src/libopensrf/osrf_prefork.c

   1 #include <opensrf/osrf_prefork.h>
   2 #include <opensrf/osrf_app_session.h>
   3 #include <opensrf/osrf_application.h>
   4 #include <signal.h>
   5
   6 //#define READ_BUFSIZE 4096
   7 #define READ_BUFSIZE 1024
   8 //#define MAX_BUFSIZE 10485760 /* 10M enough? ;) */
   9 #define ABS_MAX_CHILDREN 256
  10
  11 struct prefork_simple_struct {
  12         int max_requests;
  13         int min_children;
  14         int max_children;
  15         int fd;
  16         int data_to_child;
  17         int data_to_parent;
  18         int current_num_children;
  19         int keepalive; /* keepalive time for stateful sessions */
  20         char* appname;
  21         struct prefork_child_struct* first_child;
  22         transport_client* connection;
  23 };
  24 typedef struct prefork_simple_struct prefork_simple;
  25
  26 struct prefork_child_struct {
  27         pid_t pid;
  28         int read_data_fd;
  29         int write_data_fd;
  30         int read_status_fd;
  31         int write_status_fd;
  32         int min_children;
  33         int available;
  34         int max_requests;
  35         char* appname;
  36         int keepalive;
  37         struct prefork_child_struct* next;
  38 };
  39
  40 typedef struct prefork_child_struct prefork_child;
  41
  42 static prefork_simple* prefork_simple_init( transport_client* client,
  43         int max_requests, int min_children, int max_children );
  44 static prefork_child* launch_child( prefork_simple* forker );
  45 static void prefork_launch_children( prefork_simple* forker );
  46 static void prefork_run(prefork_simple* forker);
  47 static void add_prefork_child( prefork_simple* forker, prefork_child* child );
  48
  49 //static prefork_child* find_prefork_child( prefork_simple* forker, pid_t pid );
  50
  51 static void del_prefork_child( prefork_simple* forker, pid_t pid );
  52 static void check_children( prefork_simple* forker, int forever );
  53 static void prefork_child_process_request(prefork_child*, char* data);
  54 static int prefork_child_init_hook(prefork_child*);
  55 static prefork_child* prefork_child_init(
  56                 int max_requests, int read_data_fd, int write_data_fd,
  57                 int read_status_fd, int write_status_fd );
  58
  59 /* listens on the 'data_to_child' fd and wait for incoming data */
  60 static void prefork_child_wait( prefork_child* child );
  61 static int prefork_free( prefork_simple* );
  62 static int prefork_child_free( prefork_child* );
  63 static void osrf_prefork_register_routers( const char* appname );
  64 static void osrf_prefork_child_exit( prefork_child* );
  65
  66
  67 /* true if we just deleted a child.  This will allow us to make sure we're
  68         not trying to use freed memory */
  69 static int child_dead;
  70
  71 static void sigchld_handler( int sig );
  72
  73 int osrf_prefork_run(const char* appname) {
  74
  75         if(!appname) {
  76                 osrfLogError( OSRF_LOG_MARK, "osrf_prefork_run requires an appname to run!");
  77                 return -1;
  78         }
  79
  80         set_proc_title( "OpenSRF Listener [%s]", appname );
  81
  82         int maxr = 1000;
  83         int maxc = 10;
  84         int minc = 3;
  85     int kalive = 5;
  86
  87         osrfLogInfo( OSRF_LOG_MARK, "Loading config in osrf_forker for app %s", appname);
  88
  89         char* max_req = osrf_settings_host_value("/apps/%s/unix_config/max_requests", appname);
  90         char* min_children = osrf_settings_host_value("/apps/%s/unix_config/min_children", appname);
  91         char* max_children = osrf_settings_host_value("/apps/%s/unix_config/max_children", appname);
  92         char* keepalive = osrf_settings_host_value("/apps/%s/keepalive", appname);
  93
  94         if(!keepalive) osrfLogWarning( OSRF_LOG_MARK, "Keepalive is not defined, assuming %d", kalive);
  95         else kalive = atoi(keepalive);
  96
  97         if(!max_req) osrfLogWarning( OSRF_LOG_MARK, "Max requests not defined, assuming %d", maxr);
  98         else maxr = atoi(max_req);
  99
 100         if(!min_children) osrfLogWarning( OSRF_LOG_MARK, "Min children not defined, assuming %d", minc);
 101         else minc = atoi(min_children);
 102
