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_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         if (o == null) return null;
215         for (int i = 0; i < getNumberOfThreads(); i++) {
216             JavaThread thread = getJavaThreadAt(i);
217             if (o.equals(thread.threadObjectAddress())) {
218                 return thread;
219             }
220         }
221 
222         for (int i = 0; i < getNumberOfThreads(); i++) {
223             JavaThread thread = getJavaThreadAt(i);
224             if (thread.isLockOwned(o))
225                 return thread;
226         }
227         return null;
228     }
229 
230     public JavaThread owningThreadFromMonitor(ObjectMonitor monitor) {
231         return owningThreadFromMonitor(monitor.owner());
232     }
233 
234     // refer to Threads::get_pending_threads
235     // Get list of Java threads that are waiting to enter the specified monitor.
236     public List<JavaThread> getPendingThreads(ObjectMonitor monitor) {
237         List<JavaThread> pendingThreads = new ArrayList<>();
238         for (int i = 0; i < getNumberOfThreads(); i++) {
239             JavaThread thread = getJavaThreadAt(i);
240             if (thread.isCompilerThread() || thread.isCodeCacheSweeperThread()) {
241                 continue;
242             }
243             ObjectMonitor pending = thread.getCurrentPendingMonitor();
244             if (monitor.equals(pending)) {
245                 pendingThreads.add(thread);
246             }
247         }
248         return pendingThreads;
249     }
250 
251     // Get list of Java threads that have called Object.wait on the specified monitor.
252     public List<JavaThread> getWaitingThreads(ObjectMonitor monitor) {
253         List<JavaThread> pendingThreads = new ArrayList<>();
254         for (int i = 0; i < getNumberOfThreads(); i++) {
255             JavaThread thread = getJavaThreadAt(i);
256             ObjectMonitor waiting = thread.getCurrentWaitingMonitor();
257             if (monitor.equals(waiting)) {
258                 pendingThreads.add(thread);
259             }
260         }
261         return pendingThreads;
262     }
263 
264     // FIXME: add other accessors
265 }