1 /*
2 * Copyright (c) 2007, 2018, 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 /**
25 *
26 * @test
27 * @modules java.base/java.io:open
28 * @bug 6524062
29 * @summary Test to ensure that FOS.finalize() invokes the close() method as per
30 * the specification.
31 * @run main/othervm UnreferencedFOSClosesFd
32 */
33 import java.io.File;
34 import java.io.FileDescriptor;
35 import java.io.FileNotFoundException;
36 import java.io.FileOutputStream;
37 import java.io.IOException;
38 import java.lang.management.ManagementFactory;
39 import java.lang.management.OperatingSystemMXBean;
40 import java.lang.ref.Reference;
41 import java.lang.ref.ReferenceQueue;
42 import java.lang.ref.WeakReference;
43 import java.lang.reflect.Field;
44 import java.util.HashSet;
45 import java.util.concurrent.atomic.AtomicInteger;
46
47 import com.sun.management.UnixOperatingSystemMXBean;
48
49 public class UnreferencedFOSClosesFd {
50
51 enum CleanupType {
52 CLOSE, // Cleanup is handled via calling close
53 CLEANER} // Cleanup is handled via Cleaner
54
55 static final String FILE_NAME = "empty.txt";
56
57 /**
58 * Subclass w/ no overrides; not finalize or close.
59 * Cleanup should be via the Cleaner (not close).
60 */
61 public static class StreamOverrides extends FileOutputStream {
62
63 protected final AtomicInteger closeCounter;
64
65 public StreamOverrides(String name) throws FileNotFoundException {
66 super(name);
67 closeCounter = new AtomicInteger(0);
68 }
69
70 final AtomicInteger closeCounter() {
71 return closeCounter;
72 }
73 }
74
75 /**
76 * Subclass overrides close.
77 * Cleanup should be via AltFinalizer calling close().
78 */
79 public static class StreamOverridesClose extends StreamOverrides {
80
81 public StreamOverridesClose(String name) throws FileNotFoundException {
82 super(name);
83 }
84
85 public void close() throws IOException {
86 closeCounter.incrementAndGet();
87 super.close();
88 }
89 }
90
91 /**
92 * Subclass overrides finalize and close.
93 * Cleanup should be via the Cleaner (not close).
94 */
95 public static class StreamOverridesFinalize extends StreamOverrides {
96
97 public StreamOverridesFinalize(String name) throws FileNotFoundException {
98 super(name);
99 }
100
101 @SuppressWarnings({"deprecation","removal"})
102 protected void finalize() throws IOException {
103 super.finalize();
104 }
105 }
106
107 /**
108 * Subclass overrides finalize and close.
109 * Cleanup should be via AltFinalizer calling close().
110 */
111 public static class StreamOverridesFinalizeClose extends StreamOverridesClose {
112
113 public StreamOverridesFinalizeClose(String name) throws FileNotFoundException {
114 super(name);
115 }
116
117 @SuppressWarnings({"deprecation","removal"})
118 protected void finalize() throws IOException {
119 super.finalize();
120 }
121 }
122
123 /**
124 * Main runs each test case and reports number of failures.