 103         if(!max_children) osrfLogWarning( OSRF_LOG_MARK, "Max children not defined, assuming %d", maxc);
 104         else maxc = atoi(max_children);
 105
 106     free(keepalive);
 107         free(max_req);
 108         free(min_children);
 109         free(max_children);
 110         /* --------------------------------------------------- */
 111
 112         char* resc = va_list_to_string("%s_listener", appname);
 113
 114         if(!osrfSystemBootstrapClientResc( NULL, NULL, resc )) {
 115                 osrfLogError( OSRF_LOG_MARK, "Unable to bootstrap client for osrf_prefork_run()");
 116                 free(resc);
 117                 return -1;
 118         }
 119
 120         free(resc);
 121
 122         prefork_simple* forker = prefork_simple_init(
 123                 osrfSystemGetTransportClient(), maxr, minc, maxc);
 124
 125         if(forker == NULL) {
 126                 osrfLogError( OSRF_LOG_MARK, "osrf_prefork_run() failed to create prefork_simple object");
 127                 return -1;
 128         }
 129
 130         forker->appname = strdup(appname);
 131         forker->keepalive       = kalive;
 132
 133         prefork_launch_children(forker);
 134
 135         osrf_prefork_register_routers(appname);
 136
 137         osrfLogInfo( OSRF_LOG_MARK, "Launching osrf_forker for app %s", appname);
 138         prefork_run(forker);
 139
 140         osrfLogWarning( OSRF_LOG_MARK, "prefork_run() retuned - how??");
 141         prefork_free(forker);
 142         return 0;
 143
 144 }
 145
 146 static void osrf_prefork_register_routers( const char* appname ) {
 147
 148         osrfStringArray* arr = osrfNewStringArray(4);
 149
 150         int c = osrfConfigGetValueList( NULL, arr, "/routers/router" );
 151         char* routerName = osrfConfigGetValue( NULL, "/router_name" );
 152         transport_client* client = osrfSystemGetTransportClient();
 153
 154         osrfLogInfo( OSRF_LOG_MARK, "router name is %s and we have %d routers to connect to", routerName, c );
 155
 156         while( c ) {
 157                 char* domain = osrfStringArrayGetString(arr, --c);
 158                 if(domain) {
 159
 160                         char* jid = va_list_to_string( "%s@%s/router", routerName, domain );
 161                         osrfLogInfo( OSRF_LOG_MARK, "Registering with router %s", jid );
 162
 163                         transport_message* msg = message_init("registering", NULL, NULL, jid, NULL );
 164                         message_set_router_info( msg, NULL, NULL, appname, "register", 0 );
 165
 166                         client_send_message( client, msg );
 167                         message_free( msg );
 168                         free(jid);
 169                 }
 170         }
 171
 172         free(routerName);
 173         osrfStringArrayFree(arr);
 174 }
 175
 176 static int prefork_child_init_hook(prefork_child* child) {
 177
 178         if(!child) return -1;
 179         osrfLogDebug( OSRF_LOG_MARK, "Child init hook for child %d", child->pid);
 180         char* resc = va_list_to_string("%s_drone",child->appname);
 181
 182    /* if we're a source-client, tell the logger now that we're a new process*/
 183    char* isclient = osrfConfigGetValue(NULL, "/client");
 184    if( isclient && !strcasecmp(isclient,"true") )
 185       osrfLogSetIsClient(1);
 186    free(isclient);
 187
 188
 189         /* we want to remove traces of our parents socket connection
 190          * so we can have our own */
 191         osrfSystemIgnoreTransportClient();
 192
 193         if(!osrfSystemBootstrapClientResc( NULL, NULL, resc)) {
 194                 osrfLogError( OSRF_LOG_MARK, "Unable to bootstrap client for osrf_prefork_run()");
 195                 free(resc);
 196                 return -1;
 197         }
 198
 199         free(resc);
 200
 201         if( ! osrfAppRunChildInit(child->appname) ) {
 202                 osrfLogDebug(OSRF_LOG_MARK, "Prefork child_init succeeded\n");
 203         } else {
 204                 osrfLogError(OSRF_LOG_MARK, "Prefork child_init failed\n");
 205                 return -1;
 206         }
 207
 208         set_proc_title( "OpenSRF Drone [%s]", child->appname );
 209         return 0;
 210 }
 211
 212 static void prefork_child_process_request(prefork_child* child, char* data) {
