Robust/src/Runtime/DSTM/interface/dstmserver.c

   1 /* Coordinator => Machine that initiates the transaction request call for commiting a transaction
   2  * Participant => Machines that host the objects involved in a transaction commit */
   3
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7 #include <pthread.h>
   8 #include <netdb.h>
   9 #include <fcntl.h>
  10 #include <errno.h>
  11 #include <string.h>
  12 #include "dstm.h"
  13 #include "mlookup.h"
  14 #include "llookup.h"
  15 #include "threadnotify.h"
  16 #ifdef COMPILER
  17 #include "thread.h"
  18 #endif
  19
  20
  21 #define LISTEN_PORT 2156
  22 #define BACKLOG 10 //max pending connections
  23 #define RECEIVE_BUFFER_SIZE 2048
  24
  25 extern int classsize[];
  26
  27 objstr_t *mainobjstore;
  28 pthread_mutex_t mainobjstore_mutex;
  29 pthread_mutexattr_t mainobjstore_mutex_attr; /* Attribute for lock to make it a recursive lock */
  30 /**********************************************************
  31  * Global variables to map socketid and remote mid
  32  * to  resuse sockets
  33  **************************************************/
  34 midSocketInfo_t sockArray[NUM_MACHINES];
  35 int sockCount; //number of connections with all remote machines(one socket per mc)
  36 int sockIdFound; //track if socket file descriptor is already established
  37 pthread_mutex_t sockLock = PTHREAD_MUTEX_INITIALIZER; //lock to prevent global sock variables to be inconsistent
  38
  39 /* This function initializes the main objects store and creates the
  40  * global machine and location lookup table */
  41
  42 int dstmInit(void)
  43 {
  44         mainobjstore = objstrCreate(DEFAULT_OBJ_STORE_SIZE);
  45         /* Initialize attribute for mutex */
  46         pthread_mutexattr_init(&mainobjstore_mutex_attr);
  47         pthread_mutexattr_settype(&mainobjstore_mutex_attr, PTHREAD_MUTEX_RECURSIVE_NP);
  48         pthread_mutex_init(&mainobjstore_mutex, &mainobjstore_mutex_attr);
  49         if (mhashCreate(HASH_SIZE, LOADFACTOR))
  50                 return 1; //failure
  51
  52         if (lhashCreate(HASH_SIZE, LOADFACTOR))
  53                 return 1; //failure
  54
  55         if (notifyhashCreate(N_HASH_SIZE, N_LOADFACTOR))
  56                 return 1; //failure
  57
  58         //Initialize mid to socketid mapping array
  59         int t;
  60         sockCount = 0;
  61         for(t = 0; t < NUM_MACHINES; t++) {
  62                 sockArray[t].mid = 0;
  63                 sockArray[t].sockid = 0;
  64         }
  65
  66         return 0;
  67 }
  68
  69 /* This function starts the thread to listen on a socket
  70  * for tranaction calls */
  71 void *dstmListen()
  72 {
  73         int listenfd, acceptfd;
  74         struct sockaddr_in my_addr;
  75         struct sockaddr_in client_addr;
  76         socklen_t addrlength = sizeof(struct sockaddr);
  77         pthread_t thread_dstm_accept;
  78         int i;
  79         int setsockflag=1;
  80
  81         listenfd = socket(AF_INET, SOCK_STREAM, 0);
  82         if (listenfd == -1)
  83         {
  84                 perror("socket");
  85                 exit(1);
  86         }
  87
  88         if (setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &setsockflag, sizeof (setsockflag)) < 0) {
  89           perror("socket");
  90           exit(1);
  91         }
  92 #ifdef MAC
  93         if (setsockopt(listenfd, SOL_SOCKET, SO_NOSIGPIPE, &setsockflag, sizeof (setsockflag)) < 0) {
  94           perror("socket");
  95           exit(1);
  96         }
  97 #endif
  98
  99         my_addr.sin_family = AF_INET;
 100         my_addr.sin_port = htons(LISTEN_PORT);
 101         my_addr.sin_addr.s_addr = INADDR_ANY;
 102         memset(&(my_addr.sin_zero), '\0', 8);
 103
 104         if (bind(listenfd, (struct sockaddr *)&my_addr, addrlength) == -1)
 105         {
 106                 perror("bind");
 107                 exit(1);
 108         }
 109
 110         if (listen(listenfd, BACKLOG) == -1)
 111         {
 112                 perror("listen");
 113                 exit(1);
 114         }
 115
 116         printf("Listening on port %d, fd = %d\n", LISTEN_PORT, listenfd);
 117         while(1)
 118         {
 119           int retval;
 120           acceptfd = accept(listenfd, (struct sockaddr *)&client_addr, &addrlength);
