JDK8/Java8源码在线阅读
/*
* Copyright (c) 1995, 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
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*/
package java.net;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.FileDescriptor;
import sun.net.ConnectionResetException;
import sun.net.NetHooks;
import sun.net.ResourceManager;
/**
* Default Socket Implementation. This implementation does
* not implement any security checks.
* Note this class should <b>NOT</b> be public.
*
* @author Steven B. Byrne
*/
abstract class AbstractPlainSocketImpl extends SocketImpl
{
/* instance variable for SO_TIMEOUT */
int timeout; // timeout in millisec
// traffic class
private int trafficClass;
private boolean shut_rd = false;
private boolean shut_wr = false;
private SocketInputStream socketInputStream = null;
private SocketOutputStream socketOutputStream = null;
/* number of threads using the FileDescriptor */
protected int fdUseCount = 0;
/* lock when increment/decrementing fdUseCount */
protected final Object fdLock = new Object();
/* indicates a close is pending on the file descriptor */
protected boolean closePending = false;
/* indicates connection reset state */
private int CONNECTION_NOT_RESET = 0;
private int CONNECTION_RESET_PENDING = 1;
private int CONNECTION_RESET = 2;
private int resetState;
private final Object resetLock = new Object();
/* whether this Socket is a stream (TCP) socket or not (UDP)
*/
protected boolean stream;
/**
* Load net library into runtime.
*/
static {
java.security.AccessController.doPrivileged(
new java.security.PrivilegedAction<Void>() {
public Void run() {
System.loadLibrary("net");
return null;
}
});
}
/**
* Creates a socket with a boolean that specifies whether this
* is a stream socket (true) or an unconnected UDP socket (false).
*/
protected synchronized void create(boolean stream) throws IOException {
this.stream = stream;
if (!stream) {
ResourceManager.beforeUdpCreate();
// only create the fd after we know we will be able to create the socket
fd = new FileDescriptor();
try {
socketCreate(false);
} catch (IOException ioe) {
ResourceManager.afterUdpClose();
fd = null;
throw ioe;
}
} else {
fd = new FileDescriptor();
socketCreate(true);
}
if (socket != null)
socket.setCreated();
if (serverSocket != null)
serverSocket.setCreated();
}
/**
* Creates a socket and connects it to the specified port on
* the specified host.
* @param host the specified host
* @param port the specified port
*/
protected void connect(String host, int port)
throws UnknownHostException, IOException
{
boolean connected = false;
try {
InetAddress address = InetAddress.getByName(host);
this.port = port;
this.address = address;
connectToAddress(address, port, timeout);
connected = true;
} finally {
if (!connected) {
try {
close();
} catch (IOException ioe) {
/* Do nothing. If connect threw an exception then
it will be passed up the call stack */
}
}
}
}
/**
* Creates a socket and connects it to the specified address on
* the specified port.
* @param address the address
* @param port the specified port
*/
protected void connect(InetAddress address, int port) throws IOException {
this.port = port;
this.address = address;
try {
connectToAddress(address, port, timeout);
return;
} catch (IOException e) {
// everything failed
close();
throw e;
}
}
/**
* Creates a socket and connects it to the specified address on
* the specified port.
* @param address the address
* @param timeout the timeout value in milliseconds, or zero for no timeout.
* @throws IOException if connection fails
* @throws IllegalArgumentException if address is null or is a
* SocketAddress subclass not supported by this socket
* @since 1.4
*/
protected void connect(SocketAddress address, int timeout)
throws IOException {
boolean connected = false;
try {
if (address == null || !(address instanceof InetSocketAddress))
throw new IllegalArgumentException("unsupported address type");
InetSocketAddress addr = (InetSocketAddress) address;
if (addr.isUnresolved())
throw new UnknownHostException(addr.getHostName());
this.port = addr.getPort();
this.address = addr.getAddress();
connectToAddress(this.address, port, timeout);
connected = true;
} finally {
if (!connected) {
try {
close();
} catch (IOException ioe) {
/* Do nothing. If connect threw an exception then
it will be passed up the call stack */
}
}
}
}
private void connectToAddress(InetAddress address, int port, int timeout) throws IOException {
if (address.isAnyLocalAddress()) {
doConnect(InetAddress.getLocalHost(), port, timeout);
} else {
doConnect(address, port, timeout);
}
}
public void setOption(int opt, Object val) throws SocketException {
if (isClosedOrPending()) {
throw new SocketException("Socket Closed");
}
boolean on = true;
switch (opt) {
/* check type safety b4 going native. These should never
* fail, since only java.Socket* has access to
* PlainSocketImpl.setOption().
