J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2003-2006 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package com.sun.jdi.connect.spi; |
| 27 | |
| 28 | import java.io.IOException; |
| 29 | import com.sun.jdi.connect.TransportTimeoutException; |
| 30 | |
| 31 | /** |
| 32 | * A transport service for connections between a debugger and |
| 33 | * a target VM. |
| 34 | * |
| 35 | * <p> A transport service is a concrete subclass of this class |
| 36 | * that has a zero-argument constructor and implements the abstract |
| 37 | * methods specified below. It is the underlying service |
| 38 | * used by a {@link com.sun.jdi.connect.Transport} for |
| 39 | * connections between a debugger and a target VM. |
| 40 | * |
| 41 | * <p> A transport service is used to establish a connection |
| 42 | * between a debugger and a target VM, and to transport Java |
| 43 | * Debug Wire Protocol (JDWP) packets over an underlying |
| 44 | * communication protocol. In essence a transport service |
| 45 | * implementation binds JDWP (as specified in the |
| 46 | * <a href="../../../../../../../../../technotes/guides/jpda/jdwp-spec.html"> |
| 47 | * JDWP specification</a>) to an underlying communication |
| 48 | * protocol. A transport service implementation provides |
| 49 | * a reliable JDWP packet transportation service. JDWP |
| 50 | * packets are sent to and from the target VM without duplication |
| 51 | * or data loss. A transport service implementation may be |
| 52 | * based on an underlying communication protocol that is |
| 53 | * reliable or unreliable. If the underlying communication |
| 54 | * protocol is reliable then the transport service implementation |
| 55 | * may be relatively simple and may only need to transport JDWP |
| 56 | * packets as payloads of the underlying communication |
| 57 | * protocol. In the case of an unreliable communication |
| 58 | * protocol the transport service implementation may include |
| 59 | * additional protocol support in order to ensure that packets |
| 60 | * are not duplicated and that there is no data loss. The |
| 61 | * details of such protocols are specific to the implementation |
| 62 | * but may involve techniques such as the <i>positive |
| 63 | * acknowledgment with retransmission</i> technique used in |
| 64 | * protocols such as the Transmission Control Protocol (TCP) |
| 65 | * (see <a href="http://www.ietf.org/rfc/rfc0793.txt"> RFC 793 |
| 66 | * </a>). |
| 67 | * |
| 68 | * <p> A transport service can be used to initiate a connection |
| 69 | * to a target VM. This is done by invoking the {@link #attach} |
| 70 | * method. Alternatively, a transport service can listen and |
| 71 | * accept connections initiated by a target VM. This is done |
| 72 | * by invoking the {@link #startListening(String)} method to |
| 73 | * put the transport into listen mode. Then the {@link #accept} |
| 74 | * method is used to accept a connection initiated by a |
| 75 | * target VM. |
| 76 | * |
| 77 | * @since 1.5 |
| 78 | */ |
| 79 | |
| 80 | public abstract class TransportService { |
| 81 | |
| 82 | /** |
| 83 | * Returns a name to identify the transport service. |
| 84 | * |
| 85 | * @return The name of the transport service |
| 86 | */ |
| 87 | public abstract String name(); |
| 88 | |
| 89 | /** |
| 90 | * Returns a description of the transport service. |
| 91 | * |
| 92 | * @return The description of the transport service |
| 93 | */ |
| 94 | public abstract String description(); |
| 95 | |
| 96 | /** |
| 97 | * The transport service capabilities. |
| 98 | */ |
| 99 | public static abstract class Capabilities { |
| 100 | |
| 101 | /** |
| 102 | * Tells whether or not this transport service can support |
| 103 | * multiple concurrent connections to a single address that |
| 104 | * it is listening on. |
| 105 | * |
| 106 | * @return <tt>true</tt> if, and only if, this transport |
| 107 | * service supports multiple connections. |
| 108 | */ |
