[MT][browser] `TaskIDFromExternalContextTest` fails, Task has a negative ID

[ilonatommy]

Failing after enabling all MT library tests (https://github.com/dotnet/runtime/pull/91536).

[FAIL] System.Threading.Tasks.Tests.ParallelForTests.TaskIDFromExternalContextTest
 Task within Parallel.For must have non-negative Id
 Expected: False
 Actual:   True
    at System.Threading.Tasks.Tests.ParallelForTests.<>c.<TaskIDFromExternalContextTest>b__4_1(Int32 i)
    at System.Threading.Tasks.Parallel.<>c__DisplayClass19_0`2[[System.Object, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.Int32, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].<ForWorker>b__1(RangeWorker& currentWorker, Int64 timeout, Boolean& replicationDelegateYieldedBeforeCompletion)
 --- End of stack trace from previous location ---
    at System.Threading.Tasks.Parallel.<>c__DisplayClass19_0`2[[System.Object, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.Int32, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].<ForWorker>b__1(RangeWorker& currentWorker, Int64 timeout, Boolean& replicationDelegateYieldedBeforeCompletion)
    at System.Threading.Tasks.TaskReplicator.Run[RangeWorker](ReplicatableUserAction`1 action, ParallelOptions options, Boolean stopOnFirstFailure)
    at System.Threading.Tasks.Parallel.ForWorker[Object,Int32](Int32 fromInclusive, Int32 toExclusive, ParallelOptions parallelOptions, Action`1 body, Action`2 bodyWithState, Func`4 bodyWithLocal, Func`1 localInit, Action`1 localFinally)
   at System.Threading.Tasks.Parallel.For(Int32 fromInclusive, Int32 toExclusive, Action`1 body)
    at System.Threading.Tasks.Tests.ParallelForTests.TaskIDFromExternalContextTest()
    at System.Reflection.MethodBaseInvoker.InterpretedInvoke_Method(Object obj, IntPtr* args)
    at System.Reflection.MethodBaseInvoker.InvokeWithNoArgs(Object obj, BindingFlags invokeAttr)

Error Blob

{
  "ErrorMessage": "[FAIL] System.Threading.Tasks.Tests.ParallelForTests.TaskIDFromExternalContextTest",
  "ErrorPattern": "",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=523904

Known issue validation

Build: :mag_right: https://dev.azure.com/dnceng-public/public/_build/results?buildId=523904 Error message validated: [FAIL] System.Threading.Tasks.Tests.ParallelForTests.TaskIDFromExternalContextTest Result validation: :white_check_mark: Known issue matched with the provided build. Validation performed at: 1/11/2024 6:33:01 PM UTC

Report

Build	Definition	Test	Pull Request
533238	dotnet/runtime	WasmTestOnBrowser-System.Threading.Tasks.Parallel.Tests.WorkItemExecution	dotnet/runtime#96841
523904	dotnet/runtime	WasmTestOnBrowser-System.Threading.Tasks.Parallel.Tests.WorkItemExecution	dotnet/runtime#96618

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
0	1	2

[ghost]

Tagging subscribers to 'arch-wasm': @lewing See info in area-owners.md if you want to be subscribed.

Issue Details

---

Failing after enabling all MT library tests (https://github.com/dotnet/runtime/pull/91536).

[FAIL] System.Threading.Tasks.Tests.ParallelForTests.TaskIDFromExternalContextTest
 Task within Parallel.For must have non-negative Id
 Expected: False
 Actual:   True
    at System.Threading.Tasks.Tests.ParallelForTests.<>c.<TaskIDFromExternalContextTest>b__4_1(Int32 i)
    at System.Threading.Tasks.Parallel.<>c__DisplayClass19_0`2[[System.Object, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.Int32, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].<ForWorker>b__1(RangeWorker& currentWorker, Int64 timeout, Boolean& replicationDelegateYieldedBeforeCompletion)
 --- End of stack trace from previous location ---
    at System.Threading.Tasks.Parallel.<>c__DisplayClass19_0`2[[System.Object, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.Int32, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].<ForWorker>b__1(RangeWorker& currentWorker, Int64 timeout, Boolean& replicationDelegateYieldedBeforeCompletion)
    at System.Threading.Tasks.TaskReplicator.Run[RangeWorker](ReplicatableUserAction`1 action, ParallelOptions options, Boolean stopOnFirstFailure)
    at System.Threading.Tasks.Parallel.ForWorker[Object,Int32](Int32 fromInclusive, Int32 toExclusive, ParallelOptions parallelOptions, Action`1 body, Action`2 bodyWithState, Func`4 bodyWithLocal, Func`1 localInit, Action`1 localFinally)
   at System.Threading.Tasks.Parallel.For(Int32 fromInclusive, Int32 toExclusive, Action`1 body)
    at System.Threading.Tasks.Tests.ParallelForTests.TaskIDFromExternalContextTest()
    at System.Reflection.MethodBaseInvoker.InterpretedInvoke_Method(Object obj, IntPtr* args)
    at System.Reflection.MethodBaseInvoker.InvokeWithNoArgs(Object obj, BindingFlags invokeAttr)

