1 files changed, 145 insertions, 0 deletions
diff --git a/src/intersim/buffer_state.cpp b/src/intersim/buffer_state.cpp
new file mode 100644
index 0000000..72a327d
--- /dev/null
+++ b/src/intersim/buffer_state.cpp
@@ -0,0 +1,145 @@
+#include "booksim.hpp"
+#include <iostream>
+#include <stdlib.h>
+#include <assert.h>
+
+#include "buffer_state.hpp"
+#include "random_utils.hpp"
+
+void BufferState::init( const Configuration& config ) 
+{
+   _Init( config );
+}
+
+BufferState::BufferState( const Configuration& config, 
+                          Module *parent, const string& name ) : 
+Module( parent, name )
+{
+   _Init( config );
+}
+
+void BufferState::_Init( const Configuration& config )
+{
+   _buf_size     = config.GetInt( "vc_buf_size" );
+   _vcs          = config.GetInt( "num_vcs" );
+
+   _wait_for_tail_credit = config.GetInt( "wait_for_tail_credit" );
+
+   _in_use       = new bool [_vcs];
+   _tail_sent    = new bool [_vcs];
+   _cur_occupied = new int  [_vcs];
+
+   _last_avail   = 0;
+
+   for ( int v = 0; v < _vcs; ++v ) {
+      _in_use[v]       = false;
+      _tail_sent[v]    = false;
+      _cur_occupied[v] = 0;
+   }
+}
+
+BufferState::~BufferState( )
+{
+   delete [] _in_use;
+   delete [] _tail_sent;
+   delete [] _cur_occupied;
+}
+
+void BufferState::ProcessCredit( Credit *c )
+{
+   assert( c );
+
+   for ( int v = 0; v < c->vc_cnt; ++v ) {
+      assert( ( c->vc[v] >= 0 ) && ( c->vc[v] < _vcs ) );
+
+      if ( ( _wait_for_tail_credit ) && 
+           ( !_in_use[c->vc[v]] ) ) {
+         Error( "Received credit for idle buffer" );
+      }
+
+      if ( _cur_occupied[c->vc[v]] > 0 ) {
+         --_cur_occupied[c->vc[v]];
+
+         if ( ( _cur_occupied[c->vc[v]] == 0 ) && 
+              ( _tail_sent[c->vc[v]] ) ) {
+            _in_use[c->vc[v]] = false;
+         }
+      } else {
+         cout << "VC = " << c->vc[v] << endl;
+         Error( "Buffer occupancy fell below zero" );
+      }
+   }
+}
+
+void BufferState::SendingFlit( Flit *f )
+{
+   assert( f && ( f->vc >= 0 ) && ( f->vc < _vcs ) );
+
+   if ( _cur_occupied[f->vc] < _buf_size ) {
+      ++_cur_occupied[f->vc];
+
+      if ( f->tail ) {
+         _tail_sent[f->vc] = true;
+
+         if ( !_wait_for_tail_credit ) {
+            _in_use[f->vc] = false;
+         }
+      }
+   } else {
+      Error( "Flit sent to full buffer" );
+   }
+}
+
+void BufferState::TakeBuffer( int vc )
+{
+   assert( ( vc >= 0 ) && ( vc < _vcs ) );
+
+   if ( _in_use[vc] ) {
+      Error( "Buffer taken while in use" );
+   }
+
+   _in_use[vc]    = true;
+   _tail_sent[vc] = false;
+}
+
+bool BufferState::IsFullFor( int vc  ) const
+{
+   assert( ( vc >= 0 ) && ( vc < _vcs ) );
+   return( _cur_occupied[vc] == _buf_size ) ? true : false;
+}
+
+bool BufferState::IsAvailableFor( int vc ) const
+{
+   assert( ( vc >= 0 ) && ( vc < _vcs ) );
+   return !_in_use[vc];
+}
+
+int BufferState::FindAvailable( )
+{
+   int available_vc = -1;
+   int vc;
+
+   _last_avail = RandomInt( _vcs - 1 );
+
+   for ( int v = 0; v < _vcs; ++v ) {
+      vc = ( v + _last_avail + 1 ) % _vcs; // Round-robin
+
+      if ( IsAvailableFor( vc ) ) {
+         available_vc = vc;
+         _last_avail  = vc;
+         break;
+      }
+   }
+
+   return available_vc;
+}
+
+void BufferState::Display( ) const
+{
+   cout << _fullname << " :" << endl;
+   for ( int v = 0; v < _vcs; ++v ) {
+      cout << "  buffer class " << v << endl;
+      cout << "    in_use = " << _in_use[v] << " tail_sent = " << _tail_sent[v] << endl;
+      cout << "    occupied = " << _cur_occupied[v] << endl;
+   }
+}