Make queues copyable; change p2p-topology.cc to reflect this

examples/simple-p2p.cc

@@ -209,9 +209,17 @@ int main (int argc, char *argv[])
   DebugComponentEnable("PointToPointNetDevice");
   DebugComponentEnable("PointToPointPhy");
 #endif
-
   ObjectContainer container;
 
+  // Optionally, specify some default values for Queue objects.
+  // For this example, we specify that we want each queue to
+  // be a DropTail queue, with a limit of 30 packets.
+  // Specify DropTail for default queue type (note. this is actually
+  // the default, but included here as an example).
+  Queue::Default(DropTailQueue());
+  // Specify limit of 30 in units of packets.
+  //  Queue::Default().SetLimitPackets(30);
+
   // The node factory is designed to allow user specification
   // of the "type" of node desired for each node creation.  This
   // is done by creating a node object (the inNode below), configuring

src/devices/p2p/p2p-topology.cc

@@ -57,10 +57,8 @@ PointToPointTopology::AddPointToPointLink(
   Ipv4Mask netmask("255.255.255.252");
   NS_ASSERT (netmask.IsMatch(addra,addrb));
 
-  DropTailQueue* dtqa = new DropTailQueue();
-
   PointToPointNetDevice* neta = new PointToPointNetDevice(a);
-  neta->AddQueue(dtqa);
+  neta->AddQueue(Queue::Default().Copy());
   Ipv4Interface *interfA = new ArpIpv4Interface (a, neta);
   uint32_t indexA = a->GetIpv4 ()->AddInterface (interfA);
   neta->Attach (channel);
@@ -69,10 +67,8 @@ PointToPointTopology::AddPointToPointLink(
   interfA->SetNetworkMask (netmask);
   interfA->SetUp ();
 
-  DropTailQueue* dtqb = new DropTailQueue();
-
   PointToPointNetDevice* netb = new PointToPointNetDevice(b);
-  netb->AddQueue(dtqb);
+  netb->AddQueue(Queue::Default().Copy());
   Ipv4Interface *interfB = new ArpIpv4Interface (b, netb);
   uint32_t indexB = b->GetIpv4 ()->AddInterface (interfB);
   netb->Attach (channel);

src/node/drop-tail.cc

@@ -24,6 +24,14 @@ NS_DEBUG_COMPONENT_DEFINE ("DropTailQueue");
 
 namespace ns3 {
 
+static class QueueStackInitializationClass {
+public:
+  QueueStackInitializationClass () {
+    Queue::Default (DropTailQueue ());
+  }
+} queue_stack_initialization_class;
+
+
 DropTailQueue::DropTailQueue () :
   Queue (),
   m_packets (),
@@ -37,6 +45,11 @@ DropTailQueue::~DropTailQueue ()
   NS_DEBUG("DropTailQueue::~DropTailQueue ()");
 }
 
+DropTailQueue* DropTailQueue::Copy() const
+{
+  return new DropTailQueue(*this);
+}
+
 void 
 DropTailQueue::SetMaxPackets (uint32_t npackets)
 {

src/node/drop-tail.h

@@ -35,6 +35,7 @@ public:
   DropTailQueue ();
 
   virtual ~DropTailQueue();
+  virtual DropTailQueue* Copy() const;
 
   void SetMaxPackets (uint32_t npackets);
   uint32_t GetMaxPackets (void);

src/node/queue.cc

@@ -25,6 +25,8 @@ NS_DEBUG_COMPONENT_DEFINE ("Queue");
 
 namespace ns3 {
 
+Queue* Queue::defaultQueue = 0;
+
 Queue::Queue() : 
   m_nBytes(0), 
   m_nTotalReceivedBytes(0),
@@ -182,4 +184,20 @@ Queue::Drop (const Packet& p)
   m_traceDrop (p);
 }
 
+// Static methods for managing default queue
+
+// Set new default
+void Queue::Default(const Queue& q)
+{
+  delete defaultQueue;      // delete previous (if any)
+  defaultQueue = q.Copy();  // set new default
+}
+
+// Get current default
+Queue& Queue::Default()
+{
+  // ! Need to schedule an "at end" event to delete the default
+  return *defaultQueue;
+}
+
 }; // namespace ns3

src/node/queue.h

@@ -43,6 +43,8 @@ public:
   Queue ();
   virtual ~Queue ();
 
+  virtual Queue* Copy() const = 0;
+
   TraceResolver *CreateTraceResolver (TraceContext const &context);
 
   bool IsEmpty (void);
@@ -104,7 +106,7 @@ private:
   uint32_t m_nTotalDroppedBytes;
   uint32_t m_nTotalDroppedPackets;
 
-#if 0
+public:
   // Static methods to manage queue default
   // Set desired queue default
   static void    Default(const Queue& q);
@@ -112,7 +114,6 @@ private:
   static Queue&  Default();
   // Static variable pointing to current default queue
   static Queue* defaultQueue;
-#endif
 };
 
 }; // namespace ns3