Making several uses of Dictionary types be ConcurrentDictionary

src/fsharp/CompilerConfig.fs

@@ -5,6 +5,7 @@ module internal FSharp.Compiler.CompilerConfig
 
 open System
 open System.Collections.Generic
+open System.Collections.Concurrent
 open System.Diagnostics
 open System.IO
 open System.Text
@@ -177,8 +178,8 @@ type IRawFSharpAssemblyData =
 
 /// Cache of time stamps as we traverse a project description
 type TimeStampCache(defaultTimeStamp: DateTime) = 
-    let files = Dictionary<string, DateTime>()
-    let projects = Dictionary<IProjectReference, DateTime>(HashIdentity.Reference)
+    let files = ConcurrentDictionary<string, DateTime>()
+    let projects = ConcurrentDictionary<IProjectReference, DateTime>(HashIdentity.Reference)
     member cache.GetFileTimeStamp fileName = 
         let ok, v = files.TryGetValue fileName
         if ok then v else

src/fsharp/ExtensionTyping.fs

@@ -267,6 +267,7 @@ module internal ExtensionTyping =
     /// appears that the laziness likely serves no purpose and could be safely removed.
     and ProvidedTypeContext = 
         | NoEntries
+        // The dictionaries are safe because the ProvidedType with the ProvidedTypeContext are only accessed one thread at a time during type-checking.
         | Entries of Dictionary<ProvidedType, ILTypeRef> * Lazy<Dictionary<ProvidedType, obj>>
 
         static member Empty = NoEntries

src/fsharp/IlxGen.fs

@@ -1446,6 +1446,7 @@ and TypeDefsBuilder() =
         tdefs.Add (tdef.Name, (idx, (new TypeDefBuilder(tdef, tdefDiscards), eliminateIfEmpty)))
 
 type AnonTypeGenerationTable() =
+    // Dictionary is safe here as it will only be used during the codegen stage - will happen on a single thread.
     let dict = Dictionary<Stamp, (ILMethodRef * ILMethodRef[] * ILType)>(HashIdentity.Structural)
     member __.Table = dict
 
@@ -1456,6 +1457,7 @@ type AssemblyBuilder(cenv: cenv, anonTypeTable: AnonTypeGenerationTable) as mgbu
     let gtdefs= new TypeDefsBuilder()
 
     // The definitions of top level values, as quotations.
+    // Dictionary is safe here as it will only be used during the codegen stage - will happen on a single thread.
     let mutable reflectedDefinitions: Dictionary<Val, (string * int * Expr)> = Dictionary(HashIdentity.Reference)
     let mutable extraBindingsToGenerate = []
 
@@ -8170,6 +8172,7 @@ type IlxAssemblyGenerator(amap: ImportMap, tcGlobals: TcGlobals, tcVal: Constrai
     // The incremental state held by the ILX code generator
     let mutable ilxGenEnv = GetEmptyIlxGenEnv tcGlobals ccu
     let anonTypeTable = AnonTypeGenerationTable()
+    // Dictionaries are safe here as they will only be used during the codegen stage - will happen on a single thread.
     let intraAssemblyInfo = { StaticFieldInfo = new Dictionary<_, _>(HashIdentity.Structural) }
     let casApplied = new Dictionary<Stamp, bool>()
 

src/fsharp/InfoReader.fs

@@ -6,6 +6,7 @@ module internal FSharp.Compiler.InfoReader
 
 open System
 open System.Collections.Generic
+open System.Collections.Concurrent
 
 open FSharp.Compiler 
 open FSharp.Compiler.AbstractIL.IL
@@ -107,7 +108,7 @@ type PropertyCollector(g, amap, m, ty, optFilter, ad) =
                 PropInfosEquivByNameAndPartialSig EraseNone g amap m pinfo1 pinfo2 &&
                 pinfo1.IsDefiniteFSharpOverride = pinfo2.IsDefiniteFSharpOverride )
 
-    let props = new Dictionary<PropInfo, PropInfo>(hashIdentity)
+    let props = new ConcurrentDictionary<PropInfo, PropInfo>(hashIdentity)
 
     let add pinfo =
         match props.TryGetValue pinfo, pinfo with

src/fsharp/Optimizer.fs

@@ -32,6 +32,7 @@ open FSharp.Compiler.TcGlobals
 open FSharp.Compiler.TypeRelations
 
 open System.Collections.Generic
+open System.Collections.ObjectModel
 
 #if DEBUG
 let verboseOptimizationInfo = 
@@ -162,7 +163,7 @@ type ValInfos(entries) =
                 if dict.ContainsKey vkey then 
                     failwithf "dictionary already contains key %A" vkey
                 dict.Add(vkey, p) |> ignore
-            dict), id)
+            ReadOnlyDictionary dict), id)
 
     member x.Entries = valInfoTable.Force().Values
 

src/fsharp/TcGlobals.fs

@@ -9,6 +9,7 @@
 module internal FSharp.Compiler.TcGlobals
 
 open System.Collections.Generic
+open System.Collections.Concurrent
 open System.Diagnostics
 
 open FSharp.Compiler.AbstractIL 
@@ -360,7 +361,7 @@ type public TcGlobals(compilingFslib: bool, ilg:ILGlobals, fslibCcu: CcuThunk, d
   let mkForallTyIfNeeded d r = match d with [] -> r | tps -> TType_forall(tps, r)
 
