--- a/jdk/src/java.rmi/share/classes/sun/rmi/transport/tcp/ConnectionMultiplexer.java Sun Sep 03 19:31:11 2017 +0530
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,449 +0,0 @@
-/*
- * Copyright (c) 1996, 2017, 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.rmi.transport.tcp;
-
-import java.io.*;
-import java.util.*;
-import java.rmi.server.LogStream;
-import java.security.PrivilegedAction;
-
-import sun.rmi.runtime.Log;
-
-/**
- * ConnectionMultiplexer manages the transparent multiplexing of
- * multiple virtual connections from one endpoint to another through
- * one given real connection to that endpoint. The input and output
- * streams for the underlying real connection must be supplied.
- * A callback object is also supplied to be informed of new virtual
- * connections opened by the remote endpoint. After creation, the
- * run() method must be called in a thread created for demultiplexing
- * the connections. The openConnection() method is called to
- * initiate a virtual connection from this endpoint.
- *
- * @author Peter Jones
- */
-@SuppressWarnings("deprecation")
-final class ConnectionMultiplexer {
-
- /** "multiplex" log level */
- static int logLevel = LogStream.parseLevel(getLogLevel());
-
- private static String getLogLevel() {
- return java.security.AccessController.doPrivileged(
- (PrivilegedAction<String>) () -> System.getProperty("sun.rmi.transport.tcp.multiplex.logLevel"));
- }
-
- /* multiplex system log */
- static final Log multiplexLog =
- Log.getLog("sun.rmi.transport.tcp.multiplex",
- "multiplex", ConnectionMultiplexer.logLevel);
-
- /** multiplexing protocol operation codes */
- private final static int OPEN = 0xE1;
- private final static int CLOSE = 0xE2;
- private final static int CLOSEACK = 0xE3;
- private final static int REQUEST = 0xE4;
- private final static int TRANSMIT = 0xE5;
-
- /** object to notify for new connections from remote endpoint */
- private TCPChannel channel;
-
- /** input stream for underlying single connection */
- private InputStream in;
-
- /** output stream for underlying single connection */
- private OutputStream out;
-
- /** true if underlying connection originated from this endpoint
- (used for generating unique connection IDs) */
- private boolean orig;
-
- /** layered stream for reading formatted data from underlying connection */
- private DataInputStream dataIn;
-
- /** layered stream for writing formatted data to underlying connection */
- private DataOutputStream dataOut;
-
- /** table holding currently open connection IDs and related info */
- private Hashtable<Integer, MultiplexConnectionInfo> connectionTable = new Hashtable<>(7);
-
- /** number of currently open connections */
- private int numConnections = 0;
-
- /** maximum allowed open connections */
- private final static int maxConnections = 256;
-
- /** ID of last connection opened */
- private int lastID = 0x1001;
-
- /** true if this mechanism is still alive */
- private boolean alive = true;
-
- /**
- * Create a new ConnectionMultiplexer using the given underlying
- * input/output stream pair. The run method must be called
- * (possibly on a new thread) to handle the demultiplexing.
- * @param channel object to notify when new connection is received
- * @param in input stream of underlying connection
- * @param out output stream of underlying connection
- * @param orig true if this endpoint intiated the underlying
- * connection (needs to be set differently at both ends)
- */
- public ConnectionMultiplexer(
- TCPChannel channel,
- InputStream in,
- OutputStream out,
- boolean orig)
- {
- this.channel = channel;
- this.in = in;
- this.out = out;
- this.orig = orig;
-
- dataIn = new DataInputStream(in);
- dataOut = new DataOutputStream(out);
- }
-
- /**
- * Process multiplexing protocol received from underlying connection.
