1 /*
   2  * Copyright (c) 1998, 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package jdk.internal.misc;
  26 
  27 /**
  28  * Internal interface implemented by private extension of {@link java.util.Signal}.
  29  */
  30 public interface NativeSignal {
  31 
  32     /**
  33      * Register a native handler of the Signal.
  34      * Given handler replaces current signal handler.
  35      *
  36      * @param nativeHandler a native signal handler
  37      * @throws UnsupportedOperationException if handling of the signal is
  38      *                                       not supported by the implementation
  39      */
  40     void register(long nativeHandler);
  41 
  42     /**
  43      * Unregister a native handler of the Signal.
  44      * If given nativeHandler is the most recently registered handler for the signal,
  45      * signal handling is restored to the state prior to registering given nativeHandler
  46      * and the method returns {@code true}; otherwise the currently registered
  47      * handler is left unchanged and {@code false} is returned.
  48      *
  49      * @param nativeHandler a native signal handler
  50      * @return {@code true} if given nativeHandler was the most recently registered handler
  51      *         and was unregistered, otherwise {@code false}
  52      */
  53     boolean unregister(long nativeHandler);
  54 }