       // A table of all intrinsics that the compiler cares about
-  let v_knownIntrinsics = Dictionary<(string * string option * string * int), ValRef>(HashIdentity.Structural)
+  let v_knownIntrinsics = ConcurrentDictionary<(string * string option * string * int), ValRef>(HashIdentity.Structural)
 
   let makeIntrinsicValRefGeneral isKnown (enclosingEntity, logicalName, memberParentName, compiledNameOpt, typars, (argtys, rty))  =
       let ty = mkForallTyIfNeeded typars (mkIteratedFunTy (List.map mkSmallRefTupledTy argtys) rty)
@@ -374,7 +375,7 @@ type public TcGlobals(compilingFslib: bool, ilg:ILGlobals, fslibCcu: CcuThunk, d
       let key = (enclosingEntity.LastItemMangledName, memberParentName, compiledName, argCount)
       assert not (v_knownIntrinsics.ContainsKey(key))
       if isKnown && not (v_knownIntrinsics.ContainsKey(key)) then
-          v_knownIntrinsics.Add(key, ValRefForIntrinsic vref)
+          v_knownIntrinsics.[key] <- ValRefForIntrinsic vref
       vref
 
   let makeIntrinsicValRef info = makeIntrinsicValRefGeneral true info

src/fsharp/absil/il.fs

@@ -12,6 +12,7 @@ open System.IO
 open System.Collections
 open System.Collections.Generic
 open System.Collections.Concurrent
+open System.Collections.ObjectModel
 open System.Reflection
 open System.Text
 open System.Threading
@@ -2130,7 +2131,7 @@ and [<Sealed>] ILTypeDefs(f : unit -> ILPreTypeDef[]) =
         for pre in arr do
             let key = pre.Namespace, pre.Name
             t.[key] <- pre
-        t)
+        ReadOnlyDictionary t)
 
     member x.AsArray = [| for pre in array.Value -> pre.GetTypeDef() |]
 

src/fsharp/absil/illib.fs

@@ -6,6 +6,7 @@ module public FSharp.Compiler.AbstractIL.Internal.Library
 
 open System
 open System.Collections.Generic
+open System.Collections.Concurrent
 open System.Diagnostics
 open System.IO
 open System.Reflection
@@ -959,16 +960,18 @@ let _ = eventually { use x = null in return 1 }
 
 /// Generates unique stamps
 type UniqueStampGenerator<'T when 'T : equality>() = 
-    let encodeTab = new Dictionary<'T, int>(HashIdentity.Structural)
+    let gate = obj ()
+    let encodeTab = new ConcurrentDictionary<'T, int>(HashIdentity.Structural)
     let mutable nItems = 0
     let encode str =
         match encodeTab.TryGetValue str with
         | true, idx -> idx
         | _ ->
-            let idx = nItems
-            encodeTab.[str] <- idx
-            nItems <- nItems + 1
-            idx
+            lock gate (fun () ->
+                let idx = nItems
+                encodeTab.[str] <- idx
+                nItems <- nItems + 1
+                idx)
 
     member this.Encode str = encode str
 
@@ -977,7 +980,7 @@ type UniqueStampGenerator<'T when 'T : equality>() =
 /// memoize tables (all entries cached, never collected)
 type MemoizationTable<'T, 'U>(compute: 'T -> 'U, keyComparer: IEqualityComparer<'T>, ?canMemoize) = 
 
-    let table = new Dictionary<'T, 'U>(keyComparer) 
+    let table = new ConcurrentDictionary<'T, 'U>(keyComparer) 
 
     member t.Apply x = 
         if (match canMemoize with None -> true | Some f -> f x) then 
@@ -1066,7 +1069,7 @@ type LazyWithContext<'T, 'ctxt> =
 /// Intern tables to save space.
 module Tables = 
     let memoize f = 
-        let t = new Dictionary<_, _>(1000, HashIdentity.Structural)
+        let t = new ConcurrentDictionary<_, _>(Environment.ProcessorCount, 1000, HashIdentity.Structural)
         fun x -> 
             match t.TryGetValue x with
             | true, res -> res