*/
case SO_LINGER:
if (val == null || (!(val instanceof Integer) && !(val instanceof Boolean)))
throw new SocketException("Bad parameter for option");
if (val instanceof Boolean) {
/* true only if disabling - enabling should be Integer */
on = false;
}
break;
case SO_TIMEOUT:
if (val == null || (!(val instanceof Integer)))
throw new SocketException("Bad parameter for SO_TIMEOUT");
int tmp = ((Integer) val).intValue();
if (tmp < 0)
throw new IllegalArgumentException("timeout < 0");
timeout = tmp;
break;
case IP_TOS:
if (val == null || !(val instanceof Integer)) {
throw new SocketException("bad argument for IP_TOS");
}
trafficClass = ((Integer)val).intValue();
break;
case SO_BINDADDR:
throw new SocketException("Cannot re-bind socket");
case TCP_NODELAY:
if (val == null || !(val instanceof Boolean))
throw new SocketException("bad parameter for TCP_NODELAY");
on = ((Boolean)val).booleanValue();
break;
case SO_SNDBUF:
case SO_RCVBUF:
if (val == null || !(val instanceof Integer) ||
!(((Integer)val).intValue() > 0)) {
throw new SocketException("bad parameter for SO_SNDBUF " +
"or SO_RCVBUF");
}
break;
case SO_KEEPALIVE:
if (val == null || !(val instanceof Boolean))
throw new SocketException("bad parameter for SO_KEEPALIVE");
on = ((Boolean)val).booleanValue();
break;
case SO_OOBINLINE:
if (val == null || !(val instanceof Boolean))
throw new SocketException("bad parameter for SO_OOBINLINE");
on = ((Boolean)val).booleanValue();
break;
case SO_REUSEADDR:
if (val == null || !(val instanceof Boolean))
throw new SocketException("bad parameter for SO_REUSEADDR");
on = ((Boolean)val).booleanValue();
break;
default:
throw new SocketException("unrecognized TCP option: " + opt);
}
socketSetOption(opt, on, val);
}
public Object getOption(int opt) throws SocketException {
if (isClosedOrPending()) {
throw new SocketException("Socket Closed");
}
if (opt == SO_TIMEOUT) {
return new Integer(timeout);
}
int ret = 0;
/*
* The native socketGetOption() knows about 3 options.
* The 32 bit value it returns will be interpreted according
* to what we're asking. A return of -1 means it understands
* the option but its turned off. It will raise a SocketException
* if "opt" isn't one it understands.
*/
switch (opt) {
case TCP_NODELAY:
ret = socketGetOption(opt, null);
return Boolean.valueOf(ret != -1);
case SO_OOBINLINE:
ret = socketGetOption(opt, null);
return Boolean.valueOf(ret != -1);
case SO_LINGER:
ret = socketGetOption(opt, null);
return (ret == -1) ? Boolean.FALSE: (Object)(new Integer(ret));
case SO_REUSEADDR:
ret = socketGetOption(opt, null);
return Boolean.valueOf(ret != -1);
case SO_BINDADDR:
InetAddressContainer in = new InetAddressContainer();
ret = socketGetOption(opt, in);
return in.addr;
case SO_SNDBUF:
case SO_RCVBUF:
ret = socketGetOption(opt, null);
return new Integer(ret);
case IP_TOS:
ret = socketGetOption(opt, null);
if (ret == -1) { // ipv6 tos
return new Integer(trafficClass);
} else {
return new Integer(ret);
}
case SO_KEEPALIVE:
ret = socketGetOption(opt, null);
return Boolean.valueOf(ret != -1);
// should never get here
default:
return null;
}
}
/**
* The workhorse of the connection operation. Tries several times to
* establish a connection to the given <host, port>. If unsuccessful,
* throws an IOException indicating what went wrong.
*/
synchronized void doConnect(InetAddress address, int port, int timeout) throws IOException {
synchronized (fdLock) {
if (!closePending && (socket == null || !socket.isBound())) {
NetHooks.beforeTcpConnect(fd, address, port);
}
}
try {
acquireFD();
try {
socketConnect(address, port, timeout);
/* socket may have been closed during poll/select */
synchronized (fdLock) {
if (closePending) {
throw new SocketException ("Socket closed");
}
}
// If we have a ref. to the Socket, then sets the flags
// created, bound & connected to true.
// This is normally done in Socket.connect() but some
// subclasses of Socket may call impl.connect() directly!
if (socket != null) {
socket.setBound();
socket.setConnected();
}
} finally {
releaseFD();
}
} catch (IOException e) {
close();
throw e;
}
}
/**
* Binds the socket to the specified address of the specified local port.
* @param address the address
* @param lport the port
*/
protected synchronized void bind(InetAddress address, int lport)
throws IOException
{
synchronized (fdLock) {
if (!closePending && (socket == null || !socket.isBound())) {
NetHooks.beforeTcpBind(fd, address, lport);
}
}
socketBind(address, lport);
if (socket != null)
socket.setBound();
if (serverSocket != null)
serverSocket.setBound();
}
/**
* Listens, for a specified amount of time, for connections.
