1 /*
2 * Copyright (c) 2000, 2024, 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_amd64.Win32AMD64JavaThreadPDAccess;
32 import sun.jvm.hotspot.runtime.win32_aarch64.Win32AARCH64JavaThreadPDAccess;
33 import sun.jvm.hotspot.runtime.linux_x86.LinuxX86JavaThreadPDAccess;
34 import sun.jvm.hotspot.runtime.linux_amd64.LinuxAMD64JavaThreadPDAccess;
35 import sun.jvm.hotspot.runtime.linux_aarch64.LinuxAARCH64JavaThreadPDAccess;
36 import sun.jvm.hotspot.runtime.linux_riscv64.LinuxRISCV64JavaThreadPDAccess;
37 import sun.jvm.hotspot.runtime.linux_ppc64.LinuxPPC64JavaThreadPDAccess;
38 import sun.jvm.hotspot.runtime.bsd_x86.BsdX86JavaThreadPDAccess;
39 import sun.jvm.hotspot.runtime.bsd_amd64.BsdAMD64JavaThreadPDAccess;
40 import sun.jvm.hotspot.runtime.bsd_aarch64.BsdAARCH64JavaThreadPDAccess;
41 import sun.jvm.hotspot.utilities.*;
42 import sun.jvm.hotspot.utilities.Observable;
43 import sun.jvm.hotspot.utilities.Observer;
44
45 class ThreadsList extends VMObject {
46 private static AddressField threadsField;
47 private static CIntegerField lengthField;
48
49 static {
50 VM.registerVMInitializedObserver((o, d) -> initialize(VM.getVM().getTypeDataBase()));
51 }
52
53 private static synchronized void initialize(TypeDataBase db) {
54 Type type = db.lookupType("ThreadsList");
55 lengthField = type.getCIntegerField("_length");
56 threadsField = type.getAddressField("_threads");
57 }
58
59 public Address getJavaThreadAddressAt(int i) {
60 Address threadAddr = threadsField.getValue(addr);
61 Address at = threadAddr.getAddressAt(VM.getVM().getAddressSize() * i);
62 return at;
63 }
64
65 public long length() {
66 return lengthField.getValue(addr);
67 }
68
69 public ThreadsList(Address addr) {
70 super(addr);
71 }
72 }
73
74 public class Threads {
75 private static JavaThreadFactory threadFactory;
76 private static AddressField threadListField;
77 private static VirtualConstructor virtualConstructor;
78 private static JavaThreadPDAccess access;
79 private static ThreadsList _list;
80
81 static {
82 VM.registerVMInitializedObserver(new Observer() {
83 public void update(Observable o, Object data) {
84 initialize(VM.getVM().getTypeDataBase());
85 }
86 });
87 }
88
89 private static synchronized void initialize(TypeDataBase db) {
90 Type type = db.lookupType("ThreadsSMRSupport");
91 threadListField = type.getAddressField("_java_thread_list");
92
93 // Instantiate appropriate platform-specific JavaThreadFactory
94 String os = VM.getVM().getOS();
95 String cpu = VM.getVM().getCPU();
96
97 access = null;
98 // FIXME: find the platform specific PD class by reflection?
