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SystemBase.GetBuffer is not declared as a [ReadOnly] when used only for reading in Entities.ForEach lambda expression

Package: Entity Component System (ECS)


How to reproduce:
1. Open the attached project (
2. Enter Play Mode

Expected result: no errors are logged in the Console window when calling SystemBase.GetBuffer
Actual result: an error is spammed in the Console: 'InvalidOperationException: <>c__DisplayClass_OnUpdate_LambdaJob0.JobData._BufferFromEntity_Buffer_0 is not declared [ReadOnly] in a IJobParallelFor job. The container does not support parallel writing. Please use a more suitable container type.'

Reproducible with: 0.13.0-preview.24 (2020.1.4f1), 0.14.0-preview.18 (2020.2.0a21)
Could not test with: 0.0.12-preview.24 (2018.4.26f1), 0.11.1-preview.4 (2019.4.8f1) ('test.cs' Script is not compatible)

Passing the buffer as one of the lambda function parameters

  1. Resolution Note:

    This would be very difficult to do automatically from a codegen standpoint (we would have to examine every possible code path that could be executed and check to see if any of them write to the DynamicBuffer). We are however exploring adding a separate API for getting a read-only buffer.

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