src/fsharp/absil/ilread.fs

@@ -697,7 +697,7 @@ let mkCacheInt32 lowMem _inbase _nm _sz =
     fun f (idx: int32) ->
         let cache = 
             match !cache with
-            | null -> cache := new Dictionary<int32, _>(11)
+            | null -> cache := new ConcurrentDictionary<int32, _>(Environment.ProcessorCount, 11)
             | _ -> ()
             !cache
         match cache.TryGetValue idx with
@@ -719,7 +719,7 @@ let mkCacheGeneric lowMem _inbase _nm _sz =
     fun f (idx :'T) ->
         let cache = 
             match !cache with
-            | null -> cache := new Dictionary<_, _>(11 (* sz: int *) ) 
+            | null -> cache := new ConcurrentDictionary<_, _>(Environment.ProcessorCount, 11 (* sz: int *) ) 
             | _ -> ()
             !cache
         match cache.TryGetValue idx with

src/fsharp/lexhelp.fs

@@ -39,7 +39,7 @@ type LightSyntaxStatus(initial:bool,warn:bool) =
 /// Manage lexer resources (string interning)
 [<Sealed>]
 type LexResourceManager(?capacity: int) =
-    let strings = new System.Collections.Generic.Dictionary<string, Parser.token>(defaultArg capacity 1024)
+    let strings = new System.Collections.Concurrent.ConcurrentDictionary<string, Parser.token>(Environment.ProcessorCount, defaultArg capacity 1024)
     member x.InternIdentifierToken(s) = 
         match strings.TryGetValue s with
         | true, res -> res

tests/FSharp.Compiler.Service.Tests/SurfaceArea.netstandard.fs

@@ -18369,8 +18369,8 @@ FSharp.Compiler.AbstractIL.Internal.Library+UndefinedException: Int32 GetHashCod
 FSharp.Compiler.AbstractIL.Internal.Library+UndefinedException: Int32 GetHashCode(System.Collections.IEqualityComparer)
 FSharp.Compiler.AbstractIL.Internal.Library+UndefinedException: Void .ctor()
 FSharp.Compiler.AbstractIL.Internal.Library+UniqueStampGenerator`1[T]: Int32 Encode(T)
-FSharp.Compiler.AbstractIL.Internal.Library+UniqueStampGenerator`1[T]: KeyCollection Table
-FSharp.Compiler.AbstractIL.Internal.Library+UniqueStampGenerator`1[T]: KeyCollection get_Table()
+FSharp.Compiler.AbstractIL.Internal.Library+UniqueStampGenerator`1[T]: System.Collections.Generic.ICollection`1[T] Table
+FSharp.Compiler.AbstractIL.Internal.Library+UniqueStampGenerator`1[T]: System.Collections.Generic.ICollection`1[T] get_Table()
 FSharp.Compiler.AbstractIL.Internal.Library+UniqueStampGenerator`1[T]: Void .ctor()
 FSharp.Compiler.AbstractIL.Internal.Library+ValueOptionInternal: Microsoft.FSharp.Core.FSharpValueOption`1[a] ofOption[a](Microsoft.FSharp.Core.FSharpOption`1[a])
 FSharp.Compiler.AbstractIL.Internal.Library+ValueOptionInternal: Microsoft.FSharp.Core.FSharpValueOption`1[b] bind[a,b](Microsoft.FSharp.Core.FSharpFunc`2[a,Microsoft.FSharp.Core.FSharpValueOption`1[b]], Microsoft.FSharp.Core.FSharpValueOption`1[a])

tests/fsharpqa/Source/Conformance/ObjectOrientedTypeDefinitions/ClassTypes/MemberDeclarations/E_ClashingInstanceStaticProperties.fs

@@ -1,6 +1,6 @@
 // #Regression #Conformance #ObjectOrientedTypes #Classes #MethodsAndProperties #MemberDefinitions 
 // Regression test for FSHARP1.0:5475
-//<Expects status="error" span="(5,27-5,28)" id="FS0441">Duplicate property\. The property 'M' has the same name and signature as another property in type 'C'\.$</Expects>
+//<Expects status="error" span="(6,31-6,32)" id="FS0441">Duplicate property\. The property 'M' has the same name and signature as another property in type 'C'\.$</Expects>
 type C = class
                 member __.M = ()
                 static member M = ()

tests/fsharpqa/Source/Conformance/ObjectOrientedTypeDefinitions/ClassTypes/MemberDeclarations/E_PropertySameNameDiffArity.fs

@@ -2,7 +2,7 @@
 // Verify that one should not be able to have two properties called �X� with different arities (number of arguments).
 // This is regression test for FSHARP1.0:4529
 
-//<Expects id="FS0436" span="(11,17-11,18)" status="error">The property 'X' has the same name as another property in type 'TestType1'</Expects>
+//<Expects id="FS0436" span="(13,17-13,18)" status="error">The property 'X' has the same name as another property in type 'TestType1'</Expects>
 
 
 type TestType1( x : int ) =