1 /*
2 * Copyright (c) 2020, 2025, 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 jdk.internal.misc;
27
28 import java.io.BufferedReader;
29 import java.io.File;
30 import java.io.InputStreamReader;
31 import java.io.InputStream;
32 import java.io.IOException;
33 import java.io.PrintStream;
34 import java.net.URL;
35 import java.net.URLClassLoader;
36 import java.nio.file.InvalidPathException;
37 import java.nio.file.Path;
38 import java.util.Arrays;
39 import java.util.ArrayList;
40 import java.util.List;
41 import java.util.Map;
42 import java.util.Objects;
43 import java.util.stream.Stream;
44
45 import jdk.internal.access.SharedSecrets;
46 import jdk.internal.util.StaticProperty;
47
48 public class CDS {
49 // Must be in sync with cdsConfig.hpp
50 private static final int IS_DUMPING_ARCHIVE = 1 << 0;
51 private static final int IS_DUMPING_STATIC_ARCHIVE = 1 << 1;
52 private static final int IS_LOGGING_LAMBDA_FORM_INVOKERS = 1 << 2;
53 private static final int IS_USING_ARCHIVE = 1 << 3;
54 private static final int configStatus = getCDSConfigStatus();
55
56 /**
57 * Should we log the use of lambda form invokers?
58 */
59 public static boolean isLoggingLambdaFormInvokers() {
60 return (configStatus & IS_LOGGING_LAMBDA_FORM_INVOKERS) != 0;
61 }
62
63 /**
64 * Is the VM writing to a (static or dynamic) CDS archive.
65 */
66 public static boolean isDumpingArchive() {
67 return (configStatus & IS_DUMPING_ARCHIVE) != 0;
68 }
69
70 /**
71 * Is the VM using at least one CDS archive?
72 */
73 public static boolean isUsingArchive() {
74 return (configStatus & IS_USING_ARCHIVE) != 0;
75 }
76
77 /**
78 * Is dumping static archive.
79 */
80 public static boolean isDumpingStaticArchive() {
81 return (configStatus & IS_DUMPING_STATIC_ARCHIVE) != 0;
82 }
83
84 private static native int getCDSConfigStatus();
85 private static native void logLambdaFormInvoker(String line);
86
87 /**
88 * Initialize archived static fields in the given Class using archived
89 * values from CDS dump time. Also initialize the classes of objects in
90 * the archived graph referenced by those fields.
91 *
92 * Those static fields remain as uninitialized if there is no mapped CDS
93 * java heap data or there is any error during initialization of the
94 * object class in the archived graph.
95 */
96 public static native void initializeFromArchive(Class<?> c);
97
98 /**
99 * Ensure that the native representation of all archived java.lang.Module objects
100 * are properly restored.
101 */
102 public static native void defineArchivedModules(ClassLoader platformLoader, ClassLoader systemLoader);
103
104 /**
105 * Returns a predictable "random" seed derived from the VM's build ID and version,
106 * to be used by java.util.ImmutableCollections to ensure that archived
107 * ImmutableCollections are always sorted the same order for the same VM build.
