From fcd043f5bf0e6f20138062571b516b603d22ee90 Mon Sep 17 00:00:00 2001
From: Pavel Marek <pavel.marek@enso.org>
Date: Mon, 16 Dec 2024 12:01:25 +0100
Subject: [PATCH] BuiltinObject guards cached builtin type with WeakReference
 to context

---
 .../runtime/builtin/BuiltinObject.java          | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/engine/runtime/src/main/java/org/enso/interpreter/runtime/builtin/BuiltinObject.java b/engine/runtime/src/main/java/org/enso/interpreter/runtime/builtin/BuiltinObject.java
index 9b3503de0a06..1d085735185c 100644
--- a/engine/runtime/src/main/java/org/enso/interpreter/runtime/builtin/BuiltinObject.java
+++ b/engine/runtime/src/main/java/org/enso/interpreter/runtime/builtin/BuiltinObject.java
@@ -8,6 +8,7 @@
 import com.oracle.truffle.api.library.ExportLibrary;
 import com.oracle.truffle.api.library.ExportMessage;
 import com.oracle.truffle.api.nodes.Node;
+import java.lang.ref.WeakReference;
 import org.enso.interpreter.node.expression.builtin.Builtin;
 import org.enso.interpreter.runtime.EnsoContext;
 import org.enso.interpreter.runtime.data.EnsoObject;
@@ -27,7 +28,15 @@ public abstract class BuiltinObject extends EnsoObject {
 
   private final String builtinName;
 
-  @CompilationFinal private Builtin cachedBuiltinType;
+  /**
+   * A weak reference to the context in which this node was last executed.
+   *
+   * <p>Inspired by {@link
+   * org.enso.interpreter.node.expression.builtin.meta.EnsoProjectNode#previousCtxRef}
+   */
+  @CompilationFinal private WeakReference<EnsoContext> previousCtxRef = new WeakReference<>(null);
+
+  private Builtin cachedBuiltinType;
 
   /**
    * @param builtinName Simple name of the builtin that should be contained in {@link
@@ -44,9 +53,11 @@ public final boolean hasType() {
 
   @ExportMessage
   public final Type getType(@Bind("$node") Node node) {
-    if (cachedBuiltinType == null) {
+    var ctx = EnsoContext.get(node);
+    var previousCtx = previousCtxRef.get();
+    if (previousCtx == null || cachedBuiltinType == null || previousCtx != ctx) {
       CompilerDirectives.transferToInterpreterAndInvalidate();
-      var ctx = EnsoContext.get(node);
+      previousCtxRef = new WeakReference<>(ctx);
       cachedBuiltinType = ctx.getBuiltins().getBuiltinType(builtinName);
     }
     return cachedBuiltinType.getType();