 213         if( !child ) return;
 214
 215         transport_client* client = osrfSystemGetTransportClient();
 216
 217         if(!client_connected(client)) {
 218                 osrfSystemIgnoreTransportClient();
 219                 osrfLogWarning(OSRF_LOG_MARK, "Reconnecting child to opensrf after disconnect...");
 220                 if(!osrf_system_bootstrap_client(NULL, NULL)) {
 221                         osrfLogError( OSRF_LOG_MARK,
 222                                 "Unable to bootstrap client in prefork_child_process_request()");
 223                         sleep(1);
 224          osrf_prefork_child_exit(child);
 225                 }
 226         }
 227
 228         /* construct the message from the xml */
 229         transport_message* msg = new_message_from_xml( data );
 230
 231         osrfAppSession* session = osrf_stack_transport_handler(msg, child->appname);
 232         if(!session) return;
 233
 234         if( session->stateless && session->state != OSRF_SESSION_CONNECTED ) {
 235                 osrfAppSessionFree( session );
 236                 return;
 237         }
 238
 239         osrfLogDebug( OSRF_LOG_MARK, "Entering keepalive loop for session %s", session->session_id );
 240         int keepalive = child->keepalive;
 241         int retval;
 242         int recvd;
 243         time_t start;
 244         time_t end;
 245
 246         while(1) {
 247
 248                 osrfLogDebug(OSRF_LOG_MARK,
 249                                 "osrf_prefork calling queue_wait [%d] in keepalive loop", keepalive);
 250                 start           = time(NULL);
 251                 retval  = osrf_app_session_queue_wait(session, keepalive, &recvd);
 252                 end             = time(NULL);
 253
 254                 osrfLogDebug(OSRF_LOG_MARK, "Data received == %d", recvd);
 255
 256                 if(retval) {
 257                         osrfLogError(OSRF_LOG_MARK, "queue-wait returned non-success %d", retval);
 258                         break;
 259                 }
 260
 261                 /* see if the client disconnected from us */
 262                 if(session->state != OSRF_SESSION_CONNECTED) break;
 263
 264                 /* if no data was reveived within the timeout interval */
 265                 if( !recvd && (end - start) >= keepalive ) {
 266                         osrfLogInfo(OSRF_LOG_MARK, "No request was received in %d seconds, exiting stateful session", keepalive);
 267                         osrfAppSessionStatus(
 268                                         session,
 269                                         OSRF_STATUS_TIMEOUT,
 270                                         "osrfConnectStatus",
 271                                         0, "Disconnected on timeout" );
 272
 273                         break;
 274                 }
 275         }
 276
 277         osrfLogDebug( OSRF_LOG_MARK, "Exiting keepalive loop for session %s", session->session_id );
 278         osrfAppSessionFree( session );
 279         return;
 280 }
 281
 282
 283 static prefork_simple*  prefork_simple_init( transport_client* client,
 284                 int max_requests, int min_children, int max_children ) {
 285
 286         if( min_children > max_children ) {
 287                 osrfLogError( OSRF_LOG_MARK,  "min_children (%d) is greater "
 288                                 "than max_children (%d)", min_children, max_children );
 289                 return NULL;
 290         }
 291
 292         if( max_children > ABS_MAX_CHILDREN ) {
 293                 osrfLogError( OSRF_LOG_MARK,  "max_children (%d) is greater than ABS_MAX_CHILDREN (%d)",
 294                                 max_children, ABS_MAX_CHILDREN );
 295                 return NULL;
 296         }
 297
 298         osrfLogInfo(OSRF_LOG_MARK, "Prefork launching child with max_request=%d,"
 299                 "min_children=%d, max_children=%d", max_requests, min_children, max_children );
 300
 301         /* flesh out the struct */
 302         prefork_simple* prefork = (prefork_simple*) safe_malloc(sizeof(prefork_simple));
 303         prefork->max_requests = max_requests;
 304         prefork->min_children = min_children;
 305         prefork->max_children = max_children;
 306         prefork->fd           = 0;