 121           do {
 122             retval=pthread_create(&thread_dstm_accept, NULL, dstmAccept, (void *)acceptfd);
 123           } while(retval!=0);
 124           pthread_detach(thread_dstm_accept);
 125         }
 126 }
 127 /* This function accepts a new connection request, decodes the control message in the connection
 128  * and accordingly calls other functions to process new requests */
 129 void *dstmAccept(void *acceptfd) {
 130   int val, retval, size, sum, sockid;
 131   unsigned int oid;
 132   char *buffer;
 133   char control,ctrl;
 134   char *ptr;
 135   void *srcObj;
 136   objheader_t *h;
 137   trans_commit_data_t transinfo;
 138   unsigned short objType, *versionarry, version;
 139   unsigned int *oidarry, numoid, mid, threadid;
 140
 141   transinfo.objlocked = NULL;
 142   transinfo.objnotfound = NULL;
 143   transinfo.modptr = NULL;
 144   transinfo.numlocked = 0;
 145   transinfo.numnotfound = 0;
 146
 147   /* Receive control messages from other machines */
 148   while(true) {
 149     int ret=recv_data_errorcode((int)acceptfd, &control, sizeof(char));
 150     if (ret==-1)
 151       break;
 152     switch(control) {
 153     case READ_REQUEST:
 154       /* Read oid requested and search if available */
 155       recv_data((int)acceptfd, &oid, sizeof(unsigned int));
 156       if((srcObj = mhashSearch(oid)) == NULL) {
 157         printf("Error: Object 0x%x is not found in Main Object Store %s, %d\n", oid, __FILE__, __LINE__);
 158         break;
 159       }
 160       h = (objheader_t *) srcObj;
 161       GETSIZE(size, h);
 162       size += sizeof(objheader_t);
 163       sockid = (int) acceptfd;
 164
 165       if (h == NULL) {
 166         ctrl = OBJECT_NOT_FOUND;
 167         send_data(sockid, &ctrl, sizeof(char));
 168       } else {
 169         /* Type */
 170         char msg[]={OBJECT_FOUND, 0, 0, 0, 0};
 171         *((int *)&msg[1])=size;
 172         send_data(sockid, &msg, sizeof(msg));
 173         send_data(sockid, h, size);
 174       }
 175       break;
 176
 177     case READ_MULT_REQUEST:
 178       break;
 179
 180     case MOVE_REQUEST:
 181       break;
 182
 183     case MOVE_MULT_REQUEST:
 184       break;
 185
 186     case TRANS_REQUEST:
 187       /* Read transaction request */
 188       if((val = readClientReq(&transinfo, (int)acceptfd)) != 0) {
 189         printf("Error: In readClientReq() %s, %d\n", __FILE__, __LINE__);
 190         pthread_exit(NULL);
 191       }
 192       break;
 193     case TRANS_PREFETCH:
 194       if((val = prefetchReq((int)acceptfd)) != 0) {
 195         printf("Error: In prefetchReq() %s, %d\n", __FILE__, __LINE__);
 196         break;
 197       }
 198       break;
 199     case TRANS_PREFETCH_RESPONSE:
 200       if((val = getPrefetchResponse((int) acceptfd)) != 0) {
 201         printf("Error: In getPrefetchResponse() %s, %d\n", __FILE__, __LINE__);
 202         break;
 203       }
 204       break;
 205     case START_REMOTE_THREAD:
 206       recv_data((int)acceptfd, &oid, sizeof(unsigned int));
 207       objType = getObjType(oid);
 208       startDSMthread(oid, objType);
 209       break;
 210
 211     case THREAD_NOTIFY_REQUEST:
 212       recv_data((int)acceptfd, &numoid, sizeof(unsigned int));
 213       size = (sizeof(unsigned int) + sizeof(unsigned short)) * numoid + 2 * sizeof(unsigned int);
 214       if((buffer = calloc(1,size)) == NULL) {
 215         printf("%s() Calloc error at %s, %d\n", __func__, __FILE__, __LINE__);
 216         pthread_exit(NULL);
 217       }
 218
 219       recv_data((int)acceptfd, buffer, size);
 220
 221       oidarry = calloc(numoid, sizeof(unsigned int));
 222       memcpy(oidarry, buffer, sizeof(unsigned int) * numoid);
 223       size = sizeof(unsigned int) * numoid;
 224       versionarry = calloc(numoid, sizeof(unsigned short));
 225       memcpy(versionarry, buffer+size, sizeof(unsigned short) * numoid);
 226       size += sizeof(unsigned short) * numoid;
 227       mid = *((unsigned int *)(buffer+size));
 228       size += sizeof(unsigned int);
 229       threadid = *((unsigned int *)(buffer+size));
 230       processReqNotify(numoid, oidarry, versionarry, mid, threadid);
 231       free(buffer);
 232
 233       break;
 234
 235     case THREAD_NOTIFY_RESPONSE:
