1 /*
2 * Copyright (c) 2003, 2014, 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang.management;
27
28 import javax.management.openmbean.CompositeData;
29 import sun.management.ManagementFactoryHelper;
30 import sun.management.ThreadInfoCompositeData;
31 import static java.lang.Thread.State.*;
32
33 /**
34 * Thread information. <tt>ThreadInfo</tt> contains the information
35 * about a thread including:
36 * <h3>General thread information</h3>
37 * <ul>
38 * <li>Thread ID.</li>
39 * <li>Name of the thread.</li>
40 * </ul>
41 *
42 * <h3>Execution information</h3>
43 * <ul>
44 * <li>Thread state.</li>
45 * <li>The object upon which the thread is blocked due to:
46 * <ul>
47 * <li>waiting to enter a synchronization block/method, or</li>
48 * <li>waiting to be notified in a {@link Object#wait Object.wait} method,
49 * or</li>
50 * <li>parking due to a {@link java.util.concurrent.locks.LockSupport#park
51 * LockSupport.park} call.</li>
52 * </ul>
53 * </li>
54 * <li>The ID of the thread that owns the object
55 * that the thread is blocked.</li>
56 * <li>Stack trace of the thread.</li>
57 * <li>List of object monitors locked by the thread.</li>
58 * <li>List of <a href="LockInfo.html#OwnableSynchronizer">
59 * ownable synchronizers</a> locked by the thread.</li>
60 * </ul>
61 *
62 * <h4><a name="SyncStats">Synchronization Statistics</a></h4>
63 * <ul>
64 * <li>The number of times that the thread has blocked for
65 * synchronization or waited for notification.</li>
66 * <li>The accumulated elapsed time that the thread has blocked
67 * for synchronization or waited for notification
68 * since {@link ThreadMXBean#setThreadContentionMonitoringEnabled
69 * thread contention monitoring}
70 * was enabled. Some Java virtual machine implementation
71 * may not support this. The
72 * {@link ThreadMXBean#isThreadContentionMonitoringSupported()}
73 * method can be used to determine if a Java virtual machine
74 * supports this.</li>
75 * </ul>
76 *
77 * <p>This thread information class is designed for use in monitoring of
78 * the system, not for synchronization control.
79 *
80 * <h4>MXBean Mapping</h4>
81 * <tt>ThreadInfo</tt> is mapped to a {@link CompositeData CompositeData}
82 * with attributes as specified in
83 * the {@link #from from} method.
84 *
85 * @see ThreadMXBean#getThreadInfo
86 * @see ThreadMXBean#dumpAllThreads
87 *
88 * @author Mandy Chung
89 * @since 1.5
90 */
91
92 public class ThreadInfo {
93 private String threadName;
94 private long threadId;
95 private long blockedTime;
96 private long blockedCount;
97 private long waitedTime;
98 private long waitedCount;
99 private LockInfo lock;
100 private String lockName;
101 private long lockOwnerId;
102 private String lockOwnerName;
103 private boolean inNative;
104 private boolean suspended;
105 private Thread.State threadState;
106 private StackTraceElement[] stackTrace;
107 private MonitorInfo[] lockedMonitors;
108 private LockInfo[] lockedSynchronizers;
109
110 private static MonitorInfo[] EMPTY_MONITORS = new MonitorInfo[0];
111 private static LockInfo[] EMPTY_SYNCS = new LockInfo[0];
112
113 /**
114 * Constructor of ThreadInfo created by the JVM
115 *
116 * @param t Thread
117 * @param state Thread state
118 * @param lockObj Object on which the thread is blocked
119 * @param lockOwner the thread holding the lock
120 * @param blockedCount Number of times blocked to enter a lock
121 * @param blockedTime Approx time blocked to enter a lock
122 * @param waitedCount Number of times waited on a lock
123 * @param waitedTime Approx time waited on a lock
124 * @param stackTrace Thread stack trace
125 */
126 private ThreadInfo(Thread t, int state, Object lockObj, Thread lockOwner,
127 long blockedCount, long blockedTime,
128 long waitedCount, long waitedTime,
129 StackTraceElement[] stackTrace) {
130 initialize(t, state, lockObj, lockOwner,
131 blockedCount, blockedTime,
132 waitedCount, waitedTime, stackTrace,
133 EMPTY_MONITORS, EMPTY_SYNCS);
134 }
135
136 /**
137 * Constructor of ThreadInfo created by the JVM
138 * for {@link ThreadMXBean#getThreadInfo(long[],boolean,boolean)}
139 * and {@link ThreadMXBean#dumpAllThreads}
140 *
141 * @param t Thread
142 * @param state Thread state
