PreemptTest.java

/*
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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
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 *
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 */

/*
 * @test
 * @summary test wisp time slice preempt
 * @requires os.family == "linux"
 * @library /lib/testlibrary
 * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+EnableCoroutine -Dcom.alibaba.wisp.transparentWispSwitch=true -Dcom.alibaba.wisp.carrierEngines=1 PreemptTest

 */

import com.alibaba.wisp.engine.WispEngine;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

import static jdk.testlibrary.Asserts.assertTrue;

public class PreemptTest {
    public static void main(String[] args) throws Exception {
        doTest(PreemptTest::simpleLoop);
    }

    private static void doTest(Runnable r) throws Exception {
        WispEngine.dispatch(r);
        CountDownLatch latch = new CountDownLatch(1);
        WispEngine.dispatch(latch::countDown);
        assertTrue(latch.await(5, TimeUnit.SECONDS));
    }

    private static void complexLoop() {
        MessageDigest md;
        try {
            md = MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException e) {
            throw new Error(e);
        }

        while (true) {
            md.update("welcome to the wisp world!".getBytes());
            n = md.digest()[0];
        }
    }

    private static void simpleLoop() {
        int x;
        do {
            x = n;
        } while (x == n);
    }

    // TODO: handle safepoint consumed by state switch

    volatile static int n;
}