1 /*
2 * Copyright (c) 2013, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 import java.io.ByteArrayOutputStream;
25 import java.io.IOException;
26 import java.nio.file.Files;
27 import java.nio.file.Path;
28 import java.nio.file.Paths;
29 import java.util.concurrent.atomic.AtomicInteger;
30
31 /* @test
32 * @bug 8027351 8148940
33 * @summary Basic test of the finalize method
34 */
35
36 public class FinalizeOverride {
37 // finalizedCount is incremented when the finalize method is invoked
38 private static AtomicInteger finalizedCount = new AtomicInteger();
39
40 // finalizedSum and privateFinalizedInvoke are used to verify
41 // the right overrided finalize method is invoked
42 private static AtomicInteger finalizedSum = new AtomicInteger();
43 private static volatile boolean privateFinalizeInvoked = false;
44
45 public static void main(String[] argvs) throws IOException {
46 patchPrivateFinalize();
47
48 test(new Base(10), 10);
49 test(new Subclass(20), 0);
50 test(new SubSubclass(30), 30);
51 test(new PublicFinalize(40), 40*100+40);
52 test(new PrivateFinalize(50), 50);
53 test(new NoOverride(60), 60);
54 }
55
56 static void test(Object o, int expected) {
57 int count = finalizedCount.get();
58 int sum = finalizedSum.get();
59 privateFinalizeInvoked = false;
60
61 // force GC and finalization
62 o = null;
63 while (finalizedCount.get() != (count+1)) {
64 System.gc();
65 System.runFinalization();
66 // Running System.gc() and System.runFinalization() in a
67 // tight loop can trigger frequent safepointing that slows
68 // down the VM and, as a result, the test. (With the
69 // HotSpot VM, the effect of frequent safepointing is
70 // especially noticeable if the test is run with the
71 // -Xcomp flag.) Sleeping for a second after every
72 // garbage collection and finalization cycle gives the VM
73 // time to make progress.
74 try {
75 Thread.sleep(1000);
76 } catch (InterruptedException e) {
77 System.out.println("Main thread interrupted, continuing execution.");
78 }
79 }
80
81 if (privateFinalizeInvoked) {
82 throw new RuntimeException("private finalize method invoked");
83 }
84 if (finalizedCount.get() != (count+1)) {
85 throw new RuntimeException("Unexpected count=" + finalizedCount +
86 " expected=" + (count+1));
87 }
88 if (finalizedSum.get() != (sum+expected)) {
89 throw new RuntimeException("Unexpected sum=" + finalizedSum +
90 " prev=" + sum + " value=" + expected);
91 }
92 }
93
94 static void patchPrivateFinalize() throws IOException {
95 // patch the private f_nal_ze method name to "finalize"
96 String testClasses = System.getProperty("test.classes", ".");
97 Path p = Paths.get(testClasses, "FinalizeOverride$PrivateFinalize.class");
98 byte[] bytes = Files.readAllBytes(p);
99 int len = "f_nal_ze".length();
100 for (int i=0; i < bytes.length-len; i++) {
101 if (bytes[i] == 'f' &&
102 bytes[i+1] == '_' &&
103 bytes[i+2] == 'n' &&
104 bytes[i+3] == 'a' &&
105 bytes[i+4] == 'l' &&
106 bytes[i+5] == '_' &&
107 bytes[i+6] == 'z' &&
108 bytes[i+7] == 'e')
109 {
110 // s%_%i%
111 bytes[i+1] = 'i';
112 bytes[i+5] = 'i';
113 break;
114 }
115 }
116 Files.write(p, bytes);
117 }
118
119 static class Base {
120 protected int value;
121 Base(int v) {
122 this.value = v;
123 }
124 int called() {
125 finalizedSum.addAndGet(value);
126 return value;
127 }
128 protected void finalize() {
129 System.out.println("Base.finalize() sum += " + called());
130 finalizedCount.incrementAndGet();
131 }
132 }
133 static class PublicFinalize extends Base {
134 PublicFinalize(int v) {
135 super(v);
136 }
137 public void finalize() {
138 finalizedSum.addAndGet(value * 100);
139 System.out.println("PublicFinalize.finalize() sum += " + called() +
140 "+"+value+"*100");
141 finalizedCount.incrementAndGet();
142 }
143 }
144 static class Subclass extends Base {
145 Subclass(int v) {
146 super(v);
147 }
148 protected void finalize() {
149 // no value added to sum
150 System.out.println("Subclass.finalize() sum += 0");
151 finalizedCount.incrementAndGet();
152 }
153 }
154 static class SubSubclass extends Subclass {
155 SubSubclass(int v) {
156 super(v);
157 }
158 protected final void finalize() {
159 finalizedSum.addAndGet(value);
160 System.out.println("SubSubclass.finalize() sum +=" +value);
161 finalizedCount.incrementAndGet();
162 }
163 }
164 static class PrivateFinalize extends Base {
165 PrivateFinalize(int v) {
166 super(v);
167 }
168 private void f_nal_ze() {
169 // finalization catches any exception
170 System.out.println("Error: private finalize invoked!!");
171 privateFinalizeInvoked = true;
172 finalizedCount.incrementAndGet();
173 }
174 }
175 static class NoOverride extends PrivateFinalize {
176 NoOverride(int v) {
177 super(v);
178 }
179 }
180 }