143 * @param lockObj Object on which the thread is blocked
144 * @param lockOwner the thread holding the lock
145 * @param blockedCount Number of times blocked to enter a lock
146 * @param blockedTime Approx time blocked to enter a lock
147 * @param waitedCount Number of times waited on a lock
148 * @param waitedTime Approx time waited on a lock
149 * @param stackTrace Thread stack trace
150 * @param monitors List of locked monitors
151 * @param stackDepths List of stack depths
152 * @param synchronizers List of locked synchronizers
153 */
154 private ThreadInfo(Thread t, int state, Object lockObj, Thread lockOwner,
155 long blockedCount, long blockedTime,
156 long waitedCount, long waitedTime,
157 StackTraceElement[] stackTrace,
158 Object[] monitors,
159 int[] stackDepths,
160 Object[] synchronizers) {
161 int numMonitors = (monitors == null ? 0 : monitors.length);
162 MonitorInfo[] lockedMonitors;
163 if (numMonitors == 0) {
164 lockedMonitors = EMPTY_MONITORS;
165 } else {
166 lockedMonitors = new MonitorInfo[numMonitors];
167 for (int i = 0; i < numMonitors; i++) {
168 Object lock = monitors[i];
169 String className = lock.getClass().getName();
170 int identityHashCode = System.identityHashCode(lock);
171 int depth = stackDepths[i];
172 StackTraceElement ste = (depth >= 0 ? stackTrace[depth]
173 : null);
174 lockedMonitors[i] = new MonitorInfo(className,
175 identityHashCode,
176 depth,
177 ste);
178 }
179 }
180
181 int numSyncs = (synchronizers == null ? 0 : synchronizers.length);
182 LockInfo[] lockedSynchronizers;
183 if (numSyncs == 0) {
184 lockedSynchronizers = EMPTY_SYNCS;
185 } else {
186 lockedSynchronizers = new LockInfo[numSyncs];
187 for (int i = 0; i < numSyncs; i++) {
188 Object lock = synchronizers[i];
189 String className = lock.getClass().getName();
190 int identityHashCode = System.identityHashCode(lock);
191 lockedSynchronizers[i] = new LockInfo(className,
192 identityHashCode);
193 }
194 }
195
196 initialize(t, state, lockObj, lockOwner,
197 blockedCount, blockedTime,
198 waitedCount, waitedTime, stackTrace,
199 lockedMonitors, lockedSynchronizers);
200 }
201
202 /**
203 * Initialize ThreadInfo object
204 *
205 * @param t Thread
206 * @param state Thread state
207 * @param lockObj Object on which the thread is blocked
208 * @param lockOwner the thread holding the lock
209 * @param blockedCount Number of times blocked to enter a lock
210 * @param blockedTime Approx time blocked to enter a lock
211 * @param waitedCount Number of times waited on a lock
212 * @param waitedTime Approx time waited on a lock
213 * @param stackTrace Thread stack trace
214 * @param lockedMonitors List of locked monitors
215 * @param lockedSynchronizers List of locked synchronizers
216 */
217 private void initialize(Thread t, int state, Object lockObj, Thread lockOwner,
218 long blockedCount, long blockedTime,
219 long waitedCount, long waitedTime,
220 StackTraceElement[] stackTrace,
221 MonitorInfo[] lockedMonitors,
222 LockInfo[] lockedSynchronizers) {
223 this.threadId = t.getId();
224 this.threadName = t.getName();
225 this.threadState = ManagementFactoryHelper.toThreadState(state);
226 this.suspended = ManagementFactoryHelper.isThreadSuspended(state);
227 this.inNative = ManagementFactoryHelper.isThreadRunningNative(state);
228 this.blockedCount = blockedCount;
229 this.blockedTime = blockedTime;
230 this.waitedCount = waitedCount;
231 this.waitedTime = waitedTime;
232
233 if (lockObj == null) {
234 this.lock = null;
235 this.lockName = null;
236 } else {
237 this.lock = new LockInfo(lockObj);
238 this.lockName =
239 lock.getClassName() + '@' +
240 Integer.toHexString(lock.getIdentityHashCode());
241 }
242 if (lockOwner == null) {
243 this.lockOwnerId = -1;
244 this.lockOwnerName = null;
245 } else {
246 this.lockOwnerId = lockOwner.getId();
247 this.lockOwnerName = lockOwner.getName();
248 }
249 if (stackTrace == null) {
250 this.stackTrace = NO_STACK_TRACE;
251 } else {
252 this.stackTrace = stackTrace;
253 }
254 this.lockedMonitors = lockedMonitors;
255 this.lockedSynchronizers = lockedSynchronizers;
256 }
257
258 /*
259 * Constructs a <tt>ThreadInfo</tt> object from a
260 * {@link CompositeData CompositeData}.
