Update README and add contrib dir

contrib/tsn/model/tsn-multidrop-channel.cc

@@ -0,0 +1,154 @@
+#include "tsn-multidrop-channel.h"
+#include "tsn-multidrop-net-device.h"
+
+#include "ns3/log.h"
+#include "ns3/packet.h"
+#include "ns3/simulator.h"
+#include "ns3/trace-source-accessor.h"
+
+namespace ns3
+{
+
+NS_LOG_COMPONENT_DEFINE("TsnMultidropChannel");
+
+NS_OBJECT_ENSURE_REGISTERED(TsnMultidropChannel);
+
+TypeId
+TsnMultidropChannel::GetTypeId()
+{
+    static TypeId tid =
+        TypeId("ns3::TsnMultidropChannel")
+            .SetParent<Channel>()
+            .SetGroupName("Tsn")
+            .AddConstructor<TsnMultidropChannel>()
+            .AddAttribute("Delay",
+                          "Propagation delay through the channel",
+                          TimeValue(NanoSeconds(25)),
+                          MakeTimeAccessor(&TsnMultidropChannel::m_delay),
+                          MakeTimeChecker())
+            .AddTraceSource("TxRxEthernet",
+                            "Trace source indicating transmission of packet "
+                            "from the TsnMultidropChannel, used by the Animation "
+                            "interface.",
+                            MakeTraceSourceAccessor(&TsnMultidropChannel::m_txrxEthernet),
+                            "ns3::TsnMultidropChannel::TxRxAnimationCallback");
+    return tid;
+}
+
+
+TsnMultidropChannel::TsnMultidropChannel()
+    : Channel()
+{
+    NS_LOG_FUNCTION_NOARGS();
+}
+
+void
+TsnMultidropChannel::Attach(Ptr<TsnMultidropNetDevice> device)
+{
+    NS_LOG_FUNCTION(this << device);
+    NS_ASSERT(device);
+    NS_ASSERT(m_netDevices.size() < 255);   //Limitation from IEEE802.3cg-2019
+
+    m_netDevices.insert(m_netDevices.end(), device);
+
+    //If we have two devices connected to the channel, the channel is usable
+    if (m_netDevices.size() >= 2)
+    {
+      m_wireState = IDLE;
+    }
+}
+
+bool
+TsnMultidropChannel::TransmitStart(Ptr<const Packet> p, Ptr<TsnNetDevice> src, Time txTime)
+{
+    NS_LOG_FUNCTION(this << p << src);
+    NS_LOG_LOGIC("UID is " << p->GetUid() << ")");
+
+    NS_ASSERT(m_wireState == IDLE);
+
+    for (std::size_t i = 0; i < m_netDevices.size(); ++i)
+    {
+      if(m_netDevices[i]!=src)
+      {
+        //Start of reception => Change PLCA state
+        m_netDevices[i]->StartReception();
+
+        //Schedule reception a the end of the transmission
+        Simulator::ScheduleWithContext(m_netDevices[i]->GetNode()->GetId(),
+          txTime + m_delay,
+          &TsnMultidropNetDevice::Receive,
+          m_netDevices[i],
+          p->Copy());
+          NS_LOG_INFO(txTime + m_delay);
+      }
+    }
+
+    // Call the tx anim callback on the net device
+    // m_txrxEthernet(p, src, m_wire[wire].m_dst, txTime, txTime + m_delay);
+    return true;
+}
+
+std::size_t
+TsnMultidropChannel::GetNDevices() const
+{
+    NS_LOG_FUNCTION_NOARGS();
+    return m_netDevices.size();
+}
+
+Ptr<TsnNetDevice>
+TsnMultidropChannel::GetEthernetDevice(std::size_t i) const
+{
+    NS_LOG_FUNCTION_NOARGS();
+    NS_ASSERT(i < m_netDevices.size());
+    return m_netDevices[i];
+}
+
+Ptr<NetDevice>
+TsnMultidropChannel::GetDevice(std::size_t i) const
+{
+    NS_LOG_FUNCTION_NOARGS();
+    return GetEthernetDevice(i);
+}
+
+Time
+TsnMultidropChannel::GetDelay() const
+{
+    return m_delay;
+}
+
+
+bool
+TsnMultidropChannel::IsInitialized() const
+{
+    NS_ASSERT(m_wireState != INITIALIZING);
+    return true;
+}
+
+
+void
+TsnMultidropChannel::StartBeaconTransmission()
+{
+    NS_LOG_FUNCTION(this);
+    NS_ASSERT(m_wireState == IDLE);
+    m_wireState = TRANSMITTING;
+
+    for (std::size_t i = 0; i < m_netDevices.size(); ++i)
+    {
+      m_netDevices[i]->StartBeaconReception();
+    }
+}
+
+void
+TsnMultidropChannel::StopBeaconTransmission()
+{
+    NS_LOG_FUNCTION(this);
+    NS_ASSERT(m_wireState == TRANSMITTING);
+    m_wireState = IDLE;
+
+    for (std::size_t i = 0; i < m_netDevices.size(); ++i)
+    {
+      m_netDevices[i]->StopBeaconReception();
+    }
+}
+
+}