 307         prefork->data_to_child = 0;
 308         prefork->data_to_parent = 0;
 309         prefork->current_num_children = 0;
 310         prefork->keepalive    = 0;
 311         prefork->appname      = NULL;
 312         prefork->first_child = NULL;
 313         prefork->connection = client;
 314
 315         return prefork;
 316 }
 317
 318 static prefork_child* launch_child( prefork_simple* forker ) {
 319
 320         pid_t pid;
 321         int data_fd[2];
 322         int status_fd[2];
 323
 324         /* Set up the data pipes and add the child struct to the parent */
 325         if( pipe(data_fd) < 0 ) { /* build the data pipe*/
 326                 osrfLogError( OSRF_LOG_MARK,  "Pipe making error" );
 327                 return NULL;
 328         }
 329
 330         if( pipe(status_fd) < 0 ) {/* build the status pipe */
 331                 osrfLogError( OSRF_LOG_MARK,  "Pipe making error" );
 332                 return NULL;
 333         }
 334
 335         osrfLogInternal( OSRF_LOG_MARK,  "Pipes: %d %d %d %d", data_fd[0], data_fd[1], status_fd[0], status_fd[1] );
 336         prefork_child* child = prefork_child_init( forker->max_requests, data_fd[0],
 337                         data_fd[1], status_fd[0], status_fd[1] );
 338
 339         child->appname = strdup(forker->appname);
 340         child->keepalive = forker->keepalive;
 341
 342
 343         add_prefork_child( forker, child );
 344
 345         if( (pid=fork()) < 0 ) {
 346                 osrfLogError( OSRF_LOG_MARK,  "Forking Error" );
 347                 return NULL;
 348         }
 349
 350         if( pid > 0 ) {  /* parent */
 351
 352                 signal(SIGCHLD, sigchld_handler);
 353                 (forker->current_num_children)++;
 354                 child->pid = pid;
 355
 356                 osrfLogDebug( OSRF_LOG_MARK,  "Parent launched %d", pid );
 357                 /* *no* child pipe FD's can be closed or the parent will re-use fd's that
 358                         the children are currently using */
 359                 return child;
 360         }
 361
 362         else { /* child */
 363
 364                 osrfLogInternal( OSRF_LOG_MARK, "I am  new child with read_data_fd = %d and write_status_fd = %d",
 365                         child->read_data_fd, child->write_status_fd );
 366
 367                 child->pid = getpid();
 368                 close( child->write_data_fd );
 369                 close( child->read_status_fd );
 370
 371                 /* do the initing */
 372                 if( prefork_child_init_hook(child) == -1 ) {
 373                         osrfLogError(OSRF_LOG_MARK,
 374                                 "Forker child going away because we could not connect to OpenSRF...");
 375          osrf_prefork_child_exit(child);
 376                 }
 377
 378                 prefork_child_wait( child );
 379       osrf_prefork_child_exit(child); /* just to be sure */
 380          }
 381         return NULL;
 382 }
 383
 384 static void osrf_prefork_child_exit(prefork_child* child) {
 385    osrfAppRunExitCode();
 386    exit(0);
 387 }
 388
 389 static void prefork_launch_children( prefork_simple* forker ) {
 390         if(!forker) return;
 391         int c = 0;
 392         while( c++ < forker->min_children )
 393                 launch_child( forker );
 394 }
 395
 396
 397 static void sigchld_handler( int sig ) {
 398         signal(SIGCHLD, sigchld_handler);
 399         child_dead = 1;
 400 }
 401
 402
 403 void reap_children( prefork_simple* forker ) {
 404
 405         pid_t child_pid;
 406         int status;
 407
 408         while( (child_pid=waitpid(-1,&status,WNOHANG)) > 0)
 409                 del_prefork_child( forker, child_pid );
 410
 411         /* replenish */
 412         while( forker->current_num_children < forker->min_children )
 413                 launch_child( forker );
 414
 415         child_dead = 0;
 416 }
 417
 418 static void prefork_run(prefork_simple* forker) {
 419
 420         if( forker->first_child == NULL )
 421                 return;
 422
 423         transport_message* cur_msg = NULL;
 424
 425
 426         while(1) {
 427
 428                 if( forker->first_child == NULL ) {/* no more children */
 429                         osrfLogWarning( OSRF_LOG_MARK, "No more children..." );