261 */
262 private ThreadInfo(CompositeData cd) {
263 ThreadInfoCompositeData ticd = ThreadInfoCompositeData.getInstance(cd);
264
265 threadId = ticd.threadId();
266 threadName = ticd.threadName();
267 blockedTime = ticd.blockedTime();
268 blockedCount = ticd.blockedCount();
269 waitedTime = ticd.waitedTime();
270 waitedCount = ticd.waitedCount();
271 lockName = ticd.lockName();
272 lockOwnerId = ticd.lockOwnerId();
273 lockOwnerName = ticd.lockOwnerName();
274 threadState = ticd.threadState();
275 suspended = ticd.suspended();
276 inNative = ticd.inNative();
277 stackTrace = ticd.stackTrace();
278
279 // 6.0 attributes
280 if (ticd.isCurrentVersion()) {
281 lock = ticd.lockInfo();
282 lockedMonitors = ticd.lockedMonitors();
283 lockedSynchronizers = ticd.lockedSynchronizers();
284 } else {
285 // lockInfo is a new attribute added in 1.6 ThreadInfo
286 // If cd is a 5.0 version, construct the LockInfo object
287 // from the lockName value.
288 if (lockName != null) {
289 String result[] = lockName.split("@");
290 if (result.length == 2) {
291 int identityHashCode = Integer.parseInt(result[1], 16);
292 lock = new LockInfo(result[0], identityHashCode);
293 } else {
294 assert result.length == 2;
295 lock = null;
296 }
297 } else {
298 lock = null;
299 }
300 lockedMonitors = EMPTY_MONITORS;
301 lockedSynchronizers = EMPTY_SYNCS;
302 }
303 }
304
305 /**
306 * Returns the ID of the thread associated with this <tt>ThreadInfo</tt>.
307 *
308 * @return the ID of the associated thread.
309 */
310 public long getThreadId() {
311 return threadId;
312 }
313
314 /**
315 * Returns the name of the thread associated with this <tt>ThreadInfo</tt>.
316 *
317 * @return the name of the associated thread.
318 */
319 public String getThreadName() {
320 return threadName;
321 }
322
323 /**
324 * Returns the state of the thread associated with this <tt>ThreadInfo</tt>.
325 *
326 * @return <tt>Thread.State</tt> of the associated thread.
327 */
328 public Thread.State getThreadState() {
329 return threadState;
330 }
331
332 /**
333 * Returns the approximate accumulated elapsed time (in milliseconds)
334 * that the thread associated with this <tt>ThreadInfo</tt>
335 * has blocked to enter or reenter a monitor
336 * since thread contention monitoring is enabled.
337 * I.e. the total accumulated time the thread has been in the
338 * {@link java.lang.Thread.State#BLOCKED BLOCKED} state since thread
339 * contention monitoring was last enabled.
340 * This method returns <tt>-1</tt> if thread contention monitoring
341 * is disabled.
342 *
343 * <p>The Java virtual machine may measure the time with a high
344 * resolution timer. This statistic is reset when
345 * the thread contention monitoring is reenabled.
346 *
347 * @return the approximate accumulated elapsed time in milliseconds
348 * that a thread entered the <tt>BLOCKED</tt> state;
349 * <tt>-1</tt> if thread contention monitoring is disabled.
350 *
351 * @throws java.lang.UnsupportedOperationException if the Java
352 * virtual machine does not support this operation.
353 *
354 * @see ThreadMXBean#isThreadContentionMonitoringSupported
355 * @see ThreadMXBean#setThreadContentionMonitoringEnabled
356 */
357 public long getBlockedTime() {
358 return blockedTime;
359 }
360
361 /**
362 * Returns the total number of times that
363 * the thread associated with this <tt>ThreadInfo</tt>
364 * blocked to enter or reenter a monitor.
