1 /*
2 * Copyright (c) 1995, 2019, 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.net;
27
28 import java.io.FileDescriptor;
29 import java.io.IOException;
30 import java.io.InputStream;
31 import java.io.OutputStream;
32
33 import java.security.AccessController;
34 import java.security.PrivilegedActionException;
35 import java.security.PrivilegedExceptionAction;
36 import java.util.Collections;
37 import java.util.HashSet;
38 import java.util.Objects;
39 import java.util.Set;
40
41 import sun.net.ConnectionResetException;
42 import sun.net.NetHooks;
43 import sun.net.PlatformSocketImpl;
44 import sun.net.ResourceManager;
45 import sun.net.ext.ExtendedSocketOptions;
46 import sun.net.util.SocketExceptions;
47
48 /**
49 * Default Socket Implementation. This implementation does
50 * not implement any security checks.
51 * Note this class should <b>NOT</b> be public.
52 *
53 * @author Steven B. Byrne
54 */
55 abstract class AbstractPlainSocketImpl extends SocketImpl implements PlatformSocketImpl {
56 /* instance variable for SO_TIMEOUT */
57 int timeout; // timeout in millisec
58 // traffic class
59 private int trafficClass;
60
61 private boolean shut_rd = false;
62 private boolean shut_wr = false;
63
64 private SocketInputStream socketInputStream = null;
65 private SocketOutputStream socketOutputStream = null;
66
67 /* number of threads using the FileDescriptor */
68 protected int fdUseCount = 0;
69
70 /* lock when increment/decrementing fdUseCount */
71 protected final Object fdLock = new Object();
72
73 /* indicates a close is pending on the file descriptor */
74 protected boolean closePending = false;
75
76 /* indicates connection reset state */
77 private volatile boolean connectionReset;
78
79 /* indicates whether impl is bound */
80 boolean isBound;
81
82 /* indicates whether impl is connected */
83 volatile boolean isConnected;
84
85 /* whether this Socket is a stream (TCP) socket or not (UDP)
86 */
87 protected boolean stream;
88
89 /* whether this is a server or not */
90 final boolean isServer;
91
92 /**
93 * Load net library into runtime.
94 */
95 static {
96 java.security.AccessController.doPrivileged(
97 new java.security.PrivilegedAction<>() {
98 public Void run() {
99 System.loadLibrary("net");
100 return null;
101 }
102 });
103 }
104
105 private static volatile boolean checkedReusePort;
106 private static volatile boolean isReusePortAvailable;
107
108 /**
109 * Tells whether SO_REUSEPORT is supported.
110 */
111 static boolean isReusePortAvailable() {
112 if (!checkedReusePort) {
113 isReusePortAvailable = isReusePortAvailable0();
114 checkedReusePort = true;
115 }
116 return isReusePortAvailable;
117 }
118
119 AbstractPlainSocketImpl(boolean isServer) {
120 this.isServer = isServer;
121 }
122
123 /**
124 * Creates a socket with a boolean that specifies whether this
125 * is a stream socket (true) or an unconnected UDP socket (false).
126 */
127 protected synchronized void create(boolean stream) throws IOException {
128 this.stream = stream;
129 if (!stream) {
130 ResourceManager.beforeUdpCreate();
131 // only create the fd after we know we will be able to create the socket
132 fd = new FileDescriptor();
133 try {
134 socketCreate(false);
135 SocketCleanable.register(fd);
136 } catch (IOException ioe) {
137 ResourceManager.afterUdpClose();
138 fd = null;
139 throw ioe;
140 }
141 } else {
142 fd = new FileDescriptor();
143 socketCreate(true);
144 SocketCleanable.register(fd);
145 }
146 }
147
148 /**
149 * Creates a socket and connects it to the specified port on
150 * the specified host.