 236       size = sizeof(unsigned short) + 2 * sizeof(unsigned int);
 237       if((buffer = calloc(1,size)) == NULL) {
 238         printf("%s() Calloc error at %s, %d\n", __func__, __FILE__, __LINE__);
 239         pthread_exit(NULL);
 240       }
 241
 242       recv_data((int)acceptfd, buffer, size);
 243
 244       oid = *((unsigned int *)buffer);
 245       size = sizeof(unsigned int);
 246       version = *((unsigned short *)(buffer+size));
 247       size += sizeof(unsigned short);
 248       threadid = *((unsigned int *)(buffer+size));
 249       threadNotify(oid,version,threadid);
 250       free(buffer);
 251       break;
 252
 253     case CLOSE_CONNECTION:
 254       goto closeconnection;
 255
 256     default:
 257       printf("Error: dstmAccept() Unknown opcode %d at %s, %d\n", control, __FILE__, __LINE__);
 258     }
 259   }
 260
 261  closeconnection:
 262   /* Close connection */
 263   if (close((int)acceptfd) == -1)
 264     perror("close");
 265   pthread_exit(NULL);
 266 }
 267
 268 /* This function reads the information available in a transaction request
 269  * and makes a function call to process the request */
 270 int readClientReq(trans_commit_data_t *transinfo, int acceptfd) {
 271         char *ptr;
 272         void *modptr;
 273         unsigned int *oidmod, oid;
 274         fixed_data_t fixed;
 275         objheader_t *headaddr;
 276         int sum, i, size, n, val;
 277
 278         oidmod = NULL;
 279
 280         /* Read fixed_data_t data structure */
 281         size = sizeof(fixed) - 1;
 282         ptr = (char *)&fixed;;
 283         fixed.control = TRANS_REQUEST;
 284         recv_data((int)acceptfd, ptr+1, size);
 285
 286         /* Read list of mids */
 287         int mcount = fixed.mcount;
 288         size = mcount * sizeof(unsigned int);
 289         unsigned int listmid[mcount];
 290         ptr = (char *) listmid;
 291         recv_data((int)acceptfd, ptr, size);
 292
 293         /* Read oid and version tuples for those objects that are not modified in the transaction */
 294         int numread = fixed.numread;
 295         size = numread * (sizeof(unsigned int) + sizeof(unsigned short));
 296         char objread[size];
 297         if(numread != 0) { //If pile contains more than one object to be read,
 298                           // keep reading all objects
 299                 recv_data((int)acceptfd, objread, size);
 300         }
 301
 302         /* Read modified objects */
 303         if(fixed.nummod != 0) {
 304                 if ((modptr = calloc(1, fixed.sum_bytes)) == NULL) {
 305                         printf("calloc error for modified objects %s, %d\n", __FILE__, __LINE__);
 306                         return 1;
 307                 }
 308                 size = fixed.sum_bytes;
 309                 recv_data((int)acceptfd, modptr, size);
 310         }
 311
 312         /* Create an array of oids for modified objects */
 313         oidmod = (unsigned int *) calloc(fixed.nummod, sizeof(unsigned int));
 314         if (oidmod == NULL)
 315         {
 316                 printf("calloc error %s, %d\n", __FILE__, __LINE__);
 317                 return 1;
 318         }
 319         ptr = (char *) modptr;
 320         for(i = 0 ; i < fixed.nummod; i++) {
 321           int tmpsize;
 322           headaddr = (objheader_t *) ptr;
 323           oid = OID(headaddr);
 324           oidmod[i] = oid;
 325           GETSIZE(tmpsize, headaddr);
 326           ptr += sizeof(objheader_t) + tmpsize;
 327         }
 328
 329         /*Process the information read */
 330         if((val = processClientReq(&fixed, transinfo, listmid, objread, modptr, oidmod, acceptfd)) != 0) {
 331                 printf("Error: In processClientReq() %s, %d\n", __FILE__, __LINE__);
 332                 /* Free resources */
 333                 if(oidmod != NULL) {
 334                         free(oidmod);
 335                 }
 336                 return 1;
 337         }
 338
 339         /* Free resources */
 340         if(oidmod != NULL) {
 341                 free(oidmod);
 342         }
 343
 344         return 0;
 345 }
 346
 347 /* This function processes the Coordinator's transaction request using "handleTransReq"
 348  * function and sends a reply to the co-ordinator.
