This repository has been archived by the owner on Jan 10, 2018. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 276
/
WindowsAsynchronousFileChannelImpl.java
757 lines (656 loc) · 24.1 KB
/
WindowsAsynchronousFileChannelImpl.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
/*
* Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.nio.ch;
import java.nio.channels.*;
import java.util.concurrent.*;
import java.nio.ByteBuffer;
import java.nio.BufferOverflowException;
import java.io.IOException;
import java.io.FileDescriptor;
import sun.misc.SharedSecrets;
import sun.misc.JavaIOFileDescriptorAccess;
/**
* Windows implementation of AsynchronousFileChannel using overlapped I/O.
*/
public class WindowsAsynchronousFileChannelImpl
extends AsynchronousFileChannelImpl
implements Iocp.OverlappedChannel, Groupable
{
private static final JavaIOFileDescriptorAccess fdAccess =
SharedSecrets.getJavaIOFileDescriptorAccess();
// error when EOF is detected asynchronously.
private static final int ERROR_HANDLE_EOF = 38;
// Lazy initialization of default I/O completion port
private static class DefaultIocpHolder {
static final Iocp defaultIocp = defaultIocp();
private static Iocp defaultIocp() {
try {
return new Iocp(null, ThreadPool.createDefault()).start();
} catch (IOException ioe) {
throw new InternalError(ioe);
}
}
}
// Used for force/truncate/size methods
private static final FileDispatcher nd = new FileDispatcherImpl();
// The handle is extracted for use in native methods invoked from this class.
private final long handle;
// The key that identifies the channel's association with the I/O port
private final int completionKey;
// I/O completion port (group)
private final Iocp iocp;
private final boolean isDefaultIocp;
// Caches OVERLAPPED structure for each outstanding I/O operation
private final PendingIoCache ioCache;
private WindowsAsynchronousFileChannelImpl(FileDescriptor fdObj,
boolean reading,
boolean writing,
Iocp iocp,
boolean isDefaultIocp)
throws IOException
{
super(fdObj, reading, writing, iocp.executor());
this.handle = fdAccess.getHandle(fdObj);
this.iocp = iocp;
this.isDefaultIocp = isDefaultIocp;
this.ioCache = new PendingIoCache();
this.completionKey = iocp.associate(this, handle);
}
public static AsynchronousFileChannel open(FileDescriptor fdo,
boolean reading,
boolean writing,
ThreadPool pool)
throws IOException
{
Iocp iocp;
boolean isDefaultIocp;
if (pool == null) {
iocp = DefaultIocpHolder.defaultIocp;
isDefaultIocp = true;
} else {
iocp = new Iocp(null, pool).start();
isDefaultIocp = false;
}
try {
return new
WindowsAsynchronousFileChannelImpl(fdo, reading, writing, iocp, isDefaultIocp);
} catch (IOException x) {
// error binding to port so need to close it (if created for this channel)
if (!isDefaultIocp)
iocp.implClose();
throw x;
}
}
@Override
public <V,A> PendingFuture<V,A> getByOverlapped(long overlapped) {
return ioCache.remove(overlapped);
}
@Override
public void close() throws IOException {
closeLock.writeLock().lock();
try {
if (closed)
return; // already closed
closed = true;
} finally {
closeLock.writeLock().unlock();
}
// invalidate all locks held for this channel
invalidateAllLocks();
// close the file
close0(handle);
// waits until all I/O operations have completed
ioCache.close();
// disassociate from port
iocp.disassociate(completionKey);
// for the non-default group close the port
if (!isDefaultIocp)
iocp.detachFromThreadPool();
}
@Override
public AsynchronousChannelGroupImpl group() {
return iocp;
}
/**
* Translates Throwable to IOException
*/
private static IOException toIOException(Throwable x) {
if (x instanceof IOException) {
if (x instanceof ClosedChannelException)
x = new AsynchronousCloseException();
return (IOException)x;
}
return new IOException(x);
}
@Override
public long size() throws IOException {
try {
begin();
return nd.size(fdObj);
} finally {
end();
}
}
@Override
public AsynchronousFileChannel truncate(long size) throws IOException {
if (size < 0)
throw new IllegalArgumentException("Negative size");
if (!writing)
throw new NonWritableChannelException();
try {
begin();
if (size > nd.size(fdObj))
return this;
nd.truncate(fdObj, size);
} finally {
end();
}
return this;
}
@Override
public void force(boolean metaData) throws IOException {
try {
begin();
nd.force(fdObj, metaData);
} finally {
end();
}
}
// -- file locking --
/**
* Task that initiates locking operation and handles completion result.
