Multithread crashes

[KingSnail]

Hi I have a problem with newton running on a different thread

So my setup is like this

Main thread: Server loop + CreatePlayerController() when players join

Second Thread: Loop with NewtonUpdate()
this is done with createthreadex and not newton dThread class

8 other threads: These are Newton worker threads that are built in to Newton
I just specified 8 to Newton.

The problem is this, When the player controller gets made it creates a body first and then a player controller which creates 3 more bodies (The sensors)
As soon as first body is created I get a crash from one of the 8 Newton threads about trying to access a sensor shape which hasnt been made yet
because it gets constructed in CustomPlayerController base class.

So my question is: Is it possible to let create a new Newton body that doesnt instantly add it to the NewtonUpdate loop?

[Julio Jerez]

are you using newton 3.0?

are you creating the objet in a newton callback?
if you are you can create you body inside a newton critical section

[KingSnail]

I am using Newton 2.0

I am not creating the controller inside a call back.

I have tried using critical sections outside of callback but they end up making the thread (main thread)
that is not a newton thread go into sleep().

Is it possible to make newton create a body without adding it to the main list of bodies?

/**********************/

create_newton_body(); <----- adds body to NewtonUpdate it seems here
charactercontroller(body);
sensor1();
sensor2(); <----- Cannot read 0x0c0c... Crash here on an update thread
sensor3();

[Julio Jerez]

Use the newton Critical section. That should work.

and No in 2.00 you cannot create a body without adding it to the world.

can you create after the Newton update? That spud be very safe and clean.
I never tried to make joints in a call back. so I do not know how it will work, and now I am in the middle of a bs, windows installation
upgrading me window system to the new Intel Core two, so I can not check it out.

[KingSnail]

I cant call it after NewtonUpdate because NewtonUpdate is running async to the main thread

[Julio Jerez]

sure you can, if you are making it in a newton call back, you can also do it after the newton update.
The callback are all made in the before Newton Update exits, so there will be not disycronizatiion.

[KingSnail]

How can I make a body in a callback?
I mean why would I want to do that?

A new player connects then I want to make a body

How would I integrate this in a callback?

Sorry confused

[Julio Jerez]

I say do not do it in the call back save the information, an ddo it after NewtonUpdate returns.

[ledahut]

I am not sure but maybe freeze update while creating you player should work (use a global boolean flag for example, or just stop thread, or just use some thread priority).
But I think what you want is priority to newton update thread, so my method won't work for you.

[almaris]

I ran into this issue myself, the fix was in the customplayercontroller ctor moving this line:
==
NewtonUserJointSetFeedbackCollectorCallback (m_joint, KinematicMotion);
==
to after the sensor shape creation

[KingSnail]

Thanks, that is a another solution to the fix, I fixed it this way also:

Code: Select all

auto temp_body = CreatePlayerBody(ZoneCollisionPtr->World, avatar_->Mass, location, size, avatar_->MaterialID, avatar_);
   std::shared_ptr<CustomPlayerController>cpc(new MyPlayerController(globalFrame, maxStairStepFactor, kinematicCushion, temp_body)); //Cant do make_shared because new operator overload in newton joint class
   auto castt = std::dynamic_pointer_cast<MyPlayerController>(cpc);
   castt->BODY = temp_body;