1 /*
2 * Copyright (c) 2000, 2023, 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 package sun.jvm.hotspot.runtime;
26
27 import java.util.*;
28
29 import sun.jvm.hotspot.debugger.*;
30 import sun.jvm.hotspot.types.*;
31 import sun.jvm.hotspot.runtime.win32_x86.Win32X86JavaThreadPDAccess;
32 import sun.jvm.hotspot.runtime.win32_amd64.Win32AMD64JavaThreadPDAccess;
33 import sun.jvm.hotspot.runtime.win32_aarch64.Win32AARCH64JavaThreadPDAccess;
34 import sun.jvm.hotspot.runtime.linux_x86.LinuxX86JavaThreadPDAccess;
35 import sun.jvm.hotspot.runtime.linux_amd64.LinuxAMD64JavaThreadPDAccess;
36 import sun.jvm.hotspot.runtime.linux_aarch64.LinuxAARCH64JavaThreadPDAccess;
37 import sun.jvm.hotspot.runtime.linux_riscv64.LinuxRISCV64JavaThreadPDAccess;
38 import sun.jvm.hotspot.runtime.linux_ppc64.LinuxPPC64JavaThreadPDAccess;
39 import sun.jvm.hotspot.runtime.bsd_x86.BsdX86JavaThreadPDAccess;
40 import sun.jvm.hotspot.runtime.bsd_amd64.BsdAMD64JavaThreadPDAccess;
41 import sun.jvm.hotspot.runtime.bsd_aarch64.BsdAARCH64JavaThreadPDAccess;
42 import sun.jvm.hotspot.utilities.*;
43 import sun.jvm.hotspot.utilities.Observable;
44 import sun.jvm.hotspot.utilities.Observer;
45
46 class ThreadsList extends VMObject {
47 private static AddressField threadsField;
48 private static CIntegerField lengthField;
49
50 static {
51 VM.registerVMInitializedObserver((o, d) -> initialize(VM.getVM().getTypeDataBase()));
52 }
53
54 private static synchronized void initialize(TypeDataBase db) {
55 Type type = db.lookupType("ThreadsList");
56 lengthField = type.getCIntegerField("_length");
57 threadsField = type.getAddressField("_threads");
58 }
59
60 public Address getJavaThreadAddressAt(int i) {
61 Address threadAddr = threadsField.getValue(addr);
62 Address at = threadAddr.getAddressAt(VM.getVM().getAddressSize() * i);
63 return at;
64 }
65
66 public long length() {
67 return lengthField.getValue(addr);
68 }
69
70 public ThreadsList(Address addr) {
71 super(addr);
72 }
73 }
74
75 public class Threads {
76 private static JavaThreadFactory threadFactory;
77 private static AddressField threadListField;
78 private static VirtualConstructor virtualConstructor;
79 private static JavaThreadPDAccess access;
80 private static ThreadsList _list;
81
82 static {
83 VM.registerVMInitializedObserver(new Observer() {
84 public void update(Observable o, Object data) {
85 initialize(VM.getVM().getTypeDataBase());
86 }
87 });
88 }
89
90 private static synchronized void initialize(TypeDataBase db) {
91 Type type = db.lookupType("ThreadsSMRSupport");
92 threadListField = type.getAddressField("_java_thread_list");
93
94 // Instantiate appropriate platform-specific JavaThreadFactory
95 String os = VM.getVM().getOS();
96 String cpu = VM.getVM().getCPU();
97
98 access = null;
99 // FIXME: find the platform specific PD class by reflection?
