1 /*
2 * Copyright 2013 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. You may obtain a copy of the License at:
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package io.netty.util;
17
18 import io.netty.util.internal.RefCnt;
19
20 /**
21 * Abstract base class for classes wants to implement {@link ReferenceCounted}.
22 */
23 public abstract class AbstractReferenceCounted implements ReferenceCounted {
24
25 private final RefCnt refCnt = new RefCnt();
26
27 @Override
28 public int refCnt() {
29 return RefCnt.refCnt(refCnt);
30 }
31
32 /**
33 * An unsafe operation intended for use by a subclass that sets the reference count of the object directly
34 */
35 protected void setRefCnt(int refCnt) {
36 RefCnt.setRefCnt(this.refCnt, refCnt);
37 }
38
39 @Override
40 public ReferenceCounted retain() {
41 RefCnt.retain(refCnt);
42 return this;
43 }
44
45 @Override
46 public ReferenceCounted retain(int increment) {
47 RefCnt.retain(refCnt, increment);
48 return this;
49 }
50
51 @Override
52 public ReferenceCounted touch() {
53 return touch(null);
54 }
55
56 @Override
57 public boolean release() {
58 return handleRelease(RefCnt.release(refCnt));
59 }
60
61 @Override
62 public boolean release(int decrement) {
63 return handleRelease(RefCnt.release(refCnt, decrement));
64 }
65
66 private boolean handleRelease(boolean result) {
67 if (result) {
68 deallocate();
69 }
70 return result;
71 }
72
73 /**
74 * Called once {@link #refCnt()} is equals 0.
75 */
76 protected abstract void deallocate();
77 }