Make handle data final on RubyFiber.

Author: aardvark179

src/main/java/org/truffleruby/cext/ValueWrapperManager.java

@@ -72,11 +72,7 @@ public HandleBlockHolder makeThreadData(RubyContext context) {
     }
 
     public HandleBlockHolder getBlockHolder(RubyContext context, RubyLanguage language) {
-        RubyFiber fiber = language.getCurrentThread().getCurrentFiber();
-        if (fiber.handleData == null) {
-            fiber.handleData = makeThreadData(context);
-        }
-        return fiber.handleData;
+        return language.getCurrentThread().getCurrentFiber().handleData;
     }
 
     /* We keep a map of long wrappers that have been generated because various C extensions assume that any given fixnum
@@ -174,6 +170,11 @@ public void freeAllBlocksInMap(RubyLanguage language) {
         }
     }
 
+    public void cleanup(RubyContext context, HandleBlockHolder holder) {
+        context.getMarkingService().queueForMarking(holder.handleBlock);
+        holder.handleBlock = null;
+    }
+
     protected static class FreeHandleBlock {
         public final long start;
         public final FreeHandleBlock next;

src/main/java/org/truffleruby/core/fiber/FiberManager.java

@@ -299,6 +299,8 @@ public void start(RubyFiber fiber, Thread javaThread) {
     public void cleanup(RubyFiber fiber, Thread javaThread) {
         final ThreadManager threadManager = context.getThreadManager();
 
+        context.getValueWrapperManager().cleanup(context, fiber.handleData);
+
         fiber.alive = false;
 
         threadManager.cleanupValuesForJavaThread(javaThread);

src/main/java/org/truffleruby/core/fiber/RubyFiber.java

@@ -47,7 +47,7 @@ public final class RubyFiber extends RubyDynamicObject implements ObjectGraphNod
     public volatile Throwable uncaughtException = null;
     String sourceLocation;
     public final MarkingService.ExtensionCallStack extensionCallStack;
-    public ValueWrapperManager.HandleBlockHolder handleData = null;
+    public final ValueWrapperManager.HandleBlockHolder handleData;
 
     public RubyFiber(
             RubyClass rubyClass,
@@ -66,6 +66,7 @@ public RubyFiber(
         this.rubyThread = rubyThread;
         this.sourceLocation = sourceLocation;
         extensionCallStack = new MarkingService.ExtensionCallStack(Nil.INSTANCE);
+        handleData = new ValueWrapperManager.HandleBlockHolder();
     }
 
     public boolean isRootFiber() {