- */
- public void run() throws IOException
- {
- try {
- int op, id, length;
- MultiplexConnectionInfo info;
-
- while (true) {
-
- // read next op code from remote endpoint
- op = dataIn.readUnsignedByte();
- switch (op) {
-
- // remote endpoint initiating new connection
- case OPEN:
- id = dataIn.readUnsignedShort();
-
- if (multiplexLog.isLoggable(Log.VERBOSE)) {
- multiplexLog.log(Log.VERBOSE, "operation OPEN " + id);
- }
-
- info = connectionTable.get(id);
- if (info != null)
- throw new IOException(
- "OPEN: Connection ID already exists");
- info = new MultiplexConnectionInfo(id);
- info.in = new MultiplexInputStream(this, info, 2048);
- info.out = new MultiplexOutputStream(this, info, 2048);
- synchronized (connectionTable) {
- connectionTable.put(id, info);
- ++ numConnections;
- }
- sun.rmi.transport.Connection conn;
- conn = new TCPConnection(channel, info.in, info.out);
- channel.acceptMultiplexConnection(conn);
- break;
-
- // remote endpoint closing connection
- case CLOSE:
- id = dataIn.readUnsignedShort();
-
- if (multiplexLog.isLoggable(Log.VERBOSE)) {
- multiplexLog.log(Log.VERBOSE, "operation CLOSE " + id);
- }
-
- info = connectionTable.get(id);
- if (info == null)
- throw new IOException(
- "CLOSE: Invalid connection ID");
- info.in.disconnect();
- info.out.disconnect();
- if (!info.closed)
- sendCloseAck(info);
- synchronized (connectionTable) {
- connectionTable.remove(id);
- -- numConnections;
- }
- break;
-
- // remote endpoint acknowledging close of connection
- case CLOSEACK:
- id = dataIn.readUnsignedShort();
-
- if (multiplexLog.isLoggable(Log.VERBOSE)) {
- multiplexLog.log(Log.VERBOSE,
- "operation CLOSEACK " + id);
- }
-
- info = connectionTable.get(id);
- if (info == null)
- throw new IOException(
- "CLOSEACK: Invalid connection ID");
- if (!info.closed)
- throw new IOException(
- "CLOSEACK: Connection not closed");
- info.in.disconnect();
- info.out.disconnect();
- synchronized (connectionTable) {
- connectionTable.remove(id);
- -- numConnections;
- }
- break;
-
- // remote endpoint declaring additional bytes receivable
- case REQUEST:
- id = dataIn.readUnsignedShort();
- info = connectionTable.get(id);
- if (info == null)
- throw new IOException(
- "REQUEST: Invalid connection ID");
- length = dataIn.readInt();
-
- if (multiplexLog.isLoggable(Log.VERBOSE)) {
- multiplexLog.log(Log.VERBOSE,
- "operation REQUEST " + id + ": " + length);
- }
-
- info.out.request(length);
- break;
-
- // remote endpoint transmitting data packet
- case TRANSMIT:
- id = dataIn.readUnsignedShort();
- info = connectionTable.get(id);
- if (info == null)
- throw new IOException("SEND: Invalid connection ID");
- length = dataIn.readInt();
-
- if (multiplexLog.isLoggable(Log.VERBOSE)) {
- multiplexLog.log(Log.VERBOSE,
- "operation TRANSMIT " + id + ": " + length);
- }
-
- info.in.receive(length, dataIn);
- break;
-
- default:
- throw new IOException("Invalid operation: " +
- Integer.toHexString(op));
- }
- }
- } finally {
- shutDown();
- }
- }
-
- /**
- * Initiate a new multiplexed connection through the underlying
- * connection.
- */
- public synchronized TCPConnection openConnection() throws IOException
- {
- // generate ID that should not be already used
- // If all possible 32768 IDs are used,
- // this method will block searching for a new ID forever.
- int id;
- do {
- lastID = (++ lastID) & 0x7FFF;
- id = lastID;
-
- // The orig flag (copied to the high bit of the ID) is used
- // to have two distinct ranges to choose IDs from for the
- // two endpoints.