*/
private class LockTask<A> implements Runnable, Iocp.ResultHandler {
private final long position;
private final FileLockImpl fli;
private final PendingFuture<FileLock,A> result;
LockTask(long position,
FileLockImpl fli,
PendingFuture<FileLock,A> result)
{
this.position = position;
this.fli = fli;
this.result = result;
}
@Override
public void run() {
long overlapped = 0L;
boolean pending = false;
try {
begin();
// allocate OVERLAPPED structure
overlapped = ioCache.add(result);
// synchronize on result to avoid race with handler thread
// when lock is acquired immediately.
synchronized (result) {
int n = lockFile(handle, position, fli.size(), fli.isShared(),
overlapped);
if (n == IOStatus.UNAVAILABLE) {
// I/O is pending
pending = true;
return;
}
// acquired lock immediately
result.setResult(fli);
}
} catch (Throwable x) {
// lock failed or channel closed
removeFromFileLockTable(fli);
result.setFailure(toIOException(x));
} finally {
if (!pending && overlapped != 0L)
ioCache.remove(overlapped);
end();
}
// invoke completion handler
Invoker.invoke(result);
}
@Override
public void completed(int bytesTransferred, boolean canInvokeDirect) {
// release waiters and invoke completion handler
result.setResult(fli);
if (canInvokeDirect) {
Invoker.invokeUnchecked(result);
} else {
Invoker.invoke(result);
}
}
@Override
public void failed(int error, IOException x) {
// lock not acquired so remove from lock table
removeFromFileLockTable(fli);
// release waiters
if (isOpen()) {
result.setFailure(x);
} else {
result.setFailure(new AsynchronousCloseException());
}
Invoker.invoke(result);
}
}
@Override
<A> Future<FileLock> implLock(final long position,
final long size,
final boolean shared,
A attachment,
final CompletionHandler<FileLock,? super A> handler)
{
if (shared && !reading)
throw new NonReadableChannelException();
if (!shared && !writing)
throw new NonWritableChannelException();
// add to lock table
FileLockImpl fli = addToFileLockTable(position, size, shared);
if (fli == null) {
Throwable exc = new ClosedChannelException();
if (handler == null)
return CompletedFuture.withFailure(exc);
Invoker.invoke(this, handler, attachment, null, exc);
return null;
}
// create Future and task that will be invoked to acquire lock
PendingFuture<FileLock,A> result =
new PendingFuture<FileLock,A>(this, handler, attachment);
LockTask<A> lockTask = new LockTask<A>(position, fli, result);
result.setContext(lockTask);
// initiate I/O
if (Iocp.supportsThreadAgnosticIo()) {
lockTask.run();
} else {
boolean executed = false;
try {
Invoker.invokeOnThreadInThreadPool(this, lockTask);
executed = true;
} finally {
if (!executed) {
// rollback
removeFromFileLockTable(fli);
}
}
}
return result;
}
static final int NO_LOCK = -1; // Failed to lock
static final int LOCKED = 0; // Obtained requested lock
@Override
public FileLock tryLock(long position, long size, boolean shared)
throws IOException
{
if (shared && !reading)
throw new NonReadableChannelException();
if (!shared && !writing)
throw new NonWritableChannelException();
// add to lock table
final FileLockImpl fli = addToFileLockTable(position, size, shared);
if (fli == null)
throw new ClosedChannelException();
boolean gotLock = false;
try {
begin();
// try to acquire the lock
int res = nd.lock(fdObj, false, position, size, shared);
if (res == NO_LOCK)
return null;
gotLock = true;
return fli;
} finally {
if (!gotLock)
removeFromFileLockTable(fli);
end();
}
}
@Override
protected void implRelease(FileLockImpl fli) throws IOException {
nd.release(fdObj, fli.position(), fli.size());
}
/**
* Task that initiates read operation and handles completion result.
