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/**
 * @test
 * @summary Test parking when pinned and emitting the JFR VirtualThreadPinnedEvent throws
 * @modules java.base/java.lang:+open java.base/jdk.internal.event
 * @library /test/lib
 * @compile/module=java.base jdk/internal/event/VirtualThreadPinnedEvent.java
 * @run junit/othervm --enable-native-access=ALL-UNNAMED VirtualThreadPinnedEventThrows
 */

import java.lang.ref.Reference;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;
import java.util.concurrent.locks.LockSupport;
import jdk.internal.event.VirtualThreadPinnedEvent;

import jdk.test.lib.thread.VThreadRunner;
import jdk.test.lib.thread.VThreadPinner;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.BeforeAll;
import static org.junit.jupiter.api.Assertions.*;

class VirtualThreadPinnedEventThrows {

    @BeforeAll
    static void setup() {
        // need >=2 carriers for testing pinning when main thread is a virtual thread
        if (Thread.currentThread().isVirtual()) {
            VThreadRunner.ensureParallelism(2);
        }
    }

    /**
     * Test parking when pinned and creating the VirtualThreadPinnedEvent fails with OOME.
     */
    @Test
    void testVirtualThreadPinnedEventCreateThrows() throws Exception {
        VirtualThreadPinnedEvent.setCreateThrows(true);
        try {
            testParkWhenPinned();
        } finally {
            VirtualThreadPinnedEvent.setCreateThrows(false);
        }
    }

    /**
     * Test parking when pinned and VirtualThreadPinnedEvent.begin fails with OOME.
     */
    @Test
    void testVirtualThreadPinnedEventBeginThrows() throws Exception {
        VirtualThreadPinnedEvent.setBeginThrows(true);
        try {
            testParkWhenPinned();
        } finally {
            VirtualThreadPinnedEvent.setBeginThrows(false);
        }
    }

    /**
     * Test parking when pinned and VirtualThreadPinnedEvent.commit fails with OOME.
     */
    @Test
    void testVirtualThreadPinnedEventCommitThrows() throws Exception {
        VirtualThreadPinnedEvent.setCommitThrows(true);
        try {
            testParkWhenPinned();
        } finally {
            VirtualThreadPinnedEvent.setCommitThrows(false);
        }
    }

    /**
     * Test parking a virtual thread when pinned.
     */
    private void testParkWhenPinned() throws Exception {
        var exception = new AtomicReference<Throwable>();
        var done = new AtomicBoolean();
        Thread thread = Thread.startVirtualThread(() -> {
            try {
                VThreadPinner.runPinned(() -> {
                    while (!done.get()) {
                        LockSupport.park();
                    }
                });
            } catch (Throwable e) {
                exception.set(e);
            }
        });
        try {
            // wait for thread to park
            Thread.State state;
            while ((state = thread.getState()) != Thread.State.WAITING) {
                assertTrue(state != Thread.State.TERMINATED);
                Thread.sleep(10);
            }
        } finally {
            done.set(true);
            LockSupport.unpark(thread);
            thread.join();
        }
        assertNull(exception.get());
    }
}