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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
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/**
 * @test TestSpinPause
 * @summary JVM runtime can use SpinPause function for synchronized statements.
 *          Check different implementations of JVM SpinPause don't crash JVM.
 * @bug 8278241
 * @library /test/lib
 *
 * @requires os.arch=="aarch64"
 *
 * @run main/othervm TestSpinPause
 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=none TestSpinPause
 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=nop TestSpinPause
 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=isb TestSpinPause
 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=yield TestSpinPause
 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=nop -XX:OnSpinWaitInstCount=10 TestSpinPause
 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=isb -XX:OnSpinWaitInstCount=3 TestSpinPause
 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=yield -XX:OnSpinWaitInstCount=3 TestSpinPause
 * @run main/othervm -Xint TestSpinPause
 * @run main/othervm -Xint -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=none TestSpinPause
 * @run main/othervm -Xint -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=nop TestSpinPause
 * @run main/othervm -Xint -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=isb TestSpinPause
 * @run main/othervm -Xint -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=yield TestSpinPause
 * @run main/othervm -Xint -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=nop -XX:OnSpinWaitInstCount=10 TestSpinPause
 * @run main/othervm -Xint -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=isb -XX:OnSpinWaitInstCount=3 TestSpinPause
 * @run main/othervm -Xint -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=yield -XX:OnSpinWaitInstCount=3 TestSpinPause
 * @run main/othervm -Xcomp TestSpinPause
 * @run main/othervm -Xcomp -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=none TestSpinPause
 * @run main/othervm -Xcomp -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=nop TestSpinPause
 * @run main/othervm -Xcomp -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=isb TestSpinPause
 * @run main/othervm -Xcomp -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=yield TestSpinPause
 * @run main/othervm -Xcomp -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=nop -XX:OnSpinWaitInstCount=10 TestSpinPause
 * @run main/othervm -Xcomp -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=isb -XX:OnSpinWaitInstCount=3 TestSpinPause
 * @run main/othervm -Xcomp -XX:+UnlockDiagnosticVMOptions -XX:OnSpinWaitInst=yield -XX:OnSpinWaitInstCount=3 TestSpinPause
 */

public class TestSpinPause {
    private Integer[] valueHolder;

    private TestSpinPause () {
        valueHolder = new Integer[] {Integer.valueOf(101)};
    }

    private void getSet() {
        final int iterCount = 100;
        for (int i = 0; i < iterCount; ++i) {
           synchronized (valueHolder) {
               Integer v = valueHolder[0];
               valueHolder[0] = Integer.reverse(v);
           }
        }
    }

    public static void main(String[] args) throws Exception {
        TestSpinPause test = new TestSpinPause();
        Thread t1 = new Thread(test::getSet);
        Thread t2 = new Thread(test::getSet);
        t1.start();
        t2.start();
        t1.join();
        t2.join();
        System.out.println("Done: " + test.valueHolder[0]);
    }
}