151 * @param host the specified host
152 * @param port the specified port
153 */
154 protected void connect(String host, int port)
155 throws UnknownHostException, IOException
156 {
157 boolean connected = false;
158 try {
159 InetAddress address = InetAddress.getByName(host);
160 this.port = port;
161 this.address = address;
162
163 connectToAddress(address, port, timeout);
164 connected = true;
165 } finally {
166 if (!connected) {
167 try {
168 close();
169 } catch (IOException ioe) {
170 /* Do nothing. If connect threw an exception then
171 it will be passed up the call stack */
172 }
173 }
174 isConnected = connected;
175 }
176 }
177
178 /**
179 * Creates a socket and connects it to the specified address on
180 * the specified port.
181 * @param address the address
182 * @param port the specified port
183 */
184 protected void connect(InetAddress address, int port) throws IOException {
185 this.port = port;
186 this.address = address;
187
188 try {
189 connectToAddress(address, port, timeout);
190 isConnected = true;
191 return;
192 } catch (IOException e) {
193 // everything failed
194 close();
195 throw e;
196 }
197 }
198
199 /**
200 * Creates a socket and connects it to the specified address on
201 * the specified port.
202 * @param address the address
203 * @param timeout the timeout value in milliseconds, or zero for no timeout.
204 * @throws IOException if connection fails
205 * @throws IllegalArgumentException if address is null or is a
206 * SocketAddress subclass not supported by this socket
207 * @since 1.4
208 */
209 protected void connect(SocketAddress address, int timeout)
210 throws IOException {
211 boolean connected = false;
212 try {
213 if (address == null || !(address instanceof InetSocketAddress))
214 throw new IllegalArgumentException("unsupported address type");
215 InetSocketAddress addr = (InetSocketAddress) address;
216 if (addr.isUnresolved())
217 throw new UnknownHostException(addr.getHostName());
218 this.port = addr.getPort();
219 this.address = addr.getAddress();
220
221 connectToAddress(this.address, port, timeout);
222 connected = true;
223 } finally {
224 if (!connected) {
225 try {
226 close();
227 } catch (IOException ioe) {
228 /* Do nothing. If connect threw an exception then
229 it will be passed up the call stack */
230 }
231 }
232 isConnected = connected;
233 }
234 }
235
236 private void connectToAddress(InetAddress address, int port, int timeout) throws IOException {
237 if (address.isAnyLocalAddress()) {
238 doConnect(InetAddress.getLocalHost(), port, timeout);
239 } else {
240 doConnect(address, port, timeout);
241 }
242 }
243
244 public void setOption(int opt, Object val) throws SocketException {
245 if (isClosedOrPending()) {
246 throw new SocketException("Socket Closed");
247 }
248 boolean on = true;
249 switch (opt) {
250 /* check type safety b4 going native. These should never
251 * fail, since only java.Socket* has access to
252 * PlainSocketImpl.setOption().