365 * I.e. the number of times a thread has been in the
366 * {@link java.lang.Thread.State#BLOCKED BLOCKED} state.
367 *
368 * @return the total number of times that the thread
369 * entered the <tt>BLOCKED</tt> state.
370 */
371 public long getBlockedCount() {
372 return blockedCount;
373 }
374
375 /**
376 * Returns the approximate accumulated elapsed time (in milliseconds)
377 * that the thread associated with this <tt>ThreadInfo</tt>
378 * has waited for notification
379 * since thread contention monitoring is enabled.
380 * I.e. the total accumulated time the thread has been in the
381 * {@link java.lang.Thread.State#WAITING WAITING}
382 * or {@link java.lang.Thread.State#TIMED_WAITING TIMED_WAITING} state
383 * since thread contention monitoring is enabled.
384 * This method returns <tt>-1</tt> if thread contention monitoring
385 * is disabled.
386 *
387 * <p>The Java virtual machine may measure the time with a high
388 * resolution timer. This statistic is reset when
389 * the thread contention monitoring is reenabled.
390 *
391 * @return the approximate accumulated elapsed time in milliseconds
392 * that a thread has been in the <tt>WAITING</tt> or
393 * <tt>TIMED_WAITING</tt> state;
394 * <tt>-1</tt> if thread contention monitoring is disabled.
395 *
396 * @throws java.lang.UnsupportedOperationException if the Java
397 * virtual machine does not support this operation.
398 *
399 * @see ThreadMXBean#isThreadContentionMonitoringSupported
400 * @see ThreadMXBean#setThreadContentionMonitoringEnabled
401 */
402 public long getWaitedTime() {
403 return waitedTime;
404 }
405
406 /**
407 * Returns the total number of times that
408 * the thread associated with this <tt>ThreadInfo</tt>
409 * waited for notification.
410 * I.e. the number of times that a thread has been
411 * in the {@link java.lang.Thread.State#WAITING WAITING}
412 * or {@link java.lang.Thread.State#TIMED_WAITING TIMED_WAITING} state.
413 *
414 * @return the total number of times that the thread
415 * was in the <tt>WAITING</tt> or <tt>TIMED_WAITING</tt> state.
416 */
417 public long getWaitedCount() {
418 return waitedCount;
419 }
420
421 /**
422 * Returns the <tt>LockInfo</tt> of an object for which
423 * the thread associated with this <tt>ThreadInfo</tt>
424 * is blocked waiting.
425 * A thread can be blocked waiting for one of the following:
426 * <ul>
427 * <li>an object monitor to be acquired for entering or reentering
428 * a synchronization block/method.
429 * <br>The thread is in the {@link java.lang.Thread.State#BLOCKED BLOCKED}
430 * state waiting to enter the <tt>synchronized</tt> statement
431 * or method.
432 * </li>
433 * <li>an object monitor to be notified by another thread.
434 * <br>The thread is in the {@link java.lang.Thread.State#WAITING WAITING}
435 * or {@link java.lang.Thread.State#TIMED_WAITING TIMED_WAITING} state
436 * due to a call to the {@link Object#wait Object.wait} method.
437 * </li>
438 * <li>a synchronization object responsible for the thread parking.
439 * <br>The thread is in the {@link java.lang.Thread.State#WAITING WAITING}
440 * or {@link java.lang.Thread.State#TIMED_WAITING TIMED_WAITING} state
441 * due to a call to the
442 * {@link java.util.concurrent.locks.LockSupport#park(Object)
443 * LockSupport.park} method. The synchronization object
444 * is the object returned from
445 * {@link java.util.concurrent.locks.LockSupport#getBlocker
446 * LockSupport.getBlocker} method. Typically it is an
447 * <a href="LockInfo.html#OwnableSynchronizer"> ownable synchronizer</a>
448 * or a {@link java.util.concurrent.locks.Condition Condition}.</li>
449 * </ul>
450 *
451 * <p>This method returns <tt>null</tt> if the thread is not in any of
452 * the above conditions.
453 *
454 * @return <tt>LockInfo</tt> of an object for which the thread
455 * is blocked waiting if any; <tt>null</tt> otherwise.
456 * @since 1.6
457 */
458 public LockInfo getLockInfo() {
459 return lock;
460 }
461
462 /**
463 * Returns the {@link LockInfo#toString string representation}
464 * of an object for which the thread associated with this
465 * <tt>ThreadInfo</tt> is blocked waiting.