*/
private class ReadTask<A> implements Runnable, Iocp.ResultHandler {
private final ByteBuffer dst;
private final int pos, rem; // buffer position/remaining
private final long position; // file position
private final PendingFuture<Integer,A> result;
// set to dst if direct; otherwise set to substituted direct buffer
private volatile ByteBuffer buf;
ReadTask(ByteBuffer dst,
int pos,
int rem,
long position,
PendingFuture<Integer,A> result)
{
this.dst = dst;
this.pos = pos;
this.rem = rem;
this.position = position;
this.result = result;
}
void releaseBufferIfSubstituted() {
if (buf != dst)
Util.releaseTemporaryDirectBuffer(buf);
}
void updatePosition(int bytesTransferred) {
// if the I/O succeeded then adjust buffer position
if (bytesTransferred > 0) {
if (buf == dst) {
try {
dst.position(pos + bytesTransferred);
} catch (IllegalArgumentException x) {
// someone has changed the position; ignore
}
} else {
// had to substitute direct buffer
buf.position(bytesTransferred).flip();
try {
dst.put(buf);
} catch (BufferOverflowException x) {
// someone has changed the position; ignore
}
}
}
}
@Override
public void run() {
int n = -1;
long overlapped = 0L;
long address;
// Substitute a native buffer if not direct
if (dst instanceof DirectBuffer) {
buf = dst;
address = ((DirectBuffer)dst).address() + pos;
} else {
buf = Util.getTemporaryDirectBuffer(rem);
address = ((DirectBuffer)buf).address();
}
boolean pending = false;
try {
begin();
// allocate OVERLAPPED
overlapped = ioCache.add(result);
// initiate read
n = readFile(handle, address, rem, position, overlapped);
if (n == IOStatus.UNAVAILABLE) {
// I/O is pending
pending = true;
return;
} else if (n == IOStatus.EOF) {
result.setResult(n);
} else {
throw new InternalError("Unexpected result: " + n);
}
} catch (Throwable x) {
// failed to initiate read
result.setFailure(toIOException(x));
} finally {
if (!pending) {
// release resources
if (overlapped != 0L)
ioCache.remove(overlapped);
releaseBufferIfSubstituted();
}
end();
}
// invoke completion handler
Invoker.invoke(result);
}
/**
* Executed when the I/O has completed
*/
@Override
public void completed(int bytesTransferred, boolean canInvokeDirect) {
updatePosition(bytesTransferred);
// return direct buffer to cache if substituted
releaseBufferIfSubstituted();
// release waiters and invoke completion handler
result.setResult(bytesTransferred);
if (canInvokeDirect) {
Invoker.invokeUnchecked(result);
} else {
Invoker.invoke(result);
}
}
@Override
public void failed(int error, IOException x) {
// if EOF detected asynchronously then it is reported as error
if (error == ERROR_HANDLE_EOF) {
completed(-1, false);
} else {
// return direct buffer to cache if substituted
releaseBufferIfSubstituted();
// release waiters
if (isOpen()) {
result.setFailure(x);
} else {
result.setFailure(new AsynchronousCloseException());
}
Invoker.invoke(result);
}
}
}
@Override
<A> Future<Integer> implRead(ByteBuffer dst,
long position,
A attachment,
CompletionHandler<Integer,? super A> handler)
{
if (!reading)
throw new NonReadableChannelException();
if (position < 0)
throw new IllegalArgumentException("Negative position");
if (dst.isReadOnly())
throw new IllegalArgumentException("Read-only buffer");
// check if channel is closed
if (!isOpen()) {
Throwable exc = new ClosedChannelException();
if (handler == null)
return CompletedFuture.withFailure(exc);
Invoker.invoke(this, handler, attachment, null, exc);
return null;
}
int pos = dst.position();
int lim = dst.limit();
assert (pos <= lim);
int rem = (pos <= lim ? lim - pos : 0);
// no space remaining
if (rem == 0) {
if (handler == null)
return CompletedFuture.withResult(0);
Invoker.invoke(this, handler, attachment, 0, null);
return null;
}
// create Future and task that initiates read
PendingFuture<Integer,A> result =
new PendingFuture<Integer,A>(this, handler, attachment);
ReadTask<A> readTask = new ReadTask<A>(dst, pos, rem, position, result);
result.setContext(readTask);
// initiate I/O
if (Iocp.supportsThreadAgnosticIo()) {
readTask.run();
} else {
Invoker.invokeOnThreadInThreadPool(this, readTask);
}
return result;
}
/**
* Task that initiates write operation and handles completion result.