253 */
254 case SO_LINGER:
255 if (val == null || (!(val instanceof Integer) && !(val instanceof Boolean)))
256 throw new SocketException("Bad parameter for option");
257 if (val instanceof Boolean) {
258 /* true only if disabling - enabling should be Integer */
259 on = false;
260 }
261 break;
262 case SO_TIMEOUT:
263 if (val == null || (!(val instanceof Integer)))
264 throw new SocketException("Bad parameter for SO_TIMEOUT");
265 int tmp = ((Integer) val).intValue();
266 if (tmp < 0)
267 throw new IllegalArgumentException("timeout < 0");
268 timeout = tmp;
269 break;
270 case IP_TOS:
271 if (val == null || !(val instanceof Integer)) {
272 throw new SocketException("bad argument for IP_TOS");
273 }
274 trafficClass = ((Integer)val).intValue();
275 break;
276 case SO_BINDADDR:
277 throw new SocketException("Cannot re-bind socket");
278 case TCP_NODELAY:
279 if (val == null || !(val instanceof Boolean))
280 throw new SocketException("bad parameter for TCP_NODELAY");
281 on = ((Boolean)val).booleanValue();
282 break;
283 case SO_SNDBUF:
284 case SO_RCVBUF:
285 if (val == null || !(val instanceof Integer) ||
286 !(((Integer)val).intValue() > 0)) {
287 throw new SocketException("bad parameter for SO_SNDBUF " +
288 "or SO_RCVBUF");
289 }
290 break;
291 case SO_KEEPALIVE:
292 if (val == null || !(val instanceof Boolean))
293 throw new SocketException("bad parameter for SO_KEEPALIVE");
294 on = ((Boolean)val).booleanValue();
295 break;
296 case SO_OOBINLINE:
297 if (val == null || !(val instanceof Boolean))
298 throw new SocketException("bad parameter for SO_OOBINLINE");
299 on = ((Boolean)val).booleanValue();
300 break;
301 case SO_REUSEADDR:
302 if (val == null || !(val instanceof Boolean))
303 throw new SocketException("bad parameter for SO_REUSEADDR");
304 on = ((Boolean)val).booleanValue();
305 break;
306 case SO_REUSEPORT:
307 if (val == null || !(val instanceof Boolean))
308 throw new SocketException("bad parameter for SO_REUSEPORT");
309 if (!supportedOptions().contains(StandardSocketOptions.SO_REUSEPORT))
310 throw new UnsupportedOperationException("unsupported option");
311 on = ((Boolean)val).booleanValue();
312 break;
313 default:
314 throw new SocketException("unrecognized TCP option: " + opt);
315 }
316 socketSetOption(opt, on, val);
317 }
318 public Object getOption(int opt) throws SocketException {
319 if (isClosedOrPending()) {
320 throw new SocketException("Socket Closed");
321 }
322 if (opt == SO_TIMEOUT) {
323 return timeout;
324 }
325 int ret = 0;
326 /*
327 * The native socketGetOption() knows about 3 options.
328 * The 32 bit value it returns will be interpreted according
329 * to what we're asking. A return of -1 means it understands
330 * the option but its turned off. It will raise a SocketException
331 * if "opt" isn't one it understands.
332 */
333
334 switch (opt) {
335 case TCP_NODELAY:
336 ret = socketGetOption(opt, null);
337 return Boolean.valueOf(ret != -1);
338 case SO_OOBINLINE:
339 ret = socketGetOption(opt, null);
340 return Boolean.valueOf(ret != -1);
341 case SO_LINGER:
342 ret = socketGetOption(opt, null);
343 return (ret == -1) ? Boolean.FALSE: (Object)(ret);
344 case SO_REUSEADDR:
345 ret = socketGetOption(opt, null);
346 return Boolean.valueOf(ret != -1);
347 case SO_BINDADDR:
348 InetAddressContainer in = new InetAddressContainer();
349 ret = socketGetOption(opt, in);
350 return in.addr;
351 case SO_SNDBUF:
352 case SO_RCVBUF:
353 ret = socketGetOption(opt, null);
354 return ret;
355 case IP_TOS:
356 try {
357 ret = socketGetOption(opt, null);
358 if (ret == -1) { // ipv6 tos
359 return trafficClass;
360 } else {
361 return ret;
362 }
