Backport 82a8bd7e92a1867b0c82f051361938be8610428d

test/jdk/java/io/ObjectStreamClass/TestOSCClassLoaderLeak.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2022, 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
@@ -61,8 +61,7 @@ public void testClassLoaderLeak() throws Exception {
         con = null;
         assertNotNull(myOwnClassLoaderWeakReference.get());
 
-        ForceGC gc = new ForceGC();
-        assertTrue(gc.await(() -> myOwnClassLoaderWeakReference.get() == null));
+        assertTrue(ForceGC.wait(() -> myOwnClassLoaderWeakReference.get() == null));
     }
 }
 

test/jdk/java/lang/reflect/callerCache/ReflectionCallerCacheTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2022, 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
@@ -34,7 +34,6 @@
  */
 
 import java.io.IOException;
-import java.lang.ref.Cleaner;
 import java.lang.ref.WeakReference;
 import java.lang.reflect.*;
 import java.net.MalformedURLException;
@@ -43,11 +42,9 @@
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.concurrent.Callable;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.TimeUnit;
-import java.util.function.BooleanSupplier;
 
 import jdk.test.lib.compiler.CompilerUtils;
+import jdk.test.lib.util.ForceGC;
 import org.testng.annotations.BeforeTest;
 import org.testng.annotations.DataProvider;
 import org.testng.annotations.Test;
@@ -110,9 +107,7 @@ private void load(String classname) throws Exception {
         WeakReference<?> weakLoader = loadAndRunClass(classname);
 
         // Force garbage collection to trigger unloading of class loader
-        new ForceGC().await(() -> weakLoader.get() == null);
-
-        if (weakLoader.get() != null) {
+        if (!ForceGC.wait(() -> weakLoader.get() == null)) {
             throw new RuntimeException("Class " + classname + " not unloaded!");
         }
     }
@@ -141,37 +136,4 @@ static URL[] toURLs() {
             super("testloader", toURLs(), ClassLoader.getSystemClassLoader());
         }
     }
-
-    /**
-     * Utility class to invoke System.gc()
-     */
-    static class ForceGC {
-        private  final CountDownLatch cleanerInvoked = new CountDownLatch(1);
-        private  final Cleaner cleaner = Cleaner.create();
-
-        ForceGC() {
-            cleaner.register(new Object(), () -> cleanerInvoked.countDown());
-        }
-
-        void doit() {
-            try {
-                for (int i = 0; i < 10; i++) {
-                    System.gc();
-                    if (cleanerInvoked.await(1L, TimeUnit.SECONDS)) {
-                        return;
-                    }
-                }
-            } catch (InterruptedException unexpected) {
-                throw new AssertionError("unexpected InterruptedException");
-            }
-        }
-
-        void await(BooleanSupplier s) {
-            for (int i = 0; i < 10; i++) {
-                if (s.getAsBoolean()) return;
-                doit();
-            }
-            throw new AssertionError("failed to satisfy condition");
-        }
-    }
 }

test/jdk/sun/security/pkcs11/Provider/MultipleLogins.java

@@ -90,10 +90,8 @@ public static void main(String[] args) throws Exception {
             Security.removeProvider(providers[i].getName());
             providers[i] = null;
 
-            ForceGC gc = new ForceGC();
             int finalI = i;
-            gc.await(() -> weakRef[finalI].get() == null);
-            if (weakRef[i].get() != null) {
+            if (!ForceGC.wait(() -> weakRef[finalI].get() == null)) {
                 throw new RuntimeException("Expected SunPKCS11 Provider to be GC'ed..");
             }
         }

test/lib/jdk/test/lib/util/ForceGC.java

@@ -23,57 +23,54 @@
 
 package jdk.test.lib.util;
 
-import java.lang.ref.Cleaner;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.TimeUnit;
+import java.lang.ref.PhantomReference;
+import java.lang.ref.Reference;
+import java.lang.ref.ReferenceQueue;
 import java.util.function.BooleanSupplier;
 
 /**
  * Utility class to invoke System.gc()
  */
 public class ForceGC {
-    private final CountDownLatch cleanerInvoked = new CountDownLatch(1);
-    private final Cleaner cleaner = Cleaner.create();
-    private Object o;
-
-    public ForceGC() {
-        this.o = new Object();
-        cleaner.register(o, () -> cleanerInvoked.countDown());
-    }
-
-    private void doit(int iter) {
-        try {
-            for (int i = 0; i < 10; i++) {
-                System.gc();
-                System.out.println("doit() iter: " + iter + ", gc " + i);
-                if (cleanerInvoked.await(1L, TimeUnit.SECONDS)) {
-                    return;
-                }
-            }
-        } catch (InterruptedException unexpected) {
-            throw new AssertionError("unexpected InterruptedException");
-        }
-    }
+    // The jtreg testing timeout factor.
+    private static final double TIMEOUT_FACTOR = Double.valueOf(
+            System.getProperty("test.timeout.factor", "1.0"));
 
     /**
-     * Causes the current thread to wait until the {@code BooleanSupplier} returns true,
-     * unless the thread is interrupted or a predefined waiting time elapses.
+     * Causes the current thread to wait until the {@code booleanSupplier}
+     * returns true, or a specific waiting time elapses.  The waiting time
+     * is 1 second scaled with the jtreg testing timeout factor.
      *
-     * @param s boolean supplier
-     * @return true if the {@code BooleanSupplier} returns true and false if
-     *         the predefined waiting time elapsed before the count reaches zero.
-     * @throws InterruptedException if the current thread is interrupted while waiting
+     * @param booleanSupplier boolean supplier
+     * @return true if the {@code booleanSupplier} returns true, or false
+     *     if did not complete after the specific waiting time.
      */
-    public boolean await(BooleanSupplier s) {
-        o = null; // Keep reference to Object until now, to ensure the Cleaner
-                  // doesn't count down the latch before await() is called.
-        for (int i = 0; i < 10; i++) {
-            if (s.getAsBoolean()) return true;
-            doit(i);
-            try { Thread.sleep(1000); } catch (InterruptedException e) {
-                throw new AssertionError("unexpected interrupted sleep", e);
+    public static boolean wait(BooleanSupplier booleanSupplier) {
+        ReferenceQueue<Object> queue = new ReferenceQueue<>();
+        Object obj = new Object();
+        PhantomReference<Object> ref = new PhantomReference<>(obj, queue);
+        obj = null;
+        Reference.reachabilityFence(obj);
+        Reference.reachabilityFence(ref);
+
+        int retries = (int)(Math.round(1000L * TIMEOUT_FACTOR) / 200);
+        for (; retries >= 0; retries--) {
+            if (booleanSupplier.getAsBoolean()) {
+                return true;
+            }
+
+            System.gc();
+
+            try {
+                // The remove() will always block for the specified milliseconds
+                // if the reference has already been removed from the queue.
+                // But it is fine.  For most cases, the 1st GC is sufficient
+                // to trigger and complete the cleanup.
+                queue.remove(200L);
+            } catch (InterruptedException ie) {
+                // ignore, the loop will try again
             }
         }
-        return false;
+        return booleanSupplier.getAsBoolean();
     }
 }