Author:	ilonatommy
Assignees:	-
Labels:	arch-wasm, disabled-test, area-Build-mono, area-VM-threading-mono
Milestone:	-

[pavelsavara]

@lambdageek said "maybe we didn't implement Volatile.Read for MT? or maybe the jiterp doesn't implement it?"

cc @kg

[lambdageek]

I'm probably wrong about that 😄

Volatile.Read turns into an indirect load from a volatile local. which turns into interp_emit_memory_barrier which turns into mono_memory_barrier () at runtime.

and that is... __sync_synchronize () which is a compiler intrinsic. According to https://github.com/WebAssembly/tool-conventions/issues/59 I guess that turns into an atomic.fence instruction

[kg]

I don't remember ever implementing atomics in the jiterpreter period

[lambdageek]

yea it looks like MINT_MONO_MEMORY_BARRIER is just an unsupported opcode for the jiterp. so that doesn't enter into it

[pavelsavara]

This is how to run the test

dotnet build /p:TargetOS=browser /p:TargetArchitecture=wasm /p:Configuration=Debug /t:Test /p:Scenario=WasmTestOnBrowser /p:MonoWasmBuildVariant=multithread /p:WasmEnableThreads=true src\libraries\System.Threading.Tasks\tests\System.Threading.Tasks.Tests.csproj /p:WasmTestAppArgs="-method System.Threading.Tasks.Tests.ParallelForTests.TaskIDFromExternalContextTest"

It doesn't reproduce for me when I run it few times. Perhaps it needs to fail as part of the whole suite.

[pavelsavara]

Another Log

[16:58:55] info: [2024-01-11T16:58:55.670Z] [FAIL] System.Threading.Tasks.Tests.ParallelForTests.TaskIDFromExternalContextTest
[16:58:55] info: Task within Parallel.For must have non-negative Id
[16:58:55] info:    at System.Threading.Tasks.Tests.ParallelForTests.<>c.<TaskIDFromExternalContextTest>b__20_1(Int32 i)
[16:58:55] info:    at System.Threading.Tasks.Parallel.<>c__DisplayClass19_0`2[[System.Object, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.Int32, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].<ForWorker>b__1(RangeWorker& currentWorker, Int64 timeout, Boolean& replicationDelegateYieldedBeforeCompletion)
[16:58:55] info: --- End of stack trace from previous location ---
[16:58:55] info:    at System.Threading.Tasks.Parallel.<>c__DisplayClass19_0`2[[System.Object, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.Int32, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].<ForWorker>b__1(RangeWorker& currentWorker, Int64 timeout, Boolean& replicationDelegateYieldedBeforeCompletion)
[16:58:55] info:    at System.Threading.Tasks.TaskReplicator.Run[RangeWorker](ReplicatableUserAction`1 action, ParallelOptions options, Boolean stopOnFirstFailure)
[16:58:55] info:    at System.Threading.Tasks.Parallel.ForWorker[Object,Int32](Int32 fromInclusive, Int32 toExclusive, ParallelOptions parallelOptions, Action`1 body, Action`2 bodyWithState, Func`4 bodyWithLocal, Func`1 localInit, Action`1 localFinally)
[16:58:55] info:    at System.Threading.Tasks.Parallel.For(Int32 fromInclusive, Int32 toExclusive, Action`1 body)
[16:58:55] info:    at System.Threading.Tasks.Tests.ParallelForTests.TaskIDFromExternalContextTest()
[16:58:55] info:    at System.Reflection.MethodBaseInvoker.InterpretedInvoke_Method(Object obj, IntPtr* args)
[16:58:55] info:    at System.Reflection.MethodBaseInvoker.InvokeWithNoArgs(Object obj, BindingFlags invokeAttr)