| 109 | public abstract boolean supportsMultipleConnections(); |
| 110 | |
| 111 | |
| 112 | /** |
| 113 | * Tell whether or not this transport service supports a timeout |
| 114 | * when attaching to a target VM. |
| 115 | * |
| 116 | * @return <tt>true</tt> if, and only if, this transport |
| 117 | * service supports attaching with a timeout. |
| 118 | * |
| 119 | * @see #attach(String,long,long) |
| 120 | */ |
| 121 | public abstract boolean supportsAttachTimeout(); |
| 122 | |
| 123 | /** |
| 124 | * Tell whether or not this transport service supports a |
| 125 | * timeout while waiting for a target VM to connect. |
| 126 | * |
| 127 | * @return <tt>true</tt> if, and only if, this transport |
| 128 | * service supports timeout while waiting for |
| 129 | * a target VM to connect. |
| 130 | * |
| 131 | * @see #accept(TransportService.ListenKey,long,long) |
| 132 | */ |
| 133 | public abstract boolean supportsAcceptTimeout(); |
| 134 | |
| 135 | /** |
| 136 | * Tells whether or not this transport service supports a |
| 137 | * timeout when handshaking with the target VM. |
| 138 | * |
| 139 | * @return <tt>true</tt> if, and only if, this transport |
| 140 | * service supports a timeout while handshaking |
| 141 | * with the target VM. |
| 142 | * |
| 143 | * @see #attach(String,long,long) |
| 144 | * @see #accept(TransportService.ListenKey,long,long) |
| 145 | */ |
| 146 | public abstract boolean supportsHandshakeTimeout(); |
| 147 | |
| 148 | } |
| 149 | |
| 150 | /** |
| 151 | * Returns the capabilities of the transport service. |
| 152 | * |
| 153 | * @return the transport service capabilities |
| 154 | */ |
| 155 | public abstract Capabilities capabilities(); |
| 156 | |
| 157 | /** |
| 158 | * Attaches to the specified address. |
| 159 | * |
| 160 | * <p> Attaches to the specified address and returns a connection |
| 161 | * representing the bi-directional communication channel to the |
| 162 | * target VM. |
| 163 | * |
| 164 | * <p> Attaching to the target VM involves two steps: |
| 165 | * First, a connection is established to specified address. This |
| 166 | * is followed by a handshake to ensure that the connection is |
| 167 | * to a target VM. The handshake involves the exchange |
| 168 | * of a string <i>JDWP-Handshake</i> as specified in the <a |
| 169 | * href="../../../../../../../../../technotes/guides/jpda/jdwp-spec.html"> |
| 170 | * Java Debug Wire Protocol</a> specification. |
| 171 | * |
| 172 | * @param address |
| 173 | * The address of the target VM. |
| 174 | * |
| 175 | * @param attachTimeout |
| 176 | * If this transport service supports an attach timeout, |
| 177 | * and if <tt>attachTimeout</tt> is positive, then it specifies |
| 178 | * the timeout, in milliseconds (more or less), to use |
| 179 | * when attaching to the target VM. If the transport service |
| 180 | * does not support an attach timeout, or if <tt>attachTimeout</tt> |
| 181 | * is specified as zero then attach without any timeout. |
| 182 | * |
| 183 | * @param handshakeTimeout |
| 184 | * If this transport service supports a handshake timeout, |
| 185 | * and if <tt>handshakeTimeout</tt> is positive, then it |
| 186 | * specifies the timeout, in milliseconds (more or less), to |
| 187 | * use when handshaking with the target VM. The exact |
| 188 | * usage of the timeout are specific to the transport service. |
| 189 | * A transport service may, for example, use the handshake |
| 190 | * timeout as the inter-character timeout while waiting for |
| 191 | * the <i>JDWP-Handshake</i> message from the target VM. |
| 192 | * Alternatively, a transport service may, for example, |
| 193 | * use the handshakeTimeout as a timeout for the duration of the |
| 194 | * handshake exchange. |
| 195 | * If the transport service does not support a handshake |
| 196 | * timeout, or if <tt>handshakeTimeout</tt> is specified |
| 197 | * as zero then the handshake does not timeout if there |
| 198 | * isn't a response from the target VM. |
| 199 | * |