*/
private class WriteTask<A> implements Runnable, Iocp.ResultHandler {
private final ByteBuffer src;
private final int pos, rem; // buffer position/remaining
private final long position; // file position
private final PendingFuture<Integer,A> result;
// set to src if direct; otherwise set to substituted direct buffer
private volatile ByteBuffer buf;
WriteTask(ByteBuffer src,
int pos,
int rem,
long position,
PendingFuture<Integer,A> result)
{
this.src = src;
this.pos = pos;
this.rem = rem;
this.position = position;
this.result = result;
}
void releaseBufferIfSubstituted() {
if (buf != src)
Util.releaseTemporaryDirectBuffer(buf);
}
void updatePosition(int bytesTransferred) {
// if the I/O succeeded then adjust buffer position
if (bytesTransferred > 0) {
try {
src.position(pos + bytesTransferred);
} catch (IllegalArgumentException x) {
// someone has changed the position
}
}
}
@Override
public void run() {
int n = -1;
long overlapped = 0L;
long address;
// Substitute a native buffer if not direct
if (src instanceof DirectBuffer) {
buf = src;
address = ((DirectBuffer)src).address() + pos;
} else {
buf = Util.getTemporaryDirectBuffer(rem);
buf.put(src);
buf.flip();
// temporarily restore position as we don't know how many bytes
// will be written
src.position(pos);
address = ((DirectBuffer)buf).address();
}
try {
begin();
// allocate an OVERLAPPED structure
overlapped = ioCache.add(result);
// initiate the write
n = writeFile(handle, address, rem, position, overlapped);
if (n == IOStatus.UNAVAILABLE) {
// I/O is pending
return;
} else {
throw new InternalError("Unexpected result: " + n);
}
} catch (Throwable x) {
// failed to initiate read:
result.setFailure(toIOException(x));
// release resources
if (overlapped != 0L)
ioCache.remove(overlapped);
releaseBufferIfSubstituted();
} finally {
end();
}
// invoke completion handler
Invoker.invoke(result);
}
/**
* Executed when the I/O has completed
*/
@Override
public void completed(int bytesTransferred, boolean canInvokeDirect) {
updatePosition(bytesTransferred);
// return direct buffer to cache if substituted
releaseBufferIfSubstituted();
// release waiters and invoke completion handler
result.setResult(bytesTransferred);
if (canInvokeDirect) {
Invoker.invokeUnchecked(result);
} else {
Invoker.invoke(result);
}
}
@Override
public void failed(int error, IOException x) {
// return direct buffer to cache if substituted
releaseBufferIfSubstituted();
// release waiters and invoker completion handler
if (isOpen()) {
result.setFailure(x);
} else {
result.setFailure(new AsynchronousCloseException());
}
Invoker.invoke(result);
}
}
<A> Future<Integer> implWrite(ByteBuffer src,
long position,
A attachment,
CompletionHandler<Integer,? super A> handler)
{
if (!writing)
throw new NonWritableChannelException();
if (position < 0)
throw new IllegalArgumentException("Negative position");
// check if channel is closed
if (!isOpen()) {
Throwable exc = new ClosedChannelException();
if (handler == null)
return CompletedFuture.withFailure(exc);
Invoker.invoke(this, handler, attachment, null, exc);
return null;
}
int pos = src.position();
int lim = src.limit();
assert (pos <= lim);
int rem = (pos <= lim ? lim - pos : 0);
// nothing to write
if (rem == 0) {
if (handler == null)
return CompletedFuture.withResult(0);
Invoker.invoke(this, handler, attachment, 0, null);
return null;
}
// create Future and task to initiate write
PendingFuture<Integer,A> result =
new PendingFuture<Integer,A>(this, handler, attachment);
WriteTask<A> writeTask = new WriteTask<A>(src, pos, rem, position, result);
result.setContext(writeTask);
// initiate I/O
if (Iocp.supportsThreadAgnosticIo()) {
writeTask.run();
} else {
Invoker.invokeOnThreadInThreadPool(this, writeTask);
}
return result;
}
// -- Native methods --
private static native int readFile(long handle, long address, int len,
long offset, long overlapped) throws IOException;
private static native int writeFile(long handle, long address, int len,
long offset, long overlapped) throws IOException;
private static native int lockFile(long handle, long position, long size,
boolean shared, long overlapped) throws IOException;
private static native void close0(long handle);
static {
IOUtil.load();
}
}