1 /*
2 * Copyright (c) 2018, 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 /* @test
25 * @bug 8199433
26 * @run testng SelectWithConsumer
27 * @summary Unit test for Selector select(Consumer), select(Consumer,long) and
28 * selectNow(Consumer)
29 */
30
31 import java.io.Closeable;
32 import java.io.IOException;
33 import java.net.InetSocketAddress;
34 import java.nio.ByteBuffer;
35 import java.nio.channels.ClosedSelectorException;
36 import java.nio.channels.Pipe;
37 import java.nio.channels.SelectionKey;
38 import java.nio.channels.Selector;
39 import java.nio.channels.ServerSocketChannel;
40 import java.nio.channels.SocketChannel;
41 import java.nio.channels.WritableByteChannel;
42 import java.util.concurrent.Executors;
43 import java.util.concurrent.ScheduledExecutorService;
44 import java.util.concurrent.TimeUnit;
45 import java.util.concurrent.atomic.AtomicInteger;
46 import static java.util.concurrent.TimeUnit.*;
47
48 import org.testng.annotations.AfterTest;
49 import org.testng.annotations.Test;
50 import static org.testng.Assert.*;
51
52 @Test
53 public class SelectWithConsumer {
54
55 /**
56 * Invoke the select methods that take an action and checks that the
57 * accumulated ready ops notified to the action matches the expected ops.
58 */
59 void testActionInvoked(SelectionKey key, int expectedOps) throws Exception {
60 var callerThread = Thread.currentThread();
61 var sel = key.selector();
62 var interestOps = key.interestOps();
63 var notifiedOps = new AtomicInteger();
64
65 // select(Consumer)
66 if (expectedOps == 0)
67 sel.wakeup(); // ensure select does not block
68 notifiedOps.set(0);
69 int n = sel.select(k -> {
70 assertTrue(Thread.currentThread() == callerThread);
71 assertTrue(k == key);
72 int readyOps = key.readyOps();
73 assertTrue((readyOps & interestOps) != 0);
74 assertTrue((readyOps & notifiedOps.get()) == 0);
75 notifiedOps.set(notifiedOps.get() | readyOps);
76 });
77 assertTrue((n == 1) ^ (expectedOps == 0));
78 assertTrue(notifiedOps.get() == expectedOps);
79
80 // select(Consumer, timeout)
81 notifiedOps.set(0);
82 n = sel.select(k -> {
83 assertTrue(Thread.currentThread() == callerThread);
84 assertTrue(k == key);
85 int readyOps = key.readyOps();
86 assertTrue((readyOps & interestOps) != 0);
87 assertTrue((readyOps & notifiedOps.get()) == 0);
88 notifiedOps.set(notifiedOps.get() | readyOps);
89 }, 1000);
90 assertTrue((n == 1) ^ (expectedOps == 0));
91 assertTrue(notifiedOps.get() == expectedOps);
92
93 // selectNow(Consumer)
94 notifiedOps.set(0);
95 n = sel.selectNow(k -> {
96 assertTrue(Thread.currentThread() == callerThread);
97 assertTrue(k == key);
98 int readyOps = key.readyOps();
99 assertTrue((readyOps & interestOps) != 0);
100 assertTrue((readyOps & notifiedOps.get()) == 0);
101 notifiedOps.set(notifiedOps.get() | readyOps);
102 });
103 assertTrue((n == 1) ^ (expectedOps == 0));
104 assertTrue(notifiedOps.get() == expectedOps);
105 }
106
107 /**
108 * Test that an action is performed when a channel is ready for reading.
109 */
110 public void testReadable() throws Exception {
111 Pipe p = Pipe.open();
112 try (Selector sel = Selector.open()) {
113 Pipe.SinkChannel sink = p.sink();
114 Pipe.SourceChannel source = p.source();
115 source.configureBlocking(false);
116 SelectionKey key = source.register(sel, SelectionKey.OP_READ);
117
118 // write to sink to ensure source is readable
119 scheduleWrite(sink, messageBuffer(), 100, MILLISECONDS);
120
121 // test that action is invoked
122 testActionInvoked(key, SelectionKey.OP_READ);
123 } finally {
124 closePipe(p);
125 }
126 }
127
128 /**
129 * Test that an action is performed when a channel is ready for writing.
