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.subscriptions;
  
  import static org.junit.Assert.*;
  import static org.mockito.ArgumentMatchers.anyLong;
  import static org.mockito.Mockito.*;
  
  import java.util.List;
  import java.util.concurrent.atomic.*;
  
  import org.junit.Test;
  import org.reactivestreams.Subscription;
  
  import io.reactivex.rxjava3.core.RxJavaTest;
  import io.reactivex.rxjava3.exceptions.ProtocolViolationException;
  import io.reactivex.rxjava3.plugins.RxJavaPlugins;
  import io.reactivex.rxjava3.testsupport.TestHelper;
  
  public class SubscriptionHelperTest extends RxJavaTest {
  
      @Test
      public void checkEnum() {
          TestHelper.checkEnum(SubscriptionHelper.class);
      }
  
      @Test
      public void validateNullThrows() {
          List<Throwable> errors = TestHelper.trackPluginErrors();
          try {
              SubscriptionHelper.validate(null, null);
  
              TestHelper.assertError(errors, 0, NullPointerException.class, "next is null");
          } finally {
              RxJavaPlugins.reset();
          }
      }
  
      @Test
      public void cancelNoOp() {
          SubscriptionHelper.CANCELLED.cancel();
      }
  
      @Test
      public void set() {
          AtomicReference<Subscription> atomicSubscription = new AtomicReference<>();
  
          BooleanSubscription bs1 = new BooleanSubscription();
  
          assertTrue(SubscriptionHelper.set(atomicSubscription, bs1));
  
          BooleanSubscription bs2 = new BooleanSubscription();
  
          assertTrue(SubscriptionHelper.set(atomicSubscription, bs2));
  
          assertTrue(bs1.isCancelled());
  
          assertFalse(bs2.isCancelled());
      }
  
      @Test
      public void replace() {
          AtomicReference<Subscription> atomicSubscription = new AtomicReference<>();
  
          BooleanSubscription bs1 = new BooleanSubscription();
  
          assertTrue(SubscriptionHelper.replace(atomicSubscription, bs1));
  
          BooleanSubscription bs2 = new BooleanSubscription();
  
          assertTrue(SubscriptionHelper.replace(atomicSubscription, bs2));
  
          assertFalse(bs1.isCancelled());
  
          assertFalse(bs2.isCancelled());
      }
  
      @Test
      public void cancelRace() {
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              final AtomicReference<Subscription> atomicSubscription = new AtomicReference<>();
  
              Runnable r = new Runnable() {
                  @Override
                  public void run() {
                      SubscriptionHelper.cancel(atomicSubscription);
                  }
              };
  
              TestHelper.race(r, r);
          }
      }
  
      @Test
      public void setRace() {
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              final AtomicReference<Subscription> atomicSubscription = new AtomicReference<>();
  
              final BooleanSubscription bs1 = new BooleanSubscription();
              final BooleanSubscription bs2 = new BooleanSubscription();
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      SubscriptionHelper.set(atomicSubscription, bs1);
                  }
              };
  
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      SubscriptionHelper.set(atomicSubscription, bs2);
                  }
              };
  
              TestHelper.race(r1, r2);
  
              assertTrue(bs1.isCancelled() ^ bs2.isCancelled());
          }
      }
  
      @Test
      public void replaceRace() {
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              final AtomicReference<Subscription> atomicSubscription = new AtomicReference<>();
  
              final BooleanSubscription bs1 = new BooleanSubscription();
              final BooleanSubscription bs2 = new BooleanSubscription();
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      SubscriptionHelper.replace(atomicSubscription, bs1);
                  }
              };
  
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      SubscriptionHelper.replace(atomicSubscription, bs2);
                  }
              };
  
              TestHelper.race(r1, r2);
  
              assertFalse(bs1.isCancelled());
              assertFalse(bs2.isCancelled());
          }
      }
  
      @Test
      public void cancelAndChange() {
          AtomicReference<Subscription> atomicSubscription = new AtomicReference<>();
  
          SubscriptionHelper.cancel(atomicSubscription);
  
          BooleanSubscription bs1 = new BooleanSubscription();
          assertFalse(SubscriptionHelper.set(atomicSubscription, bs1));
          assertTrue(bs1.isCancelled());
  
          assertFalse(SubscriptionHelper.set(atomicSubscription, null));
  
          BooleanSubscription bs2 = new BooleanSubscription();
          assertFalse(SubscriptionHelper.replace(atomicSubscription, bs2));
          assertTrue(bs2.isCancelled());
  
          assertFalse(SubscriptionHelper.replace(atomicSubscription, null));
      }
  
      @Test
      public void invalidDeferredRequest() {
          AtomicReference<Subscription> atomicSubscription = new AtomicReference<>();
          AtomicLong r = new AtomicLong();
  
          List<Throwable> errors = TestHelper.trackPluginErrors();
          try {
              SubscriptionHelper.deferredRequest(atomicSubscription, r, -99);
  
              TestHelper.assertError(errors, 0, IllegalArgumentException.class, "n > 0 required but it was -99");
          } finally {
              RxJavaPlugins.reset();
          }
      }
  
      @Test
      public void deferredRace() {
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              final AtomicReference<Subscription> atomicSubscription = new AtomicReference<>();
              final AtomicLong r = new AtomicLong();
  
              final AtomicLong q = new AtomicLong();
  
              final Subscription a = new Subscription() {
                  @Override
                  public void request(long n) {
                      q.addAndGet(n);
                  }
  
                  @Override
                  public void cancel() {
  
                  }
              };
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      SubscriptionHelper.deferredSetOnce(atomicSubscription, r, a);
                  }
              };
  
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      SubscriptionHelper.deferredRequest(atomicSubscription, r, 1);
                  }
              };
  
              TestHelper.race(r1, r2);
  
              assertSame(a, atomicSubscription.get());
              assertEquals(1, q.get());
              assertEquals(0, r.get());
          }
      }
  
      @Test
      public void setOnceAndRequest() {
          AtomicReference<Subscription> ref = new AtomicReference<>();
  
          Subscription sub = mock(Subscription.class);
  
          assertTrue(SubscriptionHelper.setOnce(ref, sub, 1));
  
          verify(sub).request(1);
          verify(sub, never()).cancel();
  
          List<Throwable> errors = TestHelper.trackPluginErrors();
          try {
              sub = mock(Subscription.class);
  
              assertFalse(SubscriptionHelper.setOnce(ref, sub, 1));
  
              verify(sub, never()).request(anyLong());
              verify(sub).cancel();
  
              TestHelper.assertError(errors, 0, ProtocolViolationException.class);
          } finally {
              RxJavaPlugins.reset();
          }
      }
  }
  