Resolved Job: NullReferenceException on Burst Compilation

I have a Job in Unity. Whenever I run it with Burst compilation enabled, it causes a NullReferenceException. Whenever I run it without Burst compilation, it's fine.



I commented out most of it in an attempt to identify what specifically causes it, but it happens every time the method returning the JobHandle is called (so

updateProbsHandle = ScheduleProbsUpdate(/*a, updateLocation, jobProbs*/);

). See all below:

Code (csharp):

1. public partial class CASystem : SystemBase
2. {
3.     static NativeQueue<UnsafeList<int>> updateLocations = new NativeQueue<UnsafeList<int>>(Allocator.Persistent);
4. ...
5.     protected override void OnUpdate()
6.     {
7.         JobHandle updateProbsHandle = new JobHandle();
8.         NativeHashMap<int, double> jobProbs = new NativeHashMap<int, double>(0, Allocator.Persistent);
9.         bool updatedProbs = false;
10.         if (updateLocations.IsCreated && updateLocations.TryDequeue(out var updateLocation))
11.         {
12.             if (!updateLocation.IsCreated)
13.             {
14.                 Debug.LogError("update not created?");
15.             }
16.                 updatedProbs = true;
17.             //for (int i = 0; i < updateLocation.Length; i++)
18.             //{
19.             //    jobProbs.TryAdd(updateLocation[i], 0);
20.             //}
21.             //var a = probsFull.GetValueArray(Allocator.TempJob).AsReadOnly();
22.             updateProbsHandle = ScheduleProbsUpdate(/*a, updateLocation, jobProbs*/);
23.         }
24.     }
25. ...
26.     public static JobHandle ScheduleProbsUpdate(/*NativeArray<UnsafeHashMap<int, double>>.ReadOnly inputs, UnsafeList<int> positions, NativeHashMap<int, double> outputs*/)
27.     {
28.         JobHandle jobhandle = new UpdateProbsJob
29.         {
30.             //inputs = inputs,
31.             //positions = positions,
32.             //output = outputs
33.         }.Schedule();
34.  
35.         return jobhandle;
36.     }
37.     [BurstCompile(CompileSynchronously = true)]
38.     public struct UpdateProbsJob : IJob
39.     {
40.         //[ReadOnly] public NativeArray<UnsafeHashMap<int, double>>.ReadOnly inputs;
41.         //[ReadOnly] public UnsafeList<int> positions;
42.  
43.         //public NativeHashMap<int, double> output;
44.  
45.         public void Execute()
46.         {
47.             //if (!positions.IsCreated)
48.             //{
49.             //    Debug.LogError("positions not created?");
50.             //}
51.             //if(!output.IsCreated)
52.             //{
53.             //    Debug.LogError("output not created?");
54.             //}
55.             //for (int i = 0; i < positions.Length; i++)
56.             //{
57.             //    int index = positions[i];
58.             //    double p = 0;
59.             //    for (int j = 0; j < inputs.Length; j++)
60.             //    {
61.             //        if(!inputs[j].IsCreated)
62.             //        {
63.             //            Debug.LogError("not created?");
64.             //        }
65.             //        else
66.             //        {
67.             //            if (inputs[j].TryGetValue(index, out double item))
68.             //            {
69.             //                if (item == -1)
70.             //                {
71.             //                    p = -1;
72.             //                    break;
73.             //                }
74.             //                else if (item > p && p >= 0)
75.             //                {
76.             //                    p = item;
77.             //                }
78.             //            }
79.             //        }
80.             //    }
81.             //    output[index] = p;
82.             //}
83.         }
84.     }

As can be seen everything inside the job that uses any inputs at all has been commented out (and nothing is actually passed to the job), but it still gives a NullReferenceException whenever Burst compilation is enabled (and of course it gives the same exception with everything un-commented out).

Any suggestions?

 

Try delete the BurstCache in your library folder. There's a rare bug currently where the cache can be corrupted and a job won't be recompiled.
The burst team is aware and there should be a fix next release.

 

Looks like that was it - it's starting up fine now. Thanks!