130 */
131 public void testWritable() throws Exception {
132 Pipe p = Pipe.open();
133 try (Selector sel = Selector.open()) {
134 Pipe.SourceChannel source = p.source();
135 Pipe.SinkChannel sink = p.sink();
136 sink.configureBlocking(false);
137 SelectionKey key = sink.register(sel, SelectionKey.OP_WRITE);
138
139 // test that action is invoked
140 testActionInvoked(key, SelectionKey.OP_WRITE);
141 } finally {
142 closePipe(p);
143 }
144 }
145
146 /**
147 * Test that an action is performed when a channel is ready for both
148 * reading and writing.
149 */
150 public void testReadableAndWriteable() throws Exception {
151 ServerSocketChannel ssc = null;
152 SocketChannel sc = null;
153 SocketChannel peer = null;
154 try (Selector sel = Selector.open()) {
155 ssc = ServerSocketChannel.open().bind(new InetSocketAddress(0));
156 sc = SocketChannel.open(ssc.getLocalAddress());
157 sc.configureBlocking(false);
158 SelectionKey key = sc.register(sel, (SelectionKey.OP_READ |
159 SelectionKey.OP_WRITE));
160
161 // accept connection and write data so the source is readable
162 peer = ssc.accept();
163 peer.write(messageBuffer());
164
165 // test that action is invoked
166 testActionInvoked(key, (SelectionKey.OP_READ | SelectionKey.OP_WRITE));
167 } finally {
168 if (ssc != null) ssc.close();
169 if (sc != null) sc.close();
170 if (peer != null) peer.close();
171 }
172 }
173
174 /**
175 * Test that the action is called for two selected channels
176 */
177 public void testTwoChannels() throws Exception {
178 Pipe p = Pipe.open();
179 try (Selector sel = Selector.open()) {
180 Pipe.SourceChannel source = p.source();
181 Pipe.SinkChannel sink = p.sink();
182 source.configureBlocking(false);
183 sink.configureBlocking(false);
184 SelectionKey key1 = source.register(sel, SelectionKey.OP_READ);
185 SelectionKey key2 = sink.register(sel, SelectionKey.OP_WRITE);
186
187 // write to sink to ensure that the source is readable
188 sink.write(messageBuffer());
189
190 var counter = new AtomicInteger();
191
192 // select(Consumer)
193 counter.set(0);
194 int n = sel.select(k -> {
195 counter.incrementAndGet();
196 if (k == key1) {
197 assertTrue(k.isReadable());
198 } else if (k == key2) {
199 assertTrue(k.isWritable());
200 } else {
201 assertTrue(false);
202 }
203 });
204 assertTrue(n == 2);
205 assertTrue(counter.get() == 2);
206
207 // select(Consumer, timeout)
208 counter.set(0);
209 n = sel.select(k -> {
210 counter.incrementAndGet();
211 if (k == key1) {
212 assertTrue(k.isReadable());
213 } else if (k == key2) {
214 assertTrue(k.isWritable());
215 } else {
216 assertTrue(false);
217 }
218 }, 1000);
219 assertTrue(n == 2);
220 assertTrue(counter.get() == 2);
221
222 // selectNow(Consumer)
223 counter.set(0);
224 n = sel.selectNow(k -> {
225 counter.incrementAndGet();
226 if (k == key1) {
227 assertTrue(k.isReadable());
228 } else if (k == key2) {
229 assertTrue(k.isWritable());
230 } else {
231 assertTrue(false);
232 }
233 });
234 assertTrue(n == 2);
235 assertTrue(counter.get() == 2);
236 } finally {
237 closePipe(p);
238 }
239 }
240
241 /**
242 * Test calling select twice, the action should be invoked each time
243 */
244 public void testRepeatedSelect1() throws Exception {
245 Pipe p = Pipe.open();
246 try (Selector sel = Selector.open()) {
247 Pipe.SourceChannel source = p.source();
248 Pipe.SinkChannel sink = p.sink();
249 source.configureBlocking(false);
250 SelectionKey key = source.register(sel, SelectionKey.OP_READ);
251
252 // write to sink to ensure that the source is readable
253 sink.write(messageBuffer());
254
255 // test that action is invoked
256 testActionInvoked(key, SelectionKey.OP_READ);
257 testActionInvoked(key, SelectionKey.OP_READ);
258
259 } finally {
260 closePipe(p);
261 }
262 }
263
264 /**
265 * Test calling select twice. An I/O operation is performed after the
266 * first select so the channel will not be selected by the second select.
