From 564ebf9799563dfd1019fbcc9121339b7f94b936 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=91=D0=BE=D0=BD=D0=B4=D0=B0=D1=80=D0=B5=D0=B2=20=D0=98?=
 =?UTF-8?q?=D0=B2=D0=B0=D0=BD?= <ibond84@googlemail.com>
Date: Tue, 25 Feb 2020 20:46:33 +0100
Subject: [PATCH] thread safe FixPointer (without locking)

---
 TestSuite/pointers12.pas |  1 -
 bin/Lib/PABCSystem.pas   | 21 ++++++++++-----------
 2 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/TestSuite/pointers12.pas b/TestSuite/pointers12.pas
index 37dfab666..44efaa7c5 100644
--- a/TestSuite/pointers12.pas
+++ b/TestSuite/pointers12.pas
@@ -40,5 +40,4 @@ begin
   p := @x[2];
   p^.name := 'def';
   assert(p^.name = 'def');
-  readln;
 end.
\ No newline at end of file
diff --git a/bin/Lib/PABCSystem.pas b/bin/Lib/PABCSystem.pas
index 53fe3d307..99471197a 100644
--- a/bin/Lib/PABCSystem.pas
+++ b/bin/Lib/PABCSystem.pas
@@ -12507,32 +12507,31 @@ begin
     result := 0;
 end;
 
+type NotPinnableWrapper = class
+  [ThreadStatic]
+  static notPinnableTypes: HashSet<&Type>;
+end;
+
 // -----------------------------------------------------
 // Internal procedures for PABCRTL.dll: implementation
 // -----------------------------------------------------
 var
   __initialized := false;
-  nonPinnableLock := new object;
-  notPinnableTypes: HashSet<&Type>;
-
+  
 [System.Diagnostics.DebuggerStepThrough] 
 function __FixPointer(obj: object): GCHandle;
 begin
   if obj <> nil then
   begin
     try
-      if notPinnableTypes.Contains(obj.GetType()) then
+      if (NotPinnableWrapper.notPinnableTypes <> nil) and NotPinnableWrapper.notPinnableTypes.Contains(obj.GetType()) then
         Result := GCHandle.Alloc(obj)
       else
         Result := GCHandle.Alloc(obj, GCHandleType.Pinned);
     except
-      lock nonPinnableLock do
-      begin 
-        if notPinnableTypes = nil then 
-          notPinnableTypes := new HashSet<&Type>;
-        notPinnableTypes.Add(obj.GetType());
-      end;
-      
+      if NotPinnableWrapper.notPinnableTypes = nil then 
+          NotPinnableWrapper.notPinnableTypes := new HashSet<&Type>;
+      NotPinnableWrapper.notPinnableTypes.Add(obj.GetType());
       Result := GCHandle.Alloc(obj);
     end;
   end;