466 * This method is equivalent to calling:
467 * <blockquote>
468 * <pre>
469 * getLockInfo().toString()
470 * </pre></blockquote>
471 *
472 * <p>This method will return <tt>null</tt> if this thread is not blocked
473 * waiting for any object or if the object is not owned by any thread.
474 *
475 * @return the string representation of the object on which
476 * the thread is blocked if any;
477 * <tt>null</tt> otherwise.
478 *
479 * @see #getLockInfo
480 */
481 public String getLockName() {
482 return lockName;
483 }
484
485 /**
486 * Returns the ID of the thread which owns the object
487 * for which the thread associated with this <tt>ThreadInfo</tt>
488 * is blocked waiting.
489 * This method will return <tt>-1</tt> if this thread is not blocked
490 * waiting for any object or if the object is not owned by any thread.
491 *
492 * @return the thread ID of the owner thread of the object
493 * this thread is blocked on;
494 * <tt>-1</tt> if this thread is not blocked
495 * or if the object is not owned by any thread.
496 *
497 * @see #getLockInfo
498 */
499 public long getLockOwnerId() {
500 return lockOwnerId;
501 }
502
503 /**
504 * Returns the name of the thread which owns the object
505 * for which the thread associated with this <tt>ThreadInfo</tt>
506 * is blocked waiting.
507 * This method will return <tt>null</tt> if this thread is not blocked
508 * waiting for any object or if the object is not owned by any thread.
509 *
510 * @return the name of the thread that owns the object
511 * this thread is blocked on;
512 * <tt>null</tt> if this thread is not blocked
513 * or if the object is not owned by any thread.
514 *
515 * @see #getLockInfo
516 */
517 public String getLockOwnerName() {
518 return lockOwnerName;
519 }
520
521 /**
522 * Returns the stack trace of the thread
523 * associated with this <tt>ThreadInfo</tt>.
524 * If no stack trace was requested for this thread info, this method
525 * will return a zero-length array.
526 * If the returned array is of non-zero length then the first element of
527 * the array represents the top of the stack, which is the most recent
528 * method invocation in the sequence. The last element of the array
529 * represents the bottom of the stack, which is the least recent method
530 * invocation in the sequence.
531 *
532 * <p>Some Java virtual machines may, under some circumstances, omit one
533 * or more stack frames from the stack trace. In the extreme case,
534 * a virtual machine that has no stack trace information concerning
535 * the thread associated with this <tt>ThreadInfo</tt>
536 * is permitted to return a zero-length array from this method.
537 *
538 * @return an array of <tt>StackTraceElement</tt> objects of the thread.
539 */
540 public StackTraceElement[] getStackTrace() {
541 return stackTrace;
542 }
543
544 /**
545 * Tests if the thread associated with this <tt>ThreadInfo</tt>
546 * is suspended. This method returns <tt>true</tt> if
547 * {@link Thread#suspend} has been called.
548 *
549 * @return <tt>true</tt> if the thread is suspended;
550 * <tt>false</tt> otherwise.
551 */
552 public boolean isSuspended() {
553 return suspended;
554 }
555
556 /**
557 * Tests if the thread associated with this <tt>ThreadInfo</tt>
558 * is executing native code via the Java Native Interface (JNI).
559 * The JNI native code does not include
560 * the virtual machine support code or the compiled native
561 * code generated by the virtual machine.
562 *
563 * @return <tt>true</tt> if the thread is executing native code;
564 * <tt>false</tt> otherwise.
565 */
566 public boolean isInNative() {
567 return inNative;
568 }
569
570 /**
571 * Returns a string representation of this thread info.
572 * The format of this string depends on the implementation.
573 * The returned string will typically include
574 * the {@linkplain #getThreadName thread name},
575 * the {@linkplain #getThreadId thread ID},
576 * its {@linkplain #getThreadState state},
577 * and a {@linkplain #getStackTrace stack trace} if any.
578 *
579 * @return a string representation of this thread info.
