/
QueuedThreadPool.java
943 lines (845 loc) · 30 KB
/
QueuedThreadPool.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
//
// ========================================================================
// Copyright (c) 1995-2020 Mort Bay Consulting Pty Ltd and others.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
//
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
//
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
//
package org.eclipse.jetty.util.thread;
import java.io.Closeable;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
import org.eclipse.jetty.util.AtomicBiInteger;
import org.eclipse.jetty.util.BlockingArrayQueue;
import org.eclipse.jetty.util.StringUtil;
import org.eclipse.jetty.util.annotation.ManagedAttribute;
import org.eclipse.jetty.util.annotation.ManagedObject;
import org.eclipse.jetty.util.annotation.ManagedOperation;
import org.eclipse.jetty.util.annotation.Name;
import org.eclipse.jetty.util.component.ContainerLifeCycle;
import org.eclipse.jetty.util.component.Dumpable;
import org.eclipse.jetty.util.component.DumpableCollection;
import org.eclipse.jetty.util.component.LifeCycle;
import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;
import org.eclipse.jetty.util.thread.ThreadPool.SizedThreadPool;
@ManagedObject("A thread pool")
public class QueuedThreadPool extends ContainerLifeCycle implements ThreadFactory, SizedThreadPool, Dumpable, TryExecutor
{
private static final Logger LOG = Log.getLogger(QueuedThreadPool.class);
private static Runnable NOOP = () ->
{
};
/**
* Encodes thread counts:
* <dl>
* <dt>Hi</dt><dd>Total thread count or Integer.MIN_VALUE if the pool is stopping</dd>
* <dt>Lo</dt><dd>Net idle threads == idle threads - job queue size. Essentially if positive,
* this represents the effective number of idle threads, and if negative it represents the
* demand for more threads</dd>
* </dl>
*/
private final AtomicBiInteger _counts = new AtomicBiInteger(Integer.MIN_VALUE, 0);
private final AtomicLong _lastShrink = new AtomicLong();
private final Set<Thread> _threads = ConcurrentHashMap.newKeySet();
private final Object _joinLock = new Object();
private final BlockingQueue<Runnable> _jobs;
private final ThreadGroup _threadGroup;
private final ThreadFactory _threadFactory;
private String _name = "qtp" + hashCode();
private int _idleTimeout;
private int _maxThreads;
private int _minThreads;
private int _reservedThreads = -1;
private TryExecutor _tryExecutor = TryExecutor.NO_TRY;
private int _priority = Thread.NORM_PRIORITY;
private boolean _daemon = false;
private boolean _detailedDump = false;
private int _lowThreadsThreshold = 1;
private ThreadPoolBudget _budget;
public QueuedThreadPool()
{
this(200);
}
public QueuedThreadPool(@Name("maxThreads") int maxThreads)
{
this(maxThreads, Math.min(8, maxThreads));
}
public QueuedThreadPool(@Name("maxThreads") int maxThreads, @Name("minThreads") int minThreads)
{
this(maxThreads, minThreads, 60000);
}
public QueuedThreadPool(@Name("maxThreads") int maxThreads, @Name("minThreads") int minThreads, @Name("queue") BlockingQueue<Runnable> queue)
{
this(maxThreads, minThreads, 60000, -1, queue, null);
}
public QueuedThreadPool(@Name("maxThreads") int maxThreads, @Name("minThreads") int minThreads, @Name("idleTimeout") int idleTimeout)
{
this(maxThreads, minThreads, idleTimeout, null);
}
public QueuedThreadPool(@Name("maxThreads") int maxThreads, @Name("minThreads") int minThreads, @Name("idleTimeout") int idleTimeout, @Name("queue") BlockingQueue<Runnable> queue)
{
this(maxThreads, minThreads, idleTimeout, queue, null);
}
public QueuedThreadPool(@Name("maxThreads") int maxThreads, @Name("minThreads") int minThreads, @Name("idleTimeout") int idleTimeout, @Name("queue") BlockingQueue<Runnable> queue, @Name("threadGroup") ThreadGroup threadGroup)
{
this(maxThreads, minThreads, idleTimeout, -1, queue, threadGroup);
}
public QueuedThreadPool(@Name("maxThreads") int maxThreads, @Name("minThreads") int minThreads,
@Name("idleTimeout") int idleTimeout, @Name("reservedThreads") int reservedThreads,
