Ensure that inverted maps of symbols are not stored in aux engine cache.

Author: iamstolis

graal-js/src/com.oracle.truffle.js/src/com/oracle/truffle/js/lang/JavaScriptLanguage.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * The Universal Permissive License (UPL), Version 1.0
@@ -186,6 +186,8 @@ public final class JavaScriptLanguage extends TruffleLanguage<JSRealm> {
         ensureErrorClassesInitialized();
     }
 
+    private int realmCount;
+
     public JavaScriptLanguage() {
         this.promiseJobsQueueEmptyAssumption = Truffle.getRuntime().createAssumption("PromiseJobsQueueEmpty");
     }
@@ -359,6 +361,9 @@ private JSContext newJSContext(Env env) {
 
     @Override
     protected void initializeContext(JSRealm realm) {
+        synchronized (this) {
+            realmCount++;
+        }
         realm.initialize();
     }
 
@@ -457,6 +462,13 @@ protected void disposeContext(JSRealm realm) {
             realm.getContext().getTimeProfiler().printCumulative();
         }
         realm.dispose();
+        synchronized (this) {
+            if (--realmCount == 0) {
+                // Clear inverted maps that are no longer needed to ensure
+                // that they are not stored in aux engine cache
+                realm.getContext().clearSymbolInvertedMaps();
+            }
+        }
     }
 
     @Override

graal-js/src/com.oracle.truffle.js/src/com/oracle/truffle/js/runtime/JSContext.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * The Universal Permissive License (UPL), Version 1.0
@@ -269,6 +269,21 @@ public class JSContext {
     // Used to track singleton symbols allocations across aux engine cache runs.
     private Object symbolUsageMarker = new Object();
 
+    private final Map<Symbol, Void> unregisteredSymbols = new WeakHashMap<>();
+
+    @TruffleBoundary
+    public void unregisteredSymbolCreated(Symbol symbol) {
+        synchronized (this) {
+            unregisteredSymbols.put(symbol, null);
+        }
+    }
+
+    public void clearSymbolInvertedMaps() {
+        for (Symbol symbol : unregisteredSymbols.keySet()) {
+            symbol.clearInvertedMap();
+        }
+    }
+
     public void resetSymbolUsageMarker() {
         CompilerAsserts.neverPartOfCompilation();
         // Symbols that were used exactly once in previous executions, will most-likely