580 */
581 public String toString() {
582 StringBuilder sb = new StringBuilder("\"" + getThreadName() + "\"" +
583 " Id=" + getThreadId() + " " +
584 getThreadState());
585 if (getLockName() != null) {
586 sb.append(" on " + getLockName());
587 }
588 if (getLockOwnerName() != null) {
589 sb.append(" owned by \"" + getLockOwnerName() +
590 "\" Id=" + getLockOwnerId());
591 }
592 if (isSuspended()) {
593 sb.append(" (suspended)");
594 }
595 if (isInNative()) {
596 sb.append(" (in native)");
597 }
598 sb.append('\n');
599 int i = 0;
600 for (; i < stackTrace.length && i < MAX_FRAMES; i++) {
601 StackTraceElement ste = stackTrace[i];
602 sb.append("\tat " + ste.toString());
603 sb.append('\n');
604 if (i == 0 && getLockInfo() != null) {
605 Thread.State ts = getThreadState();
606 switch (ts) {
607 case BLOCKED:
608 sb.append("\t- blocked on " + getLockInfo());
609 sb.append('\n');
610 break;
611 case WAITING:
612 sb.append("\t- waiting on " + getLockInfo());
613 sb.append('\n');
614 break;
615 case TIMED_WAITING:
616 sb.append("\t- waiting on " + getLockInfo());
617 sb.append('\n');
618 break;
619 default:
620 }
621 }
622
623 for (MonitorInfo mi : lockedMonitors) {
624 if (mi.getLockedStackDepth() == i) {
625 sb.append("\t- locked " + mi);
626 sb.append('\n');
627 }
628 }
629 }
630 if (i < stackTrace.length) {
631 sb.append("\t...");
632 sb.append('\n');
633 }
634
635 LockInfo[] locks = getLockedSynchronizers();
636 if (locks.length > 0) {
637 sb.append("\n\tNumber of locked synchronizers = " + locks.length);
638 sb.append('\n');
639 for (LockInfo li : locks) {
640 sb.append("\t- " + li);
641 sb.append('\n');
642 }
643 }
644 sb.append('\n');
645 return sb.toString();
646 }
647 private static final int MAX_FRAMES = 8;
648
649 /**
650 * Returns a <tt>ThreadInfo</tt> object represented by the
651 * given <tt>CompositeData</tt>.
652 * The given <tt>CompositeData</tt> must contain the following attributes
653 * unless otherwise specified below:
654 * <blockquote>
655 * <table border summary="The attributes and their types the given CompositeData contains">
656 * <tr>
657 * <th align=left>Attribute Name</th>
658 * <th align=left>Type</th>
659 * </tr>
660 * <tr>
661 * <td>threadId</td>
662 * <td><tt>java.lang.Long</tt></td>
663 * </tr>
664 * <tr>
665 * <td>threadName</td>
666 * <td><tt>java.lang.String</tt></td>
667 * </tr>
668 * <tr>
669 * <td>threadState</td>
670 * <td><tt>java.lang.String</tt></td>
671 * </tr>
672 * <tr>
673 * <td>suspended</td>
674 * <td><tt>java.lang.Boolean</tt></td>
675 * </tr>
676 * <tr>
677 * <td>inNative</td>
678 * <td><tt>java.lang.Boolean</tt></td>
679 * </tr>
680 * <tr>
681 * <td>blockedCount</td>
682 * <td><tt>java.lang.Long</tt></td>
683 * </tr>
684 * <tr>
685 * <td>blockedTime</td>
686 * <td><tt>java.lang.Long</tt></td>
687 * </tr>
688 * <tr>
689 * <td>waitedCount</td>
690 * <td><tt>java.lang.Long</tt></td>
691 * </tr>
692 * <tr>
693 * <td>waitedTime</td>
694 * <td><tt>java.lang.Long</tt></td>
695 * </tr>
696 * <tr>
697 * <td>lockInfo</td>
698 * <td><tt>javax.management.openmbean.CompositeData</tt>
699 * - the mapped type for {@link LockInfo} as specified in the
700 * {@link LockInfo#from} method.
