Small cleanup of DataHOlder.

Author: aardvark179

src/main/java/org/truffleruby/cext/CExtNodes.java

@@ -1966,7 +1966,7 @@ public abstract static class DataHolderGetData extends PrimitiveArrayArgumentsNo
 
         @Specialization
         protected Object getData(DataHolder data) {
-            return data.getAddress();
+            return data.getPointer();
         }
     }
 
@@ -1975,7 +1975,7 @@ public abstract static class DataHolderSetData extends PrimitiveArrayArgumentsNo
 
         @Specialization
         protected Object setData(DataHolder data, Object address) {
-            data.setAddress(address);
+            data.setPointer(address);
             return nil;
         }
     }

src/main/java/org/truffleruby/cext/DataHolder.java

@@ -12,27 +12,29 @@
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import com.oracle.truffle.api.interop.InteropLibrary;
 import com.oracle.truffle.api.interop.TruffleObject;
+import com.oracle.truffle.api.interop.UnsupportedMessageException;
 import com.oracle.truffle.api.library.ExportLibrary;
 import com.oracle.truffle.api.library.ExportMessage;
 
 import org.truffleruby.RubyLanguage;
+import org.truffleruby.interop.TranslateInteropExceptionNode;
 
 /** This object represents a struct pointer in C held by a Ruby object. */
 @ExportLibrary(InteropLibrary.class)
 public final class DataHolder implements TruffleObject {
 
-    private volatile Object address;
+    private Object pointer;
 
     public DataHolder(Object address) {
-        this.address = address;
+        this.pointer = address;
     }
 
-    public Object getAddress() {
-        return address;
+    public Object getPointer() {
+        return pointer;
     }
 
-    public void setAddress(Object address) {
-        this.address = address;
+    public void setPointer(Object address) {
+        this.pointer = address;
     }
 
     @ExportMessage
@@ -48,13 +50,17 @@ protected Class<RubyLanguage> getLanguage() {
     @TruffleBoundary
     @Override
     public String toString() {
-        return address.toString();
+        return pointer.toString();
     }
 
     @TruffleBoundary
     @ExportMessage
     protected String toDisplayString(boolean allowSideEffects) {
         final InteropLibrary interop = InteropLibrary.getUncached();
-        return "DATA_HOLDER: " + interop.toDisplayString(address, allowSideEffects);
+        try {
+            return "DATA_HOLDER: " + interop.asString(interop.toDisplayString(pointer, allowSideEffects));
+        } catch (UnsupportedMessageException e) {
+            throw TranslateInteropExceptionNode.getUncached().execute(e);
+        }
     }
 }

src/main/java/org/truffleruby/core/DataObjectFinalizationService.java

@@ -78,7 +78,7 @@ public Object execute(DataObjectFinalizerReference ref) {
         private void runFinalizer(DataObjectFinalizerReference ref) throws Error {
             try {
                 if (!getContext().isFinalizing()) {
-                    Object data = ref.dataHolder.getAddress();
+                    Object data = ref.dataHolder.getPointer();
                     if (!nullNode.isNull(data)) {
                         final ExtensionCallStack stack = getLanguage().getCurrentThread()
                                 .getCurrentFiber().extensionCallStack;