267 */
268 public void testRepeatedSelect2() throws Exception {
269 Pipe p = Pipe.open();
270 try (Selector sel = Selector.open()) {
271 Pipe.SourceChannel source = p.source();
272 Pipe.SinkChannel sink = p.sink();
273 source.configureBlocking(false);
274 SelectionKey key = source.register(sel, SelectionKey.OP_READ);
275
276 // write to sink to ensure that the source is readable
277 sink.write(messageBuffer());
278
279 // test that action is invoked
280 testActionInvoked(key, SelectionKey.OP_READ);
281
282 // read all bytes
283 int n;
284 ByteBuffer bb = ByteBuffer.allocate(100);
285 do {
286 n = source.read(bb);
287 bb.clear();
288 } while (n > 0);
289
290 // test that action is not invoked
291 testActionInvoked(key, 0);
292 } finally {
293 closePipe(p);
294 }
295 }
296
297 /**
298 * Test timeout
299 */
300 public void testTimeout() throws Exception {
301 Pipe p = Pipe.open();
302 try (Selector sel = Selector.open()) {
303 Pipe.SourceChannel source = p.source();
304 Pipe.SinkChannel sink = p.sink();
305 source.configureBlocking(false);
306 source.register(sel, SelectionKey.OP_READ);
307 long start = System.currentTimeMillis();
308 int n = sel.select(k -> assertTrue(false), 1000L);
309 long duration = System.currentTimeMillis() - start;
310 assertTrue(n == 0);
311 assertTrue(duration > 500L);
312 } finally {
313 closePipe(p);
314 }
315 }
316
317 /**
318 * Test wakeup prior to select
319 */
320 public void testWakeupBeforeSelect() throws Exception {
321 // select(Consumer)
322 try (Selector sel = Selector.open()) {
323 sel.wakeup();
324 int n = sel.select(k -> assertTrue(false));
325 assertTrue(n == 0);
326 }
327
328 // select(Consumer, timeout)
329 try (Selector sel = Selector.open()) {
330 sel.wakeup();
331 long start = System.currentTimeMillis();
332 int n = sel.select(k -> assertTrue(false), 60*1000);
333 long duration = System.currentTimeMillis() - start;
334 assertTrue(n == 0);
335 assertTrue(duration < 5000);
336 }
337 }
338
339 /**
340 * Test wakeup during select
341 */
342 public void testWakeupDuringSelect() throws Exception {
343 // select(Consumer)
344 try (Selector sel = Selector.open()) {
345 scheduleWakeup(sel, 1, SECONDS);
346 int n = sel.select(k -> assertTrue(false));
347 assertTrue(n == 0);
348 }
349
350 // select(Consumer, timeout)
351 try (Selector sel = Selector.open()) {
352 scheduleWakeup(sel, 1, SECONDS);
353 long start = System.currentTimeMillis();
354 int n = sel.select(k -> assertTrue(false), 60*1000);
355 long duration = System.currentTimeMillis() - start;
356 assertTrue(n == 0);
357 assertTrue(duration > 500 && duration < 10*1000);
358 }
359 }
360
361 /**
362 * Test invoking select with interrupt status set
363 */
364 public void testInterruptBeforeSelect() throws Exception {
365 // select(Consumer)
366 try (Selector sel = Selector.open()) {
367 Thread.currentThread().interrupt();
368 int n = sel.select(k -> assertTrue(false));
369 assertTrue(n == 0);
370 assertTrue(Thread.currentThread().isInterrupted());
371 assertTrue(sel.isOpen());
372 } finally {
373 Thread.currentThread().interrupted(); // clear interrupt status
374 }
375
376 // select(Consumer, timeout)
377 try (Selector sel = Selector.open()) {
378 Thread.currentThread().interrupt();
379 long start = System.currentTimeMillis();
380 int n = sel.select(k -> assertTrue(false), 60*1000);
381 long duration = System.currentTimeMillis() - start;
382 assertTrue(n == 0);
383 assertTrue(duration < 5000);
384 assertTrue(Thread.currentThread().isInterrupted());