125 */
126 public static void main(String argv[]) throws Exception {
127
128
129
130 File inFile = new File(System.getProperty("test.dir", "."), FILE_NAME);
131 inFile.createNewFile();
132 inFile.deleteOnExit();
133
134 String name = inFile.getPath();
135
136 long fdCount0 = getFdCount();
137 System.out.printf("initial count of open file descriptors: %d%n", fdCount0);
138
139 int failCount = 0;
140 failCount += test(new FileOutputStream(name), CleanupType.CLEANER);
141
142 failCount += test(new StreamOverrides(name), CleanupType.CLEANER);
143
144 failCount += test(new StreamOverridesClose(name), CleanupType.CLOSE);
145
146 failCount += test(new StreamOverridesFinalize(name), CleanupType.CLEANER);
147
148 failCount += test(new StreamOverridesFinalizeClose(name), CleanupType.CLOSE);
149
150 if (failCount > 0) {
151 throw new AssertionError("Failed test count: " + failCount);
152 }
153
154 // Check the final count of open file descriptors
155 long fdCount = getFdCount();
156 System.out.printf("final count of open file descriptors: %d%n", fdCount);
157 if (fdCount != fdCount0) {
158 throw new AssertionError("raw fd count wrong: expected: " + fdCount0
159 + ", actual: " + fdCount);
160 }
161 }
162
163 // Get the count of open file descriptors, or -1 if not available
164 private static long getFdCount() {
165 OperatingSystemMXBean mxBean = ManagementFactory.getOperatingSystemMXBean();
166 return (mxBean instanceof UnixOperatingSystemMXBean)
167 ? ((UnixOperatingSystemMXBean) mxBean).getOpenFileDescriptorCount()
168 : -1L;
169 }
170
171 private static int test(FileOutputStream fos, CleanupType cleanType) throws Exception {
172
173 try {
174 System.out.printf("%nTesting %s%n", fos.getClass().getName());
175
176 // Prepare to wait for FOS to be reclaimed
177 ReferenceQueue<Object> queue = new ReferenceQueue<>();
178 HashSet<Reference<?>> pending = new HashSet<>();
179 WeakReference<FileOutputStream> msWeak = new WeakReference<>(fos, queue);
180 pending.add(msWeak);
181
182 FileDescriptor fd = fos.getFD();
183 WeakReference<FileDescriptor> fdWeak = new WeakReference<>(fd, queue);
184 pending.add(fdWeak);
185
186 Field fdField = FileDescriptor.class.getDeclaredField("fd");
187 fdField.setAccessible(true);
188 int ffd = fdField.getInt(fd);
189
190 Field altFinalizerField = FileOutputStream.class.getDeclaredField("altFinalizer");
191 altFinalizerField.setAccessible(true);
192 Object altFinalizer = altFinalizerField.get(fos);
193 if ((altFinalizer != null) ^ (cleanType == CleanupType.CLOSE)) {
194 throw new RuntimeException("Unexpected AltFinalizer: " + altFinalizer
195 + ", for " + cleanType);
196 }
197
198 Field cleanupField = FileDescriptor.class.getDeclaredField("cleanup");
199 cleanupField.setAccessible(true);
200 Object cleanup = cleanupField.get(fd);
201 System.out.printf(" cleanup: %s, alt: %s, ffd: %d, cf: %s%n",
202 cleanup, altFinalizer, ffd, cleanupField);
203 if ((cleanup != null) ^ (cleanType == CleanupType.CLEANER)) {
204 throw new Exception("unexpected cleanup: "
205 + cleanup + ", for " + cleanType);
206 }
207 if (cleanup != null) {
208 WeakReference<Object> cleanupWeak = new WeakReference<>(cleanup, queue);
209 pending.add(cleanupWeak);
210 System.out.printf(" fdWeak: %s%n msWeak: %s%n cleanupWeak: %s%n",
211 fdWeak, msWeak, cleanupWeak);
212 }
213 if (altFinalizer != null) {
214 WeakReference<Object> altFinalizerWeak = new WeakReference<>(altFinalizer, queue);
215 pending.add(altFinalizerWeak);
216 System.out.printf(" fdWeak: %s%n msWeak: %s%n altFinalizerWeak: %s%n",
217 fdWeak, msWeak, altFinalizerWeak);
218 }
219
220 AtomicInteger closeCounter = fos instanceof StreamOverrides
221 ? ((StreamOverrides) fos).closeCounter() : null;
222
223 Reference<?> r;
224 while (((r = queue.remove(1000L)) != null)
225 || !pending.isEmpty()) {
226 System.out.printf(" r: %s, pending: %d%n",
227 r, pending.size());
228 if (r != null) {
229 pending.remove(r);
230 } else {
231 fos = null;
232 fd = null;
233 cleanup = null;
234 altFinalizer = null;
235 System.gc(); // attempt to reclaim them
236 }
237 }
238 Reference.reachabilityFence(fd);
239 Reference.reachabilityFence(fos);
240 Reference.reachabilityFence(cleanup);
241 Reference.reachabilityFence(altFinalizer);
242
243 // Confirm the correct number of calls to close depending on the cleanup type
244 switch (cleanType) {
245 case CLEANER:
246 if (closeCounter != null && closeCounter.get() > 0) {
247 throw new RuntimeException("Close should not have been called: count: "
248 + closeCounter);
249 }
250 break;
251 case CLOSE:
252 if (closeCounter == null || closeCounter.get() == 0) {
253 throw new RuntimeException("Close should have been called: count: 0");
254 }
255 break;
256 }
257 } catch (Exception ex) {
258 ex.printStackTrace(System.out);
259 return 1;
260 }
261 return 0;
262 }
263 }