100 if (os.equals("win32")) {
101 if (cpu.equals("x86")) {
102 access = new Win32X86JavaThreadPDAccess();
103 } else if (cpu.equals("amd64")) {
104 access = new Win32AMD64JavaThreadPDAccess();
105 } else if (cpu.equals("aarch64")) {
106 access = new Win32AARCH64JavaThreadPDAccess();
107 }
108 } else if (os.equals("linux")) {
109 if (cpu.equals("x86")) {
110 access = new LinuxX86JavaThreadPDAccess();
111 } else if (cpu.equals("amd64")) {
112 access = new LinuxAMD64JavaThreadPDAccess();
113 } else if (cpu.equals("ppc64")) {
114 access = new LinuxPPC64JavaThreadPDAccess();
115 } else if (cpu.equals("aarch64")) {
116 access = new LinuxAARCH64JavaThreadPDAccess();
117 } else if (cpu.equals("riscv64")) {
118 access = new LinuxRISCV64JavaThreadPDAccess();
119 } else {
120 try {
121 access = (JavaThreadPDAccess)
122 Class.forName("sun.jvm.hotspot.runtime.linux_" +
123 cpu.toLowerCase() + ".Linux" + cpu.toUpperCase() +
124 "JavaThreadPDAccess").getDeclaredConstructor().newInstance();
125 } catch (Exception e) {
126 throw new RuntimeException("OS/CPU combination " + os + "/" + cpu +
127 " not yet supported");
128 }
129 }
130 } else if (os.equals("bsd")) {
131 if (cpu.equals("x86")) {
132 access = new BsdX86JavaThreadPDAccess();
133 } else if (cpu.equals("amd64") || cpu.equals("x86_64")) {
134 access = new BsdAMD64JavaThreadPDAccess();
135 }
136 } else if (os.equals("darwin")) {
137 if (cpu.equals("amd64") || cpu.equals("x86_64")) {
138 access = new BsdAMD64JavaThreadPDAccess();
139 } else if (cpu.equals("aarch64")) {
140 access = new BsdAARCH64JavaThreadPDAccess();
141 }
142 }
143
144 if (access == null) {
145 throw new RuntimeException("OS/CPU combination " + os + "/" + cpu +
146 " not yet supported");
147 }
148
149 virtualConstructor = new VirtualConstructor(db);
150 // Add mappings for all known thread types
151 virtualConstructor.addMapping("JavaThread", JavaThread.class);
152 if (!VM.getVM().isCore()) {
153 virtualConstructor.addMapping("CompilerThread", CompilerThread.class);
154 }
155 virtualConstructor.addMapping("JvmtiAgentThread", JvmtiAgentThread.class);
156 virtualConstructor.addMapping("ServiceThread", ServiceThread.class);
157 virtualConstructor.addMapping("MonitorDeflationThread", MonitorDeflationThread.class);
158 virtualConstructor.addMapping("NotificationThread", NotificationThread.class);
159 virtualConstructor.addMapping("StringDedupThread", StringDedupThread.class);
160 virtualConstructor.addMapping("AttachListenerThread", AttachListenerThread.class);
161 }
162
163 public Threads() {
164 _list = VMObjectFactory.newObject(ThreadsList.class, threadListField.getValue());
