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3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4  *
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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.
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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
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19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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24  */
25 
26 package sun.nio.fs;
27 
28 import sun.misc.Unsafe;
29 import sun.misc.Cleaner;
30 
31 /**
32  * A light-weight buffer in native memory.
33  */
34 
35 class NativeBuffer {
36     private static final Unsafe unsafe = Unsafe.getUnsafe();
37 
38     private final long address;
39     private final int size;
40     private final Cleaner cleaner;
41 
42     // optional "owner" to avoid copying
43     // (only safe for use by thread-local caches)
44     private Object owner;
45 
46     private static class Deallocator implements Runnable {
47         private final long address;
Deallocator(long address)48         Deallocator(long address) {
49             this.address = address;
50         }
run()51         public void run() {
52             unsafe.freeMemory(address);
53         }
54     }
55 
NativeBuffer(int size)56     NativeBuffer(int size) {
57         this.address = unsafe.allocateMemory(size);
58         this.size = size;
59         this.cleaner = Cleaner.create(this, new Deallocator(address));
60     }
61 
release()62     void release() {
63         NativeBuffers.releaseNativeBuffer(this);
64     }
65 
address()66     long address() {
67         return address;
68     }
69 
size()70     int size() {
71         return size;
72     }
73 
cleaner()74     Cleaner cleaner() {
75         return cleaner;
76     }
77 
78     // not synchronized; only safe for use by thread-local caches
setOwner(Object owner)79     void setOwner(Object owner) {
80         this.owner = owner;
81     }
82 
83     // not synchronized; only safe for use by thread-local caches
owner()84     Object owner() {
85         return owner;
86     }
87 }
88