@Name("queue") BlockingQueue<Runnable> queue, @Name("threadGroup") ThreadGroup threadGroup)
{
this(maxThreads, minThreads, idleTimeout, reservedThreads, queue, threadGroup, null);
}
public QueuedThreadPool(@Name("maxThreads") int maxThreads, @Name("minThreads") int minThreads,
@Name("idleTimeout") int idleTimeout, @Name("reservedThreads") int reservedThreads,
@Name("queue") BlockingQueue<Runnable> queue, @Name("threadGroup") ThreadGroup threadGroup,
@Name("threadFactory") ThreadFactory threadFactory)
{
if (maxThreads < minThreads)
throw new IllegalArgumentException("max threads (" + maxThreads + ") less than min threads (" + minThreads + ")");
setMinThreads(minThreads);
setMaxThreads(maxThreads);
setIdleTimeout(idleTimeout);
setStopTimeout(5000);
setReservedThreads(reservedThreads);
if (queue == null)
{
int capacity = Math.max(_minThreads, 8) * 1024;
queue = new BlockingArrayQueue<>(capacity, capacity);
}
_jobs = queue;
_threadGroup = threadGroup;
setThreadPoolBudget(new ThreadPoolBudget(this));
_threadFactory = threadFactory == null ? this : threadFactory;
}
@Override
public ThreadPoolBudget getThreadPoolBudget()
{
return _budget;
}
public void setThreadPoolBudget(ThreadPoolBudget budget)
{
if (budget != null && budget.getSizedThreadPool() != this)
throw new IllegalArgumentException();
_budget = budget;
}
@Override
protected void doStart() throws Exception
{
if (_reservedThreads == 0)
{
_tryExecutor = NO_TRY;
}
else
{
ReservedThreadExecutor reserved = new ReservedThreadExecutor(this, _reservedThreads);
reserved.setIdleTimeout(_idleTimeout, TimeUnit.MILLISECONDS);
_tryExecutor = reserved;
}
addBean(_tryExecutor);
_lastShrink.set(System.nanoTime());
super.doStart();
// The threads count set to MIN_VALUE is used to signal to Runners that the pool is stopped.
_counts.set(0, 0); // threads, idle
ensureThreads();
}
@Override
protected void doStop() throws Exception
{
if (LOG.isDebugEnabled())
LOG.debug("Stopping {}", this);
super.doStop();
removeBean(_tryExecutor);
_tryExecutor = TryExecutor.NO_TRY;
// Signal the Runner threads that we are stopping
int threads = _counts.getAndSetHi(Integer.MIN_VALUE);
// If stop timeout try to gracefully stop
long timeout = getStopTimeout();
BlockingQueue<Runnable> jobs = getQueue();
if (timeout > 0)
{
// Fill the job queue with noop jobs to wakeup idle threads.
for (int i = 0; i < threads; ++i)
{
jobs.offer(NOOP);
}
// try to let jobs complete naturally for half our stop time
joinThreads(System.nanoTime() + TimeUnit.MILLISECONDS.toNanos(timeout) / 2);
// If we still have threads running, get a bit more aggressive
// interrupt remaining threads
for (Thread thread : _threads)
{
if (LOG.isDebugEnabled())
LOG.debug("Interrupting {}", thread);
thread.interrupt();
}
// wait again for the other half of our stop time
joinThreads(System.nanoTime() + TimeUnit.MILLISECONDS.toNanos(timeout) / 2);
Thread.yield();
if (LOG.isDebugEnabled())
{
for (Thread unstopped : _threads)
{
StringBuilder dmp = new StringBuilder();
for (StackTraceElement element : unstopped.getStackTrace())
{
dmp.append(System.lineSeparator()).append("\tat ").append(element);
}
LOG.warn("Couldn't stop {}{}", unstopped, dmp.toString());
}
}
else
{
for (Thread unstopped : _threads)
{
LOG.warn("{} Couldn't stop {}", this, unstopped);
}
}
}
// Close any un-executed jobs
while (!_jobs.isEmpty())
{
Runnable job = _jobs.poll();
if (job instanceof Closeable)
{
try
{
((Closeable)job).close();
}
catch (Throwable t)
{
LOG.warn(t);
}
}
else if (job != NOOP)
LOG.warn("Stopped without executing or closing {}", job);
}
if (_budget != null)
_budget.reset();
synchronized (_joinLock)
{
_joinLock.notifyAll();
}
}
private void joinThreads(long stopByNanos) throws InterruptedException
{
for (Thread thread : _threads)
{
long canWait = TimeUnit.NANOSECONDS.toMillis(stopByNanos - System.nanoTime());
if (LOG.isDebugEnabled())
LOG.debug("Waiting for {} for {}", thread, canWait);
if (canWait > 0)
thread.join(canWait);
}
}
/**
* Thread Pool should use Daemon Threading.
