/*
 * Copyright (c) 1999, 2003, 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 com.sun.tools.jdi;

import com.sun.jdi.*;
import com.sun.jdi.connect.*;
import com.sun.jdi.connect.spi.*;

import java.io.IOException;
import java.util.Map;
import java.util.ResourceBundle;

class SharedMemoryTransportService extends TransportService {
    private ResourceBundle messages = null;

    
The listener returned by startListening
/** * The listener returned by startListening */
static class SharedMemoryListenKey extends ListenKey { long id; String name; SharedMemoryListenKey(long id, String name) { this.id = id; this.name = name; } long id() { return id; } void setId(long id) { this.id = id; } public String address() { return name; } public String toString() { return address(); } } SharedMemoryTransportService() { System.loadLibrary("dt_shmem"); initialize(); } public String name() { return "SharedMemory"; } public String defaultAddress() { return "javadebug"; }
Return localized description of this transport service
/** * Return localized description of this transport service */
public String description() { synchronized (this) { if (messages == null) { messages = ResourceBundle.getBundle("com.sun.tools.jdi.resources.jdi"); } } return messages.getString("memory_transportservice.description"); } public Capabilities capabilities() { return new SharedMemoryTransportServiceCapabilities(); } private native void initialize(); private native long startListening0(String address) throws IOException; private native long attach0(String address, long attachTimeout) throws IOException; private native void stopListening0(long id) throws IOException; private native long accept0(long id, long acceptTimeout) throws IOException; private native String name(long id) throws IOException; public Connection attach(String address, long attachTimeout, long handshakeTimeout) throws IOException { if (address == null) { throw new NullPointerException("address is null"); } long id = attach0(address, attachTimeout); SharedMemoryConnection conn = new SharedMemoryConnection(id); conn.handshake(handshakeTimeout); return conn; } public TransportService.ListenKey startListening(String address) throws IOException { if (address == null || address.length() == 0) { address = defaultAddress(); } long id = startListening0(address); return new SharedMemoryListenKey(id, name(id)); } public ListenKey startListening() throws IOException { return startListening(null); } public void stopListening(ListenKey listener) throws IOException { if (!(listener instanceof SharedMemoryListenKey)) { throw new IllegalArgumentException("Invalid listener"); } long id; SharedMemoryListenKey key = (SharedMemoryListenKey)listener; synchronized (key) { id = key.id(); if (id == 0) { throw new IllegalArgumentException("Invalid listener"); } // invalidate the id key.setId(0); } stopListening0(id); } public Connection accept(ListenKey listener, long acceptTimeout, long handshakeTimeout) throws IOException { if (!(listener instanceof SharedMemoryListenKey)) { throw new IllegalArgumentException("Invalid listener"); } long transportId; SharedMemoryListenKey key = (SharedMemoryListenKey)listener; synchronized (key) { transportId = key.id(); if (transportId == 0) { throw new IllegalArgumentException("Invalid listener"); } } // in theory another thread could call stopListening before // accept0 is called. In that case accept0 will try to accept // with an invalid "transport id" - this should result in an // IOException. long connectId = accept0(transportId, acceptTimeout); SharedMemoryConnection conn = new SharedMemoryConnection(connectId); conn.handshake(handshakeTimeout); return conn; } } class SharedMemoryConnection extends Connection { private long id; private Object receiveLock = new Object(); private Object sendLock = new Object(); private Object closeLock = new Object(); private boolean closed = false; private native byte receiveByte0(long id) throws IOException; private native void sendByte0(long id, byte b) throws IOException; private native void close0(long id); private native byte[] receivePacket0(long id)throws IOException; private native void sendPacket0(long id, byte b[]) throws IOException; // handshake with the target VM void handshake(long handshakeTimeout) throws IOException { byte[] hello = "JDWP-Handshake".getBytes("UTF-8"); for (int i=0; i<hello.length; i++) { sendByte0(id, hello[i]); } for (int i=0; i<hello.length; i++) { byte b = receiveByte0(id); if (b != hello[i]) { throw new IOException("handshake failed - unrecognized message from target VM"); } } } SharedMemoryConnection(long id) throws IOException { this.id = id; } public void close() { synchronized (closeLock) { if (!closed) { close0(id); closed = true; } } } public boolean isOpen() { synchronized (closeLock) { return !closed; } } public byte[] readPacket() throws IOException { if (!isOpen()) { throw new ClosedConnectionException("Connection closed"); } byte b[]; try { // only one thread may be reading at a time synchronized (receiveLock) { b = receivePacket0(id); } } catch (IOException ioe) { if (!isOpen()) { throw new ClosedConnectionException("Connection closed"); } else { throw ioe; } } return b; } public void writePacket(byte b[]) throws IOException { if (!isOpen()) { throw new ClosedConnectionException("Connection closed"); } /* * Check the packet size */ if (b.length < 11) { throw new IllegalArgumentException("packet is insufficient size"); } int b0 = b[0] & 0xff; int b1 = b[1] & 0xff; int b2 = b[2] & 0xff; int b3 = b[3] & 0xff; int len = ((b0 << 24) | (b1 << 16) | (b2 << 8) | (b3 << 0)); if (len < 11) { throw new IllegalArgumentException("packet is insufficient size"); } /* * Check that the byte array contains the complete packet */ if (len > b.length) { throw new IllegalArgumentException("length mis-match"); } try { // only one thread may be writing at a time synchronized(sendLock) { sendPacket0(id, b); } } catch (IOException ioe) { if (!isOpen()) { throw new ClosedConnectionException("Connection closed"); } else { throw ioe; } } } } class SharedMemoryTransportServiceCapabilities extends TransportService.Capabilities { public boolean supportsMultipleConnections() { return false; } public boolean supportsAttachTimeout() { return true; } public boolean supportsAcceptTimeout() { return true; } public boolean supportsHandshakeTimeout() { return false; } }