Properly detect blocks as critical when a train is not moving

[r2c2.git] / source / libr2c2 / blockallocator.cpp

diff --git a/source/libr2c2/blockallocator.cpp b/source/libr2c2/blockallocator.cpp
index 8d3381da20ecada6172781d064b9feba998e669a..347960ee2ec584029a7bc66dffaaabb56de0cdad 100644 (file)
--- a/source/libr2c2/blockallocator.cpp
+++ b/source/libr2c2/blockallocator.cpp
@@ -257,10 +257,17 @@ bool BlockAllocator::reserve_block(const BlockIter &block)
        /* Add it to the list first to present a consistent state in block_reserved
        signal. */
        blocks.push_back(block);
+
+       bool first_reserve = (cur_blocks_end==blocks.end());
+       if(first_reserve)
+               --cur_blocks_end;
+
        try
        {
                if(!block->reserve(&train))
                {
+                       if(first_reserve)
+                               cur_blocks_end = blocks.end();
                        blocks.pop_back();
                        return false;
                }
@@ -269,6 +276,8 @@ bool BlockAllocator::reserve_block(const BlockIter &block)
        }
        catch(...)
        {
+               if(first_reserve)
+                       cur_blocks_end = blocks.end();
                blocks.pop_back();
                throw;
        }
@@ -312,14 +321,14 @@ void BlockAllocator::advance_back()
 
        /* Sensors aren't guaranteed to be detriggered in order.  Go through the
        block list and locate the first sensor that's still active. */
-       Sensor *last_inactive = 0;
-       for(BlockList::iterator i=blocks.begin(); (i!=cur_blocks_end && i->block()!=&veh_block); ++i)
+       BlockList::iterator end = blocks.end();
+       for(BlockList::iterator i=blocks.begin(); i!=cur_blocks_end; ++i)
        {
+               Block *block = &**i;
                list<Sensor *> sensors;
-               if(Sensor *sensor = (*i)->get_sensor())
-                       sensors.push_back(sensor);
 
-               Block *block = &**i;
+               /* Collect all sensors from the block in the order they are expected to
+               detrigger. */
                for(TrackIter j=i->track_iter(); (j && &j->get_block()==block); j=j.next())
                        if(!j->get_attachments().empty())
                        {
@@ -329,20 +338,32 @@ void BlockAllocator::advance_back()
                                                sensors.push_back(gate);
                        }
 
-               for(list<Sensor *>::const_iterator j=sensors.begin(); j!=sensors.end(); ++j)
+               if(Sensor *sensor = (*i)->get_sensor())
+                       sensors.push_back(sensor);
+
+               /* See if any sensor is still active, and record the position of the
+               last inactive sensor. */
+               bool active_sensor = false;
+               for(list<Sensor *>::const_iterator j=sensors.begin(); (!active_sensor && j!=sensors.end()); ++j)
                {
                        if((*j)->get_state())
+                               active_sensor = true;
+                       else
+                               end = i;
+               }
+
+               // Stop if we encounter an active sensor or the train's last vehicle
+               if(block==&veh_block || active_sensor)
+               {
+                       if(end!=blocks.end())
                        {
-                               if(last_inactive)
-                               {
-                                       if(dynamic_cast<BeamGate *>(*j))
-                                               ++i;
-                                       release_blocks_begin(i);
-                               }
-                               return;
+                               /* If the last inactive sensor was in an earlier block, release
+                               that block as well. */
+                               if(i!=end)
+                                       ++end;
+                               release_blocks_begin(end);
                        }
-                       else
-                               last_inactive = *j;
+                       return;
                }
        }
 }
@@ -401,7 +422,7 @@ void BlockAllocator::reverse()
 
 void BlockAllocator::turnout_path_changing(Track &track)
 {
-       BlockList::iterator i = find_if(blocks.begin(), blocks.end(), BlockMatch(track.get_block()));
+       BlockList::iterator i = find_if(cur_blocks_end, blocks.end(), BlockMatch(track.get_block()));
        if(i!=blocks.end())
        {
                ++i;