AsyncMemoize: do not cancel and restart jobs that are being requested

docs/release-notes/.FSharp.Compiler.Service/8.0.300.md

@@ -13,4 +13,5 @@
 
 * `implicitCtorSynPats` in `SynTypeDefnSimpleRepr.General` is now `SynPat option` instead of `SynSimplePats option`. ([PR #16425](https://github.com/dotnet/fsharp/pull/16425))
 * `SyntaxVisitorBase<'T>.VisitSimplePats` now takes `SynPat` instead of `SynSimplePat list`. ([PR #16425](https://github.com/dotnet/fsharp/pull/16425))
-* Reduce allocations in compiler checking via `ValueOption` usage ([PR #16323](https://github.com/dotnet/fsharp/pull/16323))
+* Reduce allocations in compiler checking via `ValueOption` usage ([PR #16323](https://github.com/dotnet/fsharp/pull/16323))
+* Rework cancellation in `AsyncMemoize`. ([PR #16547](https://github.com/dotnet/fsharp/pull/16547))

src/Compiler/Facilities/BuildGraph.fs

@@ -17,14 +17,12 @@ let wrapThreadStaticInfo computation =
     async {
         let diagnosticsLogger = DiagnosticsThreadStatics.DiagnosticsLogger
         let phase = DiagnosticsThreadStatics.BuildPhase
-        let ct = Cancellable.Token
 
         try
             return! computation
         finally
             DiagnosticsThreadStatics.DiagnosticsLogger <- diagnosticsLogger
             DiagnosticsThreadStatics.BuildPhase <- phase
-            Cancellable.Token <- ct
     }
 
 type Async<'T> with
@@ -127,48 +125,28 @@ type NodeCode private () =
     static member RunImmediate(computation: NodeCode<'T>, ct: CancellationToken) =
         let diagnosticsLogger = DiagnosticsThreadStatics.DiagnosticsLogger
         let phase = DiagnosticsThreadStatics.BuildPhase
-        let ct2 = Cancellable.Token
 
         try
             try
                 let work =
                     async {
                         DiagnosticsThreadStatics.DiagnosticsLogger <- diagnosticsLogger
                         DiagnosticsThreadStatics.BuildPhase <- phase
-                        Cancellable.Token <- ct2
                         return! computation |> Async.AwaitNodeCode
                     }
 
                 Async.StartImmediateAsTask(work, cancellationToken = ct).Result
             finally
                 DiagnosticsThreadStatics.DiagnosticsLogger <- diagnosticsLogger
                 DiagnosticsThreadStatics.BuildPhase <- phase
-                Cancellable.Token <- ct2
         with :? AggregateException as ex when ex.InnerExceptions.Count = 1 ->
             raise (ex.InnerExceptions[0])
 
     static member RunImmediateWithoutCancellation(computation: NodeCode<'T>) =
         NodeCode.RunImmediate(computation, CancellationToken.None)
 
     static member StartAsTask_ForTesting(computation: NodeCode<'T>, ?ct: CancellationToken) =
-        let diagnosticsLogger = DiagnosticsThreadStatics.DiagnosticsLogger
-        let phase = DiagnosticsThreadStatics.BuildPhase
-        let ct2 = Cancellable.Token
-
-        try
-            let work =
-                async {
-                    DiagnosticsThreadStatics.DiagnosticsLogger <- diagnosticsLogger
-                    DiagnosticsThreadStatics.BuildPhase <- phase
-                    Cancellable.Token <- ct2
-                    return! computation |> Async.AwaitNodeCode
-                }
-
-            Async.StartAsTask(work, cancellationToken = defaultArg ct CancellationToken.None)
-        finally
-            DiagnosticsThreadStatics.DiagnosticsLogger <- diagnosticsLogger
-            DiagnosticsThreadStatics.BuildPhase <- phase
-            Cancellable.Token <- ct2
+        Async.StartAsTask(computation |> Async.AwaitNodeCode, ?cancellationToken = ct)
 
     static member CancellationToken = cancellationToken
 

src/Compiler/Interactive/fsi.fs

@@ -4089,7 +4089,6 @@ type FsiInteractionProcessor
             ?cancellationToken: CancellationToken
         ) =
         let cancellationToken = defaultArg cancellationToken CancellationToken.None
-        use _ = Cancellable.UsingToken(cancellationToken)
 
