Burst 1.5.0-pre.5 - function pointers not working

Hello @xoofx,

in the latest preview .5 the function pointers stopped working. Of course the BurstCompile attribute is both on class and method and worked just fine in previous previews.

Thanks

 

Hi @sheredom

yeah, I am using CompileFunctionPointer in a usual way, see below. I restarted the editor.
Like I mentioned this worked fine in all previous 1.5 Burst previews. The problem occurs in two separate projects in 2020.2.5f1 and 2021.1.0b9.

And regarding the direct calls, these never worked for me in all 1.5 previews when called from non-MainThread, which is essential for me. I will make a separate bug report for this though.

Code (CSharp):

1. [BurstCompile]
2. public unsafe  class DefKitPositionBasedDynamicsSystem : MonoBehaviour
3. {
4.  
5.     unsafe delegate void Integrate(float dt, int pointsCount, Vector4* positions, Vector4* predictedPositions, Vector4* velocities, float* invMasses);
6.  
7.     Integrate cachableDelegate;
8.  
9.     [BurstCompile]
10.     [AOT.MonoPInvokeCallback(typeof(Integrate))]
11.     unsafe static void IntegrateBurst(float dt, int pointsCount, Vector4* positions, Vector4* predictedPositions, Vector4* velocities, float* invMasses)
12.     {
13.         float dtInv = 1.0f / dt;
14.         for (int i = 0; i < pointsCount; i++)
15.         {
16.             if (invMasses[i] != 0.0)
17.             {
18.                 velocities[i] = (predictedPositions[i] - positions[i]) * dtInv;
19.                 positions[i] = predictedPositions[i];
20.  
21.             }
22.         }
23.     }
24.  
25.  
26.  
27.     // Use this for initialization
28.     void Start()
29.     {
30.  
31.         this.cachableDelegate = BurstCompiler.CompileFunctionPointer<Integrate>(IntegrateBurst).Invoke;
32.  
33.     }
34.  
35.     void Update()
36.     {
37.         cachableDelegate(dt, body.count, body.positionsNativePtr, body.predictedPositionsNativePtr, body.velocitiesNativePtr, body.massesInvNativePtr);
38.     }
39. }

 

Thanks @sheredom for checking this. It worked indeed but so did the code I posted in the first place

However, I kept digging and it turned out that if you add ANY, even unrelated, [DllImport] on top you will get the Burst Atrribute missing error:

Code (CSharp):

1. using UnityEngine;
2. using Unity.Burst;
3. using System.Runtime.InteropServices;
4. [BurstCompile]
5. public unsafe class NewBehaviourScript : MonoBehaviour
6. {
7. #region ADDED
8.  
9.         [DllImport("DefKit")]
10.         public unsafe static extern void PredictPositions_native(float dt, float damping, int pointsCount, Vector4* positions, Vector4* predictedPositions, Vector4* velocities, Vector4* forces, float* invMasses, Vector4[] gravity);
11.  
12. #endregion
13.  
14.     unsafe delegate void Integrate(float dt, int pointsCount, Vector4* positions, Vector4* predictedPositions, Vector4* velocities, float* invMasses);
15.     Integrate cachableDelegate;
16.     [BurstCompile]
17.     [AOT.MonoPInvokeCallback(typeof(Integrate))]
18.     static void IntegrateBurst(float dt, int pointsCount, Vector4* positions, Vector4* predictedPositions, Vector4* velocities, float* invMasses)
19.     {
20.         float dtInv = 1.0f / dt;
21.         for (int i = 0; i < pointsCount; i++)
22.         {
23.             if (invMasses[i] != 0.0)
24.             {
25.                 velocities[i] = (predictedPositions[i] - positions[i]) * dtInv;
26.                 positions[i] = predictedPositions[i];
27.             }
28.         }
29.     }
30.     // Use this for initialization
31.     void Start()
32.     {
33.         IntegrateBurst(42, 0, null, null, null, null);
34.         this.cachableDelegate = BurstCompiler.CompileFunctionPointer<Integrate>(IntegrateBurst).Invoke;
35.     }
36.     void Update()
37.     {
38.         cachableDelegate(42, 0, null, null, null, null);
39.     }
40. }
41.  

 

Thanks @sheredom!

it would be great to have a possibility to launch as well as schedule "ParallelFor" Bursted Jobs from non-MainThread. I mean to have something like a raw, bare-bone JobSystem without any safety-systems, which could be used on it's own, separately from Unity's MainThread JobSystem. Maybe it could share the same task queue with the Main JobSystem for performance reasons though. I know that I could use Task Parallel Library, but having a single code-base for both MainThread and non-MainThread cases would be great. Here is my concrete application for such appraoch https://forum.unity.com/threads/scheduling-jobs-from-not-a-mainthread.569866/#post-4861184
Cheers

 

Thanks @sheredom

 

Hi @sheredom, thanks a lot for fixing this in 1.5! It is working fine now.

 

Hi @sheredom, no problem, always happy to help. Soo... now that the Burst 1.5 is out any plans to support scheduling "unsafe" jobs from non-main thread? The function pointers are nice and performant but I still need to maintain the same code twice: Jobs for non-hardware applications and equivalent static functions for hardware ticked usage.

Thanks

 

Right, thanks @Yury-Habets