code: /*
   * 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.rxjava3.internal.util;
  
  import static org.junit.Assert.*;
  
  import java.io.IOException;
  import java.util.*;
  import java.util.concurrent.atomic.AtomicLong;
  
  import org.junit.Test;
  import org.reactivestreams.*;
  
  import io.reactivex.rxjava3.core.Observer;
  import io.reactivex.rxjava3.core.RxJavaTest;
  import io.reactivex.rxjava3.disposables.*;
  import io.reactivex.rxjava3.exceptions.*;
  import io.reactivex.rxjava3.functions.BooleanSupplier;
  import io.reactivex.rxjava3.internal.subscriptions.BooleanSubscription;
  import io.reactivex.rxjava3.observers.TestObserver;
  import io.reactivex.rxjava3.operators.SpscArrayQueue;
  import io.reactivex.rxjava3.subscribers.TestSubscriber;
  import io.reactivex.rxjava3.testsupport.TestHelper;
  
  public class QueueDrainHelperTest extends RxJavaTest {
  
      @Test
      public void isCancelled() {
          assertTrue(QueueDrainHelper.isCancelled(new BooleanSupplier() {
              @Override
              public boolean getAsBoolean() throws Exception {
                  throw new IOException();
              }
          }));
      }
  
      @Test
      public void requestMaxInt() {
          QueueDrainHelper.request(new Subscription() {
              @Override
              public void request(long n) {
                  assertEquals(Integer.MAX_VALUE, n);
              }
  
              @Override
              public void cancel() {
              }
          }, Integer.MAX_VALUE);
      }
  
      @Test
      public void requestMinInt() {
          QueueDrainHelper.request(new Subscription() {
              @Override
              public void request(long n) {
                  assertEquals(Long.MAX_VALUE, n);
              }
  
              @Override
              public void cancel() {
              }
          }, Integer.MIN_VALUE);
      }
  
      @Test
      public void requestAlmostMaxInt() {
          QueueDrainHelper.request(new Subscription() {
              @Override
              public void request(long n) {
                  assertEquals(Integer.MAX_VALUE - 1, n);
              }
  
              @Override
              public void cancel() {
              }
          }, Integer.MAX_VALUE - 1);
      }
  
      @Test
      public void postCompleteEmpty() {
          TestSubscriber<Integer> ts = new TestSubscriber<>();
          ArrayDeque<Integer> queue = new ArrayDeque<>();
          AtomicLong state = new AtomicLong();
          BooleanSupplier isCancelled = new BooleanSupplier() {
              @Override
              public boolean getAsBoolean() throws Exception {
                  return false;
              }
          };
  
          ts.onSubscribe(new BooleanSubscription());
  
          QueueDrainHelper.postComplete(ts, queue, state, isCancelled);
  
          ts.assertResult();
      }
  
      @Test
      public void postCompleteWithRequest() {
          TestSubscriber<Integer> ts = new TestSubscriber<>();
          ArrayDeque<Integer> queue = new ArrayDeque<>();
          AtomicLong state = new AtomicLong();
          BooleanSupplier isCancelled = new BooleanSupplier() {
              @Override
              public boolean getAsBoolean() throws Exception {
                  return false;
              }
          };
  
          ts.onSubscribe(new BooleanSubscription());
          queue.offer(1);
          state.getAndIncrement();
  
          QueueDrainHelper.postComplete(ts, queue, state, isCancelled);
  
          ts.assertResult(1);
      }
  
      @Test
      public void completeRequestRace() {
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              final TestSubscriber<Integer> ts = new TestSubscriber<>();
              final ArrayDeque<Integer> queue = new ArrayDeque<>();
              final AtomicLong state = new AtomicLong();
              final BooleanSupplier isCancelled = new BooleanSupplier() {
                  @Override
                  public boolean getAsBoolean() throws Exception {
                      return false;
                  }
              };
  
              ts.onSubscribe(new BooleanSubscription());
              queue.offer(1);
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      QueueDrainHelper.postCompleteRequest(1, ts, queue, state, isCancelled);
                  }
              };
  
