Emeric Vigier | 2f62582 | 2012-08-06 11:09:52 -0400 | [diff] [blame] | 1 | // |
| 2 | // tcpservice.cpp |
| 3 | // |
| 4 | // Copyright 2000 - Gianni Mariani <gianni@mariani.ws> |
| 5 | // |
| 6 | // An example of a simple chatty server using CommonC++. |
| 7 | // |
| 8 | // This simple application basically operates as a |
| 9 | // very simple chat system. From a telnet session |
| 10 | // on localhost:3999 , any messages typed from a telnet |
| 11 | // client are written to all participating sessions. |
| 12 | // |
| 13 | // This is free software licensed under the terms of the GNU |
| 14 | // Public License |
| 15 | // |
| 16 | // This example: |
| 17 | // |
| 18 | // This demostrates a simple threaded server, actually, |
| 19 | // the sessions are not all threaded though they could be |
| 20 | // if that's what you wanted. Basically it demonstrates the |
| 21 | // use of SocketService, SocketPorts and Threads. |
| 22 | // |
| 23 | // For those familiar with Unix network programming, SocketService |
| 24 | // basically encapsulates all the work to communicate with |
| 25 | // the select() or poll() system calls. SocketPorts are |
| 26 | // basically encapsulations of sessions or open file descriptors. |
| 27 | // |
| 28 | // Anyhow, this example is a very simple echo server but |
| 29 | // it echos to all connected clients. So it's a poor man's |
| 30 | // IRC ! You connect via telnet to localhost port 3999 and |
| 31 | // it will echo to all other connected clients what you type in ! |
| 32 | // |
| 33 | |
| 34 | #include <cc++/socketport.h> |
| 35 | |
| 36 | #include <iostream> |
| 37 | |
| 38 | // For starters, we need a thread safe list, we'll make one |
| 39 | // out of the STL list<> template - |
| 40 | // http://www.sgi.com/Technology/STL/index.html |
| 41 | // |
| 42 | // Thread safe list class |
| 43 | // |
| 44 | #include <list> |
| 45 | |
| 46 | #ifdef CCXX_NAMESPACES |
| 47 | using namespace std; |
| 48 | using namespace ost; |
| 49 | #endif |
| 50 | |
| 51 | class ts_list_item; |
| 52 | typedef list<ts_list_item *> ts_list; |
| 53 | |
| 54 | // a list head - containing a list and a Mutex. |
| 55 | // It would be really nice to teach stl to do this. |
| 56 | |
| 57 | class ts_list_head { |
| 58 | public: |
| 59 | |
| 60 | // No point inheriting, I'd have to implement |
| 61 | // alot of code. We'll hold off on that exercise. |
| 62 | |
| 63 | // Using the CommonC++ Mutex class. |
| 64 | Mutex linkmutex; |
| 65 | // And the STL template. |
| 66 | ts_list list_o_items; |
| 67 | |
| 68 | // Not nessasary, but nice to be explicit. |
| 69 | ts_list_head() |
| 70 | : linkmutex(), list_o_items() { |
| 71 | } |
| 72 | |
| 73 | // This thing knows how to remove and insert items. |
| 74 | void RemoveListItem( ts_list_item * li ); |
| 75 | void InsertListItem( ts_list_item * li ); |
| 76 | |
| 77 | // And it knows how to notify that it became empty |
| 78 | // or an element was deleted and it was the last one. |
| 79 | virtual void ListDepleted() { |
| 80 | } |
| 81 | |
| 82 | virtual ~ts_list_head() { |
| 83 | } |
| 84 | }; |
| 85 | |
| 86 | |
| 87 | // This item knows how to remove itself from the |
| 88 | // list it belongs to. |
| 89 | class ts_list_item { |
| 90 | public: |
| 91 | ts_list::iterator linkpoint; |
| 92 | ts_list_head * listhead; |
| 93 | |
| 94 | virtual ~ts_list_item() { |
| 95 | listhead->RemoveListItem( this ); |
| 96 | } |
| 97 | |
| 98 | ts_list_item( ts_list_head * head ) { |
| 99 | listhead = head; |
| 100 | head->InsertListItem( this ); |
| 101 | } |
| 102 | }; |
| 103 | |
| 104 | void ts_list_head::RemoveListItem( ts_list_item * li ) |
| 105 | { |
| 106 | bool is_empty; |
| 107 | linkmutex.enterMutex(); |
| 108 | list_o_items.erase( li->linkpoint ); |
| 109 | is_empty = list_o_items.empty(); |
| 110 | linkmutex.leaveMutex(); |
| 111 | |
| 112 | // There is a slim possibility that at this time |
| 113 | // we recieve a connection. |
| 114 | if ( is_empty ) { |
| 115 | ListDepleted(); |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | void ts_list_head::InsertListItem( ts_list_item * li ) |
| 120 | { |
| 121 | linkmutex.enterMutex(); |
| 122 | list_o_items.push_front( li ); |
| 123 | li->linkpoint = list_o_items.begin(); |