363 } catch (SocketException se) {
364 // TODO - should make better effort to read TOS or TCLASS
365 return trafficClass; // ipv6 tos
366 }
367 case SO_KEEPALIVE:
368 ret = socketGetOption(opt, null);
369 return Boolean.valueOf(ret != -1);
370 case SO_REUSEPORT:
371 if (!supportedOptions().contains(StandardSocketOptions.SO_REUSEPORT)) {
372 throw new UnsupportedOperationException("unsupported option");
373 }
374 ret = socketGetOption(opt, null);
375 return Boolean.valueOf(ret != -1);
376 // should never get here
377 default:
378 return null;
379 }
380 }
381
382 static final ExtendedSocketOptions extendedOptions =
383 ExtendedSocketOptions.getInstance();
384
385 private static final Set<SocketOption<?>> clientSocketOptions = clientSocketOptions();
386 private static final Set<SocketOption<?>> serverSocketOptions = serverSocketOptions();
387
388 private static Set<SocketOption<?>> clientSocketOptions() {
389 HashSet<SocketOption<?>> options = new HashSet<>();
390 options.add(StandardSocketOptions.SO_KEEPALIVE);
391 options.add(StandardSocketOptions.SO_SNDBUF);
392 options.add(StandardSocketOptions.SO_RCVBUF);
393 options.add(StandardSocketOptions.SO_REUSEADDR);
394 options.add(StandardSocketOptions.SO_LINGER);
395 options.add(StandardSocketOptions.IP_TOS);
396 options.add(StandardSocketOptions.TCP_NODELAY);
397 if (isReusePortAvailable())
398 options.add(StandardSocketOptions.SO_REUSEPORT);
399 options.addAll(ExtendedSocketOptions.clientSocketOptions());
400 return Collections.unmodifiableSet(options);
401 }
402
403 private static Set<SocketOption<?>> serverSocketOptions() {
404 HashSet<SocketOption<?>> options = new HashSet<>();
405 options.add(StandardSocketOptions.SO_RCVBUF);
406 options.add(StandardSocketOptions.SO_REUSEADDR);
407 options.add(StandardSocketOptions.IP_TOS);
408 if (isReusePortAvailable())
409 options.add(StandardSocketOptions.SO_REUSEPORT);
410 options.addAll(ExtendedSocketOptions.serverSocketOptions());
411 return Collections.unmodifiableSet(options);
412 }
413
414 @Override
415 protected Set<SocketOption<?>> supportedOptions() {
416 if (isServer)
417 return serverSocketOptions;
418 else
419 return clientSocketOptions;
420 }
421
422 @Override
423 protected <T> void setOption(SocketOption<T> name, T value) throws IOException {
424 Objects.requireNonNull(name);
425 if (!supportedOptions().contains(name))
426 throw new UnsupportedOperationException("'" + name + "' not supported");
427
428 if (!name.type().isInstance(value))
429 throw new IllegalArgumentException("Invalid value '" + value + "'");
430
431 if (isClosedOrPending())
432 throw new SocketException("Socket closed");
433
434 if (name == StandardSocketOptions.SO_KEEPALIVE) {
435 setOption(SocketOptions.SO_KEEPALIVE, value);
436 } else if (name == StandardSocketOptions.SO_SNDBUF) {
437 if (((Integer)value).intValue() < 0)
438 throw new IllegalArgumentException("Invalid send buffer size:" + value);
439 setOption(SocketOptions.SO_SNDBUF, value);
440 } else if (name == StandardSocketOptions.SO_RCVBUF) {
441 if (((Integer)value).intValue() < 0)
442 throw new IllegalArgumentException("Invalid recv buffer size:" + value);
443 setOption(SocketOptions.SO_RCVBUF, value);
444 } else if (name == StandardSocketOptions.SO_REUSEADDR) {
445 setOption(SocketOptions.SO_REUSEADDR, value);
446 } else if (name == StandardSocketOptions.SO_REUSEPORT) {
447 setOption(SocketOptions.SO_REUSEPORT, value);
448 } else if (name == StandardSocketOptions.SO_LINGER ) {
449 if (((Integer)value).intValue() < 0)
450 setOption(SocketOptions.SO_LINGER, false);
451 else
452 setOption(SocketOptions.SO_LINGER, value);
453 } else if (name == StandardSocketOptions.IP_TOS) {
