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. {@code ThreadInfo} 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 * <li>Whether a thread is a daemon thread</li>
41 * </ul>
42 *
43 * <h3>Execution information</h3>
44 * <ul>
45 * <li>Thread state.</li>
46 * <li>The object upon which the thread is blocked due to:
47 * <ul>
48 * <li>waiting to enter a synchronization block/method, or</li>
49 * <li>waiting to be notified in a {@link Object#wait Object.wait} method,
50 * or</li>
51 * <li>parking due to a {@link java.util.concurrent.locks.LockSupport#park
52 * LockSupport.park} call.</li>
53 * </ul>
54 * </li>
55 * <li>The ID of the thread that owns the object
56 * that the thread is blocked.</li>
57 * <li>Stack trace of the thread.</li>
58 * <li>List of object monitors locked by the thread.</li>
59 * <li>List of <a href="LockInfo.html#OwnableSynchronizer">
60 * ownable synchronizers</a> locked by the thread.</li>
61 * <li>Thread priority</li>
62 * </ul>
63 *
64 * <h4><a name="SyncStats">Synchronization Statistics</a></h4>
65 * <ul>
66 * <li>The number of times that the thread has blocked for
67 * synchronization or waited for notification.</li>
68 * <li>The accumulated elapsed time that the thread has blocked
69 * for synchronization or waited for notification
70 * since {@link ThreadMXBean#setThreadContentionMonitoringEnabled
71 * thread contention monitoring}
72 * was enabled. Some Java virtual machine implementation
73 * may not support this. The
74 * {@link ThreadMXBean#isThreadContentionMonitoringSupported()}
75 * method can be used to determine if a Java virtual machine
76 * supports this.</li>
77 * </ul>
78 *
79 * <p>This thread information class is designed for use in monitoring of
80 * the system, not for synchronization control.
81 *
82 * <h4>MXBean Mapping</h4>
83 * {@code ThreadInfo} is mapped to a {@link CompositeData CompositeData}
84 * with attributes as specified in
85 * the {@link #from from} method.
86 *
87 * @see ThreadMXBean#getThreadInfo
88 * @see ThreadMXBean#dumpAllThreads
89 *
90 * @author Mandy Chung
91 * @since 1.5
92 */
93
94 public class ThreadInfo {
95 private String threadName;
96 private long threadId;
97 private long blockedTime;
98 private long blockedCount;
99 private long waitedTime;
100 private long waitedCount;
101 private LockInfo lock;
102 private String lockName;
103 private long lockOwnerId;
104 private String lockOwnerName;
105 private boolean daemon;
106 private boolean inNative;
107 private boolean suspended;
108 private Thread.State threadState;
109 private int priority;
110 private StackTraceElement[] stackTrace;
111 private MonitorInfo[] lockedMonitors;
112 private LockInfo[] lockedSynchronizers;
113
114 private static MonitorInfo[] EMPTY_MONITORS = new MonitorInfo[0];
115 private static LockInfo[] EMPTY_SYNCS = new LockInfo[0];
116
117 /**
118 * Constructor of ThreadInfo created by the JVM
119 *
120 * @param t Thread
121 * @param state Thread state
122 * @param lockObj Object on which the thread is blocked
123 * @param lockOwner the thread holding the lock
124 * @param blockedCount Number of times blocked to enter a lock
125 * @param blockedTime Approx time blocked to enter a lock
126 * @param waitedCount Number of times waited on a lock
127 * @param waitedTime Approx time waited on a lock
128 * @param stackTrace Thread stack trace
129 */
130 private ThreadInfo(Thread t, int state, Object lockObj, Thread lockOwner,
