Assert sharing state of array contents when creating shared storage.

Author: aardvark179

src/main/java/org/truffleruby/core/array/library/SharedArrayStorage.java

@@ -17,8 +17,10 @@
 import org.truffleruby.core.array.ArrayGuards;
 import org.truffleruby.core.array.library.ArrayStoreLibrary.ArrayAllocator;
 import org.truffleruby.language.RubyBaseNode;
+import org.truffleruby.language.RubyDynamicObject;
 import org.truffleruby.language.objects.ObjectGraph;
 import org.truffleruby.language.objects.ObjectGraphNode;
+import org.truffleruby.language.objects.shared.SharedObjects;
 import org.truffleruby.language.objects.shared.WriteBarrierNode;
 
 import com.oracle.truffle.api.TruffleSafepoint;
@@ -43,6 +45,28 @@ public SharedArrayStorage(Object storage) {
         this.storage = storage;
     }
 
+    /* Method for checking that all elements in this array are correctly shared. This can only be called after the whole
+     * stack of adjacent objects have been shared, which may not be true at the point the storage is converted to shared
+     * storage. */
+    @TruffleBoundary
+    public boolean allElementsShared() {
+        if (storage == null || storage instanceof ZeroLengthArrayStore) {
+            return true;
+        }
+        ArrayStoreLibrary stores = ArrayStoreLibrary.getFactory()
+                .getUncached(storage);
+        var elements = stores.getIterable(storage, 0, stores.capacity(storage));
+        for (var e : elements) {
+            if (e == null || !(e instanceof RubyDynamicObject) || SharedObjects.isShared(e)) {
+                continue;
+            } else {
+                System.err.printf("Unshared element %s.\n", e);
+                return false;
+            }
+        }
+        return true;
+    }
+
     @ExportMessage
     protected static boolean accepts(SharedArrayStorage store,
             @CachedLibrary(limit = "1") ArrayStoreLibrary stores) {

src/main/java/org/truffleruby/language/objects/shared/SharedObjects.java

@@ -17,6 +17,7 @@
 import org.truffleruby.RubyLanguage;
 import org.truffleruby.core.array.RubyArray;
 import org.truffleruby.core.array.library.ArrayStoreLibrary;
+import org.truffleruby.core.array.library.SharedArrayStorage;
 import org.truffleruby.core.module.RubyModule;
 import org.truffleruby.core.proc.RubyProc;
 import org.truffleruby.core.thread.RubyThread;
@@ -135,9 +136,16 @@ public static boolean assertPropagateSharing(RubyDynamicObject source, Object va
     public static void writeBarrier(RubyLanguage language, Object value) {
         if (language.options.SHARED_OBJECTS_ENABLED && value instanceof RubyDynamicObject && !isShared(value)) {
             shareObject((RubyDynamicObject) value);
+            assert !(value instanceof RubyArray) || validateArray((RubyArray) value);
         }
     }
 
+    private static boolean validateArray(RubyArray value) {
+        Object storage = value.getStore();
+        assert storage instanceof SharedArrayStorage;
+        return ((SharedArrayStorage) storage).allElementsShared();
+    }
+
     public static void propagate(RubyLanguage language, RubyDynamicObject source, Object value) {
         if (isShared(source)) {
             writeBarrier(language, value);