From 848a39d9cf52c7158968ba3f9af4fd5d4e2b4391 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 3 Oct 2010 13:27:54 +0000
Subject: [PATCH] Prevent some undesirable recursive calls

---
 source/libmarklin/train.cpp   | 26 ++++++++++++++++++++++----
 source/libmarklin/train.h     |  2 ++
 source/libmarklin/vehicle.cpp |  3 ++-
 3 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/source/libmarklin/train.cpp b/source/libmarklin/train.cpp
index c3affef..96566a6 100644
--- a/source/libmarklin/train.cpp
+++ b/source/libmarklin/train.cpp
@@ -32,6 +32,8 @@ Train::Train(Layout &l, const VehicleType &t, unsigned a):
 	address(a),
 	priority(0),
 	pending_block(0),
+	reserving(false),
+	advancing(false),
 	controller(new AIControl(*this, new SimpleController)),
 	timetable(0),
 	active(false),
@@ -407,7 +409,11 @@ void Train::tick(const Time::TimeStamp &t, const Time::TimeDelta &dt)
 
 		float d = get_real_speed(current_speed)*(dt/Time::sec);
 		if(ok)
+		{
+			advancing = true;
 			vehicle.advance(reverse ? -d : d);
+			advancing = false;
+		}
 		else if(accurate_position)
 		{
 			overshoot_dist += d;
@@ -592,7 +598,7 @@ void Train::sensor_event(unsigned addr, bool state)
 				j->block->traverse(j->entry, &block_len);
 				travel_dist += block_len;
 
-				if(j->block->get_sensor_id()==addr)
+				if(j->block->get_sensor_id()==addr && !advancing)
 				{
 					const Block::Endpoint &bep = j->block->get_endpoints()[j->entry];
 					if(reverse)
@@ -664,7 +670,12 @@ void Train::turnout_event(unsigned addr, bool)
 		unsigned pending_addr = pending_block->get_turnout_id();
 		bool double_addr = (*pending_block->get_tracks().begin())->get_type().is_double_address();
 		if(addr==pending_addr || (double_addr && addr==pending_addr+1))
-			reserve_more();
+		{
+			if(reserving)
+				pending_block = 0;
+			else
+				reserve_more();
+		}
 	}
 }
 
@@ -717,6 +728,8 @@ unsigned Train::reserve_more()
 		}
 	}
 
+	reserving = true;
+
 	bool got_more = false;
 	BlockRef *good = last;
 	unsigned good_sens = nsens;
@@ -805,10 +818,13 @@ unsigned Train::reserve_more()
 			if(path!=static_cast<int>(entry_ep.track->get_active_path()))
 			{
 				// The turnout is set to wrong path - switch and wait for it
-				link->reserve(0);
 				pending_block = link;
 				entry_ep.track->set_active_path(path);
-				break;
+				if(pending_block)
+				{
+					link->reserve(0);
+					break;
+				}
 			}
 		}
 
@@ -830,6 +846,8 @@ unsigned Train::reserve_more()
 			last = &rsv_blocks.back();
 	}
 
+	reserving = false;
+
 	// Make any sensorless blocks at the beginning immediately current
 	list<BlockRef>::iterator i;
 	for(i=rsv_blocks.begin(); (i!=rsv_blocks.end() && !i->block->get_sensor_id()); ++i) ;
diff --git a/source/libmarklin/train.h b/source/libmarklin/train.h
index 319119b..3e7a56b 100644
--- a/source/libmarklin/train.h
+++ b/source/libmarklin/train.h
@@ -78,6 +78,8 @@ private:
 	std::list<BlockRef> cur_blocks;
 	std::list<BlockRef> rsv_blocks;
 	Block *pending_block;
+	bool reserving;
+	bool advancing;
 	Controller *controller;
 	Timetable *timetable;
 	bool active;
diff --git a/source/libmarklin/vehicle.cpp b/source/libmarklin/vehicle.cpp
index 8761bb6..ac03de1 100644
--- a/source/libmarklin/vehicle.cpp
+++ b/source/libmarklin/vehicle.cpp
@@ -213,6 +213,8 @@ void Vehicle::check_sensor(float offset, unsigned &sensor)
 	{
 		/* Sensor ID under axle has changed.  Deduce movement direction by using
 		the sensor ID under the midpoint of the vehicle. */
+		/* XXX This depends on the simulation running fast enough.  Something
+		more robust would be preferable. */
 		unsigned old = sensor;
 		sensor = s;
 		unsigned mid = track_pos.track->get_sensor_id();
@@ -220,7 +222,6 @@ void Vehicle::check_sensor(float offset, unsigned &sensor)
 		if(s && s!=mid)
 			/* There's a sensor and it's different from mid.  We've just entered
 			that sensor. */
-			// XXX The Train will reset the vehicles to the start of the sensor, which is somewhat undesirable
 			layout.get_driver().set_sensor(sensor, true);
 		if(old && old!=mid)
 			/* A sensor was under the axle and it was different from mid.  We've
-- 
2.45.2