 349  * Following this it also receives a new control message from the co-ordinator and processes this message*/
 350 int processClientReq(fixed_data_t *fixed, trans_commit_data_t *transinfo,
 351                 unsigned int *listmid, char *objread, void *modptr, unsigned int *oidmod, int acceptfd) {
 352         char control, sendctrl, retval;
 353         objheader_t *tmp_header;
 354         void *header;
 355         int  i = 0, val;
 356
 357         /* Send reply to the Coordinator */
 358         if((retval = handleTransReq(fixed, transinfo, listmid, objread, modptr,acceptfd)) == 0 ) {
 359                 printf("Error: In handleTransReq() %s, %d\n", __FILE__, __LINE__);
 360                 return 1;
 361         }
 362
 363         recv_data((int)acceptfd, &control, sizeof(char));
 364
 365         /* Process the new control message */
 366         switch(control) {
 367                 case TRANS_ABORT:
 368                         if (fixed->nummod > 0)
 369                                 free(modptr);
 370                         /* Unlock objects that was locked due to this transaction */
 371                         for(i = 0; i< transinfo->numlocked; i++) {
 372                                 if((header = mhashSearch(transinfo->objlocked[i])) == NULL) {
 373                                         printf("mhashSearch returns NULL at %s, %d\n", __FILE__, __LINE__);// find the header address
 374                                         return 1;
 375                                 }
 376                                 STATUS(((objheader_t *)header)) &= ~(LOCK);
 377                         }
 378
 379                         /* Send ack to Coordinator */
 380                         sendctrl = TRANS_UNSUCESSFUL;
 381                         send_data((int)acceptfd, &sendctrl, sizeof(char));
 382                         break;
 383
 384                 case TRANS_COMMIT:
 385                         /* Invoke the transCommit process() */
 386                         if((val = transCommitProcess(modptr, oidmod, transinfo->objlocked, fixed->nummod, transinfo->numlocked, (int)acceptfd)) != 0) {
 387                                 printf("Error: In transCommitProcess() %s, %d\n", __FILE__, __LINE__);
 388                                 /* Free memory */
 389                                 if (transinfo->objlocked != NULL) {
 390                                         free(transinfo->objlocked);
 391                                 }
 392                                 if (transinfo->objnotfound != NULL) {
 393                                         free(transinfo->objnotfound);
 394                                 }
 395                                 return 1;
 396                         }
 397                         break;
 398
 399                 case TRANS_ABORT_BUT_RETRY_COMMIT_WITH_RELOCATING:
 400                         break;
 401                 default:
 402                         printf("Error: No response to TRANS_AGREE OR DISAGREE protocol %s, %d\n", __FILE__, __LINE__);
 403                         //TODO Use fixed.trans_id  TID since Client may have died
 404                         break;
 405         }
 406
 407         /* Free memory */
 408         if (transinfo->objlocked != NULL) {
 409                 free(transinfo->objlocked);
 410         }
 411         if (transinfo->objnotfound != NULL) {
 412                 free(transinfo->objnotfound);
 413         }
 414
 415         return 0;
 416 }
 417
 418 /* This function increments counters while running a voting decision on all objects involved
 419  * in TRANS_REQUEST and If a TRANS_DISAGREE sends the response immediately back to the coordinator */
 420 char handleTransReq(fixed_data_t *fixed, trans_commit_data_t *transinfo, unsigned int *listmid, char *objread, void *modptr, int acceptfd) {
 421         int val, i = 0, j;
 422         unsigned short version;
 423         char control = 0, *ptr;
 424         unsigned int oid;
 425         unsigned int *oidnotfound, *oidlocked;
 426         void *mobj;
 427         objheader_t *headptr;
 428
 429         /* Counters and arrays to formulate decision on control message to be sent */
 430         oidnotfound = (unsigned int *) calloc(fixed->numread + fixed->nummod, sizeof(unsigned int));
 431         oidlocked = (unsigned int *) calloc(fixed->numread + fixed->nummod, sizeof(unsigned int));
 432         int objnotfound = 0, objlocked = 0;
 433         int v_nomatch = 0, v_matchlock = 0, v_matchnolock = 0;
 434
 435         /* modptr points to the beginning of the object store
 436          * created at the Pariticipant.
 437          * Object store holds the modified objects involved in the transaction request */
 438         ptr = (char *) modptr;
 439
 440         /* Process each oid in the machine pile/ group per thread */
 441         for (i = 0; i < fixed->numread + fixed->nummod; i++) {
 442                 if (i < fixed->numread) {//Objs only read and not modified
 443                         int incr = sizeof(unsigned int) + sizeof(unsigned short);// Offset that points to next position in the objread array
 444                         incr *= i;
 445                         oid = *((unsigned int *)(objread + incr));
 446                         incr += sizeof(unsigned int);
 447                         version = *((unsigned short *)(objread + incr));
 448                 } else {//Objs modified
 449                   int tmpsize;
 450                   headptr = (objheader_t *) ptr;
 451                   oid = OID(headptr);
 452                   version = headptr->version;
 453                   GETSIZE(tmpsize, headptr);
 454                   ptr += sizeof(objheader_t) + tmpsize;
 455                 }
 456
 457                 /* Check if object is still present in the machine since the beginning of TRANS_REQUEST */
 458
 459                 if ((mobj = mhashSearch(oid)) == NULL) {/* Obj not found */
 460                         /* Save the oids not found and number of oids not found for later use */
 461                         oidnotfound[objnotfound] = oid;
 462                         objnotfound++;
 463                 } else { /* If Obj found in machine (i.e. has not moved) */
 464                         /* Check if Obj is locked by any previous transaction */
 465                         if ((STATUS(((objheader_t *)mobj)) & LOCK) == LOCK) {
 466                                 if (version == ((objheader_t *)mobj)->version) {      /* If locked then match versions */
 467                                         v_matchlock++;
 468                                 } else {/* If versions don't match ...HARD ABORT */
 469                                         v_nomatch++;