165 }
166
167 /** NOTE: this returns objects of type JavaThread, CompilerThread,
168 JvmtiAgentThread, NotificationThread, MonitorDeflationThread,
169 StringDedupThread, AttachListenerThread and ServiceThread.
170 The latter seven subclasses of the former. Most operations
171 (fetching the top frame, etc.) are only allowed to be performed on
172 a "pure" JavaThread. For this reason, {@link
173 sun.jvm.hotspot.runtime.JavaThread#isJavaThread} has been
174 changed from the definition in the VM (which returns true for
175 all of these thread types) to return true for JavaThreads and
176 false for the seven subclasses. FIXME: should reconsider the
177 inheritance hierarchy; see {@link
178 sun.jvm.hotspot.runtime.JavaThread#isJavaThread}. */
179 public JavaThread getJavaThreadAt(int i) {
180 if (i < _list.length()) {
181 return createJavaThreadWrapper(_list.getJavaThreadAddressAt(i));
182 }
183 return null;
184 }
185
186 public int getNumberOfThreads() {
187 return (int) _list.length();
188 }
189
190 /** Routine for instantiating appropriately-typed wrapper for a
191 JavaThread. Currently needs to be public for OopUtilities to
192 access it. */
193 public JavaThread createJavaThreadWrapper(Address threadAddr) {
194 try {
195 JavaThread thread = (JavaThread)virtualConstructor.instantiateWrapperFor(threadAddr);
196 thread.setThreadPDAccess(access);
197 return thread;
198 } catch (Exception e) {
199 throw new RuntimeException("Unable to deduce type of thread from address " + threadAddr +
200 " (expected type JavaThread, CompilerThread, MonitorDeflationThread, AttachListenerThread," +
201 " StringDedupThread, NotificationThread, ServiceThread or JvmtiAgentThread)", e);
202 }
203 }
204
205 /** Memory operations */
206 public void oopsDo(AddressVisitor oopVisitor) {
207 // FIXME: add more of VM functionality
208 Threads threads = VM.getVM().getThreads();
209 for (int i = 0; i < threads.getNumberOfThreads(); i++) {
210 JavaThread thread = threads.getJavaThreadAt(i);
211 thread.oopsDo(oopVisitor);
212 }
213 }
214
215 private JavaThread owningThreadFromMonitor(Address o) {
216 if (o == null) return null;
217 for (int i = 0; i < getNumberOfThreads(); i++) {
218 JavaThread thread = getJavaThreadAt(i);
219 if (o.equals(thread.getLockId())) {
220 return thread;
221 }
222 }
223 return null;
224 }
225
226 public JavaThread owningThreadFromMonitor(ObjectMonitor monitor) {
227 if (monitor.isOwnedAnonymous()) {
228 if (VM.getVM().getCommandLineFlag("LockingMode").getInt() == LockingMode.getLightweight()) {
229 OopHandle object = monitor.object();
230 for (int i = 0; i < getNumberOfThreads(); i++) {
231 JavaThread thread = getJavaThreadAt(i);
232 if (thread.isLockOwned(object)) {
233 return thread;
234 }
235 }
236 // We should have found the owner, however, as the VM could be in any state, including the middle
237 // of performing GC, it is not always possible to do so. Just return null if we can't locate it.
238 System.out.println("Warning: We failed to find a thread that owns an anonymous lock. This is likely");
239 System.out.println("due to the JVM currently running a GC. Locking information may not be accurate.");
240 return null;
241 } else {
242 assert(VM.getVM().getCommandLineFlag("LockingMode").getInt() == LockingMode.getLegacy());
243 Address o = (Address)monitor.stackLocker();
244 for (int i = 0; i < getNumberOfThreads(); i++) {
245 JavaThread thread = getJavaThreadAt(i);
246 if (thread.isLockOwned(o))
247 return thread;
248 }
249 return null;
250 }
251 } else {
252 return owningThreadFromMonitor(monitor.owner());
253 }
254 }
255
256 // refer to Threads::get_pending_threads
257 // Get list of Java threads that are waiting to enter the specified monitor.
258 public List<JavaThread> getPendingThreads(ObjectMonitor monitor) {
259 List<JavaThread> pendingThreads = new ArrayList<>();
260 for (int i = 0; i < getNumberOfThreads(); i++) {
261 JavaThread thread = getJavaThreadAt(i);
262 if (thread.isCompilerThread() || thread.isCodeCacheSweeperThread()) {
263 continue;
264 }
265 ObjectMonitor pending = thread.getCurrentPendingMonitor();
266 if (monitor.equals(pending)) {
267 pendingThreads.add(thread);
268 }
269 }
270 return pendingThreads;
271 }
272
273 // Get list of Java threads that have called Object.wait on the specified monitor.
274 public List<JavaThread> getWaitingThreads(ObjectMonitor monitor) {
275 List<JavaThread> pendingThreads = new ArrayList<>();
276 for (int i = 0; i < getNumberOfThreads(); i++) {
277 JavaThread thread = getJavaThreadAt(i);
278 ObjectMonitor waiting = thread.getCurrentWaitingMonitor();
279 if (monitor.equals(waiting)) {
280 pendingThreads.add(thread);
281 }
282 }
283 return pendingThreads;
284 }
285
286 // FIXME: add other accessors
287 }