454 int i = ((Integer)value).intValue();
455 if (i < 0 || i > 255)
456 throw new IllegalArgumentException("Invalid IP_TOS value: " + value);
457 setOption(SocketOptions.IP_TOS, value);
458 } else if (name == StandardSocketOptions.TCP_NODELAY) {
459 setOption(SocketOptions.TCP_NODELAY, value);
460 } else if (extendedOptions.isOptionSupported(name)) {
461 extendedOptions.setOption(fd, name, value);
462 } else {
463 throw new AssertionError("unknown option: " + name);
464 }
465 }
466
467 @Override
468 @SuppressWarnings("unchecked")
469 protected <T> T getOption(SocketOption<T> name) throws IOException {
470 Objects.requireNonNull(name);
471 if (!supportedOptions().contains(name))
472 throw new UnsupportedOperationException("'" + name + "' not supported");
473
474 if (isClosedOrPending())
475 throw new SocketException("Socket closed");
476
477 if (name == StandardSocketOptions.SO_KEEPALIVE) {
478 return (T)getOption(SocketOptions.SO_KEEPALIVE);
479 } else if (name == StandardSocketOptions.SO_SNDBUF) {
480 return (T)getOption(SocketOptions.SO_SNDBUF);
481 } else if (name == StandardSocketOptions.SO_RCVBUF) {
482 return (T)getOption(SocketOptions.SO_RCVBUF);
483 } else if (name == StandardSocketOptions.SO_REUSEADDR) {
484 return (T)getOption(SocketOptions.SO_REUSEADDR);
485 } else if (name == StandardSocketOptions.SO_REUSEPORT) {
486 return (T)getOption(SocketOptions.SO_REUSEPORT);
487 } else if (name == StandardSocketOptions.SO_LINGER) {
488 Object value = getOption(SocketOptions.SO_LINGER);
489 if (value instanceof Boolean) {
490 assert ((Boolean)value).booleanValue() == false;
491 value = -1;
492 }
493 return (T)value;
494 } else if (name == StandardSocketOptions.IP_TOS) {
495 return (T)getOption(SocketOptions.IP_TOS);
496 } else if (name == StandardSocketOptions.TCP_NODELAY) {
497 return (T)getOption(SocketOptions.TCP_NODELAY);
498 } else if (extendedOptions.isOptionSupported(name)) {
499 return (T) extendedOptions.getOption(fd, name);
500 } else {
501 throw new AssertionError("unknown option: " + name);
502 }
503 }
504
505 /**
506 * The workhorse of the connection operation. Tries several times to
507 * establish a connection to the given <host, port>. If unsuccessful,
508 * throws an IOException indicating what went wrong.
509 */
510
511 synchronized void doConnect(InetAddress address, int port, int timeout) throws IOException {
512 synchronized (fdLock) {
513 if (!closePending && !isBound) {
514 NetHooks.beforeTcpConnect(fd, address, port);
515 }
516 }
517 try {
518 acquireFD();
519 try {
520 socketConnect(address, port, timeout);
521 /* socket may have been closed during poll/select */
522 synchronized (fdLock) {
523 if (closePending) {
524 throw new SocketException ("Socket closed");
525 }
526 }
527 } finally {
528 releaseFD();
529 }
530 } catch (IOException e) {
531 close();
532 throw SocketExceptions.of(e, new InetSocketAddress(address, port));
533 }
534 }
535
536 /**
537 * Binds the socket to the specified address of the specified local port.
538 * @param address the address
539 * @param lport the port
540 */
541 protected synchronized void bind(InetAddress address, int lport)
542 throws IOException
543 {
544 synchronized (fdLock) {
545 if (!closePending && !isBound) {
546 NetHooks.beforeTcpBind(fd, address, lport);
547 }
548 }
549 socketBind(address, lport);
550 isBound = true;
551 }
552
553 /**
554 * Listens, for a specified amount of time, for connections.
555 * @param count the amount of time to listen for connections
556 */
557 protected synchronized void listen(int count) throws IOException {
558 socketListen(count);
559 }
560
561 /**
562 * Accepts connections.