 430                         return;
 431                 }
 432
 433                 osrfLogDebug( OSRF_LOG_MARK, "Forker going into wait for data...");
 434                 cur_msg = client_recv( forker->connection, -1 );
 435
 436                 //fprintf(stderr, "Got Data %f\n", get_timestamp_millis() );
 437
 438                 if( cur_msg == NULL ) continue;
 439
 440                 int honored = 0;        /* true if we've serviced the request */
 441                 int no_recheck = 0;
 442
 443                 while( ! honored ) {
 444
 445                         if(!no_recheck) check_children( forker, 0 );
 446                         no_recheck = 0;
 447
 448                         osrfLogDebug( OSRF_LOG_MARK,  "Server received inbound data" );
 449                         int k;
 450                         prefork_child* cur_child = forker->first_child;
 451
 452                         /* Look for an available child */
 453                         for( k = 0; k < forker->current_num_children; k++ ) {
 454
 455                                 osrfLogInternal( OSRF_LOG_MARK, "Searching for available child. cur_child->pid = %d", cur_child->pid );
 456                                 osrfLogInternal( OSRF_LOG_MARK, "Current num children %d and loop %d", forker->current_num_children, k);
 457
 458                                 if( cur_child->available ) {
 459                                         osrfLogDebug( OSRF_LOG_MARK,  "forker sending data to %d", cur_child->pid );
 460
 461                                         message_prepare_xml( cur_msg );
 462                                         char* data = cur_msg->msg_xml;
 463                                         if( ! data || strlen(data) < 1 ) break;
 464
 465                                         cur_child->available = 0;
 466                                         osrfLogInternal( OSRF_LOG_MARK,  "Writing to child fd %d", cur_child->write_data_fd );
 467
 468                                         int written = 0;
 469                                         //fprintf(stderr, "Writing Data %f\n", get_timestamp_millis() );
 470                                         if( (written = write( cur_child->write_data_fd, data, strlen(data) + 1 )) < 0 ) {
 471                                                 osrfLogWarning( OSRF_LOG_MARK, "Write returned error %d", errno);
 472                                                 cur_child = cur_child->next;
 473                                                 continue;
 474                                         }
 475
 476                                         //fprintf(stderr, "Wrote %d bytes to child\n", written);
 477
 478                                         forker->first_child = cur_child->next;
 479                                         honored = 1;
 480                                         break;
 481                                 } else
 482                                         cur_child = cur_child->next;
 483                         }
 484
 485                         /* if none available, add a new child if we can */
 486                         if( ! honored ) {
 487                                 osrfLogDebug( OSRF_LOG_MARK, "Not enough children, attempting to add...");
 488
 489                                 if( forker->current_num_children < forker->max_children ) {
 490                                         osrfLogDebug( OSRF_LOG_MARK,  "Launching new child with current_num = %d",
 491                                                         forker->current_num_children );
 492
 493                                         prefork_child* new_child = launch_child( forker );
 494                     if( new_child ) {
 495
 496                                             message_prepare_xml( cur_msg );
 497                                             char* data = cur_msg->msg_xml;
 498
 499                         if( data ) {
 500                             int len = strlen(data);
 501
 502                             if( len > 0 ) {
 503                                                     new_child->available = 0;
 504                                                     osrfLogDebug( OSRF_LOG_MARK,  "Writing to new child fd %d : pid %d",
