Hello everybody.
First, thank you all for such a useful thread.
Second, I've got the same AccessViolationException :)
I am trying to cobble up some autotesting framework. It should be able to reset environment and to restart tests. Furthermore, as all of the robotics is more or less probabilistic, the tests should be run more than once.
I was tracing the bug for the whole weekend. It is 100% reproducible. So lets fix it at last. Here is my distilled code:
using EngPxy = Microsoft.Robotics.Simulation.Engine.Proxy;
using SimPxy = Microsoft.Robotics.Simulation.Proxy;
using Microsoft.Dss.ServiceModel.DsspServiceBase;
using Microsoft.Ccr.Core;
using System;
using System.Linq;
using Microsoft.Dss.Core.Attributes;
using System.ComponentModel;
using Microsoft.Dss.ServiceModel.Dssp;
using System.Collections.Generic;
using System.Xml;
using Microsoft.Robotics.Simulation.Engine;
using Microsoft.Robotics.Simulation.Physics;
using Microsoft.Robotics.PhysicalModel;
using Microsoft.Dss.Services.Serializer;
namespace Brumba.Simulation.AccessViolation
{
[Contract(Contract.Identifier)]
[DisplayName("SimulationTester")]
[Description("SimulationTester service (no description provided)")]
class AccessViolationService : DsspServiceBase
{
public static ITask Exec<T1, T2>(PortSet<T1, T2> portSet)
{
return Arbiter.Choice(portSet, (T1 p1) => { }, (T2 p2) => { Console.WriteLine("error"); });
}
[ServiceState]
AccessViolationState _state = new AccessViolationState();
[ServicePort("/SimulationTester", AllowMultipleInstances = true)]
AccessViolationOperations _mainPort = new AccessViolationOperations();
[Partner("SimEngine", Contract = Microsoft.Robotics.Simulation.Engine.Proxy.Contract.Identifier, CreationPolicy = PartnerCreationPolicy.CreateAlways)]
EngPxy.SimulationEnginePort _simEngine = new EngPxy.SimulationEnginePort();
public AccessViolationService(DsspServiceCreationPort creationPort)
: base(creationPort)
{
}
protected override void Start()
{
base.Start();
SpawnIterator(Test1);
}
private IEnumerator<ITask> Test1()
{
yield return Arbiter.FromIteratorHandler(SetUpSimulator);
GenerateEnvironment();
for (int i = 0; i < 100; ++i)
{
yield return Arbiter.FromIteratorHandler(ResetBoxes);
yield return Arbiter.Receive<DateTime>(false, TimeoutPort(500), (DateTime val) => { });
Console.WriteLine("{0}", i);
}
}
IEnumerator<ITask> SetUpSimulator()
{
yield return Exec(_simEngine.UpdatePhysicsTimeStep(0.01f));
SimPxy.SimulationState simState = null;
yield return Arbiter.Choice(_simEngine.Get(), s => simState = s, LogError);
simState.RenderMode = SimPxy.RenderMode.None;
yield return Exec(_simEngine.Replace(simState));
}
private IEnumerator<ITask> ResetBoxes()
{
SimPxy.SimulationState simState = null;
yield return Arbiter.Choice(_simEngine.Get(), st => simState = st, LogError);
simState.Pause = true;
yield return Exec(_simEngine.Replace(simState));
///Remove old boxes {
foreach (var entityNode in simState.SerializedEntities.XmlNodes.Cast<XmlElement>())
{
var desRequest = new Deserialize(new XmlNodeReader(entityNode));
SerializerPort.Post(desRequest);
DeserializeResult desEntity = null;
yield return Arbiter.Choice(desRequest.ResultPort, v => desEntity = v, LogError);
EngPxy.VisualEntity entity = (EngPxy.VisualEntity)desEntity.Instance;
if (entity is EngPxy.SingleShapeEntity)
{
yield return Exec(_simEngine.DeleteSimulationEntity(entity));
break;
}
}
///} Remove old boxes
CreateJointBoxes();
simState.Pause = false;
yield return Exec(_simEngine.Replace(simState));
}
public void CreateJointBoxes()
{
var box1 = new SingleShapeEntity(new BoxShape(_boxProps), new Vector3())
{