         if tokenizer.LexBuffer.IsPastEndOfStream then
             let stepStatus =
@@ -4218,7 +4217,6 @@ type FsiInteractionProcessor
 
     member _.EvalInteraction(ctok, sourceText, scriptFileName, diagnosticsLogger, ?cancellationToken) =
         let cancellationToken = defaultArg cancellationToken CancellationToken.None
-        use _ = Cancellable.UsingToken(cancellationToken)
         use _ = UseBuildPhase BuildPhase.Interactive
         use _ = UseDiagnosticsLogger diagnosticsLogger
         use _scope = SetCurrentUICultureForThread fsiOptions.FsiLCID
@@ -4895,7 +4893,6 @@ type FsiEvaluationSession
             SpawnInteractiveServer(fsi, fsiOptions, fsiConsoleOutput)
 
         use _ = UseBuildPhase BuildPhase.Interactive
-        use _ = Cancellable.UsingToken(CancellationToken.None)
 
         if fsiOptions.Interact then
             // page in the type check env

src/Compiler/Service/BackgroundCompiler.fs

@@ -574,9 +574,6 @@ type internal BackgroundCompiler
                         Activity.Tags.cache, cache.ToString()
                     |]
 
-            let! ct = Async.CancellationToken
-            use _ = Cancellable.UsingToken(ct)
-
             if cache then
                 let hash = sourceText.GetHashCode() |> int64
 
@@ -629,9 +626,6 @@ type internal BackgroundCompiler
                     "BackgroundCompiler.GetBackgroundParseResultsForFileInProject"
                     [| Activity.Tags.fileName, fileName; Activity.Tags.userOpName, userOpName |]
 
-            let! ct = NodeCode.CancellationToken
-            use _ = Cancellable.UsingToken(ct)
-
             let! builderOpt, creationDiags = getOrCreateBuilder (options, userOpName)
 
             match builderOpt with
@@ -783,9 +777,6 @@ type internal BackgroundCompiler
                         Activity.Tags.userOpName, userOpName
                     |]
 
-            let! ct = NodeCode.CancellationToken
-            use _ = Cancellable.UsingToken(ct)
-
             let! cachedResults =
                 node {
                     let! builderOpt, creationDiags = getAnyBuilder (options, userOpName)
@@ -846,9 +837,6 @@ type internal BackgroundCompiler
                         Activity.Tags.userOpName, userOpName
                     |]
 
-            let! ct = NodeCode.CancellationToken
-            use _ = Cancellable.UsingToken(ct)
-
             let! builderOpt, creationDiags = getOrCreateBuilder (options, userOpName)
 
             match builderOpt with
@@ -897,9 +885,6 @@ type internal BackgroundCompiler
                         Activity.Tags.userOpName, userOpName
                     |]
 
-            let! ct = NodeCode.CancellationToken
-            use _ = Cancellable.UsingToken(ct)
-
             let! builderOpt, creationDiags = getOrCreateBuilder (options, userOpName)
 
             match builderOpt with
@@ -969,9 +954,6 @@ type internal BackgroundCompiler
                         Activity.Tags.userOpName, userOpName
                     |]
 
-            let! ct = NodeCode.CancellationToken
-            use _ = Cancellable.UsingToken(ct)
-
             let! builderOpt, _ = getOrCreateBuilder (options, userOpName)
 
             match builderOpt with
@@ -991,9 +973,6 @@ type internal BackgroundCompiler
                         Activity.Tags.userOpName, userOpName
                     |]
 
-            let! ct = NodeCode.CancellationToken
-            use _ = Cancellable.UsingToken(ct)
-
             let! builderOpt, creationDiags = getOrCreateBuilder (options, userOpName)
 
             match builderOpt with
@@ -1134,9 +1113,6 @@ type internal BackgroundCompiler
                         Activity.Tags.userOpName, userOpName
                     |]
 