 505                                                                 new_child->write_data_fd, new_child->pid );
 506
 507                                                     if( write( new_child->write_data_fd, data, len + 1 ) >= 0 ) {
 508                                                         forker->first_child = new_child->next;
 509                                                         honored = 1;
 510                                 }
 511                             }
 512                         }
 513                     }
 514
 515                                 }
 516                         }
 517
 518                         if( !honored ) {
 519                                 osrfLogWarning( OSRF_LOG_MARK,  "No children available, waiting...");
 520
 521                                 check_children( forker, 1 );  /* non-poll version */
 522                                 /* tell the loop no to call check_children again, since we're calling it now */
 523                                 no_recheck = 1;
 524                         }
 525
 526                         if( child_dead )
 527                                 reap_children(forker);
 528
 529
 530                         //fprintf(stderr, "Parent done with request %f\n", get_timestamp_millis() );
 531
 532                 } // honored?
 533
 534                 message_free( cur_msg );
 535
 536         } /* top level listen loop */
 537
 538 }
 539
 540
 541 /** XXX Add a flag which tells select() to wait forever on children
 542  * in the best case, this will be faster than calling usleep(x), and
 543  * in the worst case it won't be slower and will do less logging...
 544  */
 545
 546 static void check_children( prefork_simple* forker, int forever ) {
 547
 548         //check_begin:
 549
 550         int select_ret;
 551         fd_set read_set;
 552         FD_ZERO(&read_set);
 553         int max_fd = 0;
 554         int n;
 555
 556
 557         if( child_dead )
 558                 reap_children(forker);
 559
 560         prefork_child* cur_child = forker->first_child;
 561
 562         int i;
 563         for( i = 0; i!= forker->current_num_children; i++ ) {
 564
 565                 if( cur_child->read_status_fd > max_fd )
 566                         max_fd = cur_child->read_status_fd;
 567                 FD_SET( cur_child->read_status_fd, &read_set );
 568                 cur_child = cur_child->next;
 569         }
 570
 571         FD_CLR(0,&read_set);/* just to be sure */
 572
 573         if( forever ) {
 574                 osrfLogWarning(OSRF_LOG_MARK, "We have no children available - waiting for one to show up...");
 575
 576                 if( (select_ret=select( max_fd + 1 , &read_set, NULL, NULL, NULL)) == -1 ) {
 577                         osrfLogWarning( OSRF_LOG_MARK,  "Select returned error %d on check_children", errno );
 578                 }
 579                 osrfLogInfo(OSRF_LOG_MARK, "select() completed after waiting on children to become available");
 580
 581         } else {
 582
 583                 struct timeval tv;
 584                 tv.tv_sec       = 0;
 585                 tv.tv_usec      = 0;
 586
 587                 if( (select_ret=select( max_fd + 1 , &read_set, NULL, NULL, &tv)) == -1 ) {
 588                         osrfLogWarning( OSRF_LOG_MARK,  "Select returned error %d on check_children", errno );
 589                 }
 590         }
 591
 592         if( select_ret == 0 )
 593                 return;
 594
 595         /* see if one of a child has told us it's done */
 596         cur_child = forker->first_child;
 597         int j;
 598         int num_handled = 0;
 599         for( j = 0; j!= forker->current_num_children && num_handled < select_ret ; j++ ) {
 600
 601                 if( FD_ISSET( cur_child->read_status_fd, &read_set ) ) {
 602                         //printf( "Server received status from a child %d\n", cur_child->pid );
 603                         osrfLogDebug( OSRF_LOG_MARK,  "Server received status from a child %d", cur_child->pid );
 604
 605                         num_handled++;
 606
 607                         /* now suck off the data */
 608                         char buf[64];
 609                         osrf_clearbuf( buf, sizeof(buf) );
