Changed CandidateQueue class so that NetworkLSA is always ordered in front of
RouterLSA.

Besides, some manuipliation on std::list objects are replaced using STL <algoirthm>

diff -r 0950db321270 src/routing/global-routing/candidate-queue.cc
--- a/src/routing/global-routing/candidate-queue.cc	Sat Aug 08 11:41:38 2009 +0800
+++ b/src/routing/global-routing/candidate-queue.cc	Sat Aug 08 20:34:51 2009 +0800
@@ -16,6 +16,8 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#include <algorithm>
+#include <iostream>
 #include "ns3/log.h"
 #include "ns3/assert.h"
 #include "candidate-queue.h"
@@ -25,6 +27,37 @@
 
 namespace ns3 {
 
+std::ostream&
+operator<< (std::ostream& os, const SPFVertex::VertexType& t)
+{
+  switch (t)
+  {
+  case SPFVertex::VertexRouter:  os << "router"; break;
+  case SPFVertex::VertexNetwork: os << "network"; break;
+  default:                       os << "unknown"; break;
+  };
+  return os;
+}
+
+std::ostream& 
+operator<< (std::ostream& os, const CandidateQueue& q)
+{
+  typedef CandidateQueue::CandidateList_t List_t;
+  typedef List_t::const_iterator CIter_t;
+  const CandidateQueue::CandidateList_t& list = q.m_candidates;
+
+  os << "*** CandidateQueue Begin (<id, distance, LSA-type>) ***" << std::endl;
+  for (CIter_t iter = list.begin (); iter != list.end (); iter++)
+  {
+    os << "<" 
+       << (*iter)->GetVertexId () << ", " 
+       << (*iter)->GetDistanceFromRoot () << ", " 
+       << (*iter)->GetVertexType () << ">" << std::endl;
+  }
+  os << "*** CandidateQueue End ***";
+  return os;
+}
+
 CandidateQueue::CandidateQueue()
   : m_candidates ()
 {
@@ -54,17 +87,11 @@
 {
   NS_LOG_FUNCTION (this << vNew);
 
-  CandidateList_t::iterator i = m_candidates.begin ();  
-
-  for (; i != m_candidates.end (); i++)
-    {
-      SPFVertex *v = *i;
-      if (vNew->GetDistanceFromRoot () < v->GetDistanceFromRoot ())
-        {
-          break;
-        }
-    }
-  m_candidates.insert(i, vNew);
+  CandidateList_t::iterator i = std::upper_bound (
+    m_candidates.begin (), m_candidates.end (), vNew,
+    &CandidateQueue::CompareSPFVertex
+    );
+  m_candidates.insert (i, vNew);
 }
 
   SPFVertex *
@@ -129,18 +156,33 @@
 CandidateQueue::Reorder (void)
 {
   NS_LOG_FUNCTION_NOARGS ();
-  std::list<SPFVertex*> temp;
 
-  while (!m_candidates.empty ()) {
-    SPFVertex *v = m_candidates.front ();
-    m_candidates.pop_front ();
-    temp.push_back(v);
-  }
+  m_candidates.sort (&CandidateQueue::CompareSPFVertex);
+  NS_LOG_LOGIC ("After reordering the CandidateQueue");
+  NS_LOG_LOGIC (*this);
+}
 
-  while (!temp.empty ()) {
-    Push (temp.front ());
-    temp.pop_front ();
-  }
+/*
+ * In this implementation, SPFVertex follows the ordering where
+ * a vertex is ranked first if its GetDistanceFromRoot () is smaller;
+ * In case a tie, NetworkLSA is always ranked before RouterLSA.
+ *
+ * This ordering is necessary for implementing ECMP
+ */
+bool 
+CandidateQueue::CompareSPFVertex (const SPFVertex* v1, const SPFVertex* v2)
+{
+  NS_LOG_FUNCTION (&v1 << &v2);
+
+  bool result = false;
+  if (v1->GetDistanceFromRoot () < v2->GetDistanceFromRoot ())
+    result = true;
+  else if (v1->GetDistanceFromRoot () == v2->GetDistanceFromRoot ())
+    if (v1->GetVertexType () == SPFVertex::VertexNetwork &&
+        v2->GetVertexType () == SPFVertex::VertexRouter)
+      result = true;
+   
+  return result;
 }
 
 } // namespace ns3
diff -r 0950db321270 src/routing/global-routing/candidate-queue.h
--- a/src/routing/global-routing/candidate-queue.h	Sat Aug 08 11:41:38 2009 +0800
+++ b/src/routing/global-routing/candidate-queue.h	Sat Aug 08 20:34:51 2009 +0800
@@ -176,9 +176,21 @@
  * properly deal with deep copies.
  */
   CandidateQueue& operator= (CandidateQueue& sr);
+/**
+ * \brief return true if v1 < v2
+ *
+ * SPFVertexes are added into the queue according to the ordering
+ * defined by this method. If v1 should be popped before v2, this 
+ * method return true; false otherwise
+ *
+ * \return True if v1 should be popped before v2; false otherwise
+ */
+  static bool CompareSPFVertex (const SPFVertex* v1, const SPFVertex* v2);
 
   typedef std::list<SPFVertex*> CandidateList_t;
   CandidateList_t m_candidates;
+
+  friend std::ostream& operator<< (std::ostream& os, const CandidateQueue& q);
 };
 
 } // namespace ns3
diff -r 0950db321270 src/routing/global-routing/global-route-manager-impl.cc
--- a/src/routing/global-routing/global-route-manager-impl.cc	Sat Aug 08 11:41:38 2009 +0800
+++ b/src/routing/global-routing/global-route-manager-impl.cc	Sat Aug 08 20:34:51 2009 +0800
@@ -1172,6 +1172,7 @@
 // of the routers found in the Global Router Link Records and added tehm to 
 // the candidate list.
 //
+      NS_LOG_LOGIC (candidate);
       v = candidate.Pop ();
       NS_LOG_LOGIC ("Popped vertex " << v->GetVertexId ());
 //