563 * @param si the socket impl
564 */
565 protected void accept(SocketImpl si) throws IOException {
566 si.fd = new FileDescriptor();
567 acquireFD();
568 try {
569 socketAccept(si);
570 } finally {
571 releaseFD();
572 }
573 SocketCleanable.register(si.fd);
574 }
575
576 /**
577 * Gets an InputStream for this socket.
578 */
579 protected synchronized InputStream getInputStream() throws IOException {
580 synchronized (fdLock) {
581 if (isClosedOrPending())
582 throw new IOException("Socket Closed");
583 if (shut_rd)
584 throw new IOException("Socket input is shutdown");
585 if (socketInputStream == null) {
586 PrivilegedExceptionAction<SocketInputStream> pa = () -> new SocketInputStream(this);
587 try {
588 socketInputStream = AccessController.doPrivileged(pa);
589 } catch (PrivilegedActionException e) {
590 throw (IOException) e.getCause();
591 }
592 }
593 }
594 return socketInputStream;
595 }
596
597 void setInputStream(SocketInputStream in) {
598 socketInputStream = in;
599 }
600
601 /**
602 * Gets an OutputStream for this socket.
603 */
604 protected synchronized OutputStream getOutputStream() throws IOException {
605 synchronized (fdLock) {
606 if (isClosedOrPending())
607 throw new IOException("Socket Closed");
608 if (shut_wr)
609 throw new IOException("Socket output is shutdown");
610 if (socketOutputStream == null) {
611 PrivilegedExceptionAction<SocketOutputStream> pa = () -> new SocketOutputStream(this);
612 try {
613 socketOutputStream = AccessController.doPrivileged(pa);
614 } catch (PrivilegedActionException e) {
615 throw (IOException) e.getCause();
616 }
617 }
618 }
619 return socketOutputStream;
620 }
621
622 void setFileDescriptor(FileDescriptor fd) {
623 this.fd = fd;
624 }
625
626 void setAddress(InetAddress address) {
627 this.address = address;
628 }
629
630 void setPort(int port) {
631 this.port = port;
632 }
633
634 void setLocalPort(int localport) {
635 this.localport = localport;
636 }
637
638 /**
639 * Returns the number of bytes that can be read without blocking.
640 */
641 protected synchronized int available() throws IOException {
642 if (isClosedOrPending()) {
643 throw new IOException("Stream closed.");
644 }
645
646 /*
647 * If connection has been reset or shut down for input, then return 0
648 * to indicate there are no buffered bytes.
649 */
650 if (isConnectionReset() || shut_rd) {
651 return 0;
652 }
653
654 /*
655 * If no bytes available and we were previously notified
656 * of a connection reset then we move to the reset state.
657 *
658 * If are notified of a connection reset then check
659 * again if there are bytes buffered on the socket.
660 */
661 int n = 0;
662 try {
663 n = socketAvailable();
664 } catch (ConnectionResetException exc1) {
665 setConnectionReset();
666 }
667 return n;
668 }
669
670 /**
671 * Closes the socket.
672 */
673 protected void close() throws IOException {
674 synchronized(fdLock) {
675 if (fd != null) {
676 if (!stream) {
677 ResourceManager.afterUdpClose();
678 }
679 if (fdUseCount == 0) {
680 if (closePending) {
681 return;
682 }
683 closePending = true;
684 /*
685 * We close the FileDescriptor in two-steps - first the
686 * "pre-close" which closes the socket but doesn't
687 * release the underlying file descriptor. This operation
688 * may be lengthy due to untransmitted data and a long
689 * linger interval. Once the pre-close is done we do the
690 * actual socket to release the fd.
691 */
692 try {
693 socketPreClose();
694 } finally {
695 socketClose();
696 }
697 fd = null;
698 return;
699 } else {
700 /*
701 * If a thread has acquired the fd and a close
702 * isn't pending then use a deferred close.
703 * Also decrement fdUseCount to signal the last
704 * thread that releases the fd to close it.