131 long blockedCount, long blockedTime,
132 long waitedCount, long waitedTime,
133 StackTraceElement[] stackTrace) {
134 initialize(t, state, lockObj, lockOwner,
135 blockedCount, blockedTime,
136 waitedCount, waitedTime, stackTrace,
137 EMPTY_MONITORS, EMPTY_SYNCS);
138 }
139
140 /**
141 * Constructor of ThreadInfo created by the JVM
142 * for {@link ThreadMXBean#getThreadInfo(long[],boolean,boolean)}
143 * and {@link ThreadMXBean#dumpAllThreads}
144 *
145 * @param t Thread
146 * @param state Thread state
147 * @param lockObj Object on which the thread is blocked
148 * @param lockOwner the thread holding the lock
149 * @param blockedCount Number of times blocked to enter a lock
150 * @param blockedTime Approx time blocked to enter a lock
151 * @param waitedCount Number of times waited on a lock
152 * @param waitedTime Approx time waited on a lock
153 * @param stackTrace Thread stack trace
154 * @param monitors List of locked monitors
155 * @param stackDepths List of stack depths
156 * @param synchronizers List of locked synchronizers
157 */
158 private ThreadInfo(Thread t, int state, Object lockObj, Thread lockOwner,
159 long blockedCount, long blockedTime,
160 long waitedCount, long waitedTime,
161 StackTraceElement[] stackTrace,
162 Object[] monitors,
163 int[] stackDepths,
164 Object[] synchronizers) {
165 int numMonitors = (monitors == null ? 0 : monitors.length);
166 MonitorInfo[] lockedMonitors;
167 if (numMonitors == 0) {
168 lockedMonitors = EMPTY_MONITORS;
169 } else {
170 lockedMonitors = new MonitorInfo[numMonitors];
171 for (int i = 0; i < numMonitors; i++) {
172 Object lock = monitors[i];
173 String className = lock.getClass().getName();
174 int identityHashCode = System.identityHashCode(lock);
175 int depth = stackDepths[i];
176 StackTraceElement ste = (depth >= 0 ? stackTrace[depth]
177 : null);
178 lockedMonitors[i] = new MonitorInfo(className,
179 identityHashCode,
180 depth,
181 ste);
182 }
183 }
184
185 int numSyncs = (synchronizers == null ? 0 : synchronizers.length);
186 LockInfo[] lockedSynchronizers;
187 if (numSyncs == 0) {
188 lockedSynchronizers = EMPTY_SYNCS;
189 } else {
190 lockedSynchronizers = new LockInfo[numSyncs];
191 for (int i = 0; i < numSyncs; i++) {
192 Object lock = synchronizers[i];
193 String className = lock.getClass().getName();
194 int identityHashCode = System.identityHashCode(lock);
195 lockedSynchronizers[i] = new LockInfo(className,
196 identityHashCode);
197 }
198 }
199
200 initialize(t, state, lockObj, lockOwner,
201 blockedCount, blockedTime,
202 waitedCount, waitedTime, stackTrace,
203 lockedMonitors, lockedSynchronizers);
204 }
205
206 /**
207 * Initialize ThreadInfo object
208 *
209 * @param t Thread
210 * @param state Thread state
211 * @param lockObj Object on which the thread is blocked
212 * @param lockOwner the thread holding the lock
213 * @param blockedCount Number of times blocked to enter a lock
214 * @param blockedTime Approx time blocked to enter a lock
215 * @param waitedCount Number of times waited on a lock
216 * @param waitedTime Approx time waited on a lock
217 * @param stackTrace Thread stack trace
218 * @param lockedMonitors List of locked monitors
219 * @param lockedSynchronizers List of locked synchronizers
220 */
221 private void initialize(Thread t, int state, Object lockObj, Thread lockOwner,
222 long blockedCount, long blockedTime,
223 long waitedCount, long waitedTime,
224 StackTraceElement[] stackTrace,
