1 /*
  2  * Copyright (c) 2000, 2021, 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_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("x86")) {
101                 access =  new Win32X86JavaThreadPDAccess();
102             } else if (cpu.equals("amd64")) {
103                 access =  new Win32AMD64JavaThreadPDAccess();
104             } else if (cpu.equals("aarch64")) {
105                 access =  new Win32AARCH64JavaThreadPDAccess();
106             }
107         } else if (os.equals("linux")) {
108             if (cpu.equals("x86")) {
109                 access = new LinuxX86JavaThreadPDAccess();
110             } else if (cpu.equals("amd64")) {
111                 access = new LinuxAMD64JavaThreadPDAccess();
112             } else if (cpu.equals("ppc64")) {
113                 access = new LinuxPPC64JavaThreadPDAccess();
114             } else if (cpu.equals("aarch64")) {
115                 access = new LinuxAARCH64JavaThreadPDAccess();
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("CodeCacheSweeperThread", CodeCacheSweeperThread.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     }
158 
159     public Threads() {
160         _list = VMObjectFactory.newObject(ThreadsList.class, threadListField.getValue());
161     }
162 
163     /** NOTE: this returns objects of type JavaThread, CompilerThread,
164       JvmtiAgentThread, NotificationThread, MonitorDeflationThread and ServiceThread.
165       The latter four are subclasses of the former. Most operations
166       (fetching the top frame, etc.) are only allowed to be performed on
167       a "pure" JavaThread. For this reason, {@link
168       sun.jvm.hotspot.runtime.JavaThread#isJavaThread} has been
169       changed from the definition in the VM (which returns true for
170       all of these thread types) to return true for JavaThreads and
171       false for the four subclasses. FIXME: should reconsider the
172       inheritance hierarchy; see {@link
173       sun.jvm.hotspot.runtime.JavaThread#isJavaThread}. */
174     public JavaThread getJavaThreadAt(int i) {
175         if (i < _list.length()) {
176             return createJavaThreadWrapper(_list.getJavaThreadAddressAt(i));
177         }
178         return null;
179     }
180 
181     public int getNumberOfThreads() {
182         return (int) _list.length();
183     }
184 
185     /** Routine for instantiating appropriately-typed wrapper for a
186       JavaThread. Currently needs to be public for OopUtilities to
187       access it. */
188     public JavaThread createJavaThreadWrapper(Address threadAddr) {
189         try {
190             JavaThread thread = (JavaThread)virtualConstructor.instantiateWrapperFor(threadAddr);
191             thread.setThreadPDAccess(access);
192             return thread;
193         } catch (Exception e) {
194             throw new RuntimeException("Unable to deduce type of thread from address " + threadAddr +
195             " (expected type JavaThread, CompilerThread, MonitorDeflationThread, ServiceThread, JvmtiAgentThread or CodeCacheSweeperThread)", e);
196         }
197     }
198 
199     /** Memory operations */
200     public void oopsDo(AddressVisitor oopVisitor) {
201         // FIXME: add more of VM functionality
202         Threads threads = VM.getVM().getThreads();
203         for (int i = 0; i < threads.getNumberOfThreads(); i++) {
204             JavaThread thread = threads.getJavaThreadAt(i);
205             thread.oopsDo(oopVisitor);
206         }
207     }
208 
209     // refer to Threads::owning_thread_from_monitor_owner
210     public JavaThread owningThreadFromMonitor(Address o) {
211         assert(VM.getVM().getCommandLineFlag("LockingMode").getInt() != LockingMode.getLightweight());
212         if (o == null) return null;
213         for (int i = 0; i < getNumberOfThreads(); i++) {
214             JavaThread thread = getJavaThreadAt(i);
215             if (o.equals(thread.threadObjectAddress())) {
216                 return thread;
217             }
218         }
219 
220         for (int i = 0; i < getNumberOfThreads(); i++) {
221             JavaThread thread = getJavaThreadAt(i);
222             if (thread.isLockOwned(o))
223                 return thread;
224         }
225         return null;
226     }
227 
228     public JavaThread owningThreadFromMonitor(ObjectMonitor monitor) {
229         if (VM.getVM().getCommandLineFlag("LockingMode").getInt() == LockingMode.getLightweight()) {
230             if (monitor.isOwnedAnonymous()) {
231                 OopHandle object = monitor.object();
232                 for (int i = 0; i < getNumberOfThreads(); i++) {
233                     JavaThread thread = getJavaThreadAt(i);
234                     if (thread.isLockOwned(object)) {
235                         return thread;
236                      }
237                 }
238                 throw new InternalError("We should have found a thread that owns the anonymous lock");
239             }
240             // Owner can only be threads at this point.
241             Address o = monitor.owner();
242             if (o == null) return null;
243             return new JavaThread(o);
244         } else {
245             return owningThreadFromMonitor(monitor.owner());
246         }
247     }
248 
249     // refer to Threads::get_pending_threads
250     // Get list of Java threads that are waiting to enter the specified monitor.
251     public List<JavaThread> getPendingThreads(ObjectMonitor monitor) {
252         List<JavaThread> pendingThreads = new ArrayList<>();
253         for (int i = 0; i < getNumberOfThreads(); i++) {
254             JavaThread thread = getJavaThreadAt(i);
255             if (thread.isCompilerThread() || thread.isCodeCacheSweeperThread()) {
256                 continue;
257             }
258             ObjectMonitor pending = thread.getCurrentPendingMonitor();
259             if (monitor.equals(pending)) {
260                 pendingThreads.add(thread);
261             }
262         }
263         return pendingThreads;
264     }
265 
266     // Get list of Java threads that have called Object.wait on the specified monitor.
267     public List<JavaThread> getWaitingThreads(ObjectMonitor monitor) {
268         List<JavaThread> pendingThreads = new ArrayList<>();
269         for (int i = 0; i < getNumberOfThreads(); i++) {
270             JavaThread thread = getJavaThreadAt(i);
271             ObjectMonitor waiting = thread.getCurrentWaitingMonitor();
272             if (monitor.equals(waiting)) {
273                 pendingThreads.add(thread);
274             }
275         }
276         return pendingThreads;
277     }
278 
279     // FIXME: add other accessors
280 }
--- EOF ---