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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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,
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 *
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import java.util.concurrent.atomic.AtomicInteger;
import java.util.function.Supplier;
import org.testng.annotations.Test;
import static org.testng.Assert.*;

/**
 * @test
 * @run testng ThreadLocalSupplierTest
 * @summary tests ThreadLocal<Supplier>. Adapted from java.lang.Basic functional test of ThreadLocal
 *
 * @author Jim Gish <jim.gish@oracle.com>
 */
@Test
public class ThreadLocalSupplierTest {
    static IntegerFactory theFactory = new IntegerFactory();

    static class MyThreadLocal extends ThreadLocal<Integer> {
        public volatile boolean everCalled;

        public MyThreadLocal( Supplier<Integer> f ) {
            super(f);
        }

        @Override
        protected synchronized Integer initialValue() {
            // N.B. this should never be called since we are using the factory
            // instead
            everCalled = true;
            return null;
        }
    }

    /**
     * Our one and only ThreadLocal from which we get thread ids using a
     * factory which simply increments a counter on each call of make().
     */
    static MyThreadLocal threadLocal = new MyThreadLocal(theFactory);

    static class IntegerFactory implements Supplier<Integer> {
        private AtomicInteger whatImake = new AtomicInteger(0);

        @Override
        public Integer get() {
            return whatImake.getAndIncrement();
        }

        public int numCalls() {
            return whatImake.intValue();
        }
    }

    public ThreadLocalSupplierTest() {
    }

    public void test() throws Exception {
        int threadCount = 500;
        Thread th[] = new Thread[threadCount];
        final boolean visited[] = new boolean[threadCount];

        // Create and start the threads
        for (int i = 0; i < threadCount; i++) {
            th[i] = new Thread() {
                @Override
                public void run() {
                    int threadId = threadLocal.get();
                    assertFalse(visited[threadId], "visited[" + threadId + "]=" + visited[threadId]);
                    visited[threadId] = true;
                    // check the get() again
                    int secondCheckThreadId = threadLocal.get();
                    assertEquals( secondCheckThreadId, threadId );
                    Thread.yield();
                }
            };
            th[i].start();
        }

        // Wait for the threads to finish
        for (int i = 0; i < threadCount; i++) {
            th[i].join();
        }

        assertEquals(theFactory.numCalls(), threadCount );
        // make sure the provided initialValue() has not been called
        assertFalse(threadLocal.everCalled);
        // Check results
        for (int i = 0; i < threadCount; i++) {
            assertTrue(visited[i],"visited[" + i + "]=" + visited[i]);
        }
    }
}