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