385 assertTrue(sel.isOpen());
386 } finally {
387 Thread.currentThread().interrupted(); // clear interrupt status
388 }
389 }
390
391 /**
392 * Test interrupt thread during select
393 */
394 public void testInterruptDuringSelect() throws Exception {
395 // select(Consumer)
396 try (Selector sel = Selector.open()) {
397 scheduleInterrupt(Thread.currentThread(), 1, SECONDS);
398 int n = sel.select(k -> assertTrue(false));
399 assertTrue(n == 0);
400 assertTrue(Thread.currentThread().isInterrupted());
401 assertTrue(sel.isOpen());
402 } finally {
403 Thread.currentThread().interrupted(); // clear interrupt status
404 }
405
406 // select(Consumer, timeout)
407 try (Selector sel = Selector.open()) {
408 scheduleInterrupt(Thread.currentThread(), 1, SECONDS);
409 long start = System.currentTimeMillis();
410 int n = sel.select(k -> assertTrue(false), 60*1000);
411 long duration = System.currentTimeMillis() - start;
412 assertTrue(n == 0);
413 assertTrue(duration > 500 && duration < 5000);
414 assertTrue(Thread.currentThread().isInterrupted());
415 assertTrue(sel.isOpen());
416 } finally {
417 Thread.currentThread().interrupted(); // clear interrupt status
418 }
419 }
420
421 /**
422 * Test invoking select on a closed selector
423 */
424 @Test(expectedExceptions = ClosedSelectorException.class)
425 public void testClosedSelector1() throws Exception {
426 Selector sel = Selector.open();
427 sel.close();
428 sel.select(k -> assertTrue(false));
429 }
430 @Test(expectedExceptions = ClosedSelectorException.class)
431 public void testClosedSelector2() throws Exception {
432 Selector sel = Selector.open();
433 sel.close();
434 sel.select(k -> assertTrue(false), 1000);
435 }
436 @Test(expectedExceptions = ClosedSelectorException.class)
437 public void testClosedSelector3() throws Exception {
438 Selector sel = Selector.open();
439 sel.close();
440 sel.selectNow(k -> assertTrue(false));
441 }
442
443 /**
444 * Test closing selector while in a selection operation
445 */
446 public void testCloseDuringSelect() throws Exception {
447 // select(Consumer)
448 try (Selector sel = Selector.open()) {
449 scheduleClose(sel, 3, SECONDS);
450 int n = sel.select(k -> assertTrue(false));
451 assertTrue(n == 0);
452 assertFalse(sel.isOpen());
453 }
454
455 // select(Consumer, timeout)
456 try (Selector sel = Selector.open()) {
457 scheduleClose(sel, 3, SECONDS);
458 long start = System.currentTimeMillis();
459 int n = sel.select(k -> assertTrue(false), 60*1000);
460 long duration = System.currentTimeMillis() - start;
461 assertTrue(n == 0);
462 assertTrue(duration > 2000 && duration < 10*1000);
463 assertFalse(sel.isOpen());
464 }
465 }
466
467 /**
468 * Test action closing selector
469 */
470 @Test(expectedExceptions = ClosedSelectorException.class)
471 public void testActionClosingSelector() throws Exception {
472 Pipe p = Pipe.open();
473 try (Selector sel = Selector.open()) {
474 Pipe.SourceChannel source = p.source();
475 Pipe.SinkChannel sink = p.sink();
476 source.configureBlocking(false);
477 SelectionKey key = source.register(sel, SelectionKey.OP_READ);
478
479 // write to sink to ensure that the source is readable
480 sink.write(messageBuffer());
481
482 // should relay ClosedSelectorException
483 sel.select(k -> {
484 assertTrue(k == key);
485 try {
486 sel.close();
487 } catch (IOException ioe) { }
488 });
489 } finally {
490 closePipe(p);
491 }
492 }
493
494 /**
495 * Test that the action is invoked while synchronized on the selector and
496 * its selected-key set.