graal-js/src/com.oracle.truffle.js/src/com/oracle/truffle/js/runtime/Symbol.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * The Universal Permissive License (UPL), Version 1.0
@@ -69,67 +69,67 @@ public final class Symbol implements TruffleObject {
      * A method that determines if a constructor object recognizes an object as one of the
      * constructor's instances. Called by the semantics of the instanceof operator.
      */
-    public static final Symbol SYMBOL_HAS_INSTANCE = Symbol.create(Strings.constant("Symbol.hasInstance"));
+    public static final Symbol SYMBOL_HAS_INSTANCE = createWellKnown(Strings.constant("Symbol.hasInstance"));
     /**
      * A Boolean valued property that if true indicates that an object should be flatten to its
      * array elements by Array.prototype.concat.
      */
-    public static final Symbol SYMBOL_IS_CONCAT_SPREADABLE = Symbol.create(Strings.constant("Symbol.isConcatSpreadable"));
+    public static final Symbol SYMBOL_IS_CONCAT_SPREADABLE = createWellKnown(Strings.constant("Symbol.isConcatSpreadable"));
     /**
      * A method that returns the default iterator for an object. Called by the semantics of the
      * for-of statement.
      */
-    public static final Symbol SYMBOL_ITERATOR = Symbol.create(Strings.constant("Symbol.iterator"));
+    public static final Symbol SYMBOL_ITERATOR = createWellKnown(Strings.constant("Symbol.iterator"));
     /**
      * A method that returns the default asynchronous iterator for an object. Called by the
      * semantics of the for-await-of statement.
      */
-    public static final Symbol SYMBOL_ASYNC_ITERATOR = Symbol.create(Strings.constant("Symbol.asyncIterator"));
+    public static final Symbol SYMBOL_ASYNC_ITERATOR = createWellKnown(Strings.constant("Symbol.asyncIterator"));
     /**
      * A regular expression method that matches the regular expression against a string. Called by
      * the String.prototype.match method.
      */
-    public static final Symbol SYMBOL_MATCH = Symbol.create(Strings.constant("Symbol.match"));
+    public static final Symbol SYMBOL_MATCH = createWellKnown(Strings.constant("Symbol.match"));
     /**
      * A regular expression method that returns an iterator, that yields matches of the regular
      * expression against a string. Called by the String.prototype.matchAll method.
      */
-    public static final Symbol SYMBOL_MATCH_ALL = Symbol.create(Strings.constant("Symbol.matchAll"));
+    public static final Symbol SYMBOL_MATCH_ALL = createWellKnown(Strings.constant("Symbol.matchAll"));
     /**
      * A regular expression method that replaces matched substrings of a string. Called by the
      * String.prototype.replace method.
      */
-    public static final Symbol SYMBOL_REPLACE = Symbol.create(Strings.constant("Symbol.replace"));
+    public static final Symbol SYMBOL_REPLACE = createWellKnown(Strings.constant("Symbol.replace"));
     /**
      * A regular expression method that returns the index within a string that matches the regular
      * expression. Called by the String.prototype.search method.
      */
-    public static final Symbol SYMBOL_SEARCH = Symbol.create(Strings.constant("Symbol.search"));
+    public static final Symbol SYMBOL_SEARCH = createWellKnown(Strings.constant("Symbol.search"));
     /**
      * A function valued property that is the constructor function that is used to create derived
      * objects.
      */
-    public static final Symbol SYMBOL_SPECIES = Symbol.create(Strings.constant("Symbol.species"));
+    public static final Symbol SYMBOL_SPECIES = createWellKnown(Strings.constant("Symbol.species"));
     /**
      * A regular expression method that splits a string at the indices that match the regular
      * expression. Called by the String.prototype.split method.
      */
-    public static final Symbol SYMBOL_SPLIT = Symbol.create(Strings.constant("Symbol.split"));
+    public static final Symbol SYMBOL_SPLIT = createWellKnown(Strings.constant("Symbol.split"));
     /**
      * A method that converts an object to a corresponding primitive value. Called by the
      * ToPrimitive abstract operation.
      */
-    public static final Symbol SYMBOL_TO_PRIMITIVE = Symbol.create(Strings.constant("Symbol.toPrimitive"));
+    public static final Symbol SYMBOL_TO_PRIMITIVE = createWellKnown(Strings.constant("Symbol.toPrimitive"));
     /**
      * A property whose String value that is used in the creation of the default string description
      * of an object. Called by the built-in method Object.prototype.toString.
      */
-    public static final Symbol SYMBOL_TO_STRING_TAG = Symbol.create(Strings.constant("Symbol.toStringTag"));
+    public static final Symbol SYMBOL_TO_STRING_TAG = createWellKnown(Strings.constant("Symbol.toStringTag"));
     /**
      * A property whose value is an Object whose own property names are property names that are
      * excluded from the with environment bindings of the associated object.
      */
-    public static final Symbol SYMBOL_UNSCOPABLES = Symbol.create(Strings.constant("Symbol.unscopables"));
+    public static final Symbol SYMBOL_UNSCOPABLES = createWellKnown(Strings.constant("Symbol.unscopables"));
 
     /**
      * [[Description]] of Symbol if it is a String value, {@code null} otherwise ([[Description]] is
@@ -154,6 +154,12 @@ private Symbol(TruffleString description, boolean registered, boolean isPrivate)
     }
 
     public static Symbol create(TruffleString description) {
+        Symbol symbol = new Symbol(description, false, false);
+        JavaScriptLanguage.getCurrentLanguage().getJSContext().unregisteredSymbolCreated(symbol);
+        return symbol;
+    }
+
+    private static Symbol createWellKnown(TruffleString description) {
         return new Symbol(description, false, false);
     }
 
@@ -269,4 +275,9 @@ public void setInvertedMap(Map<WeakMap, Object> invMap) {
         assert this.invertedMap == null;
         this.invertedMap = invMap;
     }
+
+    void clearInvertedMap() {
+        this.invertedMap = null;
+    }
+
 }