Test AsyncLocal diagnostics feasibility, again.

src/Compiler/Facilities/AsyncMemoize.fs

@@ -463,6 +463,8 @@ type internal AsyncMemoize<'TKey, 'TVersion, 'TValue when 'TKey: equality and 'T
 
     member this.Get'(key, computation) =
 
+        failwith "AsyncMemoize"
+
         let wrappedKey =
             { new ICacheKey<_, _> with
                 member _.GetKey() = key
@@ -474,6 +476,8 @@ type internal AsyncMemoize<'TKey, 'TVersion, 'TValue when 'TKey: equality and 'T
 
     member _.Get(key: ICacheKey<_, _>, computation) =
 
+        failwith "AsyncMemoize"
+
         let key =
             {
                 Label = key.GetLabel()

src/Compiler/Facilities/BuildGraph.fs

@@ -15,16 +15,21 @@ type NodeCode<'T> = Node of Async<'T>
 
 let wrapThreadStaticInfo computation =
     async {
-        let diagnosticsLogger = DiagnosticsThreadStatics.DiagnosticsLogger
+        let diagnosticsLogger = DiagnosticsThreadStatics.DiagnosticsLoggerNodeCode
         let phase = DiagnosticsThreadStatics.BuildPhase
 
         try
             return! computation
         finally
-            DiagnosticsThreadStatics.DiagnosticsLogger <- diagnosticsLogger
+            DiagnosticsThreadStatics.DiagnosticsLoggerNodeCode <- diagnosticsLogger
             DiagnosticsThreadStatics.BuildPhase <- phase
     }
 
+
+let reset() =
+    DiagnosticsThreadStatics.DiagnosticsLoggerNodeCode <- AssertFalseDiagnosticsLogger
+    DiagnosticsThreadStatics.BuildPhase <- BuildPhase.DefaultPhase
+
 let unwrapNode (Node(computation)) = computation
 
 type Async<'T> with
@@ -98,7 +103,7 @@ type NodeCodeBuilder() =
     member _.Using(value: CompilationGlobalsScope, binder: CompilationGlobalsScope -> NodeCode<'U>) =
         Node(
             async {
-                DiagnosticsThreadStatics.DiagnosticsLogger <- value.DiagnosticsLogger
+                DiagnosticsThreadStatics.DiagnosticsLoggerNodeCode <- value.DiagnosticsLogger
                 DiagnosticsThreadStatics.BuildPhase <- value.BuildPhase
 
                 try
@@ -125,21 +130,21 @@ type NodeCode private () =
     static let cancellationToken = Node(wrapThreadStaticInfo Async.CancellationToken)
 
     static member RunImmediate(computation: NodeCode<'T>, ct: CancellationToken) =
-        let diagnosticsLogger = DiagnosticsThreadStatics.DiagnosticsLogger
+        let diagnosticsLogger = DiagnosticsThreadStatics.DiagnosticsLoggerNodeCode
         let phase = DiagnosticsThreadStatics.BuildPhase
 
         try
             try
                 let work =
                     async {
-                        DiagnosticsThreadStatics.DiagnosticsLogger <- diagnosticsLogger
+                        DiagnosticsThreadStatics.DiagnosticsLoggerNodeCode <- diagnosticsLogger
                         DiagnosticsThreadStatics.BuildPhase <- phase
                         return! computation |> Async.AwaitNodeCode
                     }
 
                 Async.StartImmediateAsTask(work, cancellationToken = ct).Result
             finally
-                DiagnosticsThreadStatics.DiagnosticsLogger <- diagnosticsLogger
+                DiagnosticsThreadStatics.DiagnosticsLoggerNodeCode <- diagnosticsLogger
                 DiagnosticsThreadStatics.BuildPhase <- phase
         with :? AggregateException as ex when ex.InnerExceptions.Count = 1 ->
             raise (ex.InnerExceptions[0])
@@ -148,20 +153,20 @@ type NodeCode private () =
         NodeCode.RunImmediate(computation, CancellationToken.None)
 
     static member StartAsTask_ForTesting(computation: NodeCode<'T>, ?ct: CancellationToken) =
-        let diagnosticsLogger = DiagnosticsThreadStatics.DiagnosticsLogger
+        let diagnosticsLogger = DiagnosticsThreadStatics.DiagnosticsLoggerNodeCode
         let phase = DiagnosticsThreadStatics.BuildPhase
 
         try
             let work =
                 async {
-                    DiagnosticsThreadStatics.DiagnosticsLogger <- diagnosticsLogger
+                    DiagnosticsThreadStatics.DiagnosticsLoggerNodeCode <- diagnosticsLogger
                     DiagnosticsThreadStatics.BuildPhase <- phase
                     return! computation |> Async.AwaitNodeCode
                 }
 
