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         }
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     }
160 
161     public Threads() {
162         _list = VMObjectFactory.newObject(ThreadsList.class, threadListField.getValue());
163     }
164 
165     /** NOTE: this returns objects of type JavaThread, CompilerThread,
166       JvmtiAgentThread, NotificationThread, MonitorDeflationThread and ServiceThread.
167       The latter four are subclasses of the former. Most operations
168       (fetching the top frame, etc.) are only allowed to be performed on
169       a "pure" JavaThread. For this reason, {@link
170       sun.jvm.hotspot.runtime.JavaThread#isJavaThread} has been
171       changed from the definition in the VM (which returns true for
172       all of these thread types) to return true for JavaThreads and
173       false for the four subclasses. FIXME: should reconsider the
174       inheritance hierarchy; see {@link
175       sun.jvm.hotspot.runtime.JavaThread#isJavaThread}. */
176     public JavaThread getJavaThreadAt(int i) {
177         if (i < _list.length()) {
178             return createJavaThreadWrapper(_list.getJavaThreadAddressAt(i));
179         }
180         return null;
181     }
182 
183     public int getNumberOfThreads() {
184         return (int) _list.length();
185     }
186 
187     /** Routine for instantiating appropriately-typed wrapper for a
188       JavaThread. Currently needs to be public for OopUtilities to
189       access it. */
190     public JavaThread createJavaThreadWrapper(Address threadAddr) {
191         try {
192             JavaThread thread = (JavaThread)virtualConstructor.instantiateWrapperFor(threadAddr);
193             thread.setThreadPDAccess(access);
194             return thread;
195         } catch (Exception e) {
196             throw new RuntimeException("Unable to deduce type of thread from address " + threadAddr +
197             " (expected type JavaThread, CompilerThread, MonitorDeflationThread, ServiceThread or JvmtiAgentThread)", e);
198         }
199     }
200 
201     /** Memory operations */
202     public void oopsDo(AddressVisitor oopVisitor) {
203         // FIXME: add more of VM functionality
204         Threads threads = VM.getVM().getThreads();
205         for (int i = 0; i < threads.getNumberOfThreads(); i++) {
206             JavaThread thread = threads.getJavaThreadAt(i);
207             thread.oopsDo(oopVisitor);
208         }
209     }
210 
211     // refer to Threads::owning_thread_from_monitor_owner
212     public JavaThread owningThreadFromMonitor(ObjectMonitor monitor) {
213         if (monitor.isOwnedAnonymous()) {
214             OopHandle object = monitor.object();
215             for (int i = 0; i < getNumberOfThreads(); i++) {
216                 JavaThread thread = getJavaThreadAt(i);
217                 if (thread.isLockOwned(object)) {
218                     return thread;
219                 }
220             }
221             throw new InternalError("We should have found a thread that owns the anonymous lock");
222         }
223         Address o = monitor.owner();
224         if (o == null) return null;
225         for (int i = 0; i < getNumberOfThreads(); i++) {
226             JavaThread thread = getJavaThreadAt(i);
227             if (o.equals(thread.threadObjectAddress())) {
228                 return thread;
229             }
230         }
231         return null;
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 }