- if (orig)
- id |= 0x8000;
- } while (connectionTable.get(id) != null);
-
- // create multiplexing streams and bookkeeping information
- MultiplexConnectionInfo info = new MultiplexConnectionInfo(id);
- info.in = new MultiplexInputStream(this, info, 2048);
- info.out = new MultiplexOutputStream(this, info, 2048);
-
- // add to connection table if multiplexer has not died
- synchronized (connectionTable) {
- if (!alive)
- throw new IOException("Multiplexer connection dead");
- if (numConnections >= maxConnections)
- throw new IOException("Cannot exceed " + maxConnections +
- " simultaneous multiplexed connections");
- connectionTable.put(id, info);
- ++ numConnections;
- }
-
- // inform remote endpoint of new connection
- synchronized (dataOut) {
- try {
- dataOut.writeByte(OPEN);
- dataOut.writeShort(id);
- dataOut.flush();
- } catch (IOException e) {
- multiplexLog.log(Log.BRIEF, "exception: ", e);
-
- shutDown();
- throw e;
- }
- }
-
- return new TCPConnection(channel, info.in, info.out);
- }
-
- /**
- * Shut down all connections and clean up.
- */
- public void shutDown()
- {
- // inform all associated streams
- synchronized (connectionTable) {
- // return if multiplexer already officially dead
- if (!alive)
- return;
- alive = false;
-
- Enumeration<MultiplexConnectionInfo> enum_ =
- connectionTable.elements();
- while (enum_.hasMoreElements()) {
- MultiplexConnectionInfo info = enum_.nextElement();
- info.in.disconnect();
- info.out.disconnect();
- }
- connectionTable.clear();
- numConnections = 0;
- }
-
- // close underlying connection, if possible (and not already done)
- try {
- in.close();
- } catch (IOException e) {
- }
- try {
- out.close();
- } catch (IOException e) {
- }
- }
-
- /**
- * Send request for more data on connection to remote endpoint.
- * @param info connection information structure
- * @param len number of more bytes that can be received
- */
- void sendRequest(MultiplexConnectionInfo info, int len) throws IOException
- {
- synchronized (dataOut) {
- if (alive && !info.closed)
- try {
- dataOut.writeByte(REQUEST);
- dataOut.writeShort(info.id);
- dataOut.writeInt(len);
- dataOut.flush();
- } catch (IOException e) {
- multiplexLog.log(Log.BRIEF, "exception: ", e);
-
- shutDown();
- throw e;
- }
- }
- }
-
- /**
- * Send packet of requested data on connection to remote endpoint.
- * @param info connection information structure
- * @param buf array containing bytes to send
- * @param off offset of first array index of packet
- * @param len number of bytes in packet to send
- */
- void sendTransmit(MultiplexConnectionInfo info,
- byte buf[], int off, int len) throws IOException
- {
- synchronized (dataOut) {
- if (alive && !info.closed)
- try {
- dataOut.writeByte(TRANSMIT);
- dataOut.writeShort(info.id);
- dataOut.writeInt(len);
- dataOut.write(buf, off, len);
- dataOut.flush();
- } catch (IOException e) {
- multiplexLog.log(Log.BRIEF, "exception: ", e);
-
- shutDown();
- throw e;
- }
- }
- }
-
- /**
- * Inform remote endpoint that connection has been closed.
- * @param info connection information structure
- */
- void sendClose(MultiplexConnectionInfo info) throws IOException
- {
- info.out.disconnect();
- synchronized (dataOut) {
- if (alive && !info.closed)
- try {
- dataOut.writeByte(CLOSE);
- dataOut.writeShort(info.id);
- dataOut.flush();
- info.closed = true;
- } catch (IOException e) {
- multiplexLog.log(Log.BRIEF, "exception: ", e);
-
- shutDown();
- throw e;
- }
- }
- }
-
- /**
- * Acknowledge remote endpoint's closing of connection.
- * @param info connection information structure
- */
- void sendCloseAck(MultiplexConnectionInfo info) throws IOException
- {
- synchronized (dataOut) {
- if (alive && !info.closed)
- try {
- dataOut.writeByte(CLOSEACK);
- dataOut.writeShort(info.id);
- dataOut.flush();
- info.closed = true;
- } catch (IOException e) {
- multiplexLog.log(Log.BRIEF, "exception: ", e);
-
- shutDown();
- throw e;
- }
- }
- }
-
- /**
- * Shut down connection upon finalization.
- */
- @SuppressWarnings("deprecation")
- protected void finalize() throws Throwable
- {
- super.finalize();
- shutDown();
- }
-}