--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/concurrent_phase_control/CheckUnsupported.java	Thu Apr 13 16:38:39 2017 -0400
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2017, 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 gc.concurrent_phase_control;
+
+/*
+ * Utility class that provides verification of expected behavior of
+ * the Concurrent GC Phase Control WB API when the current GC does not
+ * support phase control.  The invoking test must provide WhiteBox access.
+ */
+
+import sun.hotspot.WhiteBox;
+
+public class CheckUnsupported {
+
+    private static final WhiteBox WB = WhiteBox.getWhiteBox();
+
+    public static void check(String gcName) throws Exception {
+        // Verify unsupported.
+        if (WB.supportsConcurrentGCPhaseControl()) {
+            throw new RuntimeException(
+                gcName + " unexpectedly supports phase control");
+        }
+
+        // Verify phase sequence is empty.
+        String[] phases = WB.getConcurrentGCPhases();
+        if (phases.length > 0) {
+            throw new RuntimeException(
+                gcName + " unexpectedly has non-empty phases");
+        }
+
+        // Verify IllegalStateException thrown by request attempt.
+        boolean illegalStateThrown = false;
+        try {
+            WB.requestConcurrentGCPhase("UNKNOWN PHASE");
+        } catch (IllegalStateException e) {
+            // Expected.
+            illegalStateThrown = true;
+        } catch (Exception e) {
+            throw new RuntimeException(
+                gcName + ": Unexpected exception when requesting phase: "
+                + e.toString());
+        }
+        if (!illegalStateThrown) {
+            throw new RuntimeException(
+                gcName + ": No exception when requesting phase");
+        }
+    }
+}
+