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      QueueDrainHelper.postComplete(ts, queue, state, isCancelled);
                  }
              };
  
              TestHelper.race(r1, r2);
  
              ts.assertResult(1);
          }
      }
  
      @Test
      public void postCompleteCancelled() {
          final TestSubscriber<Integer> ts = new TestSubscriber<>();
          ArrayDeque<Integer> queue = new ArrayDeque<>();
          AtomicLong state = new AtomicLong();
          BooleanSupplier isCancelled = new BooleanSupplier() {
              @Override
              public boolean getAsBoolean() throws Exception {
                  return ts.isCancelled();
              }
          };
  
          ts.onSubscribe(new BooleanSubscription());
          queue.offer(1);
          state.getAndIncrement();
          ts.cancel();
  
          QueueDrainHelper.postComplete(ts, queue, state, isCancelled);
  
          ts.assertEmpty();
      }
  
      @Test
      public void postCompleteCancelledAfterOne() {
          final TestSubscriber<Integer> ts = new TestSubscriber<Integer>() {
              @Override
              public void onNext(Integer t) {
                  super.onNext(t);
                  cancel();
              }
          };
          ArrayDeque<Integer> queue = new ArrayDeque<>();
          AtomicLong state = new AtomicLong();
          BooleanSupplier isCancelled = new BooleanSupplier() {
              @Override
              public boolean getAsBoolean() throws Exception {
                  return ts.isCancelled();
              }
          };
  
          ts.onSubscribe(new BooleanSubscription());
          queue.offer(1);
          state.getAndIncrement();
  
          QueueDrainHelper.postComplete(ts, queue, state, isCancelled);
  
          ts.assertValue(1).assertNoErrors().assertNotComplete();
      }
  
      @Test
      public void drainMaxLoopMissingBackpressure() {
          TestSubscriber<Integer> ts = new TestSubscriber<>();
          ts.onSubscribe(new BooleanSubscription());
  
          QueueDrain<Integer, Integer> qd = new QueueDrain<Integer, Integer>() {
              @Override
              public boolean cancelled() {
                  return false;
              }
  
              @Override
              public boolean done() {
                  return false;
              }
  
              @Override
              public Throwable error() {
                  return null;
              }
  
              @Override
              public boolean enter() {
                  return true;
              }
  
              @Override
              public long requested() {
                  return 0;
              }
  
              @Override
              public long produced(long n) {
                  return 0;
              }
  
              @Override
              public int leave(int m) {
                  return 0;
              }
  
              @Override
              public boolean accept(Subscriber<? super Integer> a, Integer v) {
                  return false;
              }
          };
  
          SpscArrayQueue<Integer> q = new SpscArrayQueue<>(32);
          q.offer(1);
  
          QueueDrainHelper.drainMaxLoop(q, ts, false, null, qd);
  
          ts.assertFailure(MissingBackpressureException.class);
      }
  
      @Test
      public void drainMaxLoopMissingBackpressureWithResource() {
          TestSubscriber<Integer> ts = new TestSubscriber<>();
          ts.onSubscribe(new BooleanSubscription());
  
          QueueDrain<Integer, Integer> qd = new QueueDrain<Integer, Integer>() {
              @Override
              public boolean cancelled() {
                  return false;
              }
  
              @Override
              public boolean done() {
                  return false;
              }
  
              @Override
              public Throwable error() {
                  return null;
              }
  
              @Override
              public boolean enter() {
                  return true;
              }
  
              @Override
              public long requested() {
                  return 0;
              }
  
              @Override
              public long produced(long n) {
                  return 0;
              }
  
              @Override
              public int leave(int m) {
                  return 0;
              }
  
              @Override
              public boolean accept(Subscriber<? super Integer> a, Integer v) {
                  return false;
              }
          };
  
          SpscArrayQueue<Integer> q = new SpscArrayQueue<>(32);
          q.offer(1);
  
          Disposable d = Disposable.empty();
  
