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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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 8289610 8249627 8205132 8320532
 * @summary Test that Thread stops throws UOE
 * @run junit ThreadStopTest
 */

import java.time.Duration;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.locks.LockSupport;
import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

class ThreadStopTest {

    /**
     * Test current thread calling Thread.stop on itself.
     */
    @Test
    void testCurrentThread() {
        var thread = Thread.currentThread();
        assertThrows(UnsupportedOperationException.class, thread::stop);
    }

    /**
     * Test Thread.stop on an unstarted thread.
     */
    @Test
    void testUnstartedThread() {
        Thread thread = new Thread(() -> { });
        assertThrows(UnsupportedOperationException.class, thread::stop);
        assertTrue(thread.getState() == Thread.State.NEW);
    }

    /**
     * Test Thread.stop on a thread spinning in a loop.
     */
    @Test
    void testRunnableThread() throws Exception {
        AtomicBoolean done = new AtomicBoolean();
        Thread thread = new Thread(() -> {
            while (!done.get()) {
                Thread.onSpinWait();
            }
        });
        thread.start();
        try {
            assertThrows(UnsupportedOperationException.class, thread::stop);

            // thread should not terminate
            boolean terminated = thread.join(Duration.ofMillis(500));
            assertFalse(terminated);
        } finally {
            done.set(true);
            thread.join();
        }
    }

    /**
     * Test Thread.stop on a thread that is parked.
     */
    @Test
    void testWaitingThread() throws Exception {
        Thread thread = new Thread(LockSupport::park);
        thread.start();
        try {
            // wait for thread to park
            while ((thread.getState() != Thread.State.WAITING)) {
                Thread.sleep(10);
            }
            assertThrows(UnsupportedOperationException.class, thread::stop);
            assertTrue(thread.getState() == Thread.State.WAITING);
        } finally {
            LockSupport.unpark(thread);
            thread.join();
        }
    }

    /**
     * Test Thread.stop on a terminated thread.
     */
    @Test
    void testTerminatedThread() throws Exception {
        Thread thread = new Thread(() -> { });
        thread.start();
        thread.join();
        assertThrows(UnsupportedOperationException.class, thread::stop);
        assertTrue(thread.getState() == Thread.State.TERMINATED);
    }
}