225 MonitorInfo[] lockedMonitors,
226 LockInfo[] lockedSynchronizers) {
227 this.threadId = t.getId();
228 this.threadName = t.getName();
229 this.threadState = ManagementFactoryHelper.toThreadState(state);
230 this.suspended = ManagementFactoryHelper.isThreadSuspended(state);
231 this.inNative = ManagementFactoryHelper.isThreadRunningNative(state);
232 this.blockedCount = blockedCount;
233 this.blockedTime = blockedTime;
234 this.waitedCount = waitedCount;
235 this.waitedTime = waitedTime;
236 this.daemon = t.isDaemon();
237 this.priority = t.getPriority();
238
239 if (lockObj == null) {
240 this.lock = null;
241 this.lockName = null;
242 } else {
243 this.lock = new LockInfo(lockObj);
244 this.lockName =
245 lock.getClassName() + '@' +
246 Integer.toHexString(lock.getIdentityHashCode());
247 }
248 if (lockOwner == null) {
249 this.lockOwnerId = -1;
250 this.lockOwnerName = null;
251 } else {
252 this.lockOwnerId = lockOwner.getId();
253 this.lockOwnerName = lockOwner.getName();
254 }
255 if (stackTrace == null) {
256 this.stackTrace = NO_STACK_TRACE;
257 } else {
258 this.stackTrace = stackTrace;
259 }
260 this.lockedMonitors = lockedMonitors;
261 this.lockedSynchronizers = lockedSynchronizers;
262 }
263
264 /*
265 * Constructs a {@code ThreadInfo} object from a
266 * {@link CompositeData CompositeData}.
267 */
268 private ThreadInfo(CompositeData cd) {
269 ThreadInfoCompositeData ticd = ThreadInfoCompositeData.getInstance(cd);
270
271 threadId = ticd.threadId();
272 threadName = ticd.threadName();
273 blockedTime = ticd.blockedTime();
274 blockedCount = ticd.blockedCount();
275 waitedTime = ticd.waitedTime();
276 waitedCount = ticd.waitedCount();
277 lockName = ticd.lockName();
278 lockOwnerId = ticd.lockOwnerId();
279 lockOwnerName = ticd.lockOwnerName();
280 threadState = ticd.threadState();
281 suspended = ticd.suspended();
282 inNative = ticd.inNative();
283 stackTrace = ticd.stackTrace();
284
285 // 6.0 attributes
286 if (ticd.hasV6()) {
287 lock = ticd.lockInfo();
288 lockedMonitors = ticd.lockedMonitors();
289 lockedSynchronizers = ticd.lockedSynchronizers();
290 } else {
291 // lockInfo is a new attribute added in 1.6 ThreadInfo
292 // If cd is a 5.0 version, construct the LockInfo object
293 // from the lockName value.
294 if (lockName != null) {
295 String result[] = lockName.split("@");
296 if (result.length == 2) {
297 int identityHashCode = Integer.parseInt(result[1], 16);
298 lock = new LockInfo(result[0], identityHashCode);
299 } else {
300 assert result.length == 2;
301 lock = null;
302 }
303 } else {
304 lock = null;
305 }
306 lockedMonitors = EMPTY_MONITORS;
307 lockedSynchronizers = EMPTY_SYNCS;
308 }
309
310 // 9.0 attributes
311 if (ticd.isCurrentVersion()) {
312 daemon = ticd.isDaemon();
313 priority = ticd.getPriority();
314 } else {
315 // Not ideal, but unclear what else we can do.
316 daemon = false;
317 priority = Thread.NORM_PRIORITY;
318 }
319 }
320
321 /**
322 * Returns the ID of the thread associated with this {@code ThreadInfo}.
323 *
324 * @return the ID of the associated thread.
325 */
326 public long getThreadId() {
327 return threadId;
328 }
329
330 /**
331 * Returns the name of the thread associated with this {@code ThreadInfo}.
332 *
333 * @return the name of the associated thread.
334 */
335 public String getThreadName() {
336 return threadName;
337 }
338
339 /**
340 * Returns the state of the thread associated with this {@code ThreadInfo}.
