ThreadSafe.java

/*
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 * 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.
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import java.security.Provider;
import java.security.SecureRandom;
import java.security.SecureRandomSpi;
import java.util.Map;

/*
 * @test
 * @bug 7004967
 * @summary SecureRandom should be more explicit about threading
 */
public class ThreadSafe {
    public static void main(String[] args) throws Exception {
        Provider p = new P();
        NoSync.test(SecureRandom.getInstance("S1", p), 5, 5);
        try {
            NoSync.test(SecureRandom.getInstance("S2", p), 5, 5);
            throw new Exception("Failed");
        } catch (RuntimeException re) {
            // Good
        }
        NoSync.test(SecureRandom.getInstance("S3", p), 5, 5);
        try {
            NoSync.test(SecureRandom.getInstance("S4", p), 5, 5);
            throw new Exception("Failed");
        } catch (RuntimeException re) {
            // Good
        }
    }

    public static class P extends Provider {
        public P() {

            super("P", 1.0d, "Haha");

            // Good. No attribute.
            put("SecureRandom.S1", S.class.getName());

            // Bad. Boasting ThreadSafe but isn't
            put("SecureRandom.S2", S.class.getName());
            put("SecureRandom.S2 ThreadSafe", "true");

            // Good. No attribute.
            putService(new Service(this, "SecureRandom", "S3",
                    S.class.getName(), null, null));

            // Bad. Boasting ThreadSafe but isn't
            putService(new Service(this, "SecureRandom", "S4",
                    S.class.getName(), null, Map.of("ThreadSafe", "true")));
        }
    }

    // This implementation is not itself thread safe.
    public static class S extends SecureRandomSpi {
        @java.lang.Override
        protected void engineSetSeed(byte[] seed) {
            return;
        }

        private volatile boolean inCall = false;
        @Override
        protected void engineNextBytes(byte[] bytes) {
            if (inCall) {
                throw new RuntimeException("IN CALL");
            }
            inCall = true;
            try {
                Thread.sleep(500);
            } catch (Exception e) {
                // OK
            }
            inCall = false;
        }

        @Override
        protected byte[] engineGenerateSeed(int numBytes) {
            return new byte[numBytes];
        }
    }
}