network: Make packets thread-safe

src/network/model/buffer.cc

@@ -148,6 +148,9 @@ Buffer::Recycle (struct Buffer::Data *data)
 {
   NS_LOG_FUNCTION (data);
   NS_ASSERT (data->m_count == 0);
+#ifdef NS3_MTP
+  std::atomic_thread_fence (std::memory_order_acquire);
+#endif
   Deallocate (data);
 }
 
@@ -262,8 +265,7 @@ Buffer::operator = (Buffer const&o)
   if (m_data != o.m_data) 
     {
       // not assignment to self.
-      m_data->m_count--;
-      if (m_data->m_count == 0) 
+      if (m_data->m_count-- == 1) 
         {
           Recycle (m_data);
         }
@@ -285,8 +287,7 @@ Buffer::~Buffer ()
   NS_LOG_FUNCTION (this);
   NS_ASSERT (CheckInternalState ());
   g_recommendedStart = std::max (g_recommendedStart, m_maxZeroAreaStart);
-  m_data->m_count--;
-  if (m_data->m_count == 0) 
+  if (m_data->m_count-- == 1) 
     {
       Recycle (m_data);
     }
@@ -328,8 +329,7 @@ Buffer::AddAtStart (uint32_t start)
       uint32_t newSize = GetInternalSize () + start;
       struct Buffer::Data *newData = Buffer::Create (newSize);
       memcpy (newData->m_data + start, m_data->m_data + m_start, GetInternalSize ());
-      m_data->m_count--;
-      if (m_data->m_count == 0)
+      if (m_data->m_count-- == 1) 
         {
           Buffer::Recycle (m_data);
         }
@@ -373,8 +373,7 @@ Buffer::AddAtEnd (uint32_t end)
       uint32_t newSize = GetInternalSize () + end;
       struct Buffer::Data *newData = Buffer::Create (newSize);
       memcpy (newData->m_data, m_data->m_data + m_start, GetInternalSize ());
-      m_data->m_count--;
-      if (m_data->m_count == 0) 
+      if (m_data->m_count-- == 1) 
         {
           Buffer::Recycle (m_data);
         }

src/network/model/buffer.h

@@ -23,9 +23,12 @@
 #include <stdint.h>
 #include <vector>
 #include <ostream>
+#include "ns3/atomic-counter.h"
 #include "ns3/assert.h"
 
+#ifndef NS3_MTP
 #define BUFFER_FREE_LIST 1
+#endif
 
 namespace ns3 {
 
@@ -663,7 +666,11 @@ private:
      * The reference count of an instance of this data structure.
      * Each buffer which references an instance holds a count.
      */
+#ifdef NS3_MTP
+    AtomicCounter m_count;
+#else
     uint32_t m_count;
+#endif
     /**
      * the size of the m_data field below.
      */

src/network/model/byte-tag-list.cc

@@ -19,11 +19,15 @@
  */
 #include "byte-tag-list.h"
 #include "ns3/log.h"
+#include "ns3/atomic-counter.h"
 #include <vector>
 #include <cstring>
 #include <limits>
 
+#ifndef NS3_MTP
 #define USE_FREE_LIST 1
+#endif
+
 #define FREE_LIST_SIZE 1000
 #define OFFSET_MAX (std::numeric_limits<int32_t>::max ())
 
@@ -40,7 +44,11 @@ NS_LOG_COMPONENT_DEFINE ("ByteTagList");
  */
 struct ByteTagListData {
   uint32_t size;   //!< size of the data
+#ifdef NS3_MTP
+  AtomicCounter count;
+#else
   uint32_t count;  //!< use counter (for smart deallocation)
+#endif
   uint32_t dirty;  //!< number of bytes actually in use
   uint8_t data[4]; //!< data
 };
@@ -414,9 +422,11 @@ ByteTagList::Deallocate (struct ByteTagListData *data)
     {
       return;
     }
-  data->count--;
-  if (data->count == 0)
+  if (data->count-- == 0)
     {
+#ifdef NS3_MTP
+      std::atomic_thread_fence (std::memory_order_acquire);
+#endif
       uint8_t *buffer = (uint8_t *)data;
       delete [] buffer;
     }

