[GR-69004] Lazy initialize PythonContext#polyglotForeignClasses

Author: eregon

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/Python3Core.java

@@ -848,7 +848,7 @@ private static PythonBuiltins[] initializeBuiltins(TruffleLanguage.Env env) {
     @CompilationFinal private PInt pyFalse;
     @CompilationFinal private PFloat pyNaN;
 
-    @CompilationFinal(dimensions = 1) public final PythonManagedClass[] polyglotForeignClasses = new PythonManagedClass[GetForeignObjectClassNode.Trait.COMBINATIONS];
+    @CompilationFinal(dimensions = 1) private PythonManagedClass[] polyglotForeignClasses = null;
 
     private final SysModuleState sysModuleState = new SysModuleState();
 
@@ -1362,4 +1362,19 @@ public static void writeInfo(String message) {
     public static void writeInfo(Supplier<String> messageSupplier) {
         PythonLanguage.getLogger(Python3Core.class).fine(messageSupplier);
     }
+
+    public PythonManagedClass getPolyglotForeignClasses(int traits) {
+        assert getContext().ownsGil(); // if not it would need its own synchronization
+        PythonManagedClass[] classes = polyglotForeignClasses;
+        return classes == null ? null : classes[traits];
+    }
+
+    public void setPolyglotForeignClasses(int traits, PythonManagedClass pythonClass) {
+        assert getContext().ownsGil(); // if not it would need its own synchronization
+        if (polyglotForeignClasses == null) {
+            polyglotForeignClasses = new PythonManagedClass[GetForeignObjectClassNode.Trait.COMBINATIONS];
+        }
+
+        polyglotForeignClasses[traits] = pythonClass;
+    }
 }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/object/GetForeignObjectClassNode.java

@@ -170,7 +170,7 @@ protected static int getTraits(Object object, InteropLibrary interop) {
     }
 
     private PythonManagedClass classForTraits(PythonContext context, int traits) {
-        PythonManagedClass pythonClass = context.polyglotForeignClasses[traits];
+        PythonManagedClass pythonClass = context.getPolyglotForeignClasses(traits);
         if (pythonClass == null) {
             if (isSingleContext(this)) {
                 CompilerDirectives.transferToInterpreterAndInvalidate();
@@ -183,7 +183,7 @@ private PythonManagedClass classForTraits(PythonContext context, int traits) {
     @TruffleBoundary
     private PythonManagedClass resolvePolyglotForeignClassAndSetInCache(PythonContext context, int traits) {
         PythonManagedClass pythonClass = resolvePolyglotForeignClass(context, traits);
-        context.polyglotForeignClasses[traits] = pythonClass;
+        context.setPolyglotForeignClasses(traits, pythonClass);
         return pythonClass;
     }