341 *
342 * @return {@code Thread.State} of the associated thread.
343 */
344 public Thread.State getThreadState() {
345 return threadState;
346 }
347
348 /**
349 * Returns the approximate accumulated elapsed time (in milliseconds)
350 * that the thread associated with this {@code ThreadInfo}
351 * has blocked to enter or reenter a monitor
352 * since thread contention monitoring is enabled.
353 * I.e. the total accumulated time the thread has been in the
354 * {@link java.lang.Thread.State#BLOCKED BLOCKED} state since thread
355 * contention monitoring was last enabled.
356 * This method returns {@code -1} if thread contention monitoring
357 * is disabled.
358 *
359 * <p>The Java virtual machine may measure the time with a high
360 * resolution timer. This statistic is reset when
361 * the thread contention monitoring is reenabled.
362 *
363 * @return the approximate accumulated elapsed time in milliseconds
364 * that a thread entered the {@code BLOCKED} state;
365 * {@code -1} if thread contention monitoring is disabled.
366 *
367 * @throws java.lang.UnsupportedOperationException if the Java
368 * virtual machine does not support this operation.
369 *
370 * @see ThreadMXBean#isThreadContentionMonitoringSupported
371 * @see ThreadMXBean#setThreadContentionMonitoringEnabled
372 */
373 public long getBlockedTime() {
374 return blockedTime;
375 }
376
377 /**
378 * Returns the total number of times that
379 * the thread associated with this {@code ThreadInfo}
380 * blocked to enter or reenter a monitor.
381 * I.e. the number of times a thread has been in the
382 * {@link java.lang.Thread.State#BLOCKED BLOCKED} state.
383 *
384 * @return the total number of times that the thread
385 * entered the {@code BLOCKED} state.
386 */
387 public long getBlockedCount() {
388 return blockedCount;
389 }
390
391 /**
392 * Returns the approximate accumulated elapsed time (in milliseconds)
393 * that the thread associated with this {@code ThreadInfo}
394 * has waited for notification
395 * since thread contention monitoring is enabled.
396 * I.e. the total accumulated time the thread has been in the
397 * {@link java.lang.Thread.State#WAITING WAITING}
398 * or {@link java.lang.Thread.State#TIMED_WAITING TIMED_WAITING} state
399 * since thread contention monitoring is enabled.
400 * This method returns {@code -1} if thread contention monitoring
401 * is disabled.
402 *
403 * <p>The Java virtual machine may measure the time with a high
404 * resolution timer. This statistic is reset when
405 * the thread contention monitoring is reenabled.
406 *
407 * @return the approximate accumulated elapsed time in milliseconds
408 * that a thread has been in the {@code WAITING} or
409 * {@code TIMED_WAITING} state;
410 * {@code -1} if thread contention monitoring is disabled.
411 *
412 * @throws java.lang.UnsupportedOperationException if the Java
413 * virtual machine does not support this operation.
414 *
415 * @see ThreadMXBean#isThreadContentionMonitoringSupported
416 * @see ThreadMXBean#setThreadContentionMonitoringEnabled
417 */
418 public long getWaitedTime() {
419 return waitedTime;
420 }
421
422 /**
423 * Returns the total number of times that
424 * the thread associated with this {@code ThreadInfo}
425 * waited for notification.
426 * I.e. the number of times that a thread has been
427 * in the {@link java.lang.Thread.State#WAITING WAITING}
428 * or {@link java.lang.Thread.State#TIMED_WAITING TIMED_WAITING} state.
429 *
430 * @return the total number of times that the thread
431 * was in the {@code WAITING} or {@code TIMED_WAITING} state.
432 */
433 public long getWaitedCount() {
434 return waitedCount;
435 }
436
437 /**
438 * Returns the {@code LockInfo} of an object for which
439 * the thread associated with this {@code ThreadInfo}
440 * is blocked waiting.