497 */
498 public void testLocks() throws Exception {
499 Pipe p = Pipe.open();
500 try (Selector sel = Selector.open()) {
501 Pipe.SourceChannel source = p.source();
502 Pipe.SinkChannel sink = p.sink();
503 source.configureBlocking(false);
504 SelectionKey key = source.register(sel, SelectionKey.OP_READ);
505
506 // write to sink to ensure that the source is readable
507 sink.write(messageBuffer());
508
509 // select(Consumer)
510 sel.select(k -> {
511 assertTrue(k == key);
512 assertTrue(Thread.holdsLock(sel));
513 assertFalse(Thread.holdsLock(sel.keys()));
514 assertTrue(Thread.holdsLock(sel.selectedKeys()));
515 });
516
517 // select(Consumer, timeout)
518 sel.select(k -> {
519 assertTrue(k == key);
520 assertTrue(Thread.holdsLock(sel));
521 assertFalse(Thread.holdsLock(sel.keys()));
522 assertTrue(Thread.holdsLock(sel.selectedKeys()));
523 }, 1000L);
524
525 // selectNow(Consumer)
526 sel.selectNow(k -> {
527 assertTrue(k == key);
528 assertTrue(Thread.holdsLock(sel));
529 assertFalse(Thread.holdsLock(sel.keys()));
530 assertTrue(Thread.holdsLock(sel.selectedKeys()));
531 });
532 } finally {
533 closePipe(p);
534 }
535 }
536
537 /**
538 * Test that selection operations removes cancelled keys from the selector's
539 * key and selected-key sets.
540 */
541 public void testCancel() throws Exception {
542 Pipe p = Pipe.open();
543 try (Selector sel = Selector.open()) {
544 Pipe.SinkChannel sink = p.sink();
545 Pipe.SourceChannel source = p.source();
546
547 // write to sink to ensure that the source is readable
548 sink.write(messageBuffer());
549
550 sink.configureBlocking(false);
551 source.configureBlocking(false);
552 SelectionKey key1 = sink.register(sel, SelectionKey.OP_WRITE);
553 SelectionKey key2 = source.register(sel, SelectionKey.OP_READ);
554
555 sel.selectNow();
556 assertTrue(sel.keys().contains(key1));
557 assertTrue(sel.keys().contains(key2));
558 assertTrue(sel.selectedKeys().contains(key1));
559 assertTrue(sel.selectedKeys().contains(key2));
560
561 // cancel key1
562 key1.cancel();
563 int n = sel.selectNow(k -> assertTrue(k == key2));
564 assertTrue(n == 1);
565 assertFalse(sel.keys().contains(key1));
566 assertTrue(sel.keys().contains(key2));
567 assertFalse(sel.selectedKeys().contains(key1));
568 assertTrue(sel.selectedKeys().contains(key2));
569
570 // cancel key2
571 key2.cancel();
572 n = sel.selectNow(k -> assertTrue(false));
573 assertTrue(n == 0);
574 assertFalse(sel.keys().contains(key1));
575 assertFalse(sel.keys().contains(key2));
576 assertFalse(sel.selectedKeys().contains(key1));
577 assertFalse(sel.selectedKeys().contains(key2));
578 } finally {
579 closePipe(p);
580 }
581 }
582
583 /**
584 * Test an action invoking select()
585 */
586 public void testReentrantSelect1() throws Exception {
587 Pipe p = Pipe.open();
588 try (Selector sel = Selector.open()) {
589 Pipe.SinkChannel sink = p.sink();
590 Pipe.SourceChannel source = p.source();
591 source.configureBlocking(false);
592 source.register(sel, SelectionKey.OP_READ);
593
594 // write to sink to ensure that the source is readable
595 scheduleWrite(sink, messageBuffer(), 100, MILLISECONDS);
596
597 int n = sel.select(k -> {
598 try {
599 sel.select();
600 assertTrue(false);
601 } catch (IOException ioe) {
602 throw new RuntimeException(ioe);
603 } catch (IllegalStateException expected) {
604 }
605 });
606 assertTrue(n == 1);
607 } finally {
608 closePipe(p);
609 }
610 }
611
612 /**
613 * Test an action invoking selectNow()
614 */
615 public void testReentrantSelect2() throws Exception {
616 Pipe p = Pipe.open();