108 */
109 public static native long getRandomSeedForDumping();
110
111 /**
112 * log lambda form invoker holder, name and method type
113 */
114 public static void logLambdaFormInvoker(String prefix, String holder, String name, String type) {
115 if (isLoggingLambdaFormInvokers()) {
116 logLambdaFormInvoker(prefix + " " + holder + " " + name + " " + type);
117 }
118 }
119
120 /**
121 * log species
122 */
123 public static void logSpeciesType(String prefix, String cn) {
124 if (isLoggingLambdaFormInvokers()) {
125 logLambdaFormInvoker(prefix + " " + cn);
126 }
127 }
128
129 static final String DIRECT_HOLDER_CLASS_NAME = "java.lang.invoke.DirectMethodHandle$Holder";
130 static final String DELEGATING_HOLDER_CLASS_NAME = "java.lang.invoke.DelegatingMethodHandle$Holder";
131 static final String BASIC_FORMS_HOLDER_CLASS_NAME = "java.lang.invoke.LambdaForm$Holder";
132 static final String INVOKERS_HOLDER_CLASS_NAME = "java.lang.invoke.Invokers$Holder";
133
134 private static boolean isValidHolderName(String name) {
135 return name.equals(DIRECT_HOLDER_CLASS_NAME) ||
136 name.equals(DELEGATING_HOLDER_CLASS_NAME) ||
137 name.equals(BASIC_FORMS_HOLDER_CLASS_NAME) ||
138 name.equals(INVOKERS_HOLDER_CLASS_NAME);
139 }
140
141 private static boolean isBasicTypeChar(char c) {
142 return "LIJFDV".indexOf(c) >= 0;
143 }
144
145 private static boolean isValidMethodType(String type) {
146 String[] typeParts = type.split("_");
147 // check return type (second part)
148 if (typeParts.length != 2 || typeParts[1].length() != 1
149 || !isBasicTypeChar(typeParts[1].charAt(0))) {
150 return false;
151 }
152 // first part
153 if (!isBasicTypeChar(typeParts[0].charAt(0))) {
154 return false;
155 }
156 for (int i = 1; i < typeParts[0].length(); i++) {
157 char c = typeParts[0].charAt(i);
158 if (!isBasicTypeChar(c)) {
159 if (!(c >= '0' && c <= '9')) {
160 return false;
161 }
162 }
163 }
164 return true;
165 }
166
167 // Throw exception on invalid input
168 private static void validateInputLines(String[] lines) {
169 for (String s: lines) {
170 if (!s.startsWith("[LF_RESOLVE]") && !s.startsWith("[SPECIES_RESOLVE]")) {
171 throw new IllegalArgumentException("Wrong prefix: " + s);
172 }
173
174 String[] parts = s.split(" ");
175 boolean isLF = s.startsWith("[LF_RESOLVE]");
176
177 if (isLF) {
178 if (parts.length != 4) {
179 throw new IllegalArgumentException("Incorrect number of items in the line: " + parts.length);
180 }
181 if (!isValidHolderName(parts[1])) {
182 throw new IllegalArgumentException("Invalid holder class name: " + parts[1]);
183 }
184 if (!isValidMethodType(parts[3])) {
185 throw new IllegalArgumentException("Invalid method type: " + parts[3]);
186 }
187 } else {
188 if (parts.length != 2) {
189 throw new IllegalArgumentException("Incorrect number of items in the line: " + parts.length);
190 }
191 }
192 }
193 }
194
195 /**
196 * called from vm to generate MethodHandle holder classes
197 * @return {@code Object[]} if holder classes can be generated.
198 * @param lines in format of LF_RESOLVE or SPECIES_RESOLVE output
199 */
200 private static Object[] generateLambdaFormHolderClasses(String[] lines) {
201 Objects.requireNonNull(lines);
202 validateInputLines(lines);
203 Stream<String> lineStream = Arrays.stream(lines);
204 Map<String, byte[]> result = SharedSecrets.getJavaLangInvokeAccess().generateHolderClasses(lineStream);
205 int size = result.size();
206 Object[] retArray = new Object[size * 2];
207 int index = 0;
208 for (Map.Entry<String, byte[]> entry : result.entrySet()) {
209 retArray[index++] = entry.getKey();
210 retArray[index++] = entry.getValue();
211 };
212 return retArray;
213 }
214
215 private static native void dumpClassList(String listFileName);
216 private static native void dumpDynamicArchive(String archiveFileName);
217
218 private static String drainOutput(InputStream stream, long pid, String tail, List<String> cmds) {
219 String fileName = "java_pid" + pid + "_" + tail;
220 new Thread( ()-> {
221 try (InputStreamReader isr = new InputStreamReader(stream);
222 BufferedReader rdr = new BufferedReader(isr);
223 PrintStream prt = new PrintStream(fileName)) {
224 prt.println("Command:");
225 for (String s : cmds) {
226 prt.print(s + " ");
227 }
228 prt.println("");
229 String line;
230 while((line = rdr.readLine()) != null) {
231 prt.println(line);
232 }
233 } catch (IOException e) {
234 throw new RuntimeException("IOException happens during drain stream to file " +
235 fileName + ": " + e.getMessage());
236 }}).start();
237 return fileName;
238 }
239
240 private static String[] excludeFlags = {
241 "-XX:DumpLoadedClassList=",
242 "-XX:+RecordDynamicDumpInfo",
243 "-Xshare:",
244 "-XX:SharedClassListFile=",
245 "-XX:SharedArchiveFile=",
246 "-XX:ArchiveClassesAtExit="};
247 private static boolean containsExcludedFlags(String testStr) {
248 for (String e : excludeFlags) {
249 if (testStr.contains(e)) {
250 return true;
251 }
252 }
253 return false;
254 }
255
256 /**
257 * called from jcmd VM.cds to dump static or dynamic shared archive
258 * @param isStatic true for dump static archive or false for dynnamic archive.
