fw: consumer retansmission in multicast startegy

refs: #2062

Change-Id: I2b58a289fffe262c69a797f339e40ad9037acf8f

daemon/fw/multicast-strategy.cpp

@@ -34,9 +34,15 @@ NFD_REGISTER_STRATEGY(MulticastStrategy);
 
 NFD_LOG_INIT("MulticastStrategy");
 
+const time::milliseconds MulticastStrategy::RETX_SUPPRESSION_INITIAL(10);
+const time::milliseconds MulticastStrategy::RETX_SUPPRESSION_MAX(250);
+
 MulticastStrategy::MulticastStrategy(Forwarder& forwarder, const Name& name)
   : Strategy(forwarder)
   , ProcessNackTraits(this)
+  , m_retxSuppression(RETX_SUPPRESSION_INITIAL,
+                      RetxSuppressionExponential::DEFAULT_MULTIPLIER,
+                      RETX_SUPPRESSION_MAX)
 {
   ParsedInstanceName parsed = parseInstanceName(name);
   if (!parsed.parameters.empty()) {
@@ -52,7 +58,7 @@ MulticastStrategy::MulticastStrategy(Forwarder& forwarder, const Name& name)
 const Name&
 MulticastStrategy::getStrategyName()
 {
-  static Name strategyName("/localhost/nfd/strategy/multicast/%FD%01");
+  static Name strategyName("/localhost/nfd/strategy/multicast/%FD%02");
   return strategyName;
 }
 
@@ -60,8 +66,14 @@ void
 MulticastStrategy::afterReceiveInterest(const Face& inFace, const Interest& interest,
                                         const shared_ptr<pit::Entry>& pitEntry)
 {
-  if (hasPendingOutRecords(*pitEntry)) {
-    // not a new Interest, don't forward
+  // Should the Interest be suppressed?
+  RetxSuppression::Result suppressResult = m_retxSuppression.decide(inFace, interest, *pitEntry);
+  switch (suppressResult) {
+  case RetxSuppression::NEW:
+  case RetxSuppression::FORWARD:
+    break;
+  case RetxSuppression::SUPPRESS:
+    NFD_LOG_DEBUG(interest << " from=" << inFace.getId() << " suppressed");
     return;
   }
 

daemon/fw/multicast-strategy.hpp

@@ -28,6 +28,7 @@
 
 #include "strategy.hpp"
 #include "process-nack-traits.hpp"
+#include "retx-suppression-exponential.hpp"
 
 namespace nfd {
 namespace fw {
@@ -54,6 +55,11 @@ public:
 
 private:
   friend ProcessNackTraits<MulticastStrategy>;
+  RetxSuppressionExponential m_retxSuppression;
+
+PUBLIC_WITH_TESTS_ELSE_PRIVATE:
+  static const time::milliseconds RETX_SUPPRESSION_INITIAL;
+  static const time::milliseconds RETX_SUPPRESSION_MAX;
 };
 
 } // namespace fw

tests/daemon/fw/multicast-strategy.t.cpp

@@ -38,7 +38,7 @@ using namespace nfd::tests;
 typedef StrategyTester<MulticastStrategy> MulticastStrategyTester;
 NFD_REGISTER_STRATEGY(MulticastStrategyTester);
 
-class MulticastStrategyFixture : public BaseFixture
+class MulticastStrategyFixture : public UnitTestTimeFixture
 {
 protected:
   MulticastStrategyFixture()
@@ -91,23 +91,34 @@ BOOST_AUTO_TEST_CASE(Forward2)
   BOOST_CHECK_EQUAL_COLLECTIONS(sentInterestFaceIds.begin(), sentInterestFaceIds.end(),
                                 expectedInterestFaceIds.begin(), expectedInterestFaceIds.end());
 
-  // Check retransmission suppression, sendInterestHistory should remain 2
-  strategy.afterReceiveInterest(*face3, *interest, pitEntry);
-  BOOST_CHECK_EQUAL(strategy.sendInterestHistory.size(), 2);
-}
+  const time::nanoseconds TICK = time::duration_cast<time::nanoseconds>(
+                                 MulticastStrategy::RETX_SUPPRESSION_INITIAL * 0.1);
 
-BOOST_AUTO_TEST_CASE(RejectScope)
-{
-  fib::Entry& fibEntry = *fib.insert("ndn:/localhop/uS09bub6tm").first;
-  fibEntry.addNextHop(*face2, 0);
+  // downstream retransmits frequently, but the strategy should not send Interests
+  // more often than DEFAULT_MIN_RETX_INTERVAL
+  scheduler::EventId retxFrom4Evt;
+  size_t nSentLast = strategy.sendInterestHistory.size();
+  time::steady_clock::TimePoint timeSentLast = time::steady_clock::now();
+  function<void()> periodicalRetxFrom4; // let periodicalRetxFrom4 lambda capture itself
+  periodicalRetxFrom4 = [&] {
+    pitEntry->insertOrUpdateInRecord(*face3, *interest);
+    strategy.afterReceiveInterest(*face3, *interest, pitEntry);
 
-  shared_ptr<Interest> interest = makeInterest("ndn:/localhop/uS09bub6tm/eG3MMoP6z");
-  shared_ptr<pit::Entry> pitEntry = pit.insert(*interest).first;
-  pitEntry->insertOrUpdateInRecord(*face1, *interest);
+    size_t nSent = strategy.sendInterestHistory.size();
+    if (nSent > nSentLast) {
+      // Multicast strategy should multicast the interest to other two faces
+      BOOST_CHECK_EQUAL(nSent - nSentLast, 2);
+      time::steady_clock::TimePoint timeSent = time::steady_clock::now();
+      BOOST_CHECK_GE(timeSent - timeSentLast, TICK * 8);
+      nSentLast = nSent;
+      timeSentLast = timeSent;
+    }
 
-  strategy.afterReceiveInterest(*face1, *interest, pitEntry);
-  BOOST_CHECK_EQUAL(strategy.rejectPendingInterestHistory.size(), 1);
-  BOOST_CHECK_EQUAL(strategy.sendInterestHistory.size(), 0);
+    retxFrom4Evt = scheduler::schedule(TICK * 5, periodicalRetxFrom4);
+  };
+  periodicalRetxFrom4();
+  this->advanceClocks(TICK, MulticastStrategy::RETX_SUPPRESSION_MAX * 16);
+  scheduler::cancel(retxFrom4Evt);
 }
 
 BOOST_AUTO_TEST_CASE(RejectLoopback)

tests/daemon/fw/strategy-instantiation.t.cpp

@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2014-2016,  Regents of the University of California,
+ * Copyright (c) 2014-2017,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -79,7 +79,7 @@ using Tests = boost::mpl::vector<
   Test<BestRouteStrategy, false, 1>,
   Test<BestRouteStrategy2, false, 4>,
   Test<ClientControlStrategy, false, 2>,
-  Test<MulticastStrategy, false, 1>,
+  Test<MulticastStrategy, false, 2>,
   Test<NccStrategy, false, 1>
 >;