          QueueDrainHelper.drainMaxLoop(q, ts, false, d, qd);
  
          ts.assertFailure(MissingBackpressureException.class);
  
          assertTrue(d.isDisposed());
      }
  
      @Test
      public void drainMaxLoopDontAccept() {
          TestSubscriber<Integer> ts = new TestSubscriber<>();
          ts.onSubscribe(new BooleanSubscription());
  
          QueueDrain<Integer, Integer> qd = new QueueDrain<Integer, Integer>() {
              @Override
              public boolean cancelled() {
                  return false;
              }
  
              @Override
              public boolean done() {
                  return false;
              }
  
              @Override
              public Throwable error() {
                  return null;
              }
  
              @Override
              public boolean enter() {
                  return true;
              }
  
              @Override
              public long requested() {
                  return 1;
              }
  
              @Override
              public long produced(long n) {
                  return 0;
              }
  
              @Override
              public int leave(int m) {
                  return 0;
              }
  
              @Override
              public boolean accept(Subscriber<? super Integer> a, Integer v) {
                  return false;
              }
          };
  
          SpscArrayQueue<Integer> q = new SpscArrayQueue<>(32);
          q.offer(1);
  
          QueueDrainHelper.drainMaxLoop(q, ts, false, null, qd);
  
          ts.assertEmpty();
      }
  
      @Test
      public void checkTerminatedDelayErrorEmpty() {
          TestSubscriber<Integer> ts = new TestSubscriber<>();
          ts.onSubscribe(new BooleanSubscription());
  
          QueueDrain<Integer, Integer> qd = new QueueDrain<Integer, Integer>() {
              @Override
              public boolean cancelled() {
                  return false;
              }
  
              @Override
              public boolean done() {
                  return false;
              }
  
              @Override
              public Throwable error() {
                  return null;
              }
  
              @Override
              public boolean enter() {
                  return true;
              }
  
              @Override
              public long requested() {
                  return 0;
              }
  
              @Override
              public long produced(long n) {
                  return 0;
              }
  
              @Override
              public int leave(int m) {
                  return 0;
              }
  
              @Override
              public boolean accept(Subscriber<? super Integer> a, Integer v) {
                  return false;
              }
          };
  
          SpscArrayQueue<Integer> q = new SpscArrayQueue<>(32);
  
          QueueDrainHelper.checkTerminated(true, true, ts, true, q, qd);
  
          ts.assertResult();
      }
  
      @Test
      public void checkTerminatedDelayErrorNonEmpty() {
          TestSubscriber<Integer> ts = new TestSubscriber<>();
          ts.onSubscribe(new BooleanSubscription());
  
          QueueDrain<Integer, Integer> qd = new QueueDrain<Integer, Integer>() {
              @Override
              public boolean cancelled() {
                  return false;
              }
  
              @Override
              public boolean done() {
                  return false;
              }
  
              @Override
              public Throwable error() {
                  return null;
              }
  
              @Override
              public boolean enter() {
                  return true;
              }
  
              @Override
              public long requested() {
                  return 0;
              }
  
              @Override
              public long produced(long n) {
                  return 0;
              }
  
              @Override
              public int leave(int m) {
                  return 0;
              }
  
              @Override
              public boolean accept(Subscriber<? super Integer> a, Integer v) {
                  return false;
              }
          };
  
          SpscArrayQueue<Integer> q = new SpscArrayQueue<>(32);
  
          QueueDrainHelper.checkTerminated(true, false, ts, true, q, qd);
  
          ts.assertEmpty();
      }
  
      @Test
      public void checkTerminatedDelayErrorEmptyError() {
          TestSubscriber<Integer> ts = new TestSubscriber<>();
          ts.onSubscribe(new BooleanSubscription());
  
          QueueDrain<Integer, Integer> qd = new QueueDrain<Integer, Integer>() {
              @Override
              public boolean cancelled() {
                  return false;
              }
  
              @Override
              public boolean done() {
                  return false;
              }
  
              @Override
              public Throwable error() {
                  return new TestException();
              }
  
              @Override
              public boolean enter() {
                  return true;
              }
  
              @Override
              public long requested() {
                  return 0;
              }
  