259 * @param fileName user input archive name, can be null.
260 * @return The archive name if successfully dumped.
261 */
262 private static String dumpSharedArchive(boolean isStatic, String fileName) throws Exception {
263 String cwd = new File("").getAbsolutePath(); // current dir used for printing message.
264 String currentPid = String.valueOf(ProcessHandle.current().pid());
265 String archiveFileName = fileName != null ? fileName :
266 "java_pid" + currentPid + (isStatic ? "_static.jsa" : "_dynamic.jsa");
267
268 String tempArchiveFileName = archiveFileName + ".temp";
269 File tempArchiveFile = new File(tempArchiveFileName);
270 // The operation below may cause exception if the file or its dir is protected.
271 if (!tempArchiveFile.exists()) {
272 tempArchiveFile.createNewFile();
273 }
274 tempArchiveFile.delete();
275
276 if (isStatic) {
277 String listFileName = archiveFileName + ".classlist";
278 File listFile = new File(listFileName);
279 if (listFile.exists()) {
280 listFile.delete();
281 }
282 dumpClassList(listFileName);
283 String jdkHome = StaticProperty.javaHome();
284 String classPath = System.getProperty("java.class.path");
285 List<String> cmds = new ArrayList<String>();
286 cmds.add(jdkHome + File.separator + "bin" + File.separator + "java"); // java
287 cmds.add("-cp");
288 cmds.add(classPath);
289 cmds.add("-Xlog:cds");
290 cmds.add("-Xshare:dump");
291 cmds.add("-XX:SharedClassListFile=" + listFileName);
292 cmds.add("-XX:SharedArchiveFile=" + tempArchiveFileName);
293
294 // All runtime args.
295 String[] vmArgs = VM.getRuntimeArguments();
296 if (vmArgs != null) {
297 for (String arg : vmArgs) {
298 if (arg != null && !containsExcludedFlags(arg)) {
299 cmds.add(arg);
300 }
301 }
302 }
303
304 Process proc = Runtime.getRuntime().exec(cmds.toArray(new String[0]));
305
306 // Drain stdout/stderr to files in new threads.
307 String stdOutFileName = drainOutput(proc.getInputStream(), proc.pid(), "stdout", cmds);
308 String stdErrFileName = drainOutput(proc.getErrorStream(), proc.pid(), "stderr", cmds);
309
310 proc.waitFor();
311 // done, delete classlist file.
312 listFile.delete();
313
314 // Check if archive has been successfully dumped. We won't reach here if exception happens.
315 // Throw exception if file is not created.
316 if (!tempArchiveFile.exists()) {
317 throw new RuntimeException("Archive file " + tempArchiveFileName +
318 " is not created, please check stdout file " +
319 cwd + File.separator + stdOutFileName + " or stderr file " +
320 cwd + File.separator + stdErrFileName + " for more detail");
321 }
322 } else {
323 dumpDynamicArchive(tempArchiveFileName);
324 if (!tempArchiveFile.exists()) {
325 throw new RuntimeException("Archive file " + tempArchiveFileName +
326 " is not created, please check current working directory " +
327 cwd + " for process " +
328 currentPid + " output for more detail");
329 }
330 }
331 // Override the existing archive file
332 File archiveFile = new File(archiveFileName);
333 if (archiveFile.exists()) {
334 archiveFile.delete();
335 }
336 if (!tempArchiveFile.renameTo(archiveFile)) {
337 throw new RuntimeException("Cannot rename temp file " + tempArchiveFileName + " to archive file" + archiveFileName);
338 }
339 // Everything goes well, print out the file name.
