8006628: NEED_TEST for JDK-8002870

Summary: Regression test for 8000311. Verifies that PLABStats works with zero parallel GC threads.
Reviewed-by: jmasa, johnc
Contributed-by: NFilipp Zhinkin <filipp.zhinkin@oracle.com>

test/gc/8000311/Test8000311.java

+/*
+ * Copyright (c) 2013, 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.
+ */
+
+/**
+ * @test Test8000311
+ * @key gc
+ * @bug 8000311
+ * @summary G1: ParallelGCThreads==0 broken
+ * @run main/othervm -XX:+UseG1GC -XX:ParallelGCThreads=0 -XX:+ResizePLAB -XX:+ExplicitGCInvokesConcurrent Test8000311
+ * @author filipp.zhinkin@oracle.com
+ */
+
+import java.util.*;
+
+public class Test8000311 {
+  public static void main(String args[]) {
+    for(int i = 0; i<100; i++) {
+      byte[] garbage = new byte[1000];
+      System.gc();
+    }
+  }
+}