| 124 | linkmutex.leaveMutex(); |
| 125 | } |
| 126 | |
| 127 | // ChatterSession operates on the individual connections |
| 128 | // from clients as are managed by the SocketService |
| 129 | // contained in CCExec. ChatterThread simply waits in |
| 130 | // a loop to create these, listening forever. |
| 131 | // |
| 132 | // Even though the SocketService contains a list of |
| 133 | // clients it serves, it may actually serve more than |
| 134 | // one type of session so we create our own list by |
| 135 | // inheriting the ts_list_item. |
| 136 | // |
| 137 | |
| 138 | class ChatterSession : |
| 139 | public virtual SocketPort, |
| 140 | public virtual ts_list_item { |
| 141 | public: |
| 142 | |
| 143 | enum { size_o_buf = 2048 }; |
| 144 | |
| 145 | // Nothing special to do here, it's all handled |
| 146 | // by SocketPort and ts_list_item |
| 147 | |
| 148 | virtual ~ChatterSession() { |
| 149 | cerr << "ChatterSession deleted !\n"; |
| 150 | } |
| 151 | |
| 152 | // When you create a ChatterSession it waits to accept a |
| 153 | // connection. This is done by it's own |
| 154 | ChatterSession( |
| 155 | TCPSocket & server, |
| 156 | SocketService * svc, |
| 157 | ts_list_head * head |
| 158 | ) : |
| 159 | SocketPort( NULL, server ), |
| 160 | ts_list_item( head ) { |
| 161 | cerr << "ChatterSession Created\n"; |
| 162 | |
| 163 | tpport_t port; |
| 164 | InetHostAddress ia = getPeer( & port ); |
| 165 | |
| 166 | cerr << "connecting from " << ia.getHostname() << |
| 167 | ":" << port << endl; |
| 168 | |
| 169 | // Set up non-blocking reads |
| 170 | setCompletion( false ); |
| 171 | |
| 172 | // Set yerself to time out in 10 seconds |
| 173 | setTimer( 100000 ); |
| 174 | attach(svc); |
| 175 | } |
| 176 | |
| 177 | // |
| 178 | // This is called by the SocketService thread when it the |
| 179 | // object has expired. |
| 180 | // |
| 181 | |
| 182 | virtual void expired() { |
| 183 | // Get outa here - this guy is a LOOSER - type or terminate |
| 184 | cerr << "ChatterSession Expired\n"; |
| 185 | delete this; |
| 186 | } |
| 187 | |
| 188 | // |
| 189 | // This is called by the SocketService thread when it detects |
| 190 | // that there is somthing to read on this connection. |
| 191 | // |
| 192 | |
| 193 | virtual void pending() { |
| 194 | // Implement the echo |
| 195 | |
| 196 | cerr << "Pending called\n"; |
| 197 | |
| 198 | // reset the timer |
| 199 | setTimer( 100000 ); |
| 200 | try { |
| 201 | int len; |
| 202 | unsigned int total = 0; |
| 203 | char buf[ size_o_buf ]; |
| 204 | |
| 205 | while ( (len = receive(buf, sizeof(buf) )) > 0 ) { |
| 206 | total += len; |
| 207 | cerr << "Read '"; |
| 208 | cerr.write( buf, len ); |
| 209 | cerr << "'\n"; |
| 210 | |
| 211 | // Send it to all the sessions. |
| 212 | // We probably don't really want to lock the |
| 213 | // entire list for the entire time. |
| 214 | // The best way to do this would be to place the |
| 215 | // message somewhere and use the service function. |
| 216 | // But what are examples for ? |
| 217 | |
| 218 | bool sent = false; |
| 219 | listhead->linkmutex.enterMutex(); |
| 220 | for ( |
| 221 | ts_list::iterator iter = listhead->list_o_items.begin(); |
| 222 | iter != listhead->list_o_items.end(); |
| 223 | iter ++ |
| 224 | ) { |
| 225 | ChatterSession * sess = |
| 226 | dynamic_cast< ChatterSession * >( * iter ); |
| 227 | if ( sess != this ) { |
| 228 | sess->send( buf, len ); |
| 229 | sent = true; |
| 230 | } |
| 231 | } |
| 232 | listhead->linkmutex.leaveMutex(); |
| 233 | |
| 234 | if ( ! sent ) { |
| 235 | send( |
| 236 | ( void * ) "No one else listening\n", |
| 237 | sizeof( "No one else listening\n" ) - 1 |
| 238 | ); |
| 239 | |
| 240 | send( buf, len ); |
| 241 | } |
| 242 | } |
| 243 | if (total == 0) { |
| 244 | cerr << "Broken connection!\n" << endl; |
| 245 | delete this; |
| 246 | } |
| 247 | } |
| 248 | catch ( ... ) { |
| 249 | // somthing wrong happened here ! |
| 250 | cerr << "Socket port write sent an exception !\n"; |
| 251 | } |
| 252 | |
| 253 | } |
| 254 | |
| 255 | virtual void disconnect() { |
| 256 | // Called by the SocketService thread when the client |
| 257 | // hangs up. |
| 258 | cerr << "ChatterSession disconnected!\n"; |