src/network/model/packet-metadata.cc

@@ -59,7 +59,9 @@ PacketMetadata::Enable (void)
                  "after sending any packets.  One way to fix this problem is "
                  "to call ns3::PacketMetadata::Enable () near the beginning of"
                  " the program, before any packets are sent.");
+#ifndef NS3_MTP
   m_enable = true;
+#endif
 }
 
 void 
@@ -67,7 +69,9 @@ PacketMetadata::EnableChecking (void)
 {
   NS_LOG_FUNCTION_NOARGS ();
   Enable ();
+#ifndef NS3_MTP
   m_enableChecking = true;
+#endif
 }
 
 void
@@ -77,8 +81,7 @@ PacketMetadata::ReserveCopy (uint32_t size)
   struct PacketMetadata::Data *newData = PacketMetadata::Create (m_used + size);
   memcpy (newData->m_data, m_data->m_data, m_used);
   newData->m_dirtyEnd = m_used;
-  m_data->m_count--;
-  if (m_data->m_count == 0) 
+  if (m_data->m_count-- == 1) 
     {
       PacketMetadata::Recycle (m_data);
     }
@@ -596,6 +599,9 @@ void
 PacketMetadata::Recycle (struct PacketMetadata::Data *data)
 {
   NS_LOG_FUNCTION (data);
+#ifdef NS3_MTP
+  std::atomic_thread_fence (std::memory_order_acquire);
+#endif
   if (!m_enable)
     {
       PacketMetadata::Deallocate (data);

src/network/model/packet-metadata.h

@@ -26,6 +26,7 @@
 #include "ns3/callback.h"
 #include "ns3/assert.h"
 #include "ns3/type-id.h"
+#include "ns3/atomic-counter.h"
 #include "buffer.h"
 
 namespace ns3 {
@@ -413,7 +414,11 @@ private:
    */
   struct Data {
     /** number of references to this struct Data instance. */
+#ifdef NS3_MTP
+    AtomicCounter m_count;
+#else
     uint32_t m_count;
+#endif
     /** size (in bytes) of m_data buffer below */
     uint16_t m_size;
     /** max of the m_used field over all objects which
@@ -722,8 +727,7 @@ PacketMetadata::operator = (PacketMetadata const& o)
     {
       // not self assignment
       NS_ASSERT (m_data != 0);
-      m_data->m_count--;
-      if (m_data->m_count == 0) 
+      if (m_data->m_count-- == 1) 
         {
           PacketMetadata::Recycle (m_data);
         }
@@ -740,8 +744,7 @@ PacketMetadata::operator = (PacketMetadata const& o)
 PacketMetadata::~PacketMetadata ()
 {
   NS_ASSERT (m_data != 0);
-  m_data->m_count--;
-  if (m_data->m_count == 0) 
+  if (m_data->m_count-- == 1) 
     {
       PacketMetadata::Recycle (m_data);
     }

src/network/model/packet-tag-list.h

@@ -28,6 +28,7 @@
 #include <stdint.h>
 #include <ostream>
 #include "ns3/type-id.h"
+#include "ns3/atomic-counter.h"
 
 namespace ns3 {
 
@@ -141,7 +142,11 @@ public:
   struct TagData
   {
     struct TagData * next;      /**< Pointer to next in list */
+#ifdef NS3_MTP
+    AtomicCounter count;
+#else
     uint32_t count;             /**< Number of incoming links */
+#endif
     TypeId tid;                 /**< Type of the tag serialized into #data */
     uint32_t size;              /**< Size of the \c data buffer */
     uint8_t data[1];            /**< Serialization buffer */
@@ -358,11 +363,13 @@ PacketTagList::RemoveAll (void)
   struct TagData *prev = 0;
   for (struct TagData *cur = m_next; cur != 0; cur = cur->next)
     {
-      cur->count--;
-      if (cur->count > 0) 
+      if (cur->count-- > 1) 
         {
           break;
         }
+#ifdef NS3_MTP
+      std::atomic_thread_fence (std::memory_order_acquire);
+#endif
       if (prev != 0) 
         {
           prev->~TagData ();