Remove re-analysis check for non-scripts in VS - Fixed a cross-project reference regression

src/fsharp/service/IncrementalBuild.fs

@@ -1079,6 +1079,14 @@ type IncrementalBuilder(tcGlobals,
                 return { state with finalizedBoundModel = Some result }, result
         }
 
+    let tryGetSlot (state: IncrementalBuilderState) slot =
+        match state.boundModels.[slot] with
+        | Some boundModel ->
+            (boundModel, state.stampedFileNames.[slot])
+            |> Some
+        | _ ->
+            None
+
     let tryGetBeforeSlot (state: IncrementalBuilderState) slot =
         match slot with
         | 0 (* first file *) ->
@@ -1089,12 +1097,7 @@ type IncrementalBuilder(tcGlobals,
             | _ ->
                 None
         | _ ->
-            match state.boundModels.[slot - 1] with
-            | Some boundModel ->
-                (boundModel, state.stampedFileNames.[slot - 1])
-                |> Some
-            | _ ->
-                None
+            tryGetSlot state (slot - 1)
 
     let evalUpToTargetSlot state (cache: TimeStampCache) ctok targetSlot =
         cancellable {
@@ -1192,13 +1195,6 @@ type IncrementalBuilder(tcGlobals,
         match result with
         | Some (boundModel, timestamp) -> Some (PartialCheckResults (boundModel, timestamp))
         | _ -> None
-
-
-    member builder.AreCheckResultsBeforeFileInProjectReady filename = 
-        let slotOfFile = builder.GetSlotOfFileName filename
-        match tryGetBeforeSlot currentState slotOfFile with
-        | Some _ -> true
-        | _ -> false
 
     member builder.TryGetCheckResultsBeforeFileInProject (filename) =
         let cache = TimeStampCache defaultTimeStamp
@@ -1211,6 +1207,9 @@ type IncrementalBuilder(tcGlobals,
         | Some(boundModel, timestamp) -> PartialCheckResults(boundModel, timestamp) |> Some
         | _ -> None
 
+    member builder.AreCheckResultsBeforeFileInProjectReady filename = 
+        (builder.TryGetCheckResultsBeforeFileInProject filename).IsSome
+
     member private _.GetCheckResultsBeforeSlotInProject (ctok: CompilationThreadToken, slotOfFile, enablePartialTypeChecking) = 
       cancellable {
         let cache = TimeStampCache defaultTimeStamp

src/fsharp/service/Reactor.fs

@@ -41,6 +41,7 @@ type Reactor() =
     // so that when the reactor picks up a thread from the thread pool we can set the culture
     let mutable culture = CultureInfo(CultureInfo.CurrentUICulture.Name)
 
+    let gate = obj()
     let mutable bgOpCts = new CancellationTokenSource()
 
     let sw = new System.Diagnostics.Stopwatch()
@@ -86,9 +87,11 @@ type Reactor() =
                             match bgOpOpt with 
                             | None -> None
                             | Some (bgUserOpName, bgOpName, bgOpArg, bgOp) -> 
-                                let oldBgOpCts = bgOpCts
-                                bgOpCts <- new CancellationTokenSource()
-                                oldBgOpCts.Dispose()
+                                lock gate (fun () -> 
+                                    let oldBgOpCts = bgOpCts
+                                    bgOpCts <- new CancellationTokenSource()
+                                    oldBgOpCts.Dispose()
+                                )
                                 Some (bgUserOpName, bgOpName, bgOpArg, bgOp ctok)
 
                         //Trace.TraceInformation("Reactor: --> set background op, remaining {0}", inbox.CurrentQueueLength)
@@ -113,9 +116,11 @@ type Reactor() =
                         | None -> ()
                         | Some (bgUserOpName, bgOpName, bgOpArg, bgOp) -> 
                             Trace.TraceInformation("Reactor: {0:n3} --> wait for background {1}.{2} ({3}), remaining {4}", DateTime.Now.TimeOfDay.TotalSeconds, bgUserOpName, bgOpName, bgOpArg, inbox.CurrentQueueLength)
-                            let oldBgOpCts = bgOpCts
-                            bgOpCts <- new CancellationTokenSource()
-                            oldBgOpCts.Dispose()
+                            lock gate (fun () -> 
+                                let oldBgOpCts = bgOpCts
+                                bgOpCts <- new CancellationTokenSource()
+                                oldBgOpCts.Dispose()
+                            )
 
                             try 
                                 Eventually.force bgOpCts.Token bgOp |> ignore
@@ -179,12 +184,12 @@ type Reactor() =
     // [Foreground Mailbox Accessors] -----------------------------------------------------------                
     member _.SetBackgroundOp(bgOpOpt) = 
         Trace.TraceInformation("Reactor: {0:n3} enqueue start background, length {1}", DateTime.Now.TimeOfDay.TotalSeconds, builder.CurrentQueueLength)
-        bgOpCts.Cancel()
+        lock gate (fun () -> bgOpCts.Cancel())
         builder.Post(SetBackgroundOp bgOpOpt)
 
     member _.CancelBackgroundOp() = 
         Trace.TraceInformation("FCS: trying to cancel any active background work")
-        bgOpCts.Cancel()
+        lock gate (fun () -> bgOpCts.Cancel())
 
     member _.EnqueueOp(userOpName, opName, opArg, op) =
         Trace.TraceInformation("Reactor: {0:n3} enqueue {1}.{2} ({3}), length {4}", DateTime.Now.TimeOfDay.TotalSeconds, userOpName, opName, opArg, builder.CurrentQueueLength)