--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/gc/class_unloading/TestCMSClassUnloadingEnabledHWM.java	Tue Apr 07 14:58:49 2015 +0200
@@ -0,0 +1,128 @@
+/*
+ * Copyright (c) 2014, 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
+ * @key gc
+ * @bug 8049831
+ * @library /testlibrary /testlibrary/whitebox
+ * @build TestCMSClassUnloadingEnabledHWM
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ * @run driver TestCMSClassUnloadingEnabledHWM
+ * @summary Test that -XX:-CMSClassUnloadingEnabled will trigger a Full GC when more than MetaspaceSize metadata is allocated.
+ */
+
+import com.oracle.java.testlibrary.OutputAnalyzer;
+import com.oracle.java.testlibrary.ProcessTools;
+import java.lang.management.GarbageCollectorMXBean;
+import java.lang.management.ManagementFactory;
+import java.util.ArrayList;
+import java.util.Arrays;
+import sun.hotspot.WhiteBox;
+
+public class TestCMSClassUnloadingEnabledHWM {
+  private static long MetaspaceSize = 32 * 1024 * 1024;
+  private static long YoungGenSize  = 32 * 1024 * 1024;
+
+  private static OutputAnalyzer run(boolean enableUnloading) throws Exception {
+    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+      "-Xbootclasspath/a:.",
+      "-XX:+UnlockDiagnosticVMOptions",
+      "-XX:+WhiteBoxAPI",
+      "-Xmx128m",
+      "-XX:CMSMaxAbortablePrecleanTime=1",
+      "-XX:CMSWaitDuration=50",
+      "-XX:MetaspaceSize=" + MetaspaceSize,
+      "-Xmn" + YoungGenSize,
+      "-XX:+UseConcMarkSweepGC",
+      "-XX:" + (enableUnloading ? "+" : "-") + "CMSClassUnloadingEnabled",
+      "-XX:+PrintHeapAtGC",
+      "-XX:+PrintGCDetails",
+      "-XX:+PrintGCTimeStamps",
+      TestCMSClassUnloadingEnabledHWM.AllocateBeyondMetaspaceSize.class.getName(),
+      "" + MetaspaceSize);
+    return new OutputAnalyzer(pb.start());
+  }
+
+  public static OutputAnalyzer runWithCMSClassUnloading() throws Exception {
+    return run(true);
+  }
+
+  public static OutputAnalyzer runWithoutCMSClassUnloading() throws Exception {
+    return run(false);
+  }
+
+  public static void testWithoutCMSClassUnloading() throws Exception {
+    // -XX:-CMSClassUnloadingEnabled is used, so we expect a full GC instead of a concurrent cycle.
+    OutputAnalyzer out = runWithoutCMSClassUnloading();
+
+    out.shouldMatch(".*Full GC.*");
+    out.shouldNotMatch(".*CMS Initial Mark.*");
+  }
+
+  public static void testWithCMSClassUnloading() throws Exception {
+    // -XX:+CMSClassUnloadingEnabled is used, so we expect a concurrent cycle instead of a full GC.
+    OutputAnalyzer out = runWithCMSClassUnloading();
+
+    out.shouldMatch(".*CMS Initial Mark.*");
+    out.shouldNotMatch(".*Full GC.*");
+  }
+
+  public static void main(String args[]) throws Exception {
+    testWithCMSClassUnloading();
+    testWithoutCMSClassUnloading();
+  }
+
+  public static class AllocateBeyondMetaspaceSize {
+    public static void main(String [] args) throws Exception {
+      if (args.length != 1) {
+        throw new IllegalArgumentException("Usage: <MetaspaceSize>");
+      }
+
+      WhiteBox wb = WhiteBox.getWhiteBox();
+
+      // Allocate past the MetaspaceSize limit.
+      long metaspaceSize = Long.parseLong(args[0]);
+      long allocationBeyondMetaspaceSize  = metaspaceSize * 2;
+      long metaspace = wb.allocateMetaspace(null, allocationBeyondMetaspaceSize);
+
+      // Wait for at least one GC to occur. The caller will parse the log files produced.
+      GarbageCollectorMXBean cmsGCBean = getCMSGCBean();
+      while (cmsGCBean.getCollectionCount() == 0) {
+        Thread.sleep(100);
+      }
+
+      wb.freeMetaspace(null, metaspace, metaspace);
+    }
+
+    private static GarbageCollectorMXBean getCMSGCBean() {
+      for (GarbageCollectorMXBean gcBean : ManagementFactory.getGarbageCollectorMXBeans()) {
+        if (gcBean.getObjectName().toString().equals("java.lang:type=GarbageCollector,name=ConcurrentMarkSweep")) {
+          return gcBean;
+        }
+      }
+      return null;
+    }
+  }
+}
+