| 259 | |
| 260 | delete this; |
| 261 | } |
| 262 | |
| 263 | }; |
| 264 | |
| 265 | class ChatterThread; |
| 266 | |
| 267 | // |
| 268 | // This is the main application object containing all the |
| 269 | // state for the application. It uses a SocketService object |
| 270 | // (and thread) to do all the work, however, that object could |
| 271 | // theoretically be use by more than one main application. |
| 272 | // |
| 273 | // It creates a ChatterThread to sit and wait for connections |
| 274 | // from clients. |
| 275 | |
| 276 | class CCExec : public virtual ts_list_head { |
| 277 | public: |
| 278 | |
| 279 | SocketService * service; |
| 280 | ChatterThread * my_Chatter; |
| 281 | Semaphore mainsem[1]; |
| 282 | |
| 283 | CCExec():my_Chatter(NULL) { |
| 284 | service = new SocketService( 0 ); |
| 285 | } |
| 286 | |
| 287 | virtual void ListDepleted(); |
| 288 | |
| 289 | // These methods defined later. |
| 290 | virtual ~CCExec(); |
| 291 | int RunApp( char * hn = (char *)"localhost" ); |
| 292 | |
| 293 | }; |
| 294 | |
| 295 | // |
| 296 | // ChatterThread simply creates ChatterSession all the time until |
| 297 | // it has an error. I suspect you could create as many of these |
| 298 | // as the OS could take. |
| 299 | // |
| 300 | |
| 301 | class ChatterThread : public virtual TCPSocket, public virtual Thread { |
| 302 | public: |
| 303 | |
| 304 | CCExec * exec; |
| 305 | |
| 306 | void run () { |
| 307 | while ( 1 ) { |
| 308 | try { |
| 309 | // new does all the work to accept a new connection |
| 310 | // attach itself to the SocketService AND include |
| 311 | // itself in the CCExec list of sessions. |
| 312 | new ChatterSession( |
| 313 | * ( TCPSocket * ) this, |
| 314 | exec->service, |
| 315 | exec |
| 316 | ); |
| 317 | } |
| 318 | catch ( ... ) { |
| 319 | // Bummer - there was an error. |
| 320 | cerr << "ChatterSession create failed\n"; |
| 321 | exit(); |
| 322 | } |
| 323 | } |
| 324 | } |
| 325 | |
| 326 | ChatterThread( |
| 327 | InetHostAddress & machine, |
| 328 | int port, |
| 329 | CCExec * inexec |
| 330 | |
| 331 | ) : TCPSocket( machine, port ), |
| 332 | Thread(), |
| 333 | exec( inexec ) { |
| 334 | start(); |
| 335 | } |
| 336 | |
| 337 | |
| 338 | }; |
| 339 | |
| 340 | // |
| 341 | // Bug here, this should go ahead and shut down all sessions |
| 342 | // for application. An exercise left to the reader. |
| 343 | |
| 344 | CCExec::~CCExec() |
| 345 | { |
| 346 | // MUST delete my_Chatter first or it may end up using |
| 347 | // a deleted service. |
| 348 | if ( my_Chatter ) delete my_Chatter; |
| 349 | |
| 350 | // Delete whatever is left. |
| 351 | delete service; |
| 352 | } |
| 353 | |
| 354 | // |
| 355 | // Run App would normally read some config file or take some |
| 356 | // parameters about which port to connect to and then |
| 357 | // do that ! |
| 358 | int CCExec::RunApp( char * hn ) |
| 359 | { |
| 360 | // which port ? |
| 361 | |
| 362 | InetHostAddress machine( hn ); |
| 363 | |
| 364 | if ( machine.isInetAddress() == false ) { |
| 365 | cerr << "machine is not address" << endl; |
| 366 | } |
| 367 | |
| 368 | cerr << "machine is " << machine.getHostname() << endl; |
| 369 | |
| 370 | // Start accepting connections - this will bind to the |
| 371 | // port as well. |
| 372 | try { |
| 373 | my_Chatter = new ChatterThread( |
| 374 | machine, |
| 375 | 3999, |
| 376 | this |
| 377 | ); |
| 378 | } |
| 379 | catch ( ... ) { |
| 380 | cerr << "Failed to bind\n"; |
| 381 | return false; |
| 382 | } |
| 383 | |
| 384 | return true; |
| 385 | } |
| 386 | |
| 387 | // When there is no one else connected - terminate ! |
| 388 | void CCExec::ListDepleted() |
| 389 | { |
| 390 | mainsem->post(); |
| 391 | } |
| 392 | |
| 393 | |
| 394 | int main( int argc, char ** argv ) |
| 395 | { |
| 396 | CCExec * server; |
| 397 | |
| 398 | server = new CCExec(); |
| 399 | |
| 400 | // take the first command line option as a hostname |
| 401 | // to listen to. |
| 402 | if ( argc > 1 ) { |
| 403 | server->RunApp( argv[ 1 ] ); |
| 404 | } else { |
| 405 | server->RunApp(); |
| 406 | } |
| 407 | |
| 408 | server->mainsem->wait(); |
| 409 | |
| 410 | delete server; |
| 411 | |
| 412 | return 0; |
| 413 | } |