99 if (os.equals("win32")) {
100 if (cpu.equals("amd64")) {
101 access = new Win32AMD64JavaThreadPDAccess();
102 } else if (cpu.equals("aarch64")) {
103 access = new Win32AARCH64JavaThreadPDAccess();
104 }
105 } else if (os.equals("linux")) {
106 if (cpu.equals("x86")) {
107 access = new LinuxX86JavaThreadPDAccess();
108 } else if (cpu.equals("amd64")) {
109 access = new LinuxAMD64JavaThreadPDAccess();
110 } else if (cpu.equals("ppc64")) {
111 access = new LinuxPPC64JavaThreadPDAccess();
112 } else if (cpu.equals("aarch64")) {
113 access = new LinuxAARCH64JavaThreadPDAccess();
114 } else if (cpu.equals("riscv64")) {
115 access = new LinuxRISCV64JavaThreadPDAccess();
116 } else {
117 try {
118 access = (JavaThreadPDAccess)
119 Class.forName("sun.jvm.hotspot.runtime.linux_" +
120 cpu.toLowerCase() + ".Linux" + cpu.toUpperCase() +
121 "JavaThreadPDAccess").getDeclaredConstructor().newInstance();
122 } catch (Exception e) {
123 throw new RuntimeException("OS/CPU combination " + os + "/" + cpu +
124 " not yet supported");
125 }
126 }
127 } else if (os.equals("bsd")) {
128 if (cpu.equals("x86")) {
129 access = new BsdX86JavaThreadPDAccess();
130 } else if (cpu.equals("amd64") || cpu.equals("x86_64")) {
131 access = new BsdAMD64JavaThreadPDAccess();
132 }
133 } else if (os.equals("darwin")) {
134 if (cpu.equals("amd64") || cpu.equals("x86_64")) {
135 access = new BsdAMD64JavaThreadPDAccess();
136 } else if (cpu.equals("aarch64")) {
137 access = new BsdAARCH64JavaThreadPDAccess();
138 }
139 }
140
141 if (access == null) {
142 throw new RuntimeException("OS/CPU combination " + os + "/" + cpu +
143 " not yet supported");
144 }
145
146 virtualConstructor = new VirtualConstructor(db);
147 // Add mappings for all known thread types
148 virtualConstructor.addMapping("JavaThread", JavaThread.class);
149 if (!VM.getVM().isCore()) {
150 virtualConstructor.addMapping("CompilerThread", CompilerThread.class);
151 virtualConstructor.addMapping("TrainingReplayThread", TrainingReplayThread.class);
152 }
153 virtualConstructor.addMapping("JvmtiAgentThread", JvmtiAgentThread.class);
154 virtualConstructor.addMapping("ServiceThread", ServiceThread.class);
155 virtualConstructor.addMapping("MonitorDeflationThread", MonitorDeflationThread.class);
156 virtualConstructor.addMapping("NotificationThread", NotificationThread.class);
157 virtualConstructor.addMapping("StringDedupThread", StringDedupThread.class);
158 virtualConstructor.addMapping("AttachListenerThread", AttachListenerThread.class);
159 }
160
161 public Threads() {
162 _list = VMObjectFactory.newObject(ThreadsList.class, threadListField.getValue());
