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 26 package sun.nio.fs; 27 28 import java.lang.ref.Cleaner.Cleanable; 29 import jdk.internal.misc.Unsafe; 30 import jdk.internal.ref.CleanerFactory; 31 32 /** 33 * A light-weight buffer in native memory. 34 */ 35 36 class NativeBuffer { 37 private static final Unsafe unsafe = Unsafe.getUnsafe(); 38 39 private final long address; 40 private final int size; 41 private final Cleanable cleanable; 42 43 // optional "owner" to avoid copying 44 // (only safe for use by thread-local caches) 45 private Object owner; 46 47 private static class Deallocator implements Runnable { 48 private final long address; 49 Deallocator(long address) { 50 this.address = address; 51 } 52 public void run() { 53 unsafe.freeMemory(address); 54 } 55 } 56 57 NativeBuffer(int size) { 58 this.address = unsafe.allocateMemory(size); 59 this.size = size; 60 this.cleanable = CleanerFactory.cleaner().register(this, new Deallocator(address)); 61 } 62 63 void release() { 64 NativeBuffers.releaseNativeBuffer(this); 65 } 66 67 long address() { 68 return address; 69 } 70 71 int size() { 72 return size; 73 } 74 75 void free() { 76 cleanable.clean(); 77 } 78 79 // not synchronized; only safe for use by thread-local caches 80 void setOwner(Object owner) { 81 this.owner = owner; 82 } 83 84 // not synchronized; only safe for use by thread-local caches 85 Object owner() { 86 return owner; 87 } 88 }