stackguard uses threadpool

Author: majocha

src/Compiler/Facilities/DiagnosticsLogger.fs

@@ -872,35 +872,22 @@ let internal languageFeatureNotSupportedInLibraryError (langFeature: LanguageFea
 type StackGuard(maxDepth: int, name: string) =
 
     let mutable depth = 1
+    do ignore name
 
     [<DebuggerHidden; DebuggerStepThrough>]
-    member _.Guard
-        (
-            f,
-            [<CallerMemberName; Optional; DefaultParameterValue("")>] memberName: string,
-            [<CallerFilePath; Optional; DefaultParameterValue("")>] path: string,
-            [<CallerLineNumber; Optional; DefaultParameterValue(0)>] line: int
-        ) =
-
-        Activity.addEventWithTags
-            "DiagnosticsLogger.StackGuard.Guard"
-            (seq {
-                Activity.Tags.stackGuardName, box name
-                Activity.Tags.stackGuardCurrentDepth, depth
-                Activity.Tags.stackGuardMaxDepth, maxDepth
-                Activity.Tags.callerMemberName, memberName
-                Activity.Tags.callerFilePath, path
-                Activity.Tags.callerLineNumber, line
-            })
+    member _.Guard f =
 
         depth <- depth + 1
 
         try
             if depth % maxDepth = 0 then
 
                 async {
-                    do! Async.SwitchToNewThread()
-                    Thread.CurrentThread.Name <- $"F# Extra Compilation Thread for {name} (depth {depth})"
+                    if Environment.Is64BitProcess then
+                        do! Async.SwitchToThreadPool()
+                    else
+                        do! Async.SwitchToNewThread()
+
                     return f ()
                 }
                 |> Async.RunImmediate

src/Compiler/Facilities/DiagnosticsLogger.fsi

@@ -463,13 +463,7 @@ type StackGuard =
     new: maxDepth: int * name: string -> StackGuard
 
     /// Execute the new function, on a new thread if necessary
-    member Guard:
-        f: (unit -> 'T) *
-        [<CallerMemberName; Optional; DefaultParameterValue("")>] memberName: string *
-        [<CallerFilePath; Optional; DefaultParameterValue("")>] path: string *
-        [<CallerLineNumber; Optional; DefaultParameterValue(0)>] line: int ->
-            'T
-
+    member Guard: f: (unit -> 'T) -> 'T
     static member GetDepthOption: string -> int
 
 /// This represents the global state established as each task function runs as part of the build.