441 * A thread can be blocked waiting for one of the following:
442 * <ul>
443 * <li>an object monitor to be acquired for entering or reentering
444 * a synchronization block/method.
445 * <br>The thread is in the {@link java.lang.Thread.State#BLOCKED BLOCKED}
446 * state waiting to enter the {@code synchronized} statement
447 * or method.
448 * </li>
449 * <li>an object monitor to be notified by another thread.
450 * <br>The thread is in the {@link java.lang.Thread.State#WAITING WAITING}
451 * or {@link java.lang.Thread.State#TIMED_WAITING TIMED_WAITING} state
452 * due to a call to the {@link Object#wait Object.wait} method.
453 * </li>
454 * <li>a synchronization object responsible for the thread parking.
455 * <br>The thread is in the {@link java.lang.Thread.State#WAITING WAITING}
456 * or {@link java.lang.Thread.State#TIMED_WAITING TIMED_WAITING} state
457 * due to a call to the
458 * {@link java.util.concurrent.locks.LockSupport#park(Object)
459 * LockSupport.park} method. The synchronization object
460 * is the object returned from
461 * {@link java.util.concurrent.locks.LockSupport#getBlocker
462 * LockSupport.getBlocker} method. Typically it is an
463 * <a href="LockInfo.html#OwnableSynchronizer"> ownable synchronizer</a>
464 * or a {@link java.util.concurrent.locks.Condition Condition}.</li>
465 * </ul>
466 *
467 * <p>This method returns {@code null} if the thread is not in any of
468 * the above conditions.
469 *
470 * @return {@code LockInfo} of an object for which the thread
471 * is blocked waiting if any; {@code null} otherwise.
472 * @since 1.6
473 */
474 public LockInfo getLockInfo() {
475 return lock;
476 }
477
478 /**
479 * Returns the {@link LockInfo#toString string representation}
480 * of an object for which the thread associated with this
481 * {@code ThreadInfo} is blocked waiting.
482 * This method is equivalent to calling:
483 * <blockquote>
484 * <pre>
485 * getLockInfo().toString()
486 * </pre></blockquote>
487 *
488 * <p>This method will return {@code null} if this thread is not blocked
489 * waiting for any object or if the object is not owned by any thread.
490 *
491 * @return the string representation of the object on which
492 * the thread is blocked if any;
493 * {@code null} otherwise.
494 *
495 * @see #getLockInfo
496 */
497 public String getLockName() {
498 return lockName;
499 }
500
501 /**
502 * Returns the ID of the thread which owns the object
503 * for which the thread associated with this {@code ThreadInfo}
504 * is blocked waiting.
505 * This method will return {@code -1} if this thread is not blocked
506 * waiting for any object or if the object is not owned by any thread.
507 *
508 * @return the thread ID of the owner thread of the object
509 * this thread is blocked on;
510 * {@code -1} if this thread is not blocked
511 * or if the object is not owned by any thread.
512 *
513 * @see #getLockInfo
514 */
515 public long getLockOwnerId() {
516 return lockOwnerId;
517 }
518
519 /**
520 * Returns the name of the thread which owns the object
521 * for which the thread associated with this {@code ThreadInfo}
522 * is blocked waiting.
523 * This method will return {@code null} if this thread is not blocked
524 * waiting for any object or if the object is not owned by any thread.
525 *
526 * @return the name of the thread that owns the object
527 * this thread is blocked on;
528 * {@code null} if this thread is not blocked
529 * or if the object is not owned by any thread.
530 *
531 * @see #getLockInfo
532 */
533 public String getLockOwnerName() {
534 return lockOwnerName;
535 }
536
537 /**
538 * Returns the stack trace of the thread
539 * associated with this {@code ThreadInfo}.
540 * If no stack trace was requested for this thread info, this method
541 * will return a zero-length array.