705 */
706 if (!closePending) {
707 closePending = true;
708 fdUseCount--;
709 socketPreClose();
710 }
711 }
712 }
713 }
714 }
715
716 void reset() {
717 throw new InternalError("should not get here");
718 }
719
720 /**
721 * Shutdown read-half of the socket connection;
722 */
723 protected void shutdownInput() throws IOException {
724 if (fd != null) {
725 socketShutdown(SHUT_RD);
726 if (socketInputStream != null) {
727 socketInputStream.setEOF(true);
728 }
729 shut_rd = true;
730 }
731 }
732
733 /**
734 * Shutdown write-half of the socket connection;
735 */
736 protected void shutdownOutput() throws IOException {
737 if (fd != null) {
738 socketShutdown(SHUT_WR);
739 shut_wr = true;
740 }
741 }
742
743 protected boolean supportsUrgentData () {
744 return true;
745 }
746
747 protected void sendUrgentData (int data) throws IOException {
748 if (fd == null) {
749 throw new IOException("Socket Closed");
750 }
751 socketSendUrgentData (data);
752 }
753
754 /*
755 * "Acquires" and returns the FileDescriptor for this impl
756 *
757 * A corresponding releaseFD is required to "release" the
758 * FileDescriptor.
759 */
760 FileDescriptor acquireFD() {
761 synchronized (fdLock) {
762 fdUseCount++;
763 return fd;
764 }
765 }
766
767 /*
768 * "Release" the FileDescriptor for this impl.
769 *
770 * If the use count goes to -1 then the socket is closed.
771 */
772 void releaseFD() {
773 synchronized (fdLock) {
774 fdUseCount--;
775 if (fdUseCount == -1) {
776 if (fd != null) {
777 try {
778 socketClose();
779 } catch (IOException e) {
780 } finally {
781 fd = null;
782 }
783 }
784 }
785 }
786 }
787
788 boolean isConnectionReset() {
789 return connectionReset;
790 }
791
792 void setConnectionReset() {
793 connectionReset = true;
794 }
795
796 /*
797 * Return true if already closed or close is pending
798 */
799 public boolean isClosedOrPending() {
800 /*
801 * Lock on fdLock to ensure that we wait if a
802 * close is in progress.
803 */
804 synchronized (fdLock) {
805 if (closePending || (fd == null)) {
806 return true;
807 } else {
808 return false;
809 }
810 }
811 }
812
813 /*
814 * Return the current value of SO_TIMEOUT
815 */
816 public int getTimeout() {
817 return timeout;
818 }
819
820 /*
821 * "Pre-close" a socket by dup'ing the file descriptor - this enables
822 * the socket to be closed without releasing the file descriptor.
823 */
824 private void socketPreClose() throws IOException {
825 socketClose0(true);
826 }
827
828 /*
829 * Close the socket (and release the file descriptor).
830 */
831 protected void socketClose() throws IOException {
832 SocketCleanable.unregister(fd);
833 socketClose0(false);
834 }
835
836 abstract void socketCreate(boolean stream) throws IOException;
837 abstract void socketConnect(InetAddress address, int port, int timeout)
838 throws IOException;
839 abstract void socketBind(InetAddress address, int port)
840 throws IOException;
841 abstract void socketListen(int count)
842 throws IOException;
843 abstract void socketAccept(SocketImpl s)
844 throws IOException;
845 abstract int socketAvailable()
846 throws IOException;
847 abstract void socketClose0(boolean useDeferredClose)
848 throws IOException;
849 abstract void socketShutdown(int howto)
850 throws IOException;
851 abstract void socketSetOption(int cmd, boolean on, Object value)
852 throws SocketException;
853 abstract int socketGetOption(int opt, Object iaContainerObj) throws SocketException;
854 abstract void socketSendUrgentData(int data)
855 throws IOException;
856
857 public static final int SHUT_RD = 0;
858 public static final int SHUT_WR = 1;
859
860 private static native boolean isReusePortAvailable0();
861 }