1 /*
2 * Copyright 2000-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 package sun.jvm.hotspot.runtime;
26
27 import java.util.*;
28 import sun.jvm.hotspot.debugger.*;
29 import sun.jvm.hotspot.types.*;
30
31 public class Thread extends VMObject {
32 private static long tlabFieldOffset;
33
34 private static CIntegerField suspendFlagsField;
35 // Thread::SuspendFlags enum constants
36 private static int EXTERNAL_SUSPEND;
37 private static int EXT_SUSPENDED;
38 private static int HAS_ASYNC_EXCEPTION;
39
40 private static AddressField activeHandlesField;
41 private static AddressField highestLockField;
42 private static AddressField currentPendingMonitorField;
43 private static AddressField currentWaitingMonitorField;
44
45 static {
46 VM.registerVMInitializedObserver(new Observer() {
47 public void update(Observable o, Object data) {
48 initialize(VM.getVM().getTypeDataBase());
49 }
50 });
51 }
52
53 private static synchronized void initialize(TypeDataBase db) {
54 Type type = db.lookupType("Thread");
55
56 suspendFlagsField = type.getCIntegerField("_suspend_flags");
57 EXTERNAL_SUSPEND = db.lookupIntConstant("Thread::_external_suspend").intValue();
58 EXT_SUSPENDED = db.lookupIntConstant("Thread::_ext_suspended").intValue();
59 HAS_ASYNC_EXCEPTION = db.lookupIntConstant("Thread::_has_async_exception").intValue();
60
61 tlabFieldOffset = type.getField("_tlab").getOffset();
62 activeHandlesField = type.getAddressField("_active_handles");
63 highestLockField = type.getAddressField("_highest_lock");
64 currentPendingMonitorField = type.getAddressField("_current_pending_monitor");
65 currentWaitingMonitorField = type.getAddressField("_current_waiting_monitor");
66 }
67
68 public Thread(Address addr) {
69 super(addr);
70 }
71
72 public int suspendFlags() {
73 return (int) suspendFlagsField.getValue(addr);
74 }
75
76 public boolean isExternalSuspend() {
77 return (suspendFlags() & EXTERNAL_SUSPEND) != 0;
78 }
79
80 public boolean isExtSuspended() {
81 return (suspendFlags() & EXT_SUSPENDED) != 0;
82 }
83
84 public boolean isBeingExtSuspended() {
85 return isExtSuspended() || isExternalSuspend();
86 }
87
88 // historical usage: checked for VM or external suspension
89 public boolean isAnySuspended() {
90 return isExtSuspended();
91 }
92
93 public boolean hasAsyncException() {
94 return (suspendFlags() & HAS_ASYNC_EXCEPTION) != 0;
95 }
96
97 public ThreadLocalAllocBuffer tlab() {
98 return new ThreadLocalAllocBuffer(addr.addOffsetTo(tlabFieldOffset));
99 }
100
101 public JNIHandleBlock activeHandles() {
102 Address a = activeHandlesField.getAddress(addr);
103 if (a == null) {
104 return null;
105 }
106 return new JNIHandleBlock(a);
107 }
108
109 public boolean isVMThread() { return false; }
110 public boolean isJavaThread() { return false; }
111 public boolean isCompilerThread() { return false; }
112 public boolean isHiddenFromExternalView() { return false; }
113 public boolean isJvmtiAgentThread() { return false; }
114 public boolean isWatcherThread() { return false; }
115 public boolean isConcurrentMarkSweepThread() { return false; }
116 public boolean isLowMemoryDetectorThread() { return false; }
117
118 /** Memory operations */
119 public void oopsDo(AddressVisitor oopVisitor) {
120 // FIXME: Empty for now; will later traverse JNI handles and
121 // pending exception
122 }
123
124 public Address highestLock() {
125 return highestLockField.getValue(addr);
126 }
127
128 public ObjectMonitor getCurrentPendingMonitor() {
129 Address monitorAddr = currentPendingMonitorField.getValue(addr);
130 if (monitorAddr == null) {
131 return null;
132 }
133 return new ObjectMonitor(monitorAddr);
134 }
135
136 public ObjectMonitor getCurrentWaitingMonitor() {
137 Address monitorAddr = currentWaitingMonitorField.getValue(addr);
138 if (monitorAddr == null) {
139 return null;
140 }
141 return new ObjectMonitor(monitorAddr);
142 }
143
144 public boolean isLockOwned(Address lock) {
145 if (isInStack(lock)) return true;
146 return false;
147 }
148
149 public boolean isInStack(Address a) {
150 // In the Serviceability Agent we need access to the thread's
151 // stack pointer to be able to answer this question. Since it is
152 // only a debugging system at the moment we need access to the
153 // underlying thread, which is only present for Java threads; see
154 // JavaThread.java.
155 return false;
156 }
157
158 /** Assistance for ObjectMonitor implementation */
159 Address threadObjectAddress() { return addr; }
160 }