617 try (Selector sel = Selector.open()) {
618 Pipe.SinkChannel sink = p.sink();
619 Pipe.SourceChannel source = p.source();
620
621 // write to sink to ensure that the source is readable
622 scheduleWrite(sink, messageBuffer(), 100, MILLISECONDS);
623
624 source.configureBlocking(false);
625 source.register(sel, SelectionKey.OP_READ);
626 int n = sel.select(k -> {
627 try {
628 sel.selectNow();
629 assertTrue(false);
630 } catch (IOException ioe) {
631 throw new RuntimeException(ioe);
632 } catch (IllegalStateException expected) {
633 }
634 });
635 assertTrue(n == 1);
636 } finally {
637 closePipe(p);
638 }
639 }
640
641 /**
642 * Test an action invoking select(Consumer)
643 */
644 public void testReentrantSelect3() throws Exception {
645 Pipe p = Pipe.open();
646 try (Selector sel = Selector.open()) {
647 Pipe.SinkChannel sink = p.sink();
648 Pipe.SourceChannel source = p.source();
649
650 // write to sink to ensure that the source is readable
651 scheduleWrite(sink, messageBuffer(), 100, MILLISECONDS);
652
653 source.configureBlocking(false);
654 source.register(sel, SelectionKey.OP_READ);
655 int n = sel.select(k -> {
656 try {
657 sel.select(x -> assertTrue(false));
658 assertTrue(false);
659 } catch (IOException ioe) {
660 throw new RuntimeException(ioe);
661 } catch (IllegalStateException expected) {
662 }
663 });
664 assertTrue(n == 1);
665 } finally {
666 closePipe(p);
667 }
668 }
669
670 /**
671 * Negative timeout
672 */
673 @Test(expectedExceptions = IllegalArgumentException.class)
674 public void testNegativeTimeout() throws Exception {
675 try (Selector sel = Selector.open()) {
676 sel.select(k -> { }, -1L);
677 }
678 }
679
680 /**
681 * Null action
682 */
683 @Test(expectedExceptions = NullPointerException.class)
684 public void testNull1() throws Exception {
685 try (Selector sel = Selector.open()) {
686 sel.select(null);
687 }
688 }
689 @Test(expectedExceptions = NullPointerException.class)
690 public void testNull2() throws Exception {
691 try (Selector sel = Selector.open()) {
692 sel.select(null, 1000);
693 }
694 }
695 @Test(expectedExceptions = NullPointerException.class)
696 public void testNull3() throws Exception {
697 try (Selector sel = Selector.open()) {
698 sel.selectNow(null);
699 }
700 }
701
702
703 // -- support methods ---
704
705 private final ScheduledExecutorService POOL = Executors.newScheduledThreadPool(1);
706
707 @AfterTest
708 void shutdownThreadPool() {
709 POOL.shutdown();
710 }
711
712 void scheduleWakeup(Selector sel, long delay, TimeUnit unit) {
713 POOL.schedule(() -> sel.wakeup(), delay, unit);
714 }
715
716 void scheduleInterrupt(Thread t, long delay, TimeUnit unit) {
717 POOL.schedule(() -> t.interrupt(), delay, unit);
718 }
719
720 void scheduleClose(Closeable c, long delay, TimeUnit unit) {
721 POOL.schedule(() -> {
722 try {
723 c.close();
724 } catch (IOException ioe) {
725 ioe.printStackTrace();
726 }
727 }, delay, unit);
728 }
729
730 void scheduleWrite(WritableByteChannel sink, ByteBuffer buf, long delay, TimeUnit unit) {
731 POOL.schedule(() -> {
732 try {
733 sink.write(buf);
734 } catch (IOException ioe) {
735 ioe.printStackTrace();
736 }
737 }, delay, unit);
738 }
739
740 static void closePipe(Pipe p) {
741 try { p.sink().close(); } catch (IOException ignore) { }
742 try { p.source().close(); } catch (IOException ignore) { }
743 }
744
745 static ByteBuffer messageBuffer() {
746 try {
747 return ByteBuffer.wrap("message".getBytes("UTF-8"));
748 } catch (Exception e) {
749 throw new RuntimeException(e);
750 }
751 }
752 }