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.operators.observable;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.disposables.Disposable;
  import io.reactivex.rxjava3.internal.disposables.*;
  import io.reactivex.rxjava3.observers.SerializedObserver;
  
  public final class ObservableSkipUntil<T, U> extends AbstractObservableWithUpstream<T, T> {
      final ObservableSource<U> other;
      public ObservableSkipUntil(ObservableSource<T> source, ObservableSource<U> other) {
          super(source);
          this.other = other;
      }
  
      @Override
      public void subscribeActual(Observer<? super T> child) {
  
          final SerializedObserver<T> serial = new SerializedObserver<>(child);
  
          final ArrayCompositeDisposable frc = new ArrayCompositeDisposable(2);
  
          serial.onSubscribe(frc);
  
          final SkipUntilObserver<T> sus = new SkipUntilObserver<>(serial, frc);
  
          other.subscribe(new SkipUntil(frc, sus, serial));
  
          source.subscribe(sus);
      }
  
      static final class SkipUntilObserver<T> implements Observer<T> {
  
          final Observer<? super T> downstream;
          final ArrayCompositeDisposable frc;
  
          Disposable upstream;
  
          volatile boolean notSkipping;
          boolean notSkippingLocal;
  
          SkipUntilObserver(Observer<? super T> actual, ArrayCompositeDisposable frc) {
              this.downstream = actual;
              this.frc = frc;
          }
  
          @Override
          public void onSubscribe(Disposable d) {
              if (DisposableHelper.validate(this.upstream, d)) {
                  this.upstream = d;
                  frc.setResource(0, d);
              }
          }
  
          @Override
          public void onNext(T t) {
              if (notSkippingLocal) {
                  downstream.onNext(t);
              } else
              if (notSkipping) {
                  notSkippingLocal = true;
                  downstream.onNext(t);
              }
          }
  
          @Override
          public void onError(Throwable t) {
              frc.dispose();
              downstream.onError(t);
          }
  
          @Override
          public void onComplete() {
              frc.dispose();
              downstream.onComplete();
          }
      }
  
      final class SkipUntil implements Observer<U> {
          final ArrayCompositeDisposable frc;
          final SkipUntilObserver<T> sus;
          final SerializedObserver<T> serial;
          Disposable upstream;
  
          SkipUntil(ArrayCompositeDisposable frc, SkipUntilObserver<T> sus, SerializedObserver<T> serial) {
              this.frc = frc;
              this.sus = sus;
              this.serial = serial;
          }
  
          @Override
          public void onSubscribe(Disposable d) {
              if (DisposableHelper.validate(this.upstream, d)) {
                  this.upstream = d;
                  frc.setResource(1, d);
              }
          }
  
          @Override
          public void onNext(U t) {
              upstream.dispose();
              sus.notSkipping = true;
          }
  
          @Override
          public void onError(Throwable t) {
              frc.dispose();
              serial.onError(t);
          }
  
          @Override
          public void onComplete() {
              sus.notSkipping = true;
          }
      }
  }
  