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 * Copyright (c) 2020 Alibaba Group Holding Limited. All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation. Alibaba 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).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
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 */

/*
 * @test
 * @library /lib/testlibrary
 * @summary Test to verify we can do proper wisp scheduling while calling on Unsafe.park()
 * @requires os.family == "linux"
 * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+EnableCoroutine -Dcom.alibaba.wisp.transparentWispSwitch=true UnsafeParkTest
 */

import com.alibaba.wisp.engine.WispEngine;
import sun.misc.Unsafe;

import java.lang.reflect.Field;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;

import static jdk.testlibrary.Asserts.assertTrue;


public class UnsafeParkTest {
    public static void main(String[] args) throws Exception {
        Field f = Unsafe.class.getDeclaredField("theUnsafe");
        f.setAccessible(true);
        Unsafe unsafe = (Unsafe) f.get(null);

        AtomicLong awake = new AtomicLong();

        WispEngine.dispatch(() -> {
            try {
                Thread.sleep(300);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            awake.set(System.currentTimeMillis());
        });

        long start = System.currentTimeMillis();

        unsafe.park(false, 1);
        unsafe.park(false, TimeUnit.MILLISECONDS.toNanos(500));

        assertTrue(Math.abs(awake.get() - start - 300) < 100,
                "awake should be set before unsafe.park expired " + awake.get() + " " + start);
    }
}