test/jdk/java/lang/ThreadLocal/InitialValue.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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).
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 * 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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/*
 * @test
 * @bug     5025230
 * @summary Tests to see that a set nested in initialValue works OK
 * @author  Pete Soper
 */
public class InitialValue implements Runnable {

    static ThreadLocal<String> other;
    static boolean passed;

    public class MyLocal extends ThreadLocal<String> {
        String val;
        protected String initialValue() {
            other = new ThreadLocal<String>();
            // This should reuse the map that the containing get() created
            // or visa versa (i.e. instead of a second map being created).
            other.set("Other");
            return "Initial";
        }
    }

    public void run() {
        MyLocal l = new MyLocal();
        // This should pick up the initial value
        String s1 = l.get();
        // And this should pick up the other local in this thread's locals map
        String s2 = other.get();
        if ((s2 != null) && s2.equals("Other")) {
            // JMM guarantees this will be visible to
            // another thread joining with this thread's
            // termination: no need for this to be volatile.
            passed = true;
        }
    }

    public static void main(String[] args) {
        // Starting with Mustang the main thread already has an initialized
        // ThreadLocal map at this point, so test with a second thread.
        Thread t = new Thread(new InitialValue());
        t.start();
        try {
            t.join();
        } catch (InterruptedException e) {
            throw new RuntimeException("Test Interrupted: failed");
        }
        if (!passed) {
            throw new RuntimeException("Test Failed");
        }
    }
}