542 * If the returned array is of non-zero length then the first element of
543 * the array represents the top of the stack, which is the most recent
544 * method invocation in the sequence. The last element of the array
545 * represents the bottom of the stack, which is the least recent method
546 * invocation in the sequence.
547 *
548 * <p>Some Java virtual machines may, under some circumstances, omit one
549 * or more stack frames from the stack trace. In the extreme case,
550 * a virtual machine that has no stack trace information concerning
551 * the thread associated with this {@code ThreadInfo}
552 * is permitted to return a zero-length array from this method.
553 *
554 * @return an array of {@code StackTraceElement} objects of the thread.
555 */
556 public StackTraceElement[] getStackTrace() {
557 return stackTrace;
558 }
559
560 /**
561 * Tests if the thread associated with this {@code ThreadInfo}
562 * is suspended. This method returns {@code true} if
563 * {@link Thread#suspend} has been called.
564 *
565 * @return {@code true} if the thread is suspended;
566 * {@code false} otherwise.
567 */
568 public boolean isSuspended() {
569 return suspended;
570 }
571
572 /**
573 * Tests if the thread associated with this {@code ThreadInfo}
574 * is executing native code via the Java Native Interface (JNI).
575 * The JNI native code does not include
576 * the virtual machine support code or the compiled native
577 * code generated by the virtual machine.
578 *
579 * @return {@code true} if the thread is executing native code;
580 * {@code false} otherwise.
581 */
582 public boolean isInNative() {
583 return inNative;
584 }
585
586 /**
587 * Tests if the thread associated with this {@code ThreadInfo} is
588 * a {@linkplain Thread#isDaemon daemon thread}.
589 *
590 * @return {@code true} if the thread is a daemon thread,
591 * {@code false} otherwise.
592 * @see Thread#isDaemon
593 * @since 1.9
594 */
595 public boolean isDaemon() {
596 return daemon;
597 }
598
599 /**
600 * Returns the {@linkplain Thread#getPriority() thread priority} of the
601 * thread associated with this {@code ThreadInfo}.
602 *
603 * @return The priority of the thread associated with this
604 * {@code ThreadInfo}.
605 * @since 1.9
606 */
607 public int getPriority() {
608 return priority;
609 }
610
611 /**
612 * Returns a string representation of this thread info.
613 * The format of this string depends on the implementation.
614 * The returned string will typically include
615 * the {@linkplain #getThreadName thread name},
616 * the {@linkplain #getThreadId thread ID},
617 * its {@linkplain #getThreadState state},
618 * and a {@linkplain #getStackTrace stack trace} if any.
619 *
620 * @return a string representation of this thread info.
621 */
622 public String toString() {
623 StringBuilder sb = new StringBuilder("\"" + getThreadName() + "\"" +
624 (daemon ? " daemon" : "") +
625 " prio=" + priority +
626 " Id=" + getThreadId() + " " +
627 getThreadState());
628 if (getLockName() != null) {
629 sb.append(" on " + getLockName());
630 }
631 if (getLockOwnerName() != null) {
632 sb.append(" owned by \"" + getLockOwnerName() +
633 "\" Id=" + getLockOwnerId());
634 }
635 if (isSuspended()) {
636 sb.append(" (suspended)");
637 }
638 if (isInNative()) {
639 sb.append(" (in native)");
640 }
641 sb.append('\n');
642 int i = 0;
643 for (; i < stackTrace.length && i < MAX_FRAMES; i++) {
644 StackTraceElement ste = stackTrace[i];
645 sb.append("\tat " + ste.toString());
646 sb.append('\n');
647 if (i == 0 && getLockInfo() != null) {
648 Thread.State ts = getThreadState();
649 switch (ts) {
650 case BLOCKED:
651 sb.append("\t- blocked on " + getLockInfo());
652 sb.append('\n');
653 break;
654 case WAITING:
655 sb.append("\t- waiting on " + getLockInfo());
656 sb.append('\n');
657 break;
658 case TIMED_WAITING:
659 sb.append("\t- waiting on " + getLockInfo());
660 sb.append('\n');
661 break;
662 default:
663 }
664 }
665
666 for (MonitorInfo mi : lockedMonitors) {
667 if (mi.getLockedStackDepth() == i) {
668 sb.append("\t- locked " + mi);
669 sb.append('\n');
670 }
671 }
672 }
673 if (i < stackTrace.length) {
674 sb.append("\t...");
675 sb.append('\n');
676 }
677
678 LockInfo[] locks = getLockedSynchronizers();
679 if (locks.length > 0) {
680 sb.append("\n\tNumber of locked synchronizers = " + locks.length);
681 sb.append('\n');
682 for (LockInfo li : locks) {
683 sb.append("\t- " + li);
684 sb.append('\n');
685 }
686 }
687 sb.append('\n');
688 return sb.toString();
689 }
690 private static final int MAX_FRAMES = 8;
691
692 /**
693 * Returns a {@code ThreadInfo} object represented by the
694 * given {@code CompositeData}.