             Async.StartAsTask(work, cancellationToken = defaultArg ct CancellationToken.None)
         finally
-            DiagnosticsThreadStatics.DiagnosticsLogger <- diagnosticsLogger
+            DiagnosticsThreadStatics.DiagnosticsLoggerNodeCode <- diagnosticsLogger
             DiagnosticsThreadStatics.BuildPhase <- phase
 
     static member CancellationToken = cancellationToken
@@ -205,9 +210,12 @@ type NodeCode private () =
                 let logger = concurrentLogging.GetLoggerForTask($"NodeCode.Parallel {i}")
 
                 async {
-                    DiagnosticsThreadStatics.DiagnosticsLogger <- logger
-                    DiagnosticsThreadStatics.BuildPhase <- phase
-                    return! unwrapNode computation
+                    try
+                        DiagnosticsThreadStatics.DiagnosticsLogger <- logger
+                        DiagnosticsThreadStatics.BuildPhase <- phase
+                        return! unwrapNode computation
+                    finally
+                        reset()
                 }
 
             return!
@@ -256,6 +264,7 @@ type GraphNode<'T> private (computation: NodeCode<'T>, cachedResult: ValueOption
             cachedResultNode
         else
             node {
+                use _ = new CompilationGlobalsScope()
                 Interlocked.Increment(&requestCount) |> ignore
 
                 try
@@ -284,13 +293,13 @@ type GraphNode<'T> private (computation: NodeCode<'T>, cachedResult: ValueOption
                         | ValueSome value -> return value
                         | _ ->
                             let tcs = TaskCompletionSource<'T>()
-                            let (Node(p)) = computation
 
                             Async.StartWithContinuations(
-                                async {
+                                node {
                                     Thread.CurrentThread.CurrentUICulture <- GraphNode.culture
-                                    return! p
-                                },
+                                    reset()
+                                    return! computation 
+                                } |> Async.AwaitNodeCode,
                                 (fun res ->
                                     cachedResult <- ValueSome res
                                     cachedResultNode <- node.Return res

src/Compiler/Facilities/DiagnosticsLogger.fs

@@ -375,6 +375,25 @@ type CapturingDiagnosticsLogger(nm, ?eagerFormat) =
         let errors = diagnostics.ToArray()
         errors |> Array.iter diagnosticsLogger.DiagnosticSink
 
+let currentDiagnosticsLogger = AsyncLocal<DiagnosticsLogger voption>()
+
+let checkIfSame threadStatic =
+    match currentDiagnosticsLogger.Value with
+
+    // Big hurdle in testing this is the fact that threadstatics leak from one unrelated test to another.
+    // At least that's what happens in VS test runner. In effect, at the beginning of some computation when we expect
+    // to see uninitialized threadstatic, we get some value that stayed alive from another test function.
+    // Especially FinalizeTypeCheckTask shows up here a lot.
+    // That's why we have to disregard the threadstatics at the beggining of each execution context,
+    // up to the moment of proper initialization (the first call of UseDiagnosticsLogger usually).
+    | ValueNone -> threadStatic
+
+    | ValueSome asyncLocal ->
+        match asyncLocal, threadStatic with
+        | a, t when a = t -> t // Good.
+        | _ when threadStatic = AssertFalseDiagnosticsLogger -> threadStatic // AsyncLocal is always good on thread switches. ThreadStatic needs to catch up.
+        | _ -> failwith $"AsyncLocal does not match ThreadStatic. a: {asyncLocal.DebugDisplay()} t: {threadStatic.DebugDisplay()}"
+
 /// Type holds thread-static globals for use by the compiler.
 type internal DiagnosticsThreadStatics =
     [<ThreadStatic; DefaultValue>]
@@ -393,6 +412,15 @@ type internal DiagnosticsThreadStatics =
         and set v = DiagnosticsThreadStatics.buildPhase <- v
 
     static member DiagnosticsLogger
+        with get () =
+            match box DiagnosticsThreadStatics.diagnosticsLogger with
+            | Null -> AssertFalseDiagnosticsLogger
+            | _ -> checkIfSame DiagnosticsThreadStatics.diagnosticsLogger
+        and set v =
+            currentDiagnosticsLogger.Value <- ValueSome v
+            DiagnosticsThreadStatics.diagnosticsLogger <- v
+
+    static member DiagnosticsLoggerNodeCode
         with get () =
             match box DiagnosticsThreadStatics.diagnosticsLogger with
             | Null -> AssertFalseDiagnosticsLogger
@@ -533,6 +561,8 @@ type CompilationGlobalsScope(diagnosticsLogger: DiagnosticsLogger, buildPhase: B
     let unwindEL = UseDiagnosticsLogger diagnosticsLogger
     let unwindBP = UseBuildPhase buildPhase
 
