/*
 * SPDX-License-Identifier: Apache-2.0
 *
 * The OpenSearch Contributors require contributions made to
 * this file be licensed under the Apache-2.0 license or a
 * compatible open source license.
 */

/*
 * Modifications Copyright OpenSearch Contributors. See
 * GitHub history for details.
 */

package org.opensearch.common.concurrent;

import java.util.concurrent.atomic.AtomicBoolean;

/**
 * Encapsulates logic for a one-way gate. Guarantees idempotency via the {@link AtomicBoolean} instance
 * and the return value of the {@link #close()} function.
 *
 * @opensearch.internal
 */
public class OneWayGate {

    private final AtomicBoolean closed = new AtomicBoolean();

    /**
     * Closes the gate and sets the internal boolean value in an idempotent
     * fashion. This is a one-way operation and cannot be reset.
     * @return true if the gate was closed in this invocation,
     * false if the gate was already closed
     */
    public boolean close() {
        return closed.compareAndSet(false, true);
    }

    /**
     * Indicates if the gate has been closed.
     * @return true if the gate is closed, false otherwise
     */
    public boolean isClosed() {
        return closed.get();
    }
}