From e62a7fa3832bbba11e6d630015f85ae945fac824 Mon Sep 17 00:00:00 2001 From: Albert Mingkun Yang Date: Fri, 17 Oct 2025 09:02:09 +0000 Subject: [PATCH] 8342659: Test vmTestbase/nsk/jdi/ObjectReference/referringObjects/referringObjects002/referringObjects002.java failed: Class nsk.share.jdi.TestClass1 was not unloaded Co-authored-by: Chris Plummer Reviewed-by: sspitsyn, cjplummer --- .../vmTestbase/nsk/share/ClassUnloader.java | 51 ++++++------------- .../nsk/share/jpda/AbstractDebuggeeTest.java | 12 +---- 2 files changed, 17 insertions(+), 46 deletions(-) diff --git a/test/hotspot/jtreg/vmTestbase/nsk/share/ClassUnloader.java b/test/hotspot/jtreg/vmTestbase/nsk/share/ClassUnloader.java index 5ea01fb3af4..e3b6693657c 100644 --- a/test/hotspot/jtreg/vmTestbase/nsk/share/ClassUnloader.java +++ b/test/hotspot/jtreg/vmTestbase/nsk/share/ClassUnloader.java @@ -1,5 +1,5 @@ /* - * Copyright (c) 2001, 2023, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2001, 2025, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it @@ -28,7 +28,7 @@ package nsk.share; -import java.lang.ref.Cleaner; +import java.lang.ref.PhantomReference; import java.util.*; import nsk.share.gc.gp.*; import nsk.share.test.ExecutionController; @@ -77,19 +77,9 @@ public class ClassUnloader { public static final String INTERNAL_CLASS_LOADER_NAME = "nsk.share.CustomClassLoader"; /** - * Whole amount of time in milliseconds to wait for class loader to be reclaimed. + * Phantom reference to the class loader. */ - private static final int WAIT_TIMEOUT = 15000; - - /** - * Sleep time in milliseconds for the loop waiting for the class loader to be reclaimed. - */ - private static final int WAIT_DELTA = 1000; - - /** - * Has class loader been reclaimed or not. - */ - volatile boolean is_reclaimed = false; + private PhantomReference customClassLoaderPhantomRef = null; /** * Current class loader used for loading classes. @@ -101,6 +91,14 @@ public class ClassUnloader { */ private Vector> classObjects = new Vector>(); + /** + * Has class loader been reclaimed or not. + */ + private boolean isClassLoaderReclaimed() { + return customClassLoaderPhantomRef != null + && customClassLoaderPhantomRef.refersTo(null); + } + /** * Class object of the first class been loaded with current class loader. * To get the rest loaded classes use getLoadedClass(int). @@ -138,8 +136,7 @@ public class ClassUnloader { customClassLoader = new CustomClassLoader(); classObjects.removeAllElements(); - // Register a Cleaner to inform us when the class loader has been reclaimed. - Cleaner.create().register(customClassLoader, () -> { is_reclaimed = true; } ); + customClassLoaderPhantomRef = new PhantomReference<>(customClassLoader, null); return customClassLoader; } @@ -154,8 +151,7 @@ public class ClassUnloader { this.customClassLoader = customClassLoader; classObjects.removeAllElements(); - // Register a Cleaner to inform us when the class loader has been reclaimed. - Cleaner.create().register(customClassLoader, () -> { is_reclaimed = true; } ); + customClassLoaderPhantomRef = new PhantomReference<>(customClassLoader, null); } /** @@ -244,32 +240,15 @@ public class ClassUnloader { */ public boolean unloadClass(ExecutionController stresser) { - is_reclaimed = false; - // free references to class and class loader to be able for collecting by GC - long waitTimeout = (customClassLoader == null) ? 0 : WAIT_TIMEOUT; classObjects.removeAllElements(); customClassLoader = null; // force class unloading by eating memory pool eatMemory(stresser); - // give GC chance to run and wait for receiving reclaim notification - long timeToFinish = System.currentTimeMillis() + waitTimeout; - while (!is_reclaimed && System.currentTimeMillis() < timeToFinish) { - if (!stresser.continueExecution()) { - return false; - } - try { - // suspend thread for a while - Thread.sleep(WAIT_DELTA); - } catch (InterruptedException e) { - throw new Failure("Unexpected InterruptedException while class unloading: " + e); - } - } - // force GC to unload marked class loader and its classes - if (is_reclaimed) { + if (isClassLoaderReclaimed()) { Runtime.getRuntime().gc(); return true; } diff --git a/test/hotspot/jtreg/vmTestbase/nsk/share/jpda/AbstractDebuggeeTest.java b/test/hotspot/jtreg/vmTestbase/nsk/share/jpda/AbstractDebuggeeTest.java index 0668297d211..86d5d7ecd24 100644 --- a/test/hotspot/jtreg/vmTestbase/nsk/share/jpda/AbstractDebuggeeTest.java +++ b/test/hotspot/jtreg/vmTestbase/nsk/share/jpda/AbstractDebuggeeTest.java @@ -1,5 +1,5 @@ /* - * Copyright (c) 2006, 2018, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2006, 2025, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it @@ -149,19 +149,11 @@ public class AbstractDebuggeeTest { } } - public static final int MAX_UNLOAD_ATTEMPS = 5; - public void unloadTestClass(String className, boolean expectedUnloadingResult) { ClassUnloader classUnloader = loadedClasses.get(className); - int unloadAttemps = 0; - if (classUnloader != null) { - boolean wasUnloaded = false; - - while (!wasUnloaded && (unloadAttemps++ < MAX_UNLOAD_ATTEMPS)) { - wasUnloaded = classUnloader.unloadClass(); - } + boolean wasUnloaded = classUnloader.unloadClass(); if (wasUnloaded) loadedClasses.remove(className);