Question BurstCompile and ComponentDataFromEntity + execution from ForEach

Hi there,

Trying to figure something out with Entities 0.17 and can't wrap my head around it.

I'm trying to execute something with a CFE (and with some NativeHashMap too, not included in the example below), but I can't get it to work without using some weird workaround:

- #1 When trying to use BurstCompile on both the static class and static method I'm trying to burst (using CFE), I get a BC1063 that says the CFE is passed as a ref, although explicitely an in and a local variable rather than a member than the system

- #2 Trying without BurstCompile on the static class, I observe 2 different behaviours: the direct call to the method is NOT bursted, while calling the method from a fake Entities.ForEach (only one entity in the world has that component), it does burst it properly. Which is definitely a dirty workaround

Am I missing something that would allow to burst properly the direct call to that method in OnUpdate?

note: the reason for this method to exist is to execute calculations on some NativeHashMap structure that would be extremely inefficient to reproduce as an Entities.ForEach, hence trying to get a direct call working.

Code (CSharp):

1. [BurstCompile]  // #3
2.     public class ESTest : SystemBase
3.     {
4.         [BurstCompile] // #3
5.         protected override void OnUpdate()
6.         {
7.             var cfeTest = GetComponentDataFromEntity< ECCharacter >();
8.  
9.             StaticTest.TestMethod( in cfeTest ); // #2
10.  
11.             Entities.ForEach( ( in ECOneComponentInWorld someSingleEntity ) =>
12.                     {
13.                         StaticTest.TestMethod( in cfeTest ); // #2
14.                     } )
15.                     .WithName( "singleEntityTest" )
16.                     .Run();
17.         }
18.     }
19.  
20.     // [BurstCompile]    // #1
21.     public static class StaticTest
22.     {
23.         [BurstCompile]
24.         public static void TestMethod( in ComponentDataFromEntity< ECCharacter > cfeCharacter )
25.         {
26.             var a = 0;
27.             for ( var i = 0; i < 10000000; i++ )
28.             {
29.                 a++;
30.             }
31.         }
32.     }
33.  
34.     // #1 compile error if BurstCompile on class & method -->  Burst error BC1063: Unsupported parameter `ref Unity.Entities.ComponentDataFromEntity`1<TPC.ECCharacter>
35.     // #2 with only method BurstCompile, executing TestMethod in a dummy ForEach loop runs as Bursted, while the direct call from OnUpdate is NOT Bursted
36.     // #3 (as expected) no effect from BurstCompile on the system (no compile error, no change on execution)

 

Because direct call follows FunctionPointer rules, and you can’t pass CDFE directly as an argument in that case by design. Calling method from the bursted job works differently and makes all calls from that code - burst compiled.
https://docs.unity3d.com/Packages/com.unity.burst@1.8/manual/csharp-function-pointers.html

And CDFE is exactly native container

 

I see, thanks!

Is there in that case any other choice for methods using NativeContainer to be called from anywhere else than a ForEach? A Job type that requires a minimal amount of boilerplate code maybe?