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 // refer to Threads::owning_thread_from_monitor_owner
216 public JavaThread owningThreadFromMonitor(Address o) {
217 assert(VM.getVM().getCommandLineFlag("LockingMode").getInt() != LockingMode.getLightweight());
218 if (o == null) return null;
219 for (int i = 0; i < getNumberOfThreads(); i++) {
220 JavaThread thread = getJavaThreadAt(i);
221 if (o.equals(thread.threadObjectAddress())) {
222 return thread;
223 }
224 }
225
226 for (int i = 0; i < getNumberOfThreads(); i++) {
227 JavaThread thread = getJavaThreadAt(i);
228 if (thread.isLockOwned(o))
229 return thread;
230 }
231 return null;
232 }
233
234 public JavaThread owningThreadFromMonitor(ObjectMonitor monitor) {
235 if (VM.getVM().getCommandLineFlag("LockingMode").getInt() == LockingMode.getLightweight()) {
236 if (monitor.isOwnedAnonymous()) {
237 OopHandle object = monitor.object();
238 for (int i = 0; i < getNumberOfThreads(); i++) {
239 JavaThread thread = getJavaThreadAt(i);
240 if (thread.isLockOwned(object)) {
241 return thread;
242 }
243 }
244 // We should have found the owner, however, as the VM could be in any state, including the middle
245 // of performing GC, it is not always possible to do so. Just return null if we can't locate it.
246 System.out.println("Warning: We failed to find a thread that owns an anonymous lock. This is likely");
247 System.out.println("due to the JVM currently running a GC. Locking information may not be accurate.");
248 return null;
249 }
250 // Owner can only be threads at this point.
251 Address o = monitor.owner();
252 if (o == null) return null;
253 return new JavaThread(o);
254 } else {
255 return owningThreadFromMonitor(monitor.owner());
256 }
257 }
258
259 // refer to Threads::get_pending_threads
260 // Get list of Java threads that are waiting to enter the specified monitor.
261 public List<JavaThread> getPendingThreads(ObjectMonitor monitor) {
262 List<JavaThread> pendingThreads = new ArrayList<>();
263 for (int i = 0; i < getNumberOfThreads(); i++) {
264 JavaThread thread = getJavaThreadAt(i);
265 if (thread.isCompilerThread() || thread.isCodeCacheSweeperThread()) {
266 continue;
267 }
268 ObjectMonitor pending = thread.getCurrentPendingMonitor();
269 if (monitor.equals(pending)) {
270 pendingThreads.add(thread);
271 }
272 }
273 return pendingThreads;
274 }
275
276 // Get list of Java threads that have called Object.wait on the specified monitor.
277 public List<JavaThread> getWaitingThreads(ObjectMonitor monitor) {
278 List<JavaThread> pendingThreads = new ArrayList<>();
279 for (int i = 0; i < getNumberOfThreads(); i++) {
280 JavaThread thread = getJavaThreadAt(i);
281 ObjectMonitor waiting = thread.getCurrentWaitingMonitor();
282 if (monitor.equals(waiting)) {
283 pendingThreads.add(thread);
284 }
285 }
286 return pendingThreads;
287 }
288
289 // FIXME: add other accessors
290 }