence received(this->nak_sequence_);
if (DCPS_debug_level > 0) {
received.dump();
}
size_t sz = ignored.size();
for (size_t i = 0; i < sz; ++i) {
if (ignored[i].second > received.cumulative_ack()) {
SequenceNumber high = ignored[i].second;
SequenceNumber low = ignored[i].first;
if (low < received.cumulative_ack()) {
low = received.cumulative_ack();
}
if (DCPS_debug_level > 0) {
ACE_DEBUG((LM_DEBUG, ACE_TEXT("(%P|%t) ReliableSession::send_naks local %d ")
ACE_TEXT("remote %d ignore missing [%q - %q]\n"),
this->link_->local_peer(), this->remote_peer_, low.getValue(), high.getValue()));
}
// Make contiguous between ignored sequences.
received.insert(SequenceRange(low, high));
}
}
for (NakPeerSet::iterator it(this->nak_peers_.begin());
it != this->nak_peers_.end(); ++it) {
// Update sequence to temporarily suppress repair requests for
// ranges already requested by other peers for this interval:
received.insert(*it);
}
if (received.disjoint()) {
send_naks(received);
}
// Clear peer repair requests:
this->nak_peers_.clear();
}