340 String archiveFilePath = new File(archiveFileName).getAbsolutePath();
341 System.out.println("The process was attached by jcmd and dumped a " + (isStatic ? "static" : "dynamic") + " archive " + archiveFilePath);
342 return archiveFilePath;
343 }
344
345 /**
346 * This class is used only by native JVM code at CDS dump time for loading
347 * "unregistered classes", which are archived classes that are intended to
348 * be loaded by custom class loaders during runtime.
349 * See src/hotspot/share/cds/unregisteredClasses.cpp.
350 */
351 private static class UnregisteredClassLoader extends URLClassLoader {
352 private String currentClassName;
353 private Class<?> currentSuperClass;
354 private Class<?>[] currentInterfaces;
355
356 /**
357 * Used only by native code. Construct an UnregisteredClassLoader for loading
358 * unregistered classes from the specified file. If the file doesn't exist,
359 * the exception will be caughted by native code which will print a warning message and continue.
360 *
361 * @param fileName path of the the JAR file to load unregistered classes from.
362 */
363 private UnregisteredClassLoader(String fileName) throws InvalidPathException, IOException {
364 super(toURLArray(fileName), /*parent*/null);
365 currentClassName = null;
366 currentSuperClass = null;
367 currentInterfaces = null;
368 }
369
370 private static URL[] toURLArray(String fileName) throws InvalidPathException, IOException {
371 if (!((new File(fileName)).exists())) {
372 throw new IOException("No such file: " + fileName);
373 }
374 return new URL[] {
375 // Use an intermediate File object to construct a URI/URL without
376 // authority component as URLClassPath can't handle URLs with a UNC
377 // server name in the authority component.
378 Path.of(fileName).toRealPath().toFile().toURI().toURL()
379 };
380 }
381
382
383 /**
384 * Load the class of the given <code>/name<code> from the JAR file that was given to
385 * the constructor of the current UnregisteredClassLoader instance. This class must be
386 * a direct subclass of <code>superClass</code>. This class must be declared to implement
387 * the specified <code>interfaces</code>.
388 * <p>
389 * This method must be called in a single threaded context. It will never be recursed (thus
390 * the asserts)
391 *
392 * @param name the name of the class to be loaded.
393 * @param superClass must not be null. The named class must have a super class.
394 * @param interfaces could be null if the named class does not implement any interfaces.
395 */
396 private Class<?> load(String name, Class<?> superClass, Class<?>[] interfaces)
397 throws ClassNotFoundException
398 {
399 assert currentClassName == null;
400 assert currentSuperClass == null;
401 assert currentInterfaces == null;
402
403 try {
404 currentClassName = name;
405 currentSuperClass = superClass;
406 currentInterfaces = interfaces;
407
408 return findClass(name);
409 } finally {
410 currentClassName = null;
411 currentSuperClass = null;
412 currentInterfaces = null;
413 }
414 }
415
416 /**
417 * This method must be called from inside the <code>load()</code> method. The <code>/name<code>
418 * can be only:
419 * <ul>
420 * <li> the <code>name</code> parameter for <code>load()</code>
421 * <li> the name of the <code>superClass</code> parameter for <code>load()</code>
422 * <li> the name of one of the interfaces in <code>interfaces</code> parameter for <code>load()</code>
423 * <ul>
424 *
425 * For all other cases, a <code>ClassNotFoundException</code> will be thrown.
426 */
427 protected Class<?> findClass(final String name)
428 throws ClassNotFoundException
429 {
430 Objects.requireNonNull(currentClassName);
431 Objects.requireNonNull(currentSuperClass);
432
433 if (name.equals(currentClassName)) {
434 // Note: the following call will call back to <code>this.findClass(name)</code> to
435 // resolve the super types of the named class.
436 return super.findClass(name);
437 }
438 if (name.equals(currentSuperClass.getName())) {
439 return currentSuperClass;
440 }
441 if (currentInterfaces != null) {
442 for (Class<?> c : currentInterfaces) {
443 if (name.equals(c.getName())) {
444 return c;
445 }
446 }
447 }
448
449 throw new ClassNotFoundException(name);
450 }
451 }
452 }