              @Override
              public long produced(long n) {
                  return 0;
              }
  
              @Override
              public int leave(int m) {
                  return 0;
              }
  
              @Override
              public boolean accept(Subscriber<? super Integer> a, Integer v) {
                  return false;
              }
          };
  
          SpscArrayQueue<Integer> q = new SpscArrayQueue<>(32);
  
          QueueDrainHelper.checkTerminated(true, true, ts, true, q, qd);
  
          ts.assertFailure(TestException.class);
      }
  
      @Test
      public void checkTerminatedNonDelayErrorError() {
          TestSubscriber<Integer> ts = new TestSubscriber<>();
          ts.onSubscribe(new BooleanSubscription());
  
          QueueDrain<Integer, Integer> qd = new QueueDrain<Integer, Integer>() {
              @Override
              public boolean cancelled() {
                  return false;
              }
  
              @Override
              public boolean done() {
                  return false;
              }
  
              @Override
              public Throwable error() {
                  return new TestException();
              }
  
              @Override
              public boolean enter() {
                  return true;
              }
  
              @Override
              public long requested() {
                  return 0;
              }
  
              @Override
              public long produced(long n) {
                  return 0;
              }
  
              @Override
              public int leave(int m) {
                  return 0;
              }
  
              @Override
              public boolean accept(Subscriber<? super Integer> a, Integer v) {
                  return false;
              }
          };
  
          SpscArrayQueue<Integer> q = new SpscArrayQueue<>(32);
  
          QueueDrainHelper.checkTerminated(true, false, ts, false, q, qd);
  
          ts.assertFailure(TestException.class);
      }
  
      @Test
      public void observerCheckTerminatedDelayErrorEmpty() {
          TestObserver<Integer> to = new TestObserver<>();
          to.onSubscribe(Disposable.empty());
  
          ObservableQueueDrain<Integer, Integer> qd = new ObservableQueueDrain<Integer, Integer>() {
              @Override
              public boolean cancelled() {
                  return false;
              }
  
              @Override
              public boolean done() {
                  return false;
              }
  
              @Override
              public Throwable error() {
                  return null;
              }
  
              @Override
              public boolean enter() {
                  return true;
              }
  
              @Override
              public int leave(int m) {
                  return 0;
              }
  
              @Override
              public void accept(Observer<? super Integer> a, Integer v) {
              }
          };
  
          SpscArrayQueue<Integer> q = new SpscArrayQueue<>(32);
  
          QueueDrainHelper.checkTerminated(true, true, to, true, q, null, qd);
  
          to.assertResult();
      }
  
      @Test
      public void observerCheckTerminatedDelayErrorEmptyResource() {
          TestObserver<Integer> to = new TestObserver<>();
          to.onSubscribe(Disposable.empty());
  
          ObservableQueueDrain<Integer, Integer> qd = new ObservableQueueDrain<Integer, Integer>() {
              @Override
              public boolean cancelled() {
                  return false;
              }
  
              @Override
              public boolean done() {
                  return false;
              }
  
              @Override
              public Throwable error() {
                  return null;
              }
  
              @Override
              public boolean enter() {
                  return true;
              }
  
              @Override
              public int leave(int m) {
                  return 0;
              }
  
              @Override
              public void accept(Observer<? super Integer> a, Integer v) {
              }
          };
  
          SpscArrayQueue<Integer> q = new SpscArrayQueue<>(32);
  
          Disposable d = Disposable.empty();
  
          QueueDrainHelper.checkTerminated(true, true, to, true, q, d, qd);
  
          to.assertResult();
  
          assertTrue(d.isDisposed());
      }
  
      @Test
      public void observerCheckTerminatedDelayErrorNonEmpty() {
          TestObserver<Integer> to = new TestObserver<>();
          to.onSubscribe(Disposable.empty());
  
          ObservableQueueDrain<Integer, Integer> qd = new ObservableQueueDrain<Integer, Integer>() {
              @Override
              public boolean cancelled() {
                  return false;
              }
  
              @Override
              public boolean done() {
                  return false;
              }
  
