void
ReliableSession::nak_received(ACE_Message_Block* control)
{
if (! this->active_) return; // sub send naks, then doesn't receive them.
const TransportHeader& header =
this->link_->receive_strategy()->received_header();
Serializer serializer(
control, header.swap_bytes());
MulticastPeer local_peer;
CORBA::ULong size = 0;
serializer >> local_peer; // sent as remote_peer
serializer >> size;
std::vector<SequenceRange> ranges;
for (CORBA::ULong i = 0; i < size; ++i) {
SequenceNumber::Value low;
serializer >> low;
SequenceNumber::Value high;
serializer >> high;
ranges.push_back (SequenceRange (low, high));
}
// Track peer repair requests for later suppression:
if (local_peer == this->remote_peer_) {
for (CORBA::ULong i = 0; i < size; ++i) {
this->nak_peers_.insert(ranges[i]);
}
return;
}
// Ignore sample if not destined for us:
if ((local_peer != this->link_->local_peer()) // Not to us.
|| (this->remote_peer_ != header.source_)) return; // Not from the remote peer for this session.
TransportSendBuffer* send_buffer = this->link_->send_buffer();
// Broadcast a MULTICAST_NAKACK control sample before resending to suppress
// repair requests for unrecoverable samples by providing a
// new low-water mark for affected peers:
if (!send_buffer->empty() && send_buffer->low() > ranges.begin()->first) {
send_nakack(send_buffer->low());
}
for (CORBA::ULong i = 0; i < size; ++i) {
bool ret = send_buffer->resend(ranges[i]);
if (OpenDDS::DCPS::DCPS_debug_level > 0) {
ACE_DEBUG ((LM_DEBUG, ACE_TEXT ("(%P|%t) ReliableSession::nak_received")
ACE_TEXT (" %d <- %d %d - %d resend result %d\n"),
this->link_->local_peer(), this->remote_peer_,
ranges[i].first.getValue(), ranges[i].second.getValue(), ret));
}
}
}
void
ReliableSession::syn_hook(const SequenceNumber& seq)
{
const std::vector<SequenceRange> ranges(this->nak_sequence_.present_sequence_ranges());
this->nak_sequence_.reset();
this->nak_sequence_.insert(seq);
for (std::vector<SequenceRange>::const_iterator iter = ranges.begin();
iter != ranges.end(); ++iter) {
this->nak_sequence_.insert(SequenceRange(iter->first, iter->second));
}
}
void
ReliableSession::expire_naks()
{
if (this->nak_requests_.empty()) return; // nothing to expire
ACE_Time_Value deadline(ACE_OS::gettimeofday());
deadline -= this->link_->config()->nak_timeout_;
NakRequestMap::iterator first(this->nak_requests_.begin());
NakRequestMap::iterator last(this->nak_requests_.upper_bound(deadline));
if (first == last) return; // nothing to expire
// Skip unrecoverable datagrams to
// re-establish a baseline to detect future reception gaps.
SequenceNumber lastSeq = (last == this->nak_requests_.end())
? this->nak_requests_.rbegin()->second
: last->second;
std::vector<SequenceRange> dropped;
if (this->nak_sequence_.insert(SequenceRange(this->nak_sequence_.low(),
lastSeq), dropped)) {
for (size_t i = 0; i < dropped.size(); ++i) {
this->reassembly_.data_unavailable(dropped[i]);
}
ACE_ERROR((LM_WARNING,
ACE_TEXT("(%P|%t) WARNING: ")
ACE_TEXT("ReliableSession::expire_naks: ")
ACE_TEXT("timed out waiting on remote peer %#08x%08x to send missing samples: %q - %q!\n"),
(unsigned int)(this->remote_peer_ >> 32),
(unsigned int) this->remote_peer_,
this->nak_sequence_.low().getValue(),
lastSeq.getValue()));
}
// Clear expired repair requests:
this->nak_requests_.erase(first, last);
deliver_held_data();
}
void
ReliableSession::nakack_received(ACE_Message_Block* control)
{
if (this->active_) return; // pub send syn, then doesn't receive them.
const TransportHeader& header =
this->link_->receive_strategy()->received_header();
// Not from the remote peer for this session.
if (this->remote_peer_ != header.source_) return;
Serializer serializer(control, header.swap_bytes());
SequenceNumber low;
serializer >> low;
// MULTICAST_NAKACK control samples indicate data which cannot be
// repaired by a remote peer; if any values were needed below
// this value, then the sequence needs to be shifted:
std::vector<SequenceRange> dropped;
if (this->nak_sequence_.insert(SequenceRange(this->nak_sequence_.low(),
low.previous()), dropped)) {
for (size_t i = 0; i < dropped.size(); ++i) {
this->reassembly_.data_unavailable(dropped[i]);
}
if (DCPS_debug_level > 0) {
ACE_ERROR((LM_WARNING,
ACE_TEXT("(%P|%t) WARNING: ReliableSession::nakack_received ")
ACE_TEXT("local %d remote %d [%q - %q] ")
ACE_TEXT("not repaired.\n"),
this->link_->local_peer(), this->remote_peer_,
this->nak_sequence_.low().getValue(), low.getValue()));
}
}
}
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();
}