*
* @param daemon true to enable delegation
* @see Thread#setDaemon(boolean)
*/
public void setDaemon(boolean daemon)
{
_daemon = daemon;
}
/**
* Set the maximum thread idle time.
* Threads that are idle for longer than this period may be
* stopped.
*
* @param idleTimeout Max idle time in ms.
* @see #getIdleTimeout
*/
public void setIdleTimeout(int idleTimeout)
{
_idleTimeout = idleTimeout;
ReservedThreadExecutor reserved = getBean(ReservedThreadExecutor.class);
if (reserved != null)
reserved.setIdleTimeout(idleTimeout, TimeUnit.MILLISECONDS);
}
/**
* Set the maximum number of threads.
*
* @param maxThreads maximum number of threads.
* @see #getMaxThreads
*/
@Override
public void setMaxThreads(int maxThreads)
{
if (_budget != null)
_budget.check(maxThreads);
_maxThreads = maxThreads;
if (_minThreads > _maxThreads)
_minThreads = _maxThreads;
}
/**
* Set the minimum number of threads.
*
* @param minThreads minimum number of threads
* @see #getMinThreads
*/
@Override
public void setMinThreads(int minThreads)
{
_minThreads = minThreads;
if (_minThreads > _maxThreads)
_maxThreads = _minThreads;
if (isStarted())
ensureThreads();
}
/**
* Set the number of reserved threads.
*
* @param reservedThreads number of reserved threads or -1 for heuristically determined
* @see #getReservedThreads
*/
public void setReservedThreads(int reservedThreads)
{
if (isRunning())
throw new IllegalStateException(getState());
_reservedThreads = reservedThreads;
}
/**
* @param name Name of this thread pool to use when naming threads.
*/
public void setName(String name)
{
if (isRunning())
throw new IllegalStateException("started");
_name = name;
}
/**
* Set the priority of the pool threads.
*
* @param priority the new thread priority.
*/
public void setThreadsPriority(int priority)
{
_priority = priority;
}
/**
* Get the maximum thread idle time.
*
* @return Max idle time in ms.
* @see #setIdleTimeout
*/
@ManagedAttribute("maximum time a thread may be idle in ms")
public int getIdleTimeout()
{
return _idleTimeout;
}
/**
* Get the maximum number of threads.
*
* @return maximum number of threads.
* @see #setMaxThreads
*/
@Override
@ManagedAttribute("maximum number of threads in the pool")
public int getMaxThreads()
{
return _maxThreads;
}
/**
* Get the minimum number of threads.
*
* @return minimum number of threads.
* @see #setMinThreads
*/
@Override
@ManagedAttribute("minimum number of threads in the pool")
public int getMinThreads()
{
return _minThreads;
}
/**
* Get the number of reserved threads.
*
* @return number of reserved threads or or -1 for heuristically determined
* @see #setReservedThreads
*/
@ManagedAttribute("the number of reserved threads in the pool")
public int getReservedThreads()
{
if (isStarted())
{
ReservedThreadExecutor reservedThreadExecutor = getBean(ReservedThreadExecutor.class);
if (reservedThreadExecutor != null)
return reservedThreadExecutor.getCapacity();
}
return _reservedThreads;
}
/**
* @return The name of the this thread pool
*/
@ManagedAttribute("name of the thread pool")
public String getName()
{
return _name;
}
/**
* Get the priority of the pool threads.
