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/*
* Copyright (c) 1995, 2007, 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 java.net;
import java.io.FileDescriptor;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.channels.FileChannel;
import static ikvm.internal.Winsock.*;
import static java.net.net_util_md.*;
/**
* This stream extends FileOutputStream to implement a
* SocketOutputStream. Note that this class should <b>NOT</b> be
* public.
*
* @author Jonathan Payne
* @author Arthur van Hoff
* @author Jeroen Frijters
*/
class SocketOutputStream extends FileOutputStream
{
private AbstractPlainSocketImpl impl = null;
private byte temp[] = new byte[1];
private Socket socket = null;
/**
* Creates a new SocketOutputStream. Can only be called
* by a Socket. This method needs to hang on to the owner Socket so
* that the fd will not be closed.
* @param impl the socket output stream inplemented
*/
SocketOutputStream(AbstractPlainSocketImpl impl) throws IOException {
super(impl.getFileDescriptor());
this.impl = impl;
socket = impl.getSocket();
}
/**
* Returns the unique {@link java.nio.channels.FileChannel FileChannel}
* object associated with this file output stream. </p>
*
* The <code>getChannel</code> method of <code>SocketOutputStream</code>
* returns <code>null</code> since it is a socket based stream.</p>
*
* @return the file channel associated with this file output stream
*
* @since 1.4
* @spec JSR-51
*/
public final FileChannel getChannel() {
return null;
}
/**
* Writes to the socket.
* @param fd the FileDescriptor
* @param b the data to be written
* @param off the start offset in the data
* @param len the number of bytes that are written
* @exception IOException If an I/O error has occurred.
*/
private void socketWrite0(FileDescriptor fdObj, byte[] data, int off, int len) throws IOException
{
// [IKVM] this method is a direct port of the native code in openjdk6-b18\jdk\src\windows\native\java\net\SocketOutputStream.c
final int MAX_BUFFER_LEN = 2048;
cli.System.Net.Sockets.Socket fd;
int buflen = 65536; // MAX_HEAP_BUFFER_LEN
int n;
if (IS_NULL(fdObj)) {
throw new SocketException("socket closed");
} else {
fd = fdObj.getSocket();
}
if (IS_NULL(data)) {
throw new NullPointerException("data argument");
}
while(len > 0) {
int loff = 0;
int chunkLen = Math.min(buflen, len);
int llen = chunkLen;
int retry = 0;
while(llen > 0) {
n = send(fd, data, off + loff, llen, 0);
if (n > 0) {
llen -= n;
loff += n;
continue;
}
/*
* Due to a bug in Windows Sockets (observed on NT and Windows
* 2000) it may be necessary to retry the send. The issue is that
* on blocking sockets send/WSASend is supposed to block if there
* is insufficient buffer space available. If there are a large
* number of threads blocked on write due to congestion then it's
* possile to hit the NT/2000 bug whereby send returns WSAENOBUFS.
* The workaround we use is to retry the send. If we have a
* large buffer to send (>2k) then we retry with a maximum of
* 2k buffer. If we hit the issue with <=2k buffer then we backoff
* for 1 second and retry again. We repeat this up to a reasonable
* limit before bailing out and throwing an exception. In load
* conditions we've observed that the send will succeed after 2-3
* attempts but this depends on network buffers associated with
* other sockets draining.
*/
if (WSAGetLastError() == WSAENOBUFS) {
if (llen > MAX_BUFFER_LEN) {
buflen = MAX_BUFFER_LEN;
chunkLen = MAX_BUFFER_LEN;
llen = MAX_BUFFER_LEN;
continue;
}
if (retry >= 30) {
throw new SocketException("No buffer space available - exhausted attempts to queue buffer");
}
cli.System.Threading.Thread.Sleep(1000);
retry++;
continue;
}
/*
* Send failed - can be caused by close or write error.
*/
if (WSAGetLastError() == WSAENOTSOCK) {
throw new SocketException("Socket closed");
} else {
throw NET_ThrowCurrent("socket write error");
}
}
len -= chunkLen;
off += chunkLen;
}
}
/**
* Writes to the socket with appropriate locking of the
* FileDescriptor.
* @param b the data to be written
* @param off the start offset in the data
* @param len the number of bytes that are written
* @exception IOException If an I/O error has occurred.
*/
private void socketWrite(byte b[], int off, int len) throws IOException {
if (len <= 0 || off < 0 || off + len > b.length) {
if (len == 0) {
return;
}
throw new ArrayIndexOutOfBoundsException();
}
FileDescriptor fd = impl.acquireFD();
try {
socketWrite0(fd, b, off, len);
} catch (SocketException se) {
if (se instanceof sun.net.ConnectionResetException) {
impl.setConnectionResetPending();
se = new SocketException("Connection reset");
}
if (impl.isClosedOrPending()) {
throw new SocketException("Socket closed");
} else {
throw se;
}
} finally {
impl.releaseFD();
}
}
/**
* Writes a byte to the socket.
* @param b the data to be written
* @exception IOException If an I/O error has occurred.
*/
public void write(int b) throws IOException {
temp[0] = (byte)b;
socketWrite(temp, 0, 1);
}
/**
* Writes the contents of the buffer <i>b</i> to the socket.
* @param b the data to be written
* @exception SocketException If an I/O error has occurred.
*/
public void write(byte b[]) throws IOException {
socketWrite(b, 0, b.length);
}
/**
* Writes <i>length</i> bytes from buffer <i>b</i> starting at
* offset <i>len</i>.
* @param b the data to be written
* @param off the start offset in the data
* @param len the number of bytes that are written
* @exception SocketException If an I/O error has occurred.
*/
public void write(byte b[], int off, int len) throws IOException {
socketWrite(b, off, len);
}
/**
* Closes the stream.
*/
private boolean closing = false;
public void close() throws IOException {
// Prevent recursion. See BugId 4484411
if (closing)
return;
closing = true;
if (socket != null) {
if (!socket.isClosed())
socket.close();
} else
impl.close();
closing = false;
}
/**
* Overrides finalize, the fd is closed by the Socket.
*/
protected void finalize() {}
}
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