695 * The given {@code CompositeData} must contain the following attributes
696 * unless otherwise specified below:
697 * <blockquote>
698 * <table border summary="The attributes and their types the given CompositeData contains">
699 * <tr>
700 * <th align=left>Attribute Name</th>
701 * <th align=left>Type</th>
702 * </tr>
703 * <tr>
704 * <td>threadId</td>
705 * <td>{@code java.lang.Long}</td>
706 * </tr>
707 * <tr>
708 * <td>threadName</td>
709 * <td>{@code java.lang.String}</td>
710 * </tr>
711 * <tr>
712 * <td>threadState</td>
713 * <td>{@code java.lang.String}</td>
714 * </tr>
715 * <tr>
716 * <td>suspended</td>
717 * <td>{@code java.lang.Boolean}</td>
718 * </tr>
719 * <tr>
720 * <td>inNative</td>
721 * <td>{@code java.lang.Boolean}</td>
722 * </tr>
723 * <tr>
724 * <td>blockedCount</td>
725 * <td>{@code java.lang.Long}</td>
726 * </tr>
727 * <tr>
728 * <td>blockedTime</td>
729 * <td>{@code java.lang.Long}</td>
730 * </tr>
731 * <tr>
732 * <td>waitedCount</td>
733 * <td>{@code java.lang.Long}</td>
734 * </tr>
735 * <tr>
736 * <td>waitedTime</td>
737 * <td>{@code java.lang.Long}</td>
738 * </tr>
739 * <tr>
740 * <td>lockInfo</td>
741 * <td>{@code javax.management.openmbean.CompositeData}
742 * - the mapped type for {@link LockInfo} as specified in the
743 * {@link LockInfo#from} method.
744 * <p>
745 * If {@code cd} does not contain this attribute,
746 * the {@code LockInfo} object will be constructed from
747 * the value of the {@code lockName} attribute. </td>
748 * </tr>
749 * <tr>
750 * <td>lockName</td>
751 * <td>{@code java.lang.String}</td>
752 * </tr>
753 * <tr>
754 * <td>lockOwnerId</td>
755 * <td>{@code java.lang.Long}</td>
756 * </tr>
757 * <tr>
758 * <td>lockOwnerName</td>
759 * <td>{@code java.lang.String}</td>
760 * </tr>
761 * <tr>
762 * <td><a name="StackTrace">stackTrace</a></td>
763 * <td>{@code javax.management.openmbean.CompositeData[]}
764 * <p>
765 * Each element is a {@code CompositeData} representing
766 * StackTraceElement containing the following attributes:
767 * <blockquote>
768 * <table cellspacing=1 cellpadding=0 summary="The attributes and their types the given CompositeData contains">
769 * <tr>
770 * <th align=left>Attribute Name</th>
771 * <th align=left>Type</th>
772 * </tr>
773 * <tr>
774 * <td>className</td>
775 * <td>{@code java.lang.String}</td>
776 * </tr>
777 * <tr>
778 * <td>methodName</td>
779 * <td>{@code java.lang.String}</td>
780 * </tr>
781 * <tr>
782 * <td>fileName</td>
783 * <td>{@code java.lang.String}</td>
784 * </tr>
785 * <tr>
786 * <td>lineNumber</td>
787 * <td>{@code java.lang.Integer}</td>
788 * </tr>
789 * <tr>
790 * <td>nativeMethod</td>
791 * <td>{@code java.lang.Boolean}</td>
792 * </tr>
793 * </table>
794 * </blockquote>
795 * </td>
796 * </tr>
797 * <tr>
798 * <td>lockedMonitors</td>
799 * <td>{@code javax.management.openmbean.CompositeData[]}
800 * whose element type is the mapped type for
801 * {@link MonitorInfo} as specified in the
802 * {@link MonitorInfo#from Monitor.from} method.
