routing: use unique_ptr for signal container

Change-Id: I1912f8630d0e26d8c25c2050208f6b8b0ffd9009
refs: #4268
diff --git a/src/route/name-prefix-table.cpp b/src/route/name-prefix-table.cpp
index bd7269a..4f9d91d 100644
--- a/src/route/name-prefix-table.cpp
+++ b/src/route/name-prefix-table.cpp
@@ -33,7 +33,8 @@
 
 INIT_LOGGER("NamePrefixTable");
 
-NamePrefixTable::NamePrefixTable(Nlsr& nlsr, std::shared_ptr<AfterRoutingChange>& afterRoutingChangeSignal)
+NamePrefixTable::NamePrefixTable(Nlsr& nlsr,
+                                 std::unique_ptr<AfterRoutingChange>& afterRoutingChangeSignal)
   : m_nlsr(nlsr)
 {
   m_afterRoutingChangeConnection = afterRoutingChangeSignal->connect(
diff --git a/src/route/name-prefix-table.hpp b/src/route/name-prefix-table.hpp
index f4901ba..1e11e15 100644
--- a/src/route/name-prefix-table.hpp
+++ b/src/route/name-prefix-table.hpp
@@ -41,7 +41,7 @@
   using NptEntryList = std::list<std::shared_ptr<NamePrefixTableEntry>>;
   using const_iterator = NptEntryList::const_iterator;
 
-  NamePrefixTable(Nlsr& nlsr, std::shared_ptr<AfterRoutingChange>& afterRoutingChangeSignal);
+  NamePrefixTable(Nlsr& nlsr, std::unique_ptr<AfterRoutingChange>& afterRoutingChangeSignal);
 
   ~NamePrefixTable();
 
diff --git a/src/route/routing-table.cpp b/src/route/routing-table.cpp
index 547e943..0f31885 100644
--- a/src/route/routing-table.cpp
+++ b/src/route/routing-table.cpp
@@ -35,7 +35,7 @@
 INIT_LOGGER("RoutingTable");
 
 RoutingTable::RoutingTable(ndn::Scheduler& scheduler)
-  : afterRoutingChange{std::make_shared<AfterRoutingChange>()}
+  : afterRoutingChange{ndn::make_unique<AfterRoutingChange>()}
   , m_scheduler(scheduler)
   , m_NO_NEXT_HOP{-12345}
   , m_routingCalcInterval{static_cast<uint32_t>(ROUTING_CALC_INTERVAL_DEFAULT)}
diff --git a/src/route/routing-table.hpp b/src/route/routing-table.hpp
index 274853e..60da254 100644
--- a/src/route/routing-table.hpp
+++ b/src/route/routing-table.hpp
@@ -115,7 +115,7 @@
   writeLog(int hyperbolicState);
 
 public:
-  std::shared_ptr<AfterRoutingChange> afterRoutingChange;
+  std::unique_ptr<AfterRoutingChange> afterRoutingChange;
 
 PUBLIC_WITH_TESTS_ELSE_PRIVATE:
   std::list<RoutingTableEntry> m_rTable;