/*
 * Copyright (c) 2011-2017 Pivotal Software Inc, All Rights Reserved.
 *
 * 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
 *
 *       https://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 reactor.core.publisher;

Blocks until the upstream signals its first value or completes.
Type parameters:
<T> – the value type
See Also:
https://github.com/reactor/reactive-streams-commons/**
 * Blocks until the upstream signals its first value or completes.
 *
 * @param <T> the value type
 * @see <a href="https://github.com/reactor/reactive-streams-commons">https://github.com/reactor/reactive-streams-commons</a>
 */
final class BlockingFirstSubscriber<T> extends BlockingSingleSubscriber<T> {

	@Override
	public void onNext(T t) {
		if (value == null) {
			value = t;
			dispose();
			countDown();
		}
	}

	@Override
	public void onError(Throwable t) {
		if (value == null) {
			error = t;
		}
		countDown();
	}
}