 470                                         /* Send TRANS_DISAGREE to Coordinator */
 471                                         control = TRANS_DISAGREE;
 472                                         if (objlocked > 0) {
 473                                           for(j = 0; j < objlocked; j++) {
 474                                                         if((headptr = mhashSearch(oidlocked[j])) == NULL) {
 475                                                                 printf("mhashSearch returns NULL at %s, %d\n", __FILE__, __LINE__);
 476                                                                 return 0;
 477                                                         }
 478                                                         STATUS(headptr) &= ~(LOCK);
 479                                                 }
 480                                                 free(oidlocked);
 481                                         }
 482                                         send_data(acceptfd, &control, sizeof(char));
 483                                         return control;
 484                                 }
 485                         } else {/* If Obj is not locked then lock object */
 486                                 STATUS(((objheader_t *)mobj)) |= LOCK;
 487                                 /* Save all object oids that are locked on this machine during this transaction request call */
 488                                 oidlocked[objlocked] = OID(((objheader_t *)mobj));
 489                                 objlocked++;
 490                                 if (version == ((objheader_t *)mobj)->version) { /* Check if versions match */
 491                                         v_matchnolock++;
 492                                 } else { /* If versions don't match ...HARD ABORT */
 493                                         v_nomatch++;
 494                                         control = TRANS_DISAGREE;
 495                                         if (objlocked > 0) {
 496                                                 for(j = 0; j < objlocked; j++) {
 497                                                         if((headptr = mhashSearch(oidlocked[j])) == NULL) {
 498                                                                 printf("mhashSearch returns NULL at %s, %d\n", __FILE__, __LINE__);
 499                                                                 return 0;
 500                                                         }
 501                                                         STATUS(headptr) &= ~(LOCK);
 502                                                 }
 503                                                 free(oidlocked);
 504                                         }
 505
 506                                         /* Send TRANS_DISAGREE to Coordinator */
 507                                         send_data(acceptfd, &control, sizeof(char));
 508                                         return control;
 509                                 }
 510                         }
 511                 }
 512         }
 513
 514         /* Decide what control message to send to Coordinator */
 515         if ((control = decideCtrlMessage(fixed, transinfo, &v_matchnolock, &v_matchlock, &v_nomatch, &objnotfound, &objlocked,
 516                                         modptr, oidnotfound, oidlocked, acceptfd)) == 0) {
 517                 printf("Error: In decideCtrlMessage() %s, %d\n", __FILE__, __LINE__);
 518                 return 0;
 519         }
 520
 521         return control;
 522
 523 }
 524 /* This function decides what control message such as TRANS_AGREE, TRANS_DISAGREE or TRANS_SOFT_ABORT
 525  * to send to Coordinator based on the votes of oids involved in the transaction */
 526 char decideCtrlMessage(fixed_data_t *fixed, trans_commit_data_t *transinfo, int *v_matchnolock, int *v_matchlock,
 527                 int *v_nomatch, int *objnotfound, int *objlocked, void *modptr,
 528                 unsigned int *oidnotfound, unsigned int *oidlocked, int acceptfd) {
 529         int val;
 530         char control = 0;
 531
 532         /* Condition to send TRANS_AGREE */
 533         if(*(v_matchnolock) == fixed->numread + fixed->nummod) {
 534                 control = TRANS_AGREE;
 535                 /* Send control message */
 536                 send_data(acceptfd, &control, sizeof(char));
 537         }
 538         /* Condition to send TRANS_SOFT_ABORT */
 539         if((*(v_matchlock) > 0 && *(v_nomatch) == 0) || (*(objnotfound) > 0 && *(v_nomatch) == 0)) {
 540                 control = TRANS_SOFT_ABORT;
 541
 542                 /* Send control message */
 543                 send_data(acceptfd, &control, sizeof(char));
 544
 545                 /* Send number of oids not found and the missing oids if objects are missing in the machine */
 546                 if(*(objnotfound) != 0) {
 547                         int msg[1];
 548                         msg[0] = *(objnotfound);
 549                         send_data(acceptfd, &msg, sizeof(int));
 550                         int size = sizeof(unsigned int)* *(objnotfound);
 551                         send_data(acceptfd, oidnotfound, size);
 552                 }
 553         }
 554
 555         /* Fill out the trans_commit_data_t data structure. This is required for a trans commit process
 556          * if Participant receives a TRANS_COMMIT */
 557         transinfo->objlocked = oidlocked;
 558         transinfo->objnotfound = oidnotfound;
 559         transinfo->modptr = modptr;
 560         transinfo->numlocked = *(objlocked);
 561         transinfo->numnotfound = *(objnotfound);
 562
 563         return control;
 564 }
 565
 566 /* This function processes all modified objects involved in a TRANS_COMMIT and updates pointer
 567  * addresses in lookup table and also changes version number
 568  * Sends an ACK back to Coordinator */
 569 int transCommitProcess(void *modptr, unsigned int *oidmod, unsigned int *oidlocked, int nummod, int numlocked, int acceptfd) {
 570         objheader_t *header;
 571         objheader_t *newheader;
 572         int i = 0, offset = 0;
 573         char control;
 574         int tmpsize;
 575
 576         /* Process each modified object saved in the mainobject store */
 577         for(i = 0; i < nummod; i++) {
 578                 if((header = (objheader_t *) mhashSearch(oidmod[i])) == NULL) {
 579                         printf("Error: mhashsearch returns NULL at %s, %d\n", __FILE__, __LINE__);
 580                         return 1;
 581                 }
 582                 GETSIZE(tmpsize,header);
 583                 pthread_mutex_lock(&mainobjstore_mutex);