*
* @return the priority of the pool threads.
*/
@ManagedAttribute("priority of threads in the pool")
public int getThreadsPriority()
{
return _priority;
}
/**
* Get the size of the job queue.
*
* @return Number of jobs queued waiting for a thread
*/
@ManagedAttribute("size of the job queue")
public int getQueueSize()
{
// The idle counter encodes demand, which is the effective queue size
int idle = _counts.getLo();
return Math.max(0, -idle);
}
/**
* @return whether this thread pool is using daemon threads
* @see Thread#setDaemon(boolean)
*/
@ManagedAttribute("thread pool uses daemon threads")
public boolean isDaemon()
{
return _daemon;
}
@ManagedAttribute("reports additional details in the dump")
public boolean isDetailedDump()
{
return _detailedDump;
}
public void setDetailedDump(boolean detailedDump)
{
_detailedDump = detailedDump;
}
@ManagedAttribute("threshold at which the pool is low on threads")
public int getLowThreadsThreshold()
{
return _lowThreadsThreshold;
}
public void setLowThreadsThreshold(int lowThreadsThreshold)
{
_lowThreadsThreshold = lowThreadsThreshold;
}
@Override
public void execute(Runnable job)
{
// Determine if we need to start a thread, use and idle thread or just queue this job
int startThread;
while (true)
{
// Get the atomic counts
long counts = _counts.get();
// Get the number of threads started (might not yet be running)
int threads = AtomicBiInteger.getHi(counts);
if (threads == Integer.MIN_VALUE)
throw new RejectedExecutionException(job.toString());
// Get the number of truly idle threads. This count is reduced by the
// job queue size so that any threads that are idle but are about to take
// a job from the queue are not counted.
int idle = AtomicBiInteger.getLo(counts);
// Start a thread if we have insufficient idle threads to meet demand
// and we are not at max threads.
startThread = (idle <= 0 && threads < _maxThreads) ? 1 : 0;
// The job will be run by an idle thread when available
if (!_counts.compareAndSet(counts, threads + startThread, idle + startThread - 1))
continue;
break;
}
if (!_jobs.offer(job))
{
// reverse our changes to _counts.
if (addCounts(-startThread, 1 - startThread))
LOG.warn("{} rejected {}", this, job);
throw new RejectedExecutionException(job.toString());
}
if (LOG.isDebugEnabled())
LOG.debug("queue {} startThread={}", job, startThread);
// Start a thread if one was needed
while (startThread-- > 0)
startThread();
}
@Override
public boolean tryExecute(Runnable task)
{
TryExecutor tryExecutor = _tryExecutor;
return tryExecutor != null && tryExecutor.tryExecute(task);
}
/**
* Blocks until the thread pool is {@link LifeCycle#stop stopped}.
*/
@Override
public void join() throws InterruptedException
{
synchronized (_joinLock)
{
while (isRunning())
{
_joinLock.wait();
}
}
while (isStopping())
{
Thread.sleep(1);
}
}
/**
* @return the total number of threads currently in the pool
*/
@Override
@ManagedAttribute("number of threads in the pool")
public int getThreads()
{
int threads = _counts.getHi();
return Math.max(0, threads);
}
/**
* @return the number of idle threads in the pool
*/
@Override
@ManagedAttribute("number of idle threads in the pool")
public int getIdleThreads()
{
int idle = _counts.getLo();
return Math.max(0, idle);
}
/**
* @return the number of busy threads in the pool
*/
@ManagedAttribute("number of busy threads in the pool")
public int getBusyThreads()
{
int reserved = _tryExecutor instanceof ReservedThreadExecutor ? ((ReservedThreadExecutor)_tryExecutor).getAvailable() : 0;
return getThreads() - getIdleThreads() - reserved;
}
/**
* <p>Returns whether this thread pool is low on threads.</p>
* <p>The current formula is:</p>
* <pre>
* maxThreads - threads + idleThreads - queueSize <= lowThreadsThreshold
* </pre>
*
* @return whether the pool is low on threads
* @see #getLowThreadsThreshold()
*/
@Override
@ManagedAttribute(value = "thread pool is low on threads", readonly = true)
public boolean isLowOnThreads()
{
return getMaxThreads() - getThreads() + getIdleThreads() - getQueueSize() <= getLowThreadsThreshold();
}
private void ensureThreads()
{
while (true)
{
long counts = _counts.get();
int threads = AtomicBiInteger.getHi(counts);
if (threads == Integer.MIN_VALUE)
break;
// If we have less than min threads
// OR insufficient idle threads to meet demand
int idle = AtomicBiInteger.getLo(counts);
if (threads < _minThreads || (idle < 0 && threads < _maxThreads))
{
// Then try to start a thread.