+    new() = new CompilationGlobalsScope(DiagnosticsThreadStatics.DiagnosticsLogger, DiagnosticsThreadStatics.BuildPhase)
+
     member _.DiagnosticsLogger = diagnosticsLogger
     member _.BuildPhase = buildPhase
 

src/Compiler/Facilities/DiagnosticsLogger.fsi

@@ -236,6 +236,8 @@ type DiagnosticsThreadStatics =
 
     static member DiagnosticsLogger: DiagnosticsLogger with get, set
 
+    static member DiagnosticsLoggerNodeCode: DiagnosticsLogger with get, set
+
 [<AutoOpen>]
 module DiagnosticsLoggerExtensions =
 
@@ -458,6 +460,8 @@ type StackGuard =
 type CompilationGlobalsScope =
     new: diagnosticsLogger: DiagnosticsLogger * buildPhase: BuildPhase -> CompilationGlobalsScope
 
+    new: unit -> CompilationGlobalsScope
+
     interface IDisposable
 
     member DiagnosticsLogger: DiagnosticsLogger

src/Compiler/Service/IncrementalBuild.fs

@@ -375,11 +375,13 @@ type BoundModel private (
             return diags
         } |> GraphNode
 
-    let startComputingFullTypeCheck =
-        node {
-            let! _ = tcInfoExtras.GetOrComputeValue()
-            return! diagnostics.GetOrComputeValue()
-        }
+    //let startComputingFullTypeCheck() =
+    //    async {
+    //        use _ = InitCompilationGlobalsScope()
+    //        do! tcInfoExtras.GetOrComputeValue() |> Async.AwaitNodeCode |> Async.Ignore
+    //        do! diagnostics.GetOrComputeValue() |> Async.AwaitNodeCode |> Async.Ignore
+    //    }
+    //    |> Async.Start
 
     let tcInfo, tcInfoExtras =
         match tcStateOpt with
@@ -391,7 +393,7 @@ type BoundModel private (
                 GraphNode.FromResult tcInfo, tcInfoExtras
             | _ ->
                 // start computing extras, so that typeCheckNode can be GC'd quickly 
-                startComputingFullTypeCheck |> Async.AwaitNodeCode |> Async.Catch |> Async.Ignore |> Async.Start
+                // startComputingFullTypeCheck()
                 getTcInfo typeCheckNode, tcInfoExtras
 
     member val Diagnostics = diagnostics
@@ -735,7 +737,7 @@ module IncrementalBuilderHelpers =
       }
 
     /// Finish up the typechecking to produce outputs for the rest of the compilation process
-    let FinalizeTypeCheckTask (tcConfig: TcConfig) tcGlobals partialCheck assemblyName outfile (boundModels: GraphNode<BoundModel> seq) =
+    let FinalizeTypeCheckTask (tcConfig: TcConfig) tcGlobals _partialCheck assemblyName outfile (boundModels: GraphNode<BoundModel> seq) =
       node {
         let diagnosticsLogger = CompilationDiagnosticLogger("FinalizeTypeCheckTask", tcConfig.diagnosticsOptions)
         use _ = new CompilationGlobalsScope(diagnosticsLogger, BuildPhase.TypeCheck)
@@ -751,13 +753,13 @@ module IncrementalBuilderHelpers =
         let! latestImplFiles =
             computedBoundModels
             |> Seq.map (fun boundModel -> node {
-                    if partialCheck then
-                        return None
-                    else
+                    //if partialCheck then
+                    //    return None
+                    //else
                         let! tcInfoExtras = boundModel.GetOrComputeTcInfoExtras()
                         return tcInfoExtras.latestImplFile
                 })
-            |> NodeCode.Parallel
+            |> NodeCode.Sequential
 
         let results = [
             for tcInfo, latestImplFile in Seq.zip tcInfos latestImplFiles ->
@@ -826,7 +828,7 @@ module IncrementalBuilderHelpers =
         let! partialDiagnostics =
             computedBoundModels
             |> Seq.map (fun m -> m.Diagnostics.GetOrComputeValue())
-            |> NodeCode.Parallel
+            |> NodeCode.Sequential
         let diagnostics = [
             diagnosticsLogger.GetDiagnostics()
             yield! partialDiagnostics |> Seq.rev