 584                 memcpy((char*)header + sizeof(objheader_t), ((char *)modptr + sizeof(objheader_t) + offset), tmpsize);
 585                 header->version += 1;
 586                 /* If threads are waiting on this object to be updated, notify them */
 587                 if(header->notifylist != NULL) {
 588                         notifyAll(&header->notifylist, OID(header), header->version);
 589                 }
 590                 pthread_mutex_unlock(&mainobjstore_mutex);
 591                 offset += sizeof(objheader_t) + tmpsize;
 592         }
 593
 594         if (nummod > 0)
 595                 free(modptr);
 596
 597         /* Unlock locked objects */
 598         for(i = 0; i < numlocked; i++) {
 599                 if((header = (objheader_t *) mhashSearch(oidlocked[i])) == NULL) {
 600                         printf("Error: mhashsearch returns NULL at %s, %d\n", __FILE__, __LINE__);
 601                         return 1;
 602                 }
 603                 STATUS(header) &= ~(LOCK);
 604         }
 605         //TODO Update location lookup table
 606
 607         /* Send ack to coordinator */
 608         control = TRANS_SUCESSFUL;
 609         send_data((int)acceptfd, &control, sizeof(char));
 610         return 0;
 611 }
 612
 613 /* This function recevies the oid and offset tuples from the Coordinator's prefetch call.
 614  * Looks for the objects to be prefetched in the main object store.
 615  * If objects are not found then record those and if objects are found
 616  * then use offset values to prefetch references to other objects */
 617
 618 int prefetchReq(int acceptfd) {
 619         int i, size, objsize, numbytes = 0, isArray = 0, numoffset = 0;
 620         int length, sd = -1;
 621         char *recvbuffer, *sendbuffer, control;
 622         unsigned int oid, mid;
 623         short *offsetarry;
 624         objheader_t *header;
 625         struct sockaddr_in remoteAddr;
 626
 627         do {
 628                 recv_data((int)acceptfd, &length, sizeof(int));
 629                 if(length != -1) {
 630                         size = length - sizeof(int);
 631                         if((recvbuffer = calloc(1, size)) == NULL) {
 632                                 printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
 633                                 return -1;
 634                         }
 635                         recv_data((int)acceptfd, recvbuffer, size);
 636                         oid = *((unsigned int *) recvbuffer);
 637                         mid = *((unsigned int *) (recvbuffer + sizeof(unsigned int)));
 638                         size = size - (2 * sizeof(unsigned int));
 639                         numoffset = size / sizeof(short);
 640                         if((offsetarry = calloc(numoffset, sizeof(short))) == NULL) {
 641                                 printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
 642                                 free(recvbuffer);
 643                                 return -1;
 644                         }
 645                         memcpy(offsetarry, recvbuffer + (2 * sizeof(unsigned int)), size);
 646                         free(recvbuffer);
 647                         pthread_mutex_lock(&sockLock);
 648                         sockIdFound = 0;
 649                         pthread_mutex_unlock(&sockLock);
 650             /* If socket is already established then send data reusing socket */
 651                         for(i = 0; i < NUM_MACHINES; i++) {
 652                                 if(sockArray[i].mid == mid) {
 653                                         sd = sockArray[i].sockid;
 654                                         pthread_mutex_lock(&sockLock);
 655                                         sockIdFound = 1;
 656                                         pthread_mutex_unlock(&sockLock);
 657                                         break;
 658                                 }
 659                         }
 660
 661                         if(sockIdFound == 0) {
 662                                 if(sockCount < NUM_MACHINES) {
 663                                         /* Create socket to send information */
 664                                         if ((sd = socket(AF_INET, SOCK_STREAM, 0)) < 0){
 665                                                 perror("prefetchReq():socket()");
 666                                                 return -1;
 667                                         }
 668                                         bzero(&remoteAddr, sizeof(remoteAddr));
 669                                         remoteAddr.sin_family = AF_INET;
 670                                         remoteAddr.sin_port = htons(LISTEN_PORT);
 671                                         remoteAddr.sin_addr.s_addr = htonl(mid);
 672
 673                                         if (connect(sd, (struct sockaddr *)&remoteAddr, sizeof(remoteAddr)) < 0){
 674                                                 perror("connect");
 675                                                 printf("Error: prefetchReq():error %d connecting to %s:%d\n", errno,
 676                                                                 inet_ntoa(remoteAddr.sin_addr), LISTEN_PORT);
 677                                                 close(sd);
 678                                                 return -1;
 679                                         }
 680                                         sockArray[sockCount].mid = mid;
 681                                         sockArray[sockCount].sockid = sd;
 682                                         pthread_mutex_lock(&sockLock);
 683                                         sockCount++;
 684                                         pthread_mutex_unlock(&sockLock);
 685                                 } else {
 686                                         //TODO Fix for connecting to more than 2 machines && close socket
 687                                         printf("%s(): Error: Currently works for only 2 machines\n", __func__);
 688                                         return -1;
 689                                 }
 690                         }
 691
 692                         /*Process each oid */
 693                         if ((header = mhashSearch(oid)) == NULL) {/* Obj not found */
 694                                 /* Save the oids not found in buffer for later use */
 695                                 size = sizeof(int) + sizeof(char) + sizeof(unsigned int) ;
 696                                 if((sendbuffer = calloc(1, size)) == NULL) {
 697                                         printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