if (_counts.compareAndSet(counts, threads + 1, idle + 1))
startThread();
// Otherwise continue to check state again.
continue;
}
break;
}
}
protected void startThread()
{
boolean started = false;
try
{
Thread thread = _threadFactory.newThread(_runnable);
if (LOG.isDebugEnabled())
LOG.debug("Starting {}", thread);
_threads.add(thread);
_lastShrink.set(System.nanoTime());
thread.start();
started = true;
}
finally
{
if (!started)
addCounts(-1, -1); // threads, idle
}
}
private boolean addCounts(int deltaThreads, int deltaIdle)
{
while (true)
{
long encoded = _counts.get();
int threads = AtomicBiInteger.getHi(encoded);
int idle = AtomicBiInteger.getLo(encoded);
if (threads == Integer.MIN_VALUE) // This is a marker that the pool is stopped.
return false;
long update = AtomicBiInteger.encode(threads + deltaThreads, idle + deltaIdle);
if (_counts.compareAndSet(encoded, update))
return true;
}
}
@Override
public Thread newThread(Runnable runnable)
{
Thread thread = new Thread(_threadGroup, runnable);
thread.setDaemon(isDaemon());
thread.setPriority(getThreadsPriority());
thread.setName(_name + "-" + thread.getId());
thread.setContextClassLoader(this.getClass().getClassLoader());
return thread;
}
protected void removeThread(Thread thread)
{
_threads.remove(thread);
}
@Override
public void dump(Appendable out, String indent) throws IOException
{
List<Object> threads = new ArrayList<>(getMaxThreads());
for (Thread thread : _threads)
{
StackTraceElement[] trace = thread.getStackTrace();
String stackTag = getCompressedStackTag(trace);
String baseThreadInfo = String.format("%s %s tid=%d prio=%d", thread.getName(), thread.getState(), thread.getId(), thread.getPriority());
if (!StringUtil.isBlank(stackTag))
threads.add(baseThreadInfo + " " + stackTag);
else if (isDetailedDump())
threads.add((Dumpable)(o, i) -> Dumpable.dumpObjects(o, i, baseThreadInfo, (Object[])trace));
else
threads.add(baseThreadInfo + " @ " + (trace.length > 0 ? trace[0].toString() : "???"));
}
DumpableCollection threadsDump = new DumpableCollection("threads", threads);
if (isDetailedDump())
dumpObjects(out, indent, threadsDump, new DumpableCollection("jobs", new ArrayList<>(getQueue())));
else
dumpObjects(out, indent, threadsDump);
}
private String getCompressedStackTag(StackTraceElement[] trace)
{
for (StackTraceElement t : trace)
{
if ("idleJobPoll".equals(t.getMethodName()) && t.getClassName().equals(Runner.class.getName()))
return "IDLE";
if ("reservedWait".equals(t.getMethodName()) && t.getClassName().endsWith("ReservedThread"))
return "RESERVED";
if ("select".equals(t.getMethodName()) && t.getClassName().endsWith("SelectorProducer"))
return "SELECTING";
if ("accept".equals(t.getMethodName()) && t.getClassName().contains("ServerConnector"))
return "ACCEPTING";
}
return "";
}
@Override
public String toString()
{
long count = _counts.get();
int threads = Math.max(0, AtomicBiInteger.getHi(count));
int idle = Math.max(0, AtomicBiInteger.getLo(count));
int queue = getQueueSize();
return String.format("%s[%s]@%x{%s,%d<=%d<=%d,i=%d,r=%d,q=%d}[%s]",
getClass().getSimpleName(),
_name,
hashCode(),
getState(),
getMinThreads(),
threads,
getMaxThreads(),
idle,
getReservedThreads(),
queue,
_tryExecutor);
}
private final Runnable _runnable = new Runner();
/**
* <p>Runs the given job in the {@link Thread#currentThread() current thread}.</p>
* <p>Subclasses may override to perform pre/post actions before/after the job is run.</p>
*
* @param job the job to run
*/
protected void runJob(Runnable job)
{
job.run();
}
/**
* @return the job queue
*/
protected BlockingQueue<Runnable> getQueue()
{
return _jobs;
}
/**
* @param queue the job queue
* @deprecated pass the queue to the constructor instead
*/
@Deprecated
public void setQueue(BlockingQueue<Runnable> queue)
{
throw new UnsupportedOperationException("Use constructor injection");
}
/**
* @param id the thread ID to interrupt.
