on setting class attributes, invalidate the finality assumption up the MRO chain in order to de-specialize from the constant cached class attribute value read

Author: cosminbasca

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/attributes/LookupAttributeInMRONode.java

@@ -48,6 +48,9 @@
 import com.oracle.truffle.api.dsl.Fallback;
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.nodes.ExplodeLoop;
+import com.oracle.truffle.api.object.Location;
+import com.oracle.truffle.api.object.Property;
+import com.oracle.truffle.api.object.Shape;
 
 public abstract class LookupAttributeInMRONode extends PBaseNode {
 
@@ -113,12 +116,20 @@ protected PythonClass findClassInMRO(PythonClass klass) {
         return null;
     }
 
-    @Specialization(guards = {"klass == cachedKlass", "cachedAttrKlass != null"}, limit = "5", assumptions = "lookupStable", rewriteOn = IllegalStateException.class)
+    protected Location getLocationOrNull(Shape shape) {
+        Property prop = shape.getProperty(key);
+        return prop == null ? null : prop.getLocation();
+    }
+
+    @Specialization(guards = {"klass == cachedKlass", "cachedAttrKlass != null"}, limit = "5", assumptions = {"lookupStable", "finalAssumption"}, rewriteOn = IllegalStateException.class)
     protected Object lookupConstantMROCached(@SuppressWarnings("unused") PythonClass klass,
                     @Cached("klass") @SuppressWarnings("unused") PythonClass cachedKlass,
                     @Cached("cachedKlass.getLookupStableAssumption()") @SuppressWarnings("unused") Assumption lookupStable,
                     @Cached("create()") ReadAttributeFromObjectNode readAttrNode,
-                    @Cached("findClassInMRO(cachedKlass)") @SuppressWarnings("unused") PythonClass cachedAttrKlass) {
+                    @Cached("findClassInMRO(cachedKlass)") PythonClass cachedAttrKlass,
+                    @Cached("cachedAttrKlass.getStorage().getShape()") @SuppressWarnings("unused") Shape cachedShape,
+                    @Cached("getLocationOrNull(cachedShape)") @SuppressWarnings("unused") Location loc,
+                    @Cached("loc.getFinalAssumption()") @SuppressWarnings("unused") Assumption finalAssumption) {
         Object value = readAttrNode.execute(cachedAttrKlass, key);
         if (value == PNone.NO_VALUE) {
             // in case the attribute was deleted

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/attributes/SetAttributeNode.java

@@ -51,6 +51,7 @@
 import com.oracle.truffle.api.dsl.NodeChildren;
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.frame.VirtualFrame;
+import com.oracle.truffle.api.object.DynamicObject;
 import com.oracle.truffle.api.profiles.ValueProfile;
 
 @NodeChildren({@NodeChild(value = "object", type = PNode.class), @NodeChild(value = "key", type = PNode.class), @NodeChild(value = "rhs", type = PNode.class)})
@@ -88,6 +89,23 @@ public PNode getPrimaryNode() {
         return getObject();
     }
 
+    @Specialization
+    protected Object doClass(PythonClass cls, Object key, Object value,
+                    @Cached("createIdentityProfile()") ValueProfile setattributeProfile,
+                    @Cached("create(__SETATTR__)") LookupAttributeInMRONode setattributeLookup,
+                    @Cached("create()") CallTernaryMethodNode callSetattr) {
+        Object descr = setattributeProfile.profile(setattributeLookup.execute(cls));
+        PythonClass[] mro = cls.getMethodResolutionOrder();
+        for (int i = 0; i < mro.length; i++) {
+            PythonClass kls = mro[i];
+            DynamicObject storage = kls.getStorage();
+            if (storage.containsKey(key)) {
+                storage.getShape().getProperty(key).getLocation().getFinalAssumption().invalidate();
+            }
+        }
+        return callSetattr.execute(descr, cls, key, value);
+    }
+
     @Specialization
     protected Object doIt(Object object, Object key, Object value,
                     @Cached("createIdentityProfile()") ValueProfile setattributeProfile,