1 /*

     2  * Copyright (c) 2008, 2009, 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 sun.jkernel;

    26 

    27 /**

    28  * A mutex which works even between different processes.  Currently implemented

    29  * only on Win32.

    30  *

    31  *@author Ethan Nicholas

    32  */

    33 public class Mutex {

    34     static {

    35         try {

    36             System.loadLibrary("jkernel");

    37         }

    38         catch (Exception e) {

    39             throw new Error(e);

    40         }

    41     }

    42 

    43     private String uniqueId;

    44     private long handle;

    45 

    46     public static Mutex create(String uniqueId) {

    47         return new Mutex(uniqueId);

    48     }

    49 

    50 

    51     private Mutex(String uniqueId) {

    52         this.uniqueId = uniqueId;

    53         this.handle = createNativeMutex(uniqueId);

    54     }

    55 

    56 

    57     private static native long createNativeMutex(String uniqueId);

    58 

    59 

    60     public native void acquire();

    61 

    62 

    63     public native boolean acquire(int timeout);

    64 

    65 

    66     public native void release();

    67 

    68 

    69     public native void destroyNativeMutex();

    70 

    71 

    72     public void dispose() {

    73         destroyNativeMutex();

    74         handle = 0;

    75     }

    76 

    77 

    78     public void finalize() {

    79         dispose();

    80     }

    81 

    82 

    83     public String toString() {

    84         return "Mutex[" + uniqueId + "]";

    85     }

    86 }