/*
 * Copyright (c) 1998, 2016, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package jdk.internal.misc;

/**
 * Internal interface implemented by private extension of {@link java.util.Signal}.
 */
public interface NativeSignal {

    /**
     * Register a native handler of the Signal.
     * Given handler replaces current signal handler.
     *
     * @param nativeHandler a native signal handler
     * @throws UnsupportedOperationException if handling of the signal is
     *                                       not supported by the implementation
     */
    void register(long nativeHandler);

    /**
     * Unregister a native handler of the Signal.
     * If given nativeHandler is the most recently registered handler for the signal,
     * signal handling is restored to the state prior to registering given nativeHandler
     * and the method returns {@code true}; otherwise the currently registered
     * handler is left unchanged and {@code false} is returned.
     *
     * @param nativeHandler a native signal handler
     * @return {@code true} if given nativeHandler was the most recently registered handler
     *         and was unregistered, otherwise {@code false}
     */
    boolean unregister(long nativeHandler);
}