701 * <p>
702 * If <tt>cd</tt> does not contain this attribute,
703 * the <tt>LockInfo</tt> object will be constructed from
704 * the value of the <tt>lockName</tt> attribute. </td>
705 * </tr>
706 * <tr>
707 * <td>lockName</td>
708 * <td><tt>java.lang.String</tt></td>
709 * </tr>
710 * <tr>
711 * <td>lockOwnerId</td>
712 * <td><tt>java.lang.Long</tt></td>
713 * </tr>
714 * <tr>
715 * <td>lockOwnerName</td>
716 * <td><tt>java.lang.String</tt></td>
717 * </tr>
718 * <tr>
719 * <td><a name="StackTrace">stackTrace</a></td>
720 * <td><tt>javax.management.openmbean.CompositeData[]</tt>
721 * <p>
722 * Each element is a <tt>CompositeData</tt> representing
723 * StackTraceElement containing the following attributes:
724 * <blockquote>
725 * <table cellspacing=1 cellpadding=0 summary="The attributes and their types the given CompositeData contains">
726 * <tr>
727 * <th align=left>Attribute Name</th>
728 * <th align=left>Type</th>
729 * </tr>
730 * <tr>
731 * <td>className</td>
732 * <td><tt>java.lang.String</tt></td>
733 * </tr>
734 * <tr>
735 * <td>methodName</td>
736 * <td><tt>java.lang.String</tt></td>
737 * </tr>
738 * <tr>
739 * <td>fileName</td>
740 * <td><tt>java.lang.String</tt></td>
741 * </tr>
742 * <tr>
743 * <td>lineNumber</td>
744 * <td><tt>java.lang.Integer</tt></td>
745 * </tr>
746 * <tr>
747 * <td>nativeMethod</td>
748 * <td><tt>java.lang.Boolean</tt></td>
749 * </tr>
750 * </table>
751 * </blockquote>
752 * </td>
753 * </tr>
754 * <tr>
755 * <td>lockedMonitors</td>
756 * <td><tt>javax.management.openmbean.CompositeData[]</tt>
757 * whose element type is the mapped type for
758 * {@link MonitorInfo} as specified in the
759 * {@link MonitorInfo#from Monitor.from} method.
760 * <p>
761 * If <tt>cd</tt> does not contain this attribute,
762 * this attribute will be set to an empty array. </td>
763 * </tr>
764 * <tr>
765 * <td>lockedSynchronizers</td>
766 * <td><tt>javax.management.openmbean.CompositeData[]</tt>
767 * whose element type is the mapped type for
768 * {@link LockInfo} as specified in the {@link LockInfo#from} method.
769 * <p>
770 * If <tt>cd</tt> does not contain this attribute,
771 * this attribute will be set to an empty array. </td>
772 * </tr>
773 * </table>
774 * </blockquote>
775 *
776 * @param cd <tt>CompositeData</tt> representing a <tt>ThreadInfo</tt>
777 *
778 * @throws IllegalArgumentException if <tt>cd</tt> does not
779 * represent a <tt>ThreadInfo</tt> with the attributes described
780 * above.
781 *
782 * @return a <tt>ThreadInfo</tt> object represented
783 * by <tt>cd</tt> if <tt>cd</tt> is not <tt>null</tt>;
784 * <tt>null</tt> otherwise.
785 */
786 public static ThreadInfo from(CompositeData cd) {
787 if (cd == null) {
788 return null;
789 }
790
791 if (cd instanceof ThreadInfoCompositeData) {
792 return ((ThreadInfoCompositeData) cd).getThreadInfo();
793 } else {
794 return new ThreadInfo(cd);
795 }
796 }
797
798 /**
799 * Returns an array of {@link MonitorInfo} objects, each of which
800 * represents an object monitor currently locked by the thread
801 * associated with this <tt>ThreadInfo</tt>.
802 * If no locked monitor was requested for this thread info or
803 * no monitor is locked by the thread, this method
804 * will return a zero-length array.
805 *
806 * @return an array of <tt>MonitorInfo</tt> objects representing
807 * the object monitors locked by the thread.
808 *
809 * @since 1.6
810 */
811 public MonitorInfo[] getLockedMonitors() {
812 return lockedMonitors;
813 }
814
815 /**
816 * Returns an array of {@link LockInfo} objects, each of which
817 * represents an <a href="LockInfo.html#OwnableSynchronizer">ownable
818 * synchronizer</a> currently locked by the thread associated with
819 * this <tt>ThreadInfo</tt>. If no locked synchronizer was
820 * requested for this thread info or no synchronizer is locked by
821 * the thread, this method will return a zero-length array.
822 *
823 * @return an array of <tt>LockInfo</tt> objects representing
824 * the ownable synchronizers locked by the thread.
825 *
826 * @since 1.6
827 */
828 public LockInfo[] getLockedSynchronizers() {
829 return lockedSynchronizers;
830 }
831
832 private static final StackTraceElement[] NO_STACK_TRACE =
833 new StackTraceElement[0];
834 }