| 200 | * @return The Connection representing the bi-directional |
| 201 | * communication channel to the target VM. |
| 202 | * |
| 203 | * @throws TransportTimeoutException |
| 204 | * If a timeout occurs while establishing the connection. |
| 205 | * |
| 206 | * @throws IOException |
| 207 | * If an I/O error occurs (including a timeout when |
| 208 | * handshaking). |
| 209 | * |
| 210 | * @throws IllegalArgumentException |
| 211 | * If the address is invalid or the value of the |
| 212 | * attach timeout or handshake timeout is negative. |
| 213 | * |
| 214 | * @see TransportService.Capabilities#supportsAttachTimeout() |
| 215 | */ |
| 216 | public abstract Connection attach(String address, long attachTimeout, |
| 217 | long handshakeTimeout) throws IOException; |
| 218 | |
| 219 | /** |
| 220 | * A <i>listen key</i>. |
| 221 | * |
| 222 | * <p> A <tt>TransportService</tt> may listen on multiple, yet |
| 223 | * different, addresses at the same time. To uniquely identify |
| 224 | * each <tt>listener</tt> a listen key is created each time that |
| 225 | * {@link #startListening startListening} is called. The listen |
| 226 | * key is used in calls to the {@link #accept accept} method |
| 227 | * to accept inbound connections to that listener. A listen |
| 228 | * key is valid until it is used as an argument to {@link |
| 229 | * #stopListening stopListening} to stop the transport |
| 230 | * service from listening on an address. |
| 231 | */ |
| 232 | public static abstract class ListenKey { |
| 233 | |
| 234 | /** |
| 235 | * Returns a string representation of the listen key. |
| 236 | */ |
| 237 | public abstract String address(); |
| 238 | } |
| 239 | |
| 240 | /** |
| 241 | * Listens on the specified address for inbound connections. |
| 242 | * |
| 243 | * <p> This method starts the transport service listening on |
| 244 | * the specified address so that it can subsequently accept |
| 245 | * an inbound connection. It does not wait until an inbound |
| 246 | * connection is established. |
| 247 | * |
| 248 | * @param address |
| 249 | * The address to start listening for connections, |
| 250 | * or <tt>null</tt> to listen on an address choosen |
| 251 | * by the transport service. |
| 252 | * |
| 253 | * @return a listen key to be used in subsequent calls to be |
| 254 | * {@link #accept accept} or {@link #stopListening |
| 255 | * stopListening} methods. |
| 256 | * |
| 257 | * @throws IOException |
| 258 | * If an I/O error occurs. |
| 259 | * |
| 260 | * @throws IllegalArgumentException |
| 261 | * If the specific address is invalid |
| 262 | */ |
| 263 | public abstract ListenKey startListening(String address) throws IOException; |
| 264 | |
| 265 | /** |
| 266 | * Listens on an address choosen by the transport service. |
| 267 | * |
| 268 | * <p> This convenience method works as if by invoking {@link |
| 269 | * #startListening(String) startListening(<tt>null</tt>)}. </p> |
| 270 | * |
| 271 | * @return a listen key to be used in subsequent calls to be |
| 272 | * {@link #accept accept} or {@link #stopListening |
| 273 | * stopListening} methods. |
| 274 | * |
| 275 | * @throws IOException |
| 276 | * If an I/O error occurs. |
| 277 | */ |
| 278 | public abstract ListenKey startListening() throws IOException; |
| 279 | |
| 280 | /** |
| 281 | * Stop listening for inbound connections. |
| 282 | * |
| 283 | * <p> Invoking this method while another thread is blocked |
| 284 | * in {@link #accept accept}, with the same listen key, |
| 285 | * waiting to accept a connection will cause that thread to |
| 286 | * throw an IOException. If the thread blocked in accept |
| 287 | * has already accepted a connection from a target VM and |
| 288 | * is in the process of handshaking with the target VM then |
| 289 | * invoking this method will not cause the thread to throw |
| 290 | * an exception. |
| 291 | * |
| 292 | * @param listenKey |
| 293 | * The listen key obtained from a previous call to {@link |
