--- /dev/null	2016-04-01 19:18:14.000000000 +0800
+++ new/test/sun/security/provider/SecureRandom/CommonSeeder.java	2016-04-01 19:18:14.000000000 +0800
@@ -0,0 +1,123 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+import sun.security.provider.AbstractDrbg;
+import sun.security.provider.EntropySource;
+import java.security.DrbgParameters;
+import java.security.SecureRandom;
+import java.security.Security;
+
+/**
+ * @test
+ * @bug 8051408
+ * @modules java.base/sun.security.provider
+ * @run main/othervm CommonSeeder
+ * @summary check entropy reading of DRBGs
+ */
+public class CommonSeeder {
+
+    static class MyES implements EntropySource {
+        int count = 100;
+        int lastCount = 100;
+
+        @Override
+        public byte[] getEntropy(int entropy, int minLength,
+                                 int maxLength, boolean pr) {
+            count--;
+            return new byte[minLength];
+        }
+
+        /**
+         * Confirms genEntropy() has been called {@code less} times
+         * since last check.
+         */
+        public void checkUsage(int less) throws Exception {
+            if (lastCount != count + less) {
+                throw new Exception(String.format(
+                        "lastCount = %d, count = %d, less = %d",
+                        lastCount, count, less));
+            }
+            lastCount = count;
+        }
+    }
+
+    public static void main(String[] args) throws Exception {
+
+        byte[] result = new byte[10];
+        MyES es = new MyES();
+
+        // Set es as the default entropy source, overriding SeedGenerator.
+        setDefaultSeeder(es);
+
+        // Nothing happened yet
+        es.checkUsage(0);
+
+        SecureRandom sr;
+        sr = SecureRandom.getInstance("DRBG");
+
+        // No entropy reading if only getInstance
+        es.checkUsage(0);
+
+        // Entropy is read at 1st nextBytes of the 1st DRBG
+        sr.nextInt();
+        es.checkUsage(1);
+
+        for (String mech: new String[]{"Hash_DRBG", "HMAC_DRBG", "CTR_DRBG"}) {
+            System.out.println("Testing " + mech + "...");
+
+            // DRBG with pr_false will never read entropy again no matter
+            // if nextBytes or reseed is called.
+
+            Security.setProperty("drbg", mech);
+            sr = SecureRandom.getInstance("DRBG");
+            sr.nextInt();
+            sr.reseed();
+            es.checkUsage(0);
+
+            // DRBG with pr_true always read from default entropy, and
+            // its nextBytes always reseed itself
+
+            Security.setProperty("drbg", mech + ",pr_and_reseed");
+            sr = SecureRandom.getInstance("DRBG");
+
+            sr.nextInt();
+            es.checkUsage(2); // one instantiate, one reseed
+            sr.nextInt();
+            es.checkUsage(1); // one reseed in nextBytes
+            sr.reseed();
+            es.checkUsage(1); // one reseed
+            sr.nextBytes(result, DrbgParameters.nextBytes(-1, false, null));
+            es.checkUsage(0); // pr_false for this call
+            sr.nextBytes(result, DrbgParameters.nextBytes(-1, true, null));
+            es.checkUsage(1); // pr_true for this call
+            sr.reseed(DrbgParameters.reseed(true, null));
+            es.checkUsage(1); // reseed from es
+            sr.reseed(DrbgParameters.reseed(false, null));
+            es.checkUsage(0); // reseed from AbstractDrbg.SeederHolder.seeder
+        }
+    }
+
+    static void setDefaultSeeder(EntropySource es) throws Exception {
+        AbstractDrbg.defaultES = es;
+    }
+}