 698                                         free(offsetarry);
 699                                         close(sd);
 700                                         return -1;
 701                                 }
 702                                 *((int *) sendbuffer) = size;
 703                                 *((char *)(sendbuffer + sizeof(int))) = OBJECT_NOT_FOUND;
 704                                 *((unsigned int *)(sendbuffer + sizeof(int) + sizeof(char))) = oid;
 705
 706                                 control = TRANS_PREFETCH_RESPONSE;
 707                                 if(sendPrefetchResponse(sd, &control, sendbuffer, &size) != 0) {
 708                                         free(offsetarry);
 709                                         printf("Error: %s() in sending prefetch response at %s, %d\n",
 710                                                         __func__, __FILE__, __LINE__);
 711                                         close(sd);
 712                                         return -1;
 713                                 }
 714                         } else { /* Object Found */
 715                                 int incr = 0;
 716                                 GETSIZE(objsize, header);
 717                                 size = sizeof(int) + sizeof(char) + sizeof(unsigned int) + sizeof(objheader_t) + objsize;
 718                                 if((sendbuffer = calloc(1, size)) == NULL) {
 719                                         printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
 720                                         free(offsetarry);
 721                                         close(sd);
 722                                         return -1;
 723                                 }
 724                                 *((int *) (sendbuffer + incr)) = size;
 725                                 incr += sizeof(int);
 726                                 *((char *)(sendbuffer + incr)) = OBJECT_FOUND;
 727                                 incr += sizeof(char);
 728                                 *((unsigned int *)(sendbuffer+incr)) = oid;
 729                                 incr += sizeof(unsigned int);
 730                                 memcpy(sendbuffer + incr, header, objsize + sizeof(objheader_t));
 731
 732                                 control = TRANS_PREFETCH_RESPONSE;
 733                                 if(sendPrefetchResponse(sd, &control, sendbuffer, &size) != 0) {
 734                                         free(offsetarry);
 735                                         printf("Error: %s() in sending prefetch response at %s, %d\n",
 736                                                         __func__, __FILE__, __LINE__);
 737                                         close(sd);
 738                                         return -1;
 739                                 }
 740
 741                                 /* Calculate the oid corresponding to the offset value */
 742                                 for(i = 0 ; i< numoffset ; i++) {
 743                                         /* Check for arrays  */
 744                                         if(TYPE(header) > NUMCLASSES) {
 745                                                 isArray = 1;
 746                                         }
 747                                         if(isArray == 1) {
 748                                                 int elementsize = classsize[TYPE(header)];
 749                                                 struct ArrayObject *ao = (struct ArrayObject *) (((char *)header) + sizeof(objheader_t));
 750                                                 unsigned short length = ao->___length___;
 751                                                 /* Check if array out of bounds */
 752                                                 if(offsetarry[i]< 0 || offsetarry[i] >= length) {
 753                                                         break;
 754                                                 }
 755                                                 oid = *((unsigned int *)(((char *)header) + sizeof(objheader_t) + sizeof(struct ArrayObject) + (elementsize*offsetarry[i])));
 756                                         } else {
 757                                                 oid = *((unsigned int *)(((char *)header) + sizeof(objheader_t) + offsetarry[i]));
 758                                         }
 759
 760                                         if((header = mhashSearch(oid)) == NULL) {
 761                                                 size = sizeof(int) + sizeof(char) + sizeof(unsigned int) ;
 762                                                 if((sendbuffer = calloc(1, size)) == NULL) {
 763                                                         printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
 764                                                         free(offsetarry);
 765                                                         close(sd);
 766                                                         return -1;
 767                                                 }
 768                                                 *((int *) sendbuffer) = size;
 769                                                 *((char *)(sendbuffer + sizeof(int))) = OBJECT_NOT_FOUND;
 770                                                 *((unsigned int *)(sendbuffer + sizeof(int) + sizeof(char))) = oid;
 771
 772                                                 control = TRANS_PREFETCH_RESPONSE;
 773                                                 if(sendPrefetchResponse(sd, &control, sendbuffer, &size) != 0) {
 774                                                         free(offsetarry);
 775                                                         printf("Error: %s() in sending prefetch response at %s, %d\n",
 776                                                                         __FILE__, __LINE__);
 777                                                         close(sd);
 778                                                         return -1;
 779                                                 }
 780                                                 break;
 781                                         } else {/* Obj Found */
 782                                                 int incr = 0;
 783                                                 GETSIZE(objsize, header);
 784                                                 size = sizeof(int) + sizeof(char) + sizeof(unsigned int) + sizeof(objheader_t) + objsize;
 785                                                 if((sendbuffer = calloc(1, size)) == NULL) {
