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.completable;
  
  import java.util.concurrent.atomic.*;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.disposables.*;
  import io.reactivex.rxjava3.plugins.RxJavaPlugins;
  
  public final class CompletableMergeArray extends Completable {
      final CompletableSource[] sources;
  
      public CompletableMergeArray(CompletableSource[] sources) {
          this.sources = sources;
      }
  
      @Override
      public void subscribeActual(final CompletableObserver observer) {
          final CompositeDisposable set = new CompositeDisposable();
          final AtomicBoolean once = new AtomicBoolean();
  
          InnerCompletableObserver shared = new InnerCompletableObserver(observer, once, set, sources.length + 1);
          observer.onSubscribe(shared);
  
          for (CompletableSource c : sources) {
              if (set.isDisposed()) {
                  return;
              }
  
              if (c == null) {
                  set.dispose();
                  NullPointerException npe = new NullPointerException("A completable source is null");
                  shared.onError(npe);
                  return;
              }
  
              c.subscribe(shared);
          }
  
          shared.onComplete();
      }
  
      static final class InnerCompletableObserver extends AtomicInteger implements CompletableObserver, Disposable {
          private static final long serialVersionUID = -8360547806504310570L;
  
          final CompletableObserver downstream;
  
          final AtomicBoolean once;
  
          final CompositeDisposable set;
  
          InnerCompletableObserver(CompletableObserver actual, AtomicBoolean once, CompositeDisposable set, int n) {
              this.downstream = actual;
              this.once = once;
              this.set = set;
              this.lazySet(n);
          }
  
          @Override
          public void onSubscribe(Disposable d) {
              set.add(d);
          }
  
          @Override
          public void onError(Throwable e) {
              set.dispose();
              if (once.compareAndSet(false, true)) {
                  downstream.onError(e);
              } else {
                  RxJavaPlugins.onError(e);
              }
          }
  
          @Override
          public void onComplete() {
              if (decrementAndGet() == 0) {
                  // errors don't decrement this
                  downstream.onComplete();
              }
          }
  
          @Override
          public void dispose() {
              set.dispose();
              once.set(true);
          }
  
          @Override
          public boolean isDisposed() {
              return set.isDisposed();
          }
      }
  }
  