* @return true if the thread was found and interrupted.
*/
@ManagedOperation("interrupts a pool thread")
public boolean interruptThread(@Name("id") long id)
{
for (Thread thread : _threads)
{
if (thread.getId() == id)
{
thread.interrupt();
return true;
}
}
return false;
}
/**
* @param id the thread ID to interrupt.
* @return the stack frames dump
*/
@ManagedOperation("dumps a pool thread stack")
public String dumpThread(@Name("id") long id)
{
for (Thread thread : _threads)
{
if (thread.getId() == id)
{
StringBuilder buf = new StringBuilder();
buf.append(thread.getId()).append(" ").append(thread.getName()).append(" ");
buf.append(thread.getState()).append(":").append(System.lineSeparator());
for (StackTraceElement element : thread.getStackTrace())
{
buf.append(" at ").append(element.toString()).append(System.lineSeparator());
}
return buf.toString();
}
}
return null;
}
private class Runner implements Runnable
{
private Runnable idleJobPoll(long idleTimeout) throws InterruptedException
{
if (idleTimeout <= 0)
return _jobs.take();
return _jobs.poll(idleTimeout, TimeUnit.MILLISECONDS);
}
@Override
public void run()
{
if (LOG.isDebugEnabled())
LOG.debug("Runner started for {}", QueuedThreadPool.this);
boolean idle = true;
try
{
Runnable job = null;
while (true)
{
// If we had a job,
if (job != null)
{
// signal that we are idle again
if (!addCounts(0, 1))
break;
idle = true;
}
// else check we are still running
else if (_counts.getHi() == Integer.MIN_VALUE)
{
break;
}
try
{
// Look for an immediately available job
job = _jobs.poll();
if (job == null)
{
// No job immediately available maybe we should shrink?
long idleTimeout = getIdleTimeout();
if (idleTimeout > 0 && getThreads() > _minThreads)
{
long last = _lastShrink.get();
long now = System.nanoTime();
if ((now - last) > TimeUnit.MILLISECONDS.toNanos(idleTimeout) && _lastShrink.compareAndSet(last, now))
{
if (LOG.isDebugEnabled())
LOG.debug("shrinking {}", QueuedThreadPool.this);
break;
}
}
// Wait for a job, only after we have checked if we should shrink
job = idleJobPoll(idleTimeout);
// If still no job?
if (job == null)
// continue to try again
continue;
}
idle = false;
// run job
if (LOG.isDebugEnabled())
LOG.debug("run {} in {}", job, QueuedThreadPool.this);
runJob(job);
if (LOG.isDebugEnabled())
LOG.debug("ran {} in {}", job, QueuedThreadPool.this);
}
catch (InterruptedException e)
{
if (LOG.isDebugEnabled())
LOG.debug("interrupted {} in {}", job, QueuedThreadPool.this);
LOG.ignore(e);
}
catch (Throwable e)
{
LOG.warn(e);
}
finally
{
// Clear any interrupted status
Thread.interrupted();
}
}
}
finally
{
Thread thread = Thread.currentThread();
removeThread(thread);
// Decrement the total thread count and the idle count if we had no job
addCounts(-1, idle ? -1 : 0);
if (LOG.isDebugEnabled())
LOG.debug("{} exited for {}", thread, QueuedThreadPool.this);
// There is a chance that we shrunk just as a job was queued for us, so
// check again if we have sufficient threads to meet demand
ensureThreads();
}
}
}
}