-            let! ct = NodeCode.CancellationToken
-            use _ = Cancellable.UsingToken(ct)
-
             let! builderOpt, _ = getOrCreateBuilder (options, userOpName)
 
             match builderOpt with
@@ -1185,8 +1161,6 @@ type internal BackgroundCompiler
     /// Parse and typecheck the whole project (the implementation, called recursively as project graph is evaluated)
     member private _.ParseAndCheckProjectImpl(options, userOpName) =
         node {
-            let! ct = NodeCode.CancellationToken
-            use _ = Cancellable.UsingToken(ct)
 
             let! builderOpt, creationDiags = getOrCreateBuilder (options, userOpName)
 
@@ -1327,9 +1301,6 @@ type internal BackgroundCompiler
             // Do we assume .NET Framework references for scripts?
             let assumeDotNetFramework = defaultArg assumeDotNetFramework true
 
-            let! ct = Cancellable.token ()
-            use _ = Cancellable.UsingToken(ct)
-
             let extraFlags =
                 if previewEnabled then
                     [| "--langversion:preview" |]
@@ -1452,8 +1423,6 @@ type internal BackgroundCompiler
                 |]
 
         async {
-            let! ct = Async.CancellationToken
-            use _ = Cancellable.UsingToken(ct)
 
             let! ct = Async.CancellationToken
             // If there was a similar entry (as there normally will have been) then re-establish an empty builder .  This

src/Compiler/Service/FSharpCheckerResults.fs

@@ -3585,8 +3585,6 @@ type FsiInteractiveChecker(legacyReferenceResolver, tcConfig: TcConfig, tcGlobal
 
     member _.ParseAndCheckInteraction(sourceText: ISourceText, ?userOpName: string) =
         cancellable {
-            let! ct = Cancellable.token ()
-            use _ = Cancellable.UsingToken(ct)
 
             let userOpName = defaultArg userOpName "Unknown"
             let fileName = Path.Combine(tcConfig.implicitIncludeDir, "stdin.fsx")

src/Compiler/Service/TransparentCompiler.fs

@@ -1762,8 +1762,6 @@ type internal TransparentCompiler
         node {
             //use _ =
             //    Activity.start "ParseFile" [| Activity.Tags.fileName, fileName |> Path.GetFileName |]
-            let! ct = NodeCode.CancellationToken
-            use _ = Cancellable.UsingToken(ct)
 
             // TODO: might need to deal with exceptions here:
             let tcConfigB, sourceFileNames, _ = ComputeTcConfigBuilder projectSnapshot
@@ -1792,6 +1790,7 @@ type internal TransparentCompiler
         ignore userOpName
 
         node {
+
             match! ComputeItemKeyStore(fileName, projectSnapshot) with
             | None -> return Seq.empty
             | Some itemKeyStore -> return itemKeyStore.FindAll symbol.Item
@@ -1818,8 +1817,6 @@ type internal TransparentCompiler
                 userOpName: string
             ) : NodeCode<FSharpCheckFileAnswer> =
             node {
-                let! ct = NodeCode.CancellationToken
-                use _ = Cancellable.UsingToken(ct)
 
                 let! snapshot =
                     FSharpProjectSnapshot.FromOptions(options, fileName, fileVersion, sourceText)
@@ -1842,8 +1839,6 @@ type internal TransparentCompiler
                 userOpName: string
             ) : NodeCode<FSharpCheckFileAnswer option> =
             node {
-                let! ct = NodeCode.CancellationToken
-                use _ = Cancellable.UsingToken(ct)
 
                 let! snapshot =
                     FSharpProjectSnapshot.FromOptions(options, fileName, fileVersion, sourceText)
@@ -1897,8 +1892,6 @@ type internal TransparentCompiler
                 userOpName: string
             ) : NodeCode<seq<range>> =
             node {
-                let! ct = NodeCode.CancellationToken
-                use _ = Cancellable.UsingToken(ct)
 
                 ignore canInvalidateProject
                 let! snapshot = FSharpProjectSnapshot.FromOptions options |> NodeCode.AwaitAsync
@@ -1914,8 +1907,6 @@ type internal TransparentCompiler
 
         member this.GetAssemblyData(options: FSharpProjectOptions, fileName, userOpName: string) : NodeCode<ProjectAssemblyDataResult> =
             node {
-                let! ct = NodeCode.CancellationToken
-                use _ = Cancellable.UsingToken(ct)
 
