1 /*
2 * Copyright (c) 2000, 2022, 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("CodeCacheSweeperThread", CodeCacheSweeperThread.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 }
161
162 public Threads() {
163 _list = VMObjectFactory.newObject(ThreadsList.class, threadListField.getValue());
164 }
165
166 /** NOTE: this returns objects of type JavaThread, CompilerThread,
167 JvmtiAgentThread, NotificationThread, MonitorDeflationThread and ServiceThread.
168 The latter four are 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 four 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, ServiceThread, JvmtiAgentThread or CodeCacheSweeperThread)", e);
199 }
200 }
201
202 /** Memory operations */
203 public void oopsDo(AddressVisitor oopVisitor) {
204 // FIXME: add more of VM functionality
205 Threads threads = VM.getVM().getThreads();
206 for (int i = 0; i < threads.getNumberOfThreads(); i++) {
207 JavaThread thread = threads.getJavaThreadAt(i);
208 thread.oopsDo(oopVisitor);
209 }
210 }
211
212 // refer to Threads::owning_thread_from_monitor_owner
213 public JavaThread owningThreadFromMonitor(Address o) {
214 assert(VM.getVM().getCommandLineFlag("LockingMode").getInt() != LockingMode.getLightweight());
215 if (o == null) return null;
216 for (int i = 0; i < getNumberOfThreads(); i++) {
217 JavaThread thread = getJavaThreadAt(i);
218 if (o.equals(thread.threadObjectAddress())) {
219 return thread;
220 }
221 }
222
223 for (int i = 0; i < getNumberOfThreads(); i++) {
224 JavaThread thread = getJavaThreadAt(i);
225 if (thread.isLockOwned(o))
226 return thread;
227 }
228 return null;
229 }
230
231 public JavaThread owningThreadFromMonitor(ObjectMonitor monitor) {
232 if (VM.getVM().getCommandLineFlag("LockingMode").getInt() == LockingMode.getLightweight()) {
233 if (monitor.isOwnedAnonymous()) {
234 OopHandle object = monitor.object();
235 for (int i = 0; i < getNumberOfThreads(); i++) {
236 JavaThread thread = getJavaThreadAt(i);
237 if (thread.isLockOwned(object)) {
238 return thread;
239 }
240 }
241 // We should have found the owner, however, as the VM could be in any state, including the middle
242 // of performing GC, it is not always possible to do so. Just return null if we can't locate it.
243 System.out.println("Warning: We failed to find a thread that owns an anonymous lock. This is likely");
244 System.out.println("due to the JVM currently running a GC. Locking information may not be accurate.");
245 return null;
246 }
247 // Owner can only be threads at this point.
248 Address o = monitor.owner();
249 if (o == null) return null;
250 return new JavaThread(o);
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 }