--- /dev/null	2020-03-26 16:04:28.000000000 -0700
+++ new/test/lib/jdk/test/lib/util/ForceGC.java	2020-03-26 16:04:26.000000000 -0700
@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2020, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.test.lib.util;
+
+import java.lang.ref.Cleaner;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+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();
+    public ForceGC() {
+        cleaner.register(new Object(), () -> cleanerInvoked.countDown());
+    }
+
+    private void doit() {
+        try {
+            for (int i = 0; i < 10; i++) {
+                System.gc();
+                System.out.println("gc " + i);
+                if (cleanerInvoked.await(1L, TimeUnit.SECONDS)) {
+                    return;
+                }
+            }
+        } catch (InterruptedException unexpected) {
+            throw new AssertionError("unexpected InterruptedException");
+        }
+    }
+
+    /**
+     * Causes the current thread to wait until the {@code BooleanSupplier} returns true,
+     * unless the thread is interrupted or a predefined waiting time elapses.
+     *
+     * @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
+     */
+    public boolean await(BooleanSupplier s) {
+        for (int i = 0; i < 10; i++) {
+            if (s.getAsBoolean()) return true;
+            doit();
+        }
+        return false;
+    }
+}