src/libstack/osrf_prefork.c

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