 610                         if( (n=read(cur_child->read_status_fd, buf, 63))  < 0 ) {
 611                                 osrfLogWarning( OSRF_LOG_MARK, "Read error after select in child status read with errno %d", errno);
 612                         }
 613
 614                         osrfLogDebug( OSRF_LOG_MARK,  "Read %d bytes from status buffer: %s", n, buf );
 615                         cur_child->available = 1;
 616                 }
 617                 cur_child = cur_child->next;
 618         }
 619
 620 }
 621
 622
 623 static void prefork_child_wait( prefork_child* child ) {
 624
 625         int i,n;
 626         growing_buffer* gbuf = buffer_init( READ_BUFSIZE );
 627         char buf[READ_BUFSIZE];
 628         osrf_clearbuf( buf, sizeof(buf) );
 629
 630         for( i = 0; i < child->max_requests; i++ ) {
 631
 632                 n = -1;
 633                 int gotdata = 0;
 634                 clr_fl(child->read_data_fd, O_NONBLOCK );
 635
 636                 while( (n=read(child->read_data_fd, buf, READ_BUFSIZE-1)) > 0 ) {
 637                         osrfLogDebug(OSRF_LOG_MARK, "Prefork child read %d bytes of data", n);
 638                         if(!gotdata)
 639                                 set_fl(child->read_data_fd, O_NONBLOCK );
 640                         buffer_add( gbuf, buf );
 641                         osrf_clearbuf( buf, sizeof(buf) );
 642                         gotdata = 1;
 643                 }
 644
 645                 if( errno == EAGAIN ) n = 0;
 646
 647       if( errno == EPIPE ) {
 648          osrfLogDebug(OSRF_LOG_MARK, "C child attempted read on broken pipe, exiting...");
 649          break;
 650       }
 651
 652                 if( n < 0 ) {
 653                         osrfLogWarning( OSRF_LOG_MARK,  "Prefork child read returned error with errno %d", errno );
 654                         break;
 655
 656                 } else if( gotdata ) {
 657                         osrfLogDebug(OSRF_LOG_MARK, "Prefork child got a request.. processing..");
 658                         prefork_child_process_request(child, gbuf->buf);
 659                         buffer_reset( gbuf );
 660                 }
 661
 662                 if( i < child->max_requests - 1 )
 663                         write( child->write_status_fd, "available" /*less than 64 bytes*/, 9 );
 664         }
 665
 666         buffer_free(gbuf);
 667
 668         osrfLogDebug( OSRF_LOG_MARK, "Child with max-requests=%d, num-served=%d exiting...[%ld]",
 669                         child->max_requests, i, (long) getpid() );
 670
 671    osrf_prefork_child_exit(child); /* just to be sure */
 672 }
 673
 674
 675 static void add_prefork_child( prefork_simple* forker, prefork_child* child ) {
 676
 677         if( forker->first_child == NULL ) {
 678                 forker->first_child = child;
 679                 child->next = child;
 680                 return;
 681         }
 682
 683         /* we put the child in as the last because, regardless,
 684                 we have to do the DLL splice dance, and this is the
 685            simplest way */
 686
 687         prefork_child* start_child = forker->first_child;
 688         while(1) {
 689                 if( forker->first_child->next == start_child )
 690                         break;
 691                 forker->first_child = forker->first_child->next;
 692         }
 693
 694         /* here we know that forker->first_child is the last element
 695                 in the list and start_child is the first.  Insert the
 696                 new child between them*/
 697
 698         forker->first_child->next = child;
 699         child->next = start_child;
 700         return;
 701 }
 702
 703 //static prefork_child* find_prefork_child( prefork_simple* forker, pid_t pid ) {
 704 //
 705 //      if( forker->first_child == NULL ) { return NULL; }
 706 //      prefork_child* start_child = forker->first_child;
 707 //      do {
 708 //              if( forker->first_child->pid == pid )
 709 //                      return forker->first_child;
 710 //      } while( (forker->first_child = forker->first_child->next) != start_child );
 711 //
 712 //      return NULL;
 713 //}
 714
 715
 716 static void del_prefork_child( prefork_simple* forker, pid_t pid ) {
 717