                 let! snapshot = FSharpProjectSnapshot.FromOptions options |> NodeCode.AwaitAsync
                 return! this.GetAssemblyData(snapshot.ProjectSnapshot, fileName, userOpName)
@@ -1936,8 +1927,6 @@ type internal TransparentCompiler
                 userOpName: string
             ) : NodeCode<FSharpParseFileResults * FSharpCheckFileResults> =
             node {
-                let! ct = NodeCode.CancellationToken
-                use _ = Cancellable.UsingToken(ct)
 
                 let! snapshot = FSharpProjectSnapshot.FromOptions options |> NodeCode.AwaitAsync
 
@@ -1953,8 +1942,6 @@ type internal TransparentCompiler
                 userOpName: string
             ) : NodeCode<FSharpParseFileResults> =
             node {
-                let! ct = NodeCode.CancellationToken
-                use _ = Cancellable.UsingToken(ct)
 
                 let! snapshot = FSharpProjectSnapshot.FromOptions options |> NodeCode.AwaitAsync
                 return! this.ParseFile(fileName, snapshot.ProjectSnapshot, userOpName)
@@ -1969,8 +1956,6 @@ type internal TransparentCompiler
             ) : NodeCode<(FSharpParseFileResults * FSharpCheckFileResults) option> =
             node {
                 ignore builder
-                let! ct = NodeCode.CancellationToken
-                use _ = Cancellable.UsingToken(ct)
 
                 let! snapshot =
                     FSharpProjectSnapshot.FromOptions(options, fileName, 1, sourceText)
@@ -2023,8 +2008,6 @@ type internal TransparentCompiler
             ) : NodeCode<EditorServices.SemanticClassificationView option> =
             node {
                 ignore userOpName
-                let! ct = NodeCode.CancellationToken
-                use _ = Cancellable.UsingToken(ct)
 
                 let! snapshot = FSharpProjectSnapshot.FromOptions options |> NodeCode.AwaitAsync
                 return! ComputeSemanticClassification(fileName, snapshot.ProjectSnapshot)
@@ -2048,8 +2031,6 @@ type internal TransparentCompiler
                 userOpName: string
             ) : NodeCode<FSharpParseFileResults * FSharpCheckFileAnswer> =
             node {
-                let! ct = NodeCode.CancellationToken
-                use _ = Cancellable.UsingToken(ct)
 
                 let! snapshot =
                     FSharpProjectSnapshot.FromOptions(options, fileName, fileVersion, sourceText)
@@ -2063,8 +2044,6 @@ type internal TransparentCompiler
 
         member this.ParseAndCheckProject(options: FSharpProjectOptions, userOpName: string) : NodeCode<FSharpCheckProjectResults> =
             node {
-                let! ct = NodeCode.CancellationToken
-                use _ = Cancellable.UsingToken(ct)
 
                 ignore userOpName
                 let! snapshot = FSharpProjectSnapshot.FromOptions options |> NodeCode.AwaitAsync
@@ -2073,8 +2052,6 @@ type internal TransparentCompiler
 
         member this.ParseAndCheckProject(projectSnapshot: FSharpProjectSnapshot, userOpName: string) : NodeCode<FSharpCheckProjectResults> =
             node {
-                let! ct = NodeCode.CancellationToken
-                use _ = Cancellable.UsingToken(ct)
 
                 ignore userOpName
                 return! ComputeParseAndCheckProject projectSnapshot.ProjectSnapshot

src/Compiler/Service/service.fs

@@ -348,8 +348,6 @@ type FSharpChecker
         use _ = Activity.start "FSharpChecker.Compile" [| Activity.Tags.userOpName, _userOpName |]
 
         async {
-            let! ct = Async.CancellationToken
-            use _ = Cancellable.UsingToken(ct)
 
             let ctok = CompilationThreadToken()
             return CompileHelpers.compileFromArgs (ctok, argv, legacyReferenceResolver, None, None)
@@ -485,8 +483,6 @@ type FSharpChecker
         let userOpName = defaultArg userOpName "Unknown"
 
         node {
-            let! ct = NodeCode.CancellationToken
-            use _ = Cancellable.UsingToken(ct)
 
             if fastCheck <> Some true || not captureIdentifiersWhenParsing then
                 return! backgroundCompiler.FindReferencesInFile(fileName, options, symbol, canInvalidateProject, userOpName)