163 }
164
165 /** NOTE: this returns objects of type JavaThread, CompilerThread,
166 JvmtiAgentThread, NotificationThread, MonitorDeflationThread,
167 StringDedupThread, AttachListenerThread and ServiceThread.
168 The latter seven subclasses of the former. Most operations
169 (fetching the top frame, etc.) are only allowed to be performed on
170 a "pure" JavaThread. For this reason, {@link
171 sun.jvm.hotspot.runtime.JavaThread#isJavaThread} has been
172 changed from the definition in the VM (which returns true for
173 all of these thread types) to return true for JavaThreads and
174 false for the seven subclasses. FIXME: should reconsider the
175 inheritance hierarchy; see {@link
176 sun.jvm.hotspot.runtime.JavaThread#isJavaThread}. */
177 public JavaThread getJavaThreadAt(int i) {
178 if (i < _list.length()) {
179 return createJavaThreadWrapper(_list.getJavaThreadAddressAt(i));
180 }
181 return null;
182 }
183
184 public int getNumberOfThreads() {
185 return (int) _list.length();
186 }
187
188 /** Routine for instantiating appropriately-typed wrapper for a
189 JavaThread. Currently needs to be public for OopUtilities to
190 access it. */
191 public JavaThread createJavaThreadWrapper(Address threadAddr) {
192 try {
193 JavaThread thread = (JavaThread)virtualConstructor.instantiateWrapperFor(threadAddr);
194 thread.setThreadPDAccess(access);
195 return thread;
196 } catch (Exception e) {
197 throw new RuntimeException("Unable to deduce type of thread from address " + threadAddr +
198 " (expected type JavaThread, CompilerThread, MonitorDeflationThread, AttachListenerThread," +
199 " StringDedupThread, NotificationThread, ServiceThread or JvmtiAgentThread)", e);
200 }
201 }
202
203 /** Memory operations */
204 public void oopsDo(AddressVisitor oopVisitor) {
205 // FIXME: add more of VM functionality
206 Threads threads = VM.getVM().getThreads();
207 for (int i = 0; i < threads.getNumberOfThreads(); i++) {
208 JavaThread thread = threads.getJavaThreadAt(i);
209 thread.oopsDo(oopVisitor);
210 }
211 }
212
213 private JavaThread owningThreadFromMonitor(Address o) {
214 if (o == null) return null;
215 for (int i = 0; i < getNumberOfThreads(); i++) {
216 JavaThread thread = getJavaThreadAt(i);
217 if (o.equals(thread.getLockId())) {
218 return thread;
219 }
220 }
221 return null;
222 }
223
224 public JavaThread owningThreadFromMonitor(ObjectMonitor monitor) {
225 if (monitor.isOwnedAnonymous()) {
226 if (VM.getVM().getCommandLineFlag("LockingMode").getInt() == LockingMode.getLightweight()) {
227 OopHandle object = monitor.object();
228 for (int i = 0; i < getNumberOfThreads(); i++) {
229 JavaThread thread = getJavaThreadAt(i);
230 if (thread.isLockOwned(object)) {
231 return thread;
232 }
233 }
234 // We should have found the owner, however, as the VM could be in any state, including the middle
235 // of performing GC, it is not always possible to do so. Just return null if we can't locate it.
236 System.out.println("Warning: We failed to find a thread that owns an anonymous lock. This is likely");
237 System.out.println("due to the JVM currently running a GC. Locking information may not be accurate.");
238 return null;
239 } else {
240 assert(VM.getVM().getCommandLineFlag("LockingMode").getInt() == LockingMode.getLegacy());
241 Address o = (Address)monitor.stackLocker();
242 for (int i = 0; i < getNumberOfThreads(); i++) {
243 JavaThread thread = getJavaThreadAt(i);
244 if (thread.isLockOwned(o))
245 return thread;
246 }
247 return null;
248 }
249 } else {
250 return owningThreadFromMonitor(monitor.owner());
251 }
252 }
253
254 // refer to Threads::get_pending_threads
255 // Get list of Java threads that are waiting to enter the specified monitor.
256 public List<JavaThread> getPendingThreads(ObjectMonitor monitor) {
257 List<JavaThread> pendingThreads = new ArrayList<>();
258 for (int i = 0; i < getNumberOfThreads(); i++) {
259 JavaThread thread = getJavaThreadAt(i);
260 if (thread.isCompilerThread() || thread.isCodeCacheSweeperThread()) {
261 continue;
262 }
263 ObjectMonitor pending = thread.getCurrentPendingMonitor();
264 if (monitor.equals(pending)) {
265 pendingThreads.add(thread);
266 }
267 }
268 return pendingThreads;
269 }
270
271 // Get list of Java threads that have called Object.wait on the specified monitor.
272 public List<JavaThread> getWaitingThreads(ObjectMonitor monitor) {
273 List<JavaThread> pendingThreads = new ArrayList<>();
274 for (int i = 0; i < getNumberOfThreads(); i++) {
275 JavaThread thread = getJavaThreadAt(i);
276 ObjectMonitor waiting = thread.getCurrentWaitingMonitor();
277 if (monitor.equals(waiting)) {
278 pendingThreads.add(thread);
279 }
280 }
281 return pendingThreads;
282 }
283
284 // FIXME: add other accessors
285 }