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 virtualConstructor.addMapping("TrainingReplayThread", TrainingReplayThread.class);
155 }
156 virtualConstructor.addMapping("JvmtiAgentThread", JvmtiAgentThread.class);
157 virtualConstructor.addMapping("ServiceThread", ServiceThread.class);
158 virtualConstructor.addMapping("MonitorDeflationThread", MonitorDeflationThread.class);
159 virtualConstructor.addMapping("NotificationThread", NotificationThread.class);
160 virtualConstructor.addMapping("StringDedupThread", StringDedupThread.class);
161 virtualConstructor.addMapping("AttachListenerThread", AttachListenerThread.class);
162 }
163
164 public Threads() {
165 _list = VMObjectFactory.newObject(ThreadsList.class, threadListField.getValue());
166 }
167
168 /** NOTE: this returns objects of type JavaThread, CompilerThread,
169 JvmtiAgentThread, NotificationThread, MonitorDeflationThread,
170 StringDedupThread, AttachListenerThread and ServiceThread.
171 The latter seven subclasses of the former. Most operations
172 (fetching the top frame, etc.) are only allowed to be performed on
173 a "pure" JavaThread. For this reason, {@link
174 sun.jvm.hotspot.runtime.JavaThread#isJavaThread} has been
175 changed from the definition in the VM (which returns true for
176 all of these thread types) to return true for JavaThreads and
177 false for the seven subclasses. FIXME: should reconsider the
178 inheritance hierarchy; see {@link
179 sun.jvm.hotspot.runtime.JavaThread#isJavaThread}. */
180 public JavaThread getJavaThreadAt(int i) {
181 if (i < _list.length()) {
182 return createJavaThreadWrapper(_list.getJavaThreadAddressAt(i));
183 }
184 return null;
185 }
186
187 public int getNumberOfThreads() {
188 return (int) _list.length();
189 }
190
191 /** Routine for instantiating appropriately-typed wrapper for a
192 JavaThread. Currently needs to be public for OopUtilities to
193 access it. */
194 public JavaThread createJavaThreadWrapper(Address threadAddr) {
195 try {
196 JavaThread thread = (JavaThread)virtualConstructor.instantiateWrapperFor(threadAddr);
197 thread.setThreadPDAccess(access);
198 return thread;
199 } catch (Exception e) {
200 throw new RuntimeException("Unable to deduce type of thread from address " + threadAddr +
201 " (expected type JavaThread, CompilerThread, MonitorDeflationThread, AttachListenerThread," +
202 " StringDedupThread, NotificationThread, ServiceThread or JvmtiAgentThread)", e);
203 }
204 }
205
206 /** Memory operations */
207 public void oopsDo(AddressVisitor oopVisitor) {
208 // FIXME: add more of VM functionality
209 Threads threads = VM.getVM().getThreads();
210 for (int i = 0; i < threads.getNumberOfThreads(); i++) {
211 JavaThread thread = threads.getJavaThreadAt(i);
212 thread.oopsDo(oopVisitor);
213 }
214 }
215
216 // refer to Threads::owning_thread_from_monitor_owner
217 public JavaThread owningThreadFromMonitor(Address o) {
218 assert(VM.getVM().getCommandLineFlag("LockingMode").getInt() != LockingMode.getLightweight());
219 if (o == null) return null;
220 for (int i = 0; i < getNumberOfThreads(); i++) {
221 JavaThread thread = getJavaThreadAt(i);
222 if (o.equals(thread.threadObjectAddress())) {
223 return thread;
224 }
225 }
226
227 for (int i = 0; i < getNumberOfThreads(); i++) {
228 JavaThread thread = getJavaThreadAt(i);
229 if (thread.isLockOwned(o))
230 return thread;
231 }
232 return null;
233 }
234
235 public JavaThread owningThreadFromMonitor(ObjectMonitor monitor) {
236 if (VM.getVM().getCommandLineFlag("LockingMode").getInt() == LockingMode.getLightweight()) {
237 if (monitor.isOwnedAnonymous()) {
238 OopHandle object = monitor.object();
239 for (int i = 0; i < getNumberOfThreads(); i++) {
240 JavaThread thread = getJavaThreadAt(i);
241 if (thread.isLockOwned(object)) {
242 return thread;
243 }
244 }
245 // We should have found the owner, however, as the VM could be in any state, including the middle
246 // of performing GC, it is not always possible to do so. Just return null if we can't locate it.
247 System.out.println("Warning: We failed to find a thread that owns an anonymous lock. This is likely");
248 System.out.println("due to the JVM currently running a GC. Locking information may not be accurate.");
249 return null;
250 }
251 // Owner can only be threads at this point.
252 Address o = monitor.owner();
253 if (o == null) return null;
254 return new JavaThread(o);
255 } else {
256 return owningThreadFromMonitor(monitor.owner());
257 }
258 }
259
260 // refer to Threads::get_pending_threads
261 // Get list of Java threads that are waiting to enter the specified monitor.
262 public List<JavaThread> getPendingThreads(ObjectMonitor monitor) {
263 List<JavaThread> pendingThreads = new ArrayList<>();
264 for (int i = 0; i < getNumberOfThreads(); i++) {
265 JavaThread thread = getJavaThreadAt(i);
266 if (thread.isCompilerThread() || thread.isCodeCacheSweeperThread()) {
267 continue;
268 }
269 ObjectMonitor pending = thread.getCurrentPendingMonitor();
270 if (monitor.equals(pending)) {
271 pendingThreads.add(thread);
272 }
273 }
274 return pendingThreads;
275 }
276
277 // Get list of Java threads that have called Object.wait on the specified monitor.
278 public List<JavaThread> getWaitingThreads(ObjectMonitor monitor) {
279 List<JavaThread> pendingThreads = new ArrayList<>();
280 for (int i = 0; i < getNumberOfThreads(); i++) {
281 JavaThread thread = getJavaThreadAt(i);
282 ObjectMonitor waiting = thread.getCurrentWaitingMonitor();
283 if (monitor.equals(waiting)) {
284 pendingThreads.add(thread);
285 }
286 }
287 return pendingThreads;
288 }
289
290 // FIXME: add other accessors
291 }