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 org.reactivestreams.*;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.disposables.*;
  import io.reactivex.rxjava3.internal.disposables.DisposableHelper;
  import io.reactivex.rxjava3.internal.subscriptions.SubscriptionHelper;
  import io.reactivex.rxjava3.internal.util.AtomicThrowable;
  
  public final class CompletableMerge extends Completable {
      final Publisher<? extends CompletableSource> source;
      final int maxConcurrency;
      final boolean delayErrors;
  
      public CompletableMerge(Publisher<? extends CompletableSource> source, int maxConcurrency, boolean delayErrors) {
          this.source = source;
          this.maxConcurrency = maxConcurrency;
          this.delayErrors = delayErrors;
      }
  
      @Override
      public void subscribeActual(CompletableObserver observer) {
          CompletableMergeSubscriber parent = new CompletableMergeSubscriber(observer, maxConcurrency, delayErrors);
          source.subscribe(parent);
      }
  
      static final class CompletableMergeSubscriber
      extends AtomicInteger
      implements FlowableSubscriber<CompletableSource>, Disposable {
  
          private static final long serialVersionUID = -2108443387387077490L;
  
          final CompletableObserver downstream;
          final int maxConcurrency;
          final boolean delayErrors;
  
          final AtomicThrowable errors;
  
          final CompositeDisposable set;
  
          Subscription upstream;
  
          CompletableMergeSubscriber(CompletableObserver actual, int maxConcurrency, boolean delayErrors) {
              this.downstream = actual;
              this.maxConcurrency = maxConcurrency;
              this.delayErrors = delayErrors;
              this.set = new CompositeDisposable();
              this.errors = new AtomicThrowable();
              lazySet(1);
          }
  
          @Override
          public void dispose() {
              upstream.cancel();
              set.dispose();
              errors.tryTerminateAndReport();
          }
  
          @Override
          public boolean isDisposed() {
              return set.isDisposed();
          }
  
          @Override
          public void onSubscribe(Subscription s) {
              if (SubscriptionHelper.validate(this.upstream, s)) {
                  this.upstream = s;
                  downstream.onSubscribe(this);
                  if (maxConcurrency == Integer.MAX_VALUE) {
                      s.request(Long.MAX_VALUE);
                  } else {
                      s.request(maxConcurrency);
                  }
              }
          }
  
          @Override
          public void onNext(CompletableSource t) {
              getAndIncrement();
  
              MergeInnerObserver inner = new MergeInnerObserver();
              set.add(inner);
              t.subscribe(inner);
          }
  
          @Override
          public void onError(Throwable t) {
              if (!delayErrors) {
                  set.dispose();
  
                  if (errors.tryAddThrowableOrReport(t)) {
                      if (getAndSet(0) > 0) {
                          errors.tryTerminateConsumer(downstream);
                      }
                  }
              } else {
                  if (errors.tryAddThrowableOrReport(t)) {
                      if (decrementAndGet() == 0) {
                          errors.tryTerminateConsumer(downstream);
                      }
                  }
              }
          }
  
          @Override
          public void onComplete() {
              if (decrementAndGet() == 0) {
                  errors.tryTerminateConsumer(downstream);
              }
          }
  
          void innerError(MergeInnerObserver inner, Throwable t) {
              set.delete(inner);
              if (!delayErrors) {
                  upstream.cancel();
                  set.dispose();
  
                  if (errors.tryAddThrowableOrReport(t)) {
                      if (getAndSet(0) > 0) {
                          errors.tryTerminateConsumer(downstream);
                      }
                  }
              } else {
                  if (errors.tryAddThrowableOrReport(t)) {
                      if (decrementAndGet() == 0) {
                          errors.tryTerminateConsumer(downstream);
                      } else {
                          if (maxConcurrency != Integer.MAX_VALUE) {
                              upstream.request(1);
                          }
                      }
                  }
              }
          }
  
          void innerComplete(MergeInnerObserver inner) {
              set.delete(inner);
              if (decrementAndGet() == 0) {
                  errors.tryTerminateConsumer(downstream);
              } else {
                  if (maxConcurrency != Integer.MAX_VALUE) {
                      upstream.request(1);
                  }
              }
          }
  
          final class MergeInnerObserver
          extends AtomicReference<Disposable>
          implements CompletableObserver, Disposable {
              private static final long serialVersionUID = 251330541679988317L;
  
              @Override
              public void onSubscribe(Disposable d) {
                  DisposableHelper.setOnce(this, d);
              }
  
              @Override
              public void onError(Throwable e) {
                  innerError(this, e);
              }
  
              @Override
              public void onComplete() {
                  innerComplete(this);
              }
  
              @Override
              public boolean isDisposed() {
                  return DisposableHelper.isDisposed(get());
              }
  
              @Override
              public void dispose() {
                  DisposableHelper.dispose(this);
              }
          }
      }
  }
  