 786                                                         printf("Calloc error at %s,%d\n", __func__, __FILE__, __LINE__);
 787                                                         free(offsetarry);
 788                                                         close(sd);
 789                                                         return -1;
 790                                                 }
 791                                                 *((int *) (sendbuffer + incr)) = size;
 792                                                 incr += sizeof(int);
 793                                                 *((char *)(sendbuffer + incr)) = OBJECT_FOUND;
 794                                                 incr += sizeof(char);
 795                                                 *((unsigned int *)(sendbuffer+incr)) = oid;
 796                                                 incr += sizeof(unsigned int);
 797                                                 memcpy(sendbuffer + incr, header, objsize + sizeof(objheader_t));
 798
 799                                                 control = TRANS_PREFETCH_RESPONSE;
 800                                                 if(sendPrefetchResponse(sd, &control, sendbuffer, &size) != 0) {
 801                                                         free(offsetarry);
 802                                                         printf("Error: %s() in sending prefetch response at %s, %d\n",
 803                                                                         __func__, __FILE__, __LINE__);
 804                                                         close(sd);
 805                                                         return -1;
 806                                                 }
 807                                         }
 808                                         isArray = 0;
 809                                 }
 810                                 free(offsetarry);
 811                         }
 812                 }
 813         } while (length != -1);
 814         return 0;
 815 }
 816
 817 int sendPrefetchResponse(int sd, char *control, char *sendbuffer, int *size) {
 818         int numbytes = 0;
 819
 820         send_data(sd, control, sizeof(char));
 821         /* Send the buffer with its size */
 822         int length = *(size);
 823         send_data(sd, sendbuffer, length);
 824         free(sendbuffer);
 825         return 0;
 826 }
 827
 828 void processReqNotify(unsigned int numoid, unsigned int *oidarry, unsigned short *versionarry, unsigned int mid, unsigned int threadid) {
 829         objheader_t *header;
 830         unsigned int oid;
 831         unsigned short newversion;
 832         char msg[1+  2 * sizeof(unsigned int) + sizeof(unsigned short)];
 833         int sd;
 834         struct sockaddr_in remoteAddr;
 835         int bytesSent;
 836         int size;
 837
 838         int i = 0;
 839         while(i < numoid) {
 840                 oid = *(oidarry + i);
 841                 if((header = (objheader_t *) mhashSearch(oid)) == NULL) {
 842                         printf("Error: mhashsearch returns NULL at %s, %d\n", __FILE__, __LINE__);
 843                         return;
 844                 } else {
 845                         /* Check to see if versions are same */
 846 checkversion:
 847                         if ((STATUS(header) & LOCK) != LOCK) {
 848                                 //FIXME make locking atomic
 849                                 STATUS(header) |= LOCK;
 850                                 newversion = header->version;
 851                                 if(newversion == *(versionarry + i)) {
 852                                         //Add to the notify list
 853                                         if((header->notifylist = insNode(header->notifylist, threadid, mid)) == NULL) {
 854                                                 printf("Error: Obj notify list points to NULL %s, %d\n", __FILE__, __LINE__);
 855                                                 return;
 856                                         }
 857                                         STATUS(header) &= ~(LOCK);
 858                                 } else {
 859                                         STATUS(header) &= ~(LOCK);
 860                                         if ((sd = socket(AF_INET, SOCK_STREAM, 0)) < 0){
 861                                                 perror("processReqNotify():socket()");
 862                                                 return;
 863                                         }
 864                                         bzero(&remoteAddr, sizeof(remoteAddr));
 865                                         remoteAddr.sin_family = AF_INET;
 866                                         remoteAddr.sin_port = htons(LISTEN_PORT);
 867                                         remoteAddr.sin_addr.s_addr = htonl(mid);
 868
 869                                         if (connect(sd, (struct sockaddr *)&remoteAddr, sizeof(remoteAddr)) < 0){
 870                                                 printf("Error: processReqNotify():error %d connecting to %s:%d\n", errno,
 871                                                                 inet_ntoa(remoteAddr.sin_addr), LISTEN_PORT);
 872                                                 close(sd);
 873                                                 return;
 874                                         } else {
 875                                                 //Send Update notification
 876                                                 msg[0] = THREAD_NOTIFY_RESPONSE;
 877                                                 *((unsigned int *)&msg[1]) = oid;
 878                                                 size = sizeof(unsigned int);
 879                                                 *((unsigned short *)(&msg[1]+size)) = newversion;
 880                                                 size += sizeof(unsigned short);
 881                                                 *((unsigned int *)(&msg[1]+size)) = threadid;
 882                                                 size = 1+ 2*sizeof(unsigned int) + sizeof(unsigned short);
 883                                                 send_data(sd, msg, size);
 884                                         }
 885                                         close(sd);
 886                                 }
 887                         } else {
 888                                 randomdelay();
 889                                 goto checkversion;
 890                         }
 891                 }
 892                 i++;
 893         }
 894         free(oidarry);
 895         free(versionarry);
 896 }