803 * <p>
804 * If {@code cd} does not contain this attribute,
805 * this attribute will be set to an empty array. </td>
806 * </tr>
807 * <tr>
808 * <td>lockedSynchronizers</td>
809 * <td>{@code javax.management.openmbean.CompositeData[]}
810 * whose element type is the mapped type for
811 * {@link LockInfo} as specified in the {@link LockInfo#from} method.
812 * <p>
813 * If {@code cd} does not contain this attribute,
814 * this attribute will be set to an empty array. </td>
815 * </tr>
816 * <tr>
817 * <td>daemon</td>
818 * <td>{@code java.lang.Boolean}</td>
819 * </tr>
820 * <tr>
821 * <td>priority</td>
822 * <td>{@code java.lang.Integer}</td>
823 * </tr>
824 * </table>
825 * </blockquote>
826 *
827 * @param cd {@code CompositeData} representing a {@code ThreadInfo}
828 *
829 * @throws IllegalArgumentException if {@code cd} does not
830 * represent a {@code ThreadInfo} with the attributes described
831 * above.
832 *
833 * @return a {@code ThreadInfo} object represented
834 * by {@code cd} if {@code cd} is not {@code null};
835 * {@code null} otherwise.
836 */
837 public static ThreadInfo from(CompositeData cd) {
838 if (cd == null) {
839 return null;
840 }
841
842 if (cd instanceof ThreadInfoCompositeData) {
843 return ((ThreadInfoCompositeData) cd).getThreadInfo();
844 } else {
845 return new ThreadInfo(cd);
846 }
847 }
848
849 /**
850 * Returns an array of {@link MonitorInfo} objects, each of which
851 * represents an object monitor currently locked by the thread
852 * associated with this {@code ThreadInfo}.
853 * If no locked monitor was requested for this thread info or
854 * no monitor is locked by the thread, this method
855 * will return a zero-length array.
856 *
857 * @return an array of {@code MonitorInfo} objects representing
858 * the object monitors locked by the thread.
859 *
860 * @since 1.6
861 */
862 public MonitorInfo[] getLockedMonitors() {
863 return lockedMonitors;
864 }
865
866 /**
867 * Returns an array of {@link LockInfo} objects, each of which
868 * represents an <a href="LockInfo.html#OwnableSynchronizer">ownable
869 * synchronizer</a> currently locked by the thread associated with
870 * this {@code ThreadInfo}. If no locked synchronizer was
871 * requested for this thread info or no synchronizer is locked by
872 * the thread, this method will return a zero-length array.
873 *
874 * @return an array of {@code LockInfo} objects representing
875 * the ownable synchronizers locked by the thread.
876 *
877 * @since 1.6
878 */
879 public LockInfo[] getLockedSynchronizers() {
880 return lockedSynchronizers;
881 }
882
883 private static final StackTraceElement[] NO_STACK_TRACE =
884 new StackTraceElement[0];
885 }