State = { Name = "box1", Pose = { Position = new Vector3(0, 2f, 0), Orientation = new Quaternion(0, 0, 1f, 0.25f) } }
};
box1.InsertEntity(new SingleShapeEntity(new BoxShape(_boxProps), new Vector3())
{
State = { Name = "box2", Pose = { Position = new Vector3(0.3f, 0, 0) } }
});
SimulationEngine.GlobalInstancePort.Insert(box1);
}
private void GenerateEnvironment()
{
var ground = new HeightFieldEntity("Ground", "WoodFloor.dds", new MaterialProperties("ground", 0f, 0.5f, 0.5f));
SimulationEngine.GlobalInstancePort.Insert(ground);
SkyDomeEntity sky = new SkyDomeEntity("skydome.dds", "sky_diff.dds");
SimulationEngine.GlobalInstancePort.Insert(sky);
var sun = new LightSourceEntity(LightSourceEntityType.Directional)
{
State = { Name = "Sun" },
Direction = new Vector3(0.5f, -.75f, 0.5f)
};
SimulationEngine.GlobalInstancePort.Insert(sun);
}
static readonly BoxShapeProperties _boxProps = new BoxShapeProperties("box1 props", 1, new Pose(), new Vector3(0.1f, 0.1f, 0.1f))
{
Material = new MaterialProperties("ChassisMaterial", 0.0f, 0.5f, 0.5f),
DiffuseColor = new Vector4(1, 0, 0, 0)
};
}
}
The AccessViolationService has Simulation Engine as a partner. It spawns Test1 method during Start. Test1 turns off rendering (that does not influence the bug, it occurs with or without rendering), decreases simulation step (that's kind of catalyst for the
bug). Then generates fixed environment (the floor, the sky and the sun) and begin in the loop to execute test and reset it's movable parts.
The gist of the test - throwing two joint boxes on the floor from the height of 2 meters. The whole bug is about colliding items, when nothing collides all is ok. The child item is the necessary condition for the bug. In ResetBoxes I pause the simulator,
delete old boxes (I assume that parent box goes first), recreate boxes, unpause the simulator - it is really Vincent's code.
The loop consists of 100 iteration. It never goes beyond 20 (the bug likes twelfth iteration the most). Some details about the bug.
1. Stack trace (everytime it is the same):
в Microsoft.Robotics.Simulation.Physics.Utilities.FindShapeFromNxShape(NxShape* nxShape)
в Microsoft.Robotics.Simulation.Physics.ActorContactReport.onContactNotify(ActorContactReport* , NxContactPair* pair, UInt32 events)
в Microsoft.Robotics.Simulation.Physics.PhysicsEngine.GetPreviousFrameResults(Boolean waitForResults)
в Microsoft.Robotics.Simulation.Engine.SimulationEngine.Update(GraphicsDevice device, Double appTime, Double elapsedTime, Double elapsedRealTime)
в Microsoft.Robotics.Simulation.Engine.SimulationEngine.Application_Idle(Object sender, EventArgs e)
в System.Windows.Forms.Application.ThreadContext.System.Windows.Forms.UnsafeNativeMethods.IMsoComponent.FDoIdle(Int32 grfidlef)
в System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
в System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
в System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
в System.Windows.Forms.Application.Run(Form mainForm)
в Microsoft.Robotics.Simulation.Engine.SimulationEngine.StartRenderLoop()
в System.Threading.ThreadHelper.ThreadStart_Context(Object state)
в System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
в System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
в System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
в System.Threading.ThreadHelper.ThreadStart()
2. I can see in IntelliTrace panel that there is always a number of thrown and caught NullReferenceExceptions before AccessViolationException.
It occures on two machines (Windows 8 32, Windows 7 64), both of them have 8 cores.
This bug is a real blocker for my work. At the very least I need a workaround (I doubt it exists). Thank you.