| 294 | * #startListening(String)} or {@link #startListening()}. |
| 295 | * |
| 296 | * @throws IllegalArgumentException |
| 297 | * If the listen key is invalid |
| 298 | * |
| 299 | * @throws IOException |
| 300 | * If an I/O error occurs. |
| 301 | */ |
| 302 | public abstract void stopListening(ListenKey listenKey) throws IOException; |
| 303 | |
| 304 | /** |
| 305 | * Accept a connection from a target VM. |
| 306 | * |
| 307 | * <p> Waits (indefinitely or with timeout) to accept a connection |
| 308 | * from a target VM. Returns a connection representing the |
| 309 | * bi-directional communication channel to the target VM. |
| 310 | * |
| 311 | * <p> Accepting a connection from a target VM involves two |
| 312 | * steps. First, the transport service waits to accept |
| 313 | * the connection from the target VM. Once the connection is |
| 314 | * established a handshake is performed to ensure that the |
| 315 | * connection is indeed to a target VM. The handshake involves |
| 316 | * the exchange of a string <i>JDWP-Handshake</i> as specified |
| 317 | * in the <a |
| 318 | * href="../../../../../../../../../technotes/guides/jpda/jdwp-spec.html"> |
| 319 | * Java Debug Wire Protocol</a> specification. |
| 320 | * |
| 321 | * @param listenKey |
| 322 | * A listen key obtained from a previous call to {@link |
| 323 | * #startListening(String)} or {@link #startListening()}. |
| 324 | * |
| 325 | * @param acceptTimeout |
| 326 | * if this transport service supports an accept timeout, and |
| 327 | * if <tt>acceptTimeout</tt> is positive then block for up to |
| 328 | * <tt>acceptTimeout</tt> milliseconds, more or less, while waiting |
| 329 | * for the target VM to connect. |
| 330 | * If the transport service does not support an accept timeout |
| 331 | * or if <tt>acceptTimeout</tt> is zero then block indefinitely |
| 332 | * for a target VM to connect. |
| 333 | * |
| 334 | * @param handshakeTimeout |
| 335 | * If this transport service supports a handshake timeout, |
| 336 | * and if <tt>handshakeTimeout</tt> is positive, then it |
| 337 | * specifies the timeout, in milliseconds (more or less), to |
| 338 | * use when handshaking with the target VM. The exact |
| 339 | * usage of the timeout is specific to the transport service. |
| 340 | * A transport service may, for example, use the handshake |
| 341 | * timeout as the inter-character timeout while waiting for |
| 342 | * the <i>JDWP-Handshake</i> message from the target VM. |
| 343 | * Alternatively, a transport service may, for example, |
| 344 | * use the timeout as a timeout for the duration of the |
| 345 | * handshake exchange. |
| 346 | * If the transport service does not support a handshake |
| 347 | * timeout, of if <tt>handshakeTimeout</tt> is specified |
| 348 | * as zero then the handshake does not timeout if there |
| 349 | * isn't a response from the target VM. |
| 350 | * |
| 351 | * @return The Connection representing the bi-directional |
| 352 | * communication channel to the target VM. |
| 353 | * |
| 354 | * @throws TransportTimeoutException |
| 355 | * If a timeout occurs while waiting for a target VM |
| 356 | * to connect. |
| 357 | * |
| 358 | * @throws IOException |
| 359 | * If an I/O error occurs (including a timeout when |
| 360 | * handshaking). |
| 361 | * |
| 362 | * @throws IllegalArgumentException |
| 363 | * If the value of the acceptTimeout argument, or |
| 364 | * handshakeTimeout is negative, or an invalid listen key |
| 365 | * is provided. |
| 366 | * |
| 367 | * @throws IllegalStateException |
| 368 | * If {@link #stopListening stopListening} has already been |
| 369 | * called with this listen key and the transport service |
| 370 | * is no longer listening for inbound connections. |
| 371 | * |
| 372 | * @see TransportService.Capabilities#supportsAcceptTimeout() |
| 373 | */ |
| 374 | public abstract Connection accept(ListenKey listenKey, long acceptTimeout, |
| 375 | long handshakeTimeout) throws IOException; |
| 376 | |
| 377 | } |