src/test/java/io/reactivex/rxjava4/schedulers/TrampolineSchedulerTest.java - 4.x - githubmirror/RxJava

src/test/java/io/reactivex/rxjava4/schedulers/TrampolineSchedulerTest.java
122 строки5 KB
David Karnok
4.x: Convert from JUnit 4 to JUnit 6 (#8202)
30 июн 2026, 12:01
30 июн 2026, 12:01531388f
/*
 * Copyright (c) 2016-present, RxJava Contributors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is
 * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
 * the License for the specific language governing permissions and limitations under the License.
 */

package io.reactivex.rxjava4.schedulers;

import static org.junit.jupiter.api.Assertions.assertEquals;

import java.util.*;
import java.util.concurrent.Flow.*;
import java.util.concurrent.TimeUnit;

import org.junit.jupiter.api.Test;

import io.reactivex.rxjava4.core.*;
import io.reactivex.rxjava4.core.Scheduler.Worker;
import io.reactivex.rxjava4.disposables.*;
import io.reactivex.rxjava4.functions.Function;
import io.reactivex.rxjava4.internal.functions.Functions;
import io.reactivex.rxjava4.subscribers.TestSubscriber;
import io.reactivex.rxjava4.testsupport.TestHelper;

public class TrampolineSchedulerTest extends AbstractSchedulerTests {

    @Override
    protected Scheduler getScheduler() {
        return Schedulers.trampoline();
    }

    @Test
    public final void mergeWithCurrentThreadScheduler1() {

        final String currentThreadName = Thread.currentThread().getName();

        Flowable<Integer> f1 = Flowable.<Integer> just(1, 2, 3, 4, 5);
        Flowable<Integer> f2 = Flowable.<Integer> just(6, 7, 8, 9, 10);
        Flowable<String> f = Flowable.<Integer> mergeArray(f1, f2)
        .subscribeOn(Schedulers.trampoline())
        .map(t -> {
            assertEquals(Thread.currentThread().getName(), currentThreadName);
            return "Value_" + t + "_Thread_" + Thread.currentThread().getName();
        });

        f.blockingForEach(t -> System.out.println("t: " + t));
    }

    @Test
    public void nestedTrampolineWithUnsubscribe() {
        final ArrayList<String> workDone = new ArrayList<>();
        final CompositeDisposable workers = new CompositeDisposable();
        Worker worker = Schedulers.trampoline().createWorker();
        try {
            workers.add(worker);
            worker.schedule(() -> workers.add(doWorkOnNewTrampoline("A", workDone)));

            final Worker worker2 = Schedulers.trampoline().createWorker();
            workers.add(worker2);
            worker2.schedule(() -> {
                workers.add(doWorkOnNewTrampoline("B", workDone));
                // we unsubscribe worker2 ... it should not affect work scheduled on a separate Trampline.Worker
                worker2.dispose();
            });

            assertEquals(6, workDone.size());
            assertEquals(Arrays.asList("A.1", "A.B.1", "A.B.2", "B.1", "B.B.1", "B.B.2"), workDone);
        } finally {
            workers.dispose();
        }
    }

    /**
     * This is a regression test for #1702. Concurrent work scheduling that is improperly synchronized can cause an
     * action to be added or removed onto the priority queue during a poll, which can result in NPEs during queue
     * sifting. While it is difficult to isolate the issue directly, we can easily trigger the behavior by spamming the
     * trampoline with enqueue requests from multiple threads concurrently.
     */
    @Test
    public void trampolineWorkerHandlesConcurrentScheduling() {
        final Worker trampolineWorker = Schedulers.trampoline().createWorker();
        final Subscriber<Object> subscriber = TestHelper.mockSubscriber();
        final TestSubscriber<Disposable> ts = new TestSubscriber<>(subscriber);

        // Spam the trampoline with actions.
        Flowable.range(0, 50)
                .flatMap((Function<Integer, Publisher<Disposable>>) _ -> Flowable
                        .interval(1, TimeUnit.MICROSECONDS)
                        .map(_ -> trampolineWorker.schedule(Functions.EMPTY_RUNNABLE)).take(100))
                .subscribeOn(Schedulers.computation())
                .subscribe(ts);
        ts.awaitDone(5, TimeUnit.SECONDS);
        ts.assertNoErrors();
    }

    private static Worker doWorkOnNewTrampoline(final String key, final ArrayList<String> workDone) {
        Worker worker = Schedulers.trampoline().createWorker();
        worker.schedule(() -> {
            String msg = key + ".1";
            workDone.add(msg);
            System.out.println(msg);
            Worker worker3 = Schedulers.trampoline().createWorker();
            worker3.schedule(createPrintAction(key + ".B.1", workDone));
            worker3.schedule(createPrintAction(key + ".B.2", workDone));
        });
        return worker;
    }

    private static Runnable createPrintAction(final String message, final ArrayList<String> workDone) {
        return () -> {
            System.out.println(message);
            workDone.add(message);
        };
    }
}