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 {
 131         int val, retval, size, sum, sockid;
 132         unsigned int oid;
 133         char *buffer;
 134         char control,ctrl;
 135         char *ptr;
 136         void *srcObj;
 137         objheader_t *h;
 138         trans_commit_data_t transinfo;
 139         unsigned short objType, *versionarry, version;
 140         unsigned int *oidarry, numoid, mid, threadid;
 141
 142         transinfo.objlocked = NULL;
 143         transinfo.objnotfound = NULL;
 144         transinfo.modptr = NULL;
 145         transinfo.numlocked = 0;
 146         transinfo.numnotfound = 0;
 147
 148         /* Receive control messages from other machines */
 149         recv_data((int)acceptfd, &control, sizeof(char));
 150
 151         switch(control) {
 152                 case READ_REQUEST:
 153             do {
 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                                 recv_data((int)acceptfd, &control, sizeof(char));
 176             } while(control == READ_REQUEST);
 177                         break;
 178
 179                 case READ_MULT_REQUEST:
 180                         break;
 181
 182                 case MOVE_REQUEST:
 183                         break;
 184
 185                 case MOVE_MULT_REQUEST:
 186                         break;
 187
 188                 case TRANS_REQUEST:
 189                         /* Read transaction request */
 190                         if((val = readClientReq(&transinfo, (int)acceptfd)) != 0) {
 191                                 printf("Error: In readClientReq() %s, %d\n", __FILE__, __LINE__);
 192                                 pthread_exit(NULL);
 193                         }
 194                         break;
 195                 case TRANS_PREFETCH:
 196                         do {
 197                                 if((val = prefetchReq((int)acceptfd)) != 0) {
 198                                         printf("Error: In prefetchReq() %s, %d\n", __FILE__, __LINE__);
 199                                         break;
 200                                 }
 201                                 recv_data((int)acceptfd, &control, sizeof(char));
 202                         } while (control == TRANS_PREFETCH);
 203                         break;
 204                 case TRANS_PREFETCH_RESPONSE:
 205                         do {
 206                                 if((val = getPrefetchResponse((int) acceptfd)) != 0) {
 207                                         printf("Error: In getPrefetchResponse() %s, %d\n", __FILE__, __LINE__);
 208                                         break;
 209                                 }
 210                                 recv_data((int)acceptfd, &control, sizeof(char));
 211                         } while (control == TRANS_PREFETCH_RESPONSE);
 212                         break;
 213                 case START_REMOTE_THREAD:
 214                         recv_data((int)acceptfd, &oid, sizeof(unsigned int));
 215                         objType = getObjType(oid);
 216                         startDSMthread(oid, objType);
 217                         break;
 218
 219                 case THREAD_NOTIFY_REQUEST:
 220                         recv_data((int)acceptfd, &numoid, sizeof(unsigned int));
 221                         size = (sizeof(unsigned int) + sizeof(unsigned short)) * numoid + 2 * sizeof(unsigned int);
 222                         if((buffer = calloc(1,size)) == NULL) {
 223                                 printf("%s() Calloc error at %s, %d\n", __func__, __FILE__, __LINE__);
 224                                 pthread_exit(NULL);
 225                         }
 226
 227                         recv_data((int)acceptfd, buffer, size);
 228
 229                         oidarry = calloc(numoid, sizeof(unsigned int));
 230                         memcpy(oidarry, buffer, sizeof(unsigned int) * numoid);
 231                         size = sizeof(unsigned int) * numoid;
 232                         versionarry = calloc(numoid, sizeof(unsigned short));
 233                         memcpy(versionarry, buffer+size, sizeof(unsigned short) * numoid);
 234                         size += sizeof(unsigned short) * numoid;
 235                         mid = *((unsigned int *)(buffer+size));
 236                         size += sizeof(unsigned int);
 237                         threadid = *((unsigned int *)(buffer+size));
 238                         processReqNotify(numoid, oidarry, versionarry, mid, threadid);
 239                         free(buffer);
 240
 241                         break;
 242
 243                 case THREAD_NOTIFY_RESPONSE:
 244                         size = sizeof(unsigned short) + 2 * sizeof(unsigned int);
 245                         if((buffer = calloc(1,size)) == NULL) {
 246                                 printf("%s() Calloc error at %s, %d\n", __func__, __FILE__, __LINE__);
 247                                 pthread_exit(NULL);