              @Override
              public Throwable error() {
                  return null;
              }
  
              @Override
              public boolean enter() {
                  return true;
              }
  
              @Override
              public int leave(int m) {
                  return 0;
              }
  
              @Override
              public void accept(Observer<? super Integer> a, Integer v) {
              }
          };
  
          SpscArrayQueue<Integer> q = new SpscArrayQueue<>(32);
  
          QueueDrainHelper.checkTerminated(true, false, to, true, q, null, qd);
  
          to.assertEmpty();
      }
  
      @Test
      public void observerCheckTerminatedDelayErrorEmptyError() {
          TestObserver<Integer> to = new TestObserver<>();
          to.onSubscribe(Disposable.empty());
  
          ObservableQueueDrain<Integer, Integer> qd = new ObservableQueueDrain<Integer, Integer>() {
              @Override
              public boolean cancelled() {
                  return false;
              }
  
              @Override
              public boolean done() {
                  return false;
              }
  
              @Override
              public Throwable error() {
                  return new TestException();
              }
  
              @Override
              public boolean enter() {
                  return true;
              }
  
              @Override
              public int leave(int m) {
                  return 0;
              }
  
              @Override
              public void accept(Observer<? super Integer> a, Integer v) {
              }
          };
  
          SpscArrayQueue<Integer> q = new SpscArrayQueue<>(32);
  
          QueueDrainHelper.checkTerminated(true, true, to, true, q, null, qd);
  
          to.assertFailure(TestException.class);
      }
  
      @Test
      public void observerCheckTerminatedNonDelayErrorError() {
          TestObserver<Integer> to = new TestObserver<>();
          to.onSubscribe(Disposable.empty());
  
          ObservableQueueDrain<Integer, Integer> qd = new ObservableQueueDrain<Integer, Integer>() {
              @Override
              public boolean cancelled() {
                  return false;
              }
  
              @Override
              public boolean done() {
                  return false;
              }
  
              @Override
              public Throwable error() {
                  return new TestException();
              }
  
              @Override
              public boolean enter() {
                  return true;
              }
  
              @Override
              public int leave(int m) {
                  return 0;
              }
  
              @Override
              public void accept(Observer<? super Integer> a, Integer v) {
              }
          };
  
          SpscArrayQueue<Integer> q = new SpscArrayQueue<>(32);
  
          QueueDrainHelper.checkTerminated(true, false, to, false, q, null, qd);
  
          to.assertFailure(TestException.class);
      }
  
      @Test
      public void observerCheckTerminatedNonDelayErrorErrorResource() {
          TestObserver<Integer> to = new TestObserver<>();
          to.onSubscribe(Disposable.empty());
  
          ObservableQueueDrain<Integer, Integer> qd = new ObservableQueueDrain<Integer, Integer>() {
              @Override
              public boolean cancelled() {
                  return false;
              }
  
              @Override
              public boolean done() {
                  return false;
              }
  
              @Override
              public Throwable error() {
                  return new TestException();
              }
  
              @Override
              public boolean enter() {
                  return true;
              }
  
              @Override
              public int leave(int m) {
                  return 0;
              }
  
              @Override
              public void accept(Observer<? super Integer> a, Integer v) {
              }
          };
  
          SpscArrayQueue<Integer> q = new SpscArrayQueue<>(32);
  
          Disposable d = Disposable.empty();
  
          QueueDrainHelper.checkTerminated(true, false, to, false, q, d, qd);
  
          to.assertFailure(TestException.class);
  
          assertTrue(d.isDisposed());
      }
  
      @Test
      public void postCompleteAlreadyComplete() {
  
          TestSubscriber<Integer> ts = new TestSubscriber<>();
  
          Queue<Integer> q = new ArrayDeque<>();
          q.offer(1);
  
          AtomicLong state = new AtomicLong(QueueDrainHelper.COMPLETED_MASK);
  
          QueueDrainHelper.postComplete(ts, q, state, new BooleanSupplier() {
              @Override
              public boolean getAsBoolean() throws Exception {
                  return false;
              }
          });
      }
  }
  