 718         if( forker->first_child == NULL ) { return; }
 719
 720         (forker->current_num_children)--;
 721         osrfLogDebug( OSRF_LOG_MARK, "Deleting Child: %d", pid );
 722
 723         prefork_child* start_child = forker->first_child; /* starting point */
 724         prefork_child* cur_child        = start_child; /* current pointer */
 725         prefork_child* prev_child       = start_child; /* the trailing pointer */
 726
 727         /* special case where there is only one in the list */
 728         if( start_child == start_child->next ) {
 729                 if( start_child->pid == pid ) {
 730                         forker->first_child = NULL;
 731
 732                         close( start_child->read_data_fd );
 733                         close( start_child->write_data_fd );
 734                         close( start_child->read_status_fd );
 735                         close( start_child->write_status_fd );
 736
 737                         prefork_child_free( start_child );
 738                 }
 739                 return;
 740         }
 741
 742
 743         /* special case where the first item in the list needs to be removed */
 744         if( start_child->pid == pid ) {
 745
 746                 /* find the last one so we can remove the start_child */
 747                 do {
 748                         prev_child = cur_child;
 749                         cur_child = cur_child->next;
 750                 }while( cur_child != start_child );
 751
 752                 /* now cur_child == start_child */
 753                 prev_child->next = cur_child->next;
 754                 forker->first_child = prev_child;
 755
 756                 close( cur_child->read_data_fd );
 757                 close( cur_child->write_data_fd );
 758                 close( cur_child->read_status_fd );
 759                 close( cur_child->write_status_fd );
 760
 761                 prefork_child_free( cur_child );
 762                 return;
 763         }
 764
 765         do {
 766                 prev_child = cur_child;
 767                 cur_child = cur_child->next;
 768
 769                 if( cur_child->pid == pid ) {
 770                         prev_child->next = cur_child->next;
 771
 772                         close( cur_child->read_data_fd );
 773                         close( cur_child->write_data_fd );
 774                         close( cur_child->read_status_fd );
 775                         close( cur_child->write_status_fd );
 776
 777                         prefork_child_free( cur_child );
 778                         return;
 779                 }
 780
 781         } while(cur_child != start_child);
 782 }
 783
 784
 785
 786
 787 static prefork_child* prefork_child_init(
 788         int max_requests, int read_data_fd, int write_data_fd,
 789         int read_status_fd, int write_status_fd ) {
 790
 791         prefork_child* child = (prefork_child*) safe_malloc(sizeof(prefork_child));
 792         child->pid              = 0;
 793         child->max_requests             = max_requests;
 794         child->read_data_fd             = read_data_fd;
 795         child->write_data_fd            = write_data_fd;
 796         child->read_status_fd   = read_status_fd;
 797         child->write_status_fd  = write_status_fd;
 798         child->min_children     = 0;
 799         child->available                        = 1;
 800         child->appname          = NULL;
 801         child->keepalive        = 0;
 802         child->next             = NULL;
 803
 804         return child;
 805 }
 806
 807
 808 static int prefork_free( prefork_simple* prefork ) {
 809
 810         while( prefork->first_child != NULL ) {
 811                 osrfLogInfo( OSRF_LOG_MARK,  "Killing children and sleeping 1 to reap..." );
 812                 kill( 0,        SIGKILL );
 813                 sleep(1);
 814         }
 815
 816         client_free(prefork->connection);
 817         free(prefork->appname);
 818         free( prefork );
 819         return 1;
 820 }
 821
 822 static int prefork_child_free( prefork_child* child ) {
 823         free(child->appname);
 824         close(child->read_data_fd);
 825         close(child->write_status_fd);
 826         free( child );
 827         return 1;
 828 }
 829