* @param count the amount of time to listen for connections
*/
protected synchronized void listen(int count) throws IOException {
socketListen(count);
}
/**
* Accepts connections.
* @param s the connection
*/
protected void accept(SocketImpl s) throws IOException {
acquireFD();
try {
socketAccept(s);
} finally {
releaseFD();
}
}
/**
* Gets an InputStream for this socket.
*/
protected synchronized InputStream getInputStream() throws IOException {
synchronized (fdLock) {
if (isClosedOrPending())
throw new IOException("Socket Closed");
if (shut_rd)
throw new IOException("Socket input is shutdown");
if (socketInputStream == null)
socketInputStream = new SocketInputStream(this);
}
return socketInputStream;
}
void setInputStream(SocketInputStream in) {
socketInputStream = in;
}
/**
* Gets an OutputStream for this socket.
*/
protected synchronized OutputStream getOutputStream() throws IOException {
synchronized (fdLock) {
if (isClosedOrPending())
throw new IOException("Socket Closed");
if (shut_wr)
throw new IOException("Socket output is shutdown");
if (socketOutputStream == null)
socketOutputStream = new SocketOutputStream(this);
}
return socketOutputStream;
}
void setFileDescriptor(FileDescriptor fd) {
this.fd = fd;
}
void setAddress(InetAddress address) {
this.address = address;
}
void setPort(int port) {
this.port = port;
}
void setLocalPort(int localport) {
this.localport = localport;
}
/**
* Returns the number of bytes that can be read without blocking.
*/
protected synchronized int available() throws IOException {
if (isClosedOrPending()) {
throw new IOException("Stream closed.");
}
/*
* If connection has been reset or shut down for input, then return 0
* to indicate there are no buffered bytes.
*/
if (isConnectionReset() || shut_rd) {
return 0;
}
/*
* If no bytes available and we were previously notified
* of a connection reset then we move to the reset state.
*
* If are notified of a connection reset then check
* again if there are bytes buffered on the socket.
*/
int n = 0;
try {
n = socketAvailable();
if (n == 0 && isConnectionResetPending()) {
setConnectionReset();
}
} catch (ConnectionResetException exc1) {
setConnectionResetPending();
try {
n = socketAvailable();
if (n == 0) {
setConnectionReset();
}
} catch (ConnectionResetException exc2) {
}
}
return n;
}
/**
* Closes the socket.
*/
protected void close() throws IOException {
synchronized(fdLock) {
if (fd != null) {
if (!stream) {
ResourceManager.afterUdpClose();
}
if (fdUseCount == 0) {
if (closePending) {
return;
}
closePending = true;
/*
* We close the FileDescriptor in two-steps - first the
* "pre-close" which closes the socket but doesn't
* release the underlying file descriptor. This operation
* may be lengthy due to untransmitted data and a long
* linger interval. Once the pre-close is done we do the
* actual socket to release the fd.
*/
try {
socketPreClose();
} finally {
socketClose();
}
fd = null;
return;
} else {
/*
* If a thread has acquired the fd and a close
* isn't pending then use a deferred close.
* Also decrement fdUseCount to signal the last
* thread that releases the fd to close it.
*/
if (!closePending) {
closePending = true;
fdUseCount--;
socketPreClose();
}
}
}
}
}
void reset() throws IOException {
if (fd != null) {
socketClose();
}
fd = null;
super.reset();
}
/**
* Shutdown read-half of the socket connection;
*/
protected void shutdownInput() throws IOException {
if (fd != null) {
socketShutdown(SHUT_RD);
if (socketInputStream != null) {
socketInputStream.setEOF(true);
}
shut_rd = true;
}
}
/**
* Shutdown write-half of the socket connection;
*/
protected void shutdownOutput() throws IOException {
if (fd != null) {
socketShutdown(SHUT_WR);
shut_wr = true;
}
}
protected boolean supportsUrgentData () {
return true;
}
protected void sendUrgentData (int data) throws IOException {
if (fd == null) {
throw new IOException("Socket Closed");
}
socketSendUrgentData (data);
}
/**
* Cleans up if the user forgets to close it.
*/
protected void finalize() throws IOException {
close();
}
/*
* "Acquires" and returns the FileDescriptor for this impl
*
* A corresponding releaseFD is required to "release" the
* FileDescriptor.
*/
FileDescriptor acquireFD() {
synchronized (fdLock) {
fdUseCount++;
return fd;
}
}
/*
* "Release" the FileDescriptor for this impl.
*
* If the use count goes to -1 then the socket is closed.
*/
void releaseFD() {
synchronized (fdLock) {
fdUseCount--;
if (fdUseCount == -1) {
if (fd != null) {
try {
socketClose();
} catch (IOException e) {
} finally {
fd = null;
}
}
}
}
}
public boolean isConnectionReset() {
synchronized (resetLock) {
return (resetState == CONNECTION_RESET);
}
}
public boolean isConnectionResetPending() {
synchronized (resetLock) {
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