 248                         }
 249
 250                         recv_data((int)acceptfd, buffer, size);
 251
 252                         oid = *((unsigned int *)buffer);
 253                         size = sizeof(unsigned int);
 254                         version = *((unsigned short *)(buffer+size));
 255                         size += sizeof(unsigned short);
 256                         threadid = *((unsigned int *)(buffer+size));
 257                         threadNotify(oid,version,threadid);
 258                         free(buffer);
 259
 260                         break;
 261                 default:
 262                         printf("Error: dstmAccept() Unknown opcode %d at %s, %d\n", control, __FILE__, __LINE__);
 263         }
 264
 265         /* Close connection */
 266         if (close((int)acceptfd) == -1)
 267                 perror("close");
 268         pthread_exit(NULL);
 269 }
 270
 271 /* This function reads the information available in a transaction request
 272  * and makes a function call to process the request */
 273 int readClientReq(trans_commit_data_t *transinfo, int acceptfd) {
 274         char *ptr;
 275         void *modptr;
 276         unsigned int *oidmod, oid;
 277         fixed_data_t fixed;
 278         objheader_t *headaddr;
 279         int sum, i, size, n, val;
 280
 281         oidmod = NULL;
 282
 283         /* Read fixed_data_t data structure */
 284         size = sizeof(fixed) - 1;
 285         ptr = (char *)&fixed;;
 286         fixed.control = TRANS_REQUEST;
 287         recv_data((int)acceptfd, ptr+1, size);
 288
 289         /* Read list of mids */
 290         int mcount = fixed.mcount;
 291         size = mcount * sizeof(unsigned int);
 292         unsigned int listmid[mcount];
 293         ptr = (char *) listmid;
 294         recv_data((int)acceptfd, ptr, size);
 295
 296         /* Read oid and version tuples for those objects that are not modified in the transaction */
 297         int numread = fixed.numread;
 298         size = numread * (sizeof(unsigned int) + sizeof(unsigned short));
 299         char objread[size];
 300         if(numread != 0) { //If pile contains more than one object to be read,
 301                           // keep reading all objects
 302                 recv_data((int)acceptfd, objread, size);
 303         }
 304
 305         /* Read modified objects */
 306         if(fixed.nummod != 0) {
 307                 if ((modptr = calloc(1, fixed.sum_bytes)) == NULL) {
 308                         printf("calloc error for modified objects %s, %d\n", __FILE__, __LINE__);
 309                         return 1;
 310                 }
 311                 size = fixed.sum_bytes;
 312                 recv_data((int)acceptfd, modptr, size);
 313         }
 314
 315         /* Create an array of oids for modified objects */
 316         oidmod = (unsigned int *) calloc(fixed.nummod, sizeof(unsigned int));
 317         if (oidmod == NULL)
 318         {
 319                 printf("calloc error %s, %d\n", __FILE__, __LINE__);
 320                 return 1;
 321         }
 322         ptr = (char *) modptr;
 323         for(i = 0 ; i < fixed.nummod; i++) {
 324           int tmpsize;
 325           headaddr = (objheader_t *) ptr;
 326           oid = OID(headaddr);
 327           oidmod[i] = oid;
 328           GETSIZE(tmpsize, headaddr);
 329           ptr += sizeof(objheader_t) + tmpsize;
 330         }
 331
 332         /*Process the information read */
 333         if((val = processClientReq(&fixed, transinfo, listmid, objread, modptr, oidmod, acceptfd)) != 0) {
 334                 printf("Error: In processClientReq() %s, %d\n", __FILE__, __LINE__);
 335                 /* Free resources */
 336                 if(oidmod != NULL) {
 337                         free(oidmod);
 338                 }
 339                 return 1;
 340         }
 341
 342         /* Free resources */
 343         if(oidmod != NULL) {
 344                 free(oidmod);
 345         }
 346
 347         return 0;
 348 }
 349
 350 /* This function processes the Coordinator's transaction request using "handleTransReq"
 351  * function and sends a reply to the co-ordinator.
 352  * Following this it also receives a new control message from the co-ordinator and processes this message*/
 353 int processClientReq(fixed_data_t *fixed, trans_commit_data_t *transinfo,
 354                 unsigned int *listmid, char *objread, void *modptr, unsigned int *oidmod, int acceptfd) {
 355         char control, sendctrl, retval;
 356         objheader_t *tmp_header;
 357         void *header;
 358         int  i = 0, val;
 359
 360         /* Send reply to the Coordinator */
 361         if((retval = handleTransReq(fixed, transinfo, listmid, objread, modptr,acceptfd)) == 0 ) {
 362                 printf("Error: In handleTransReq() %s, %d\n", __FILE__, __LINE__);
 363                 return 1;
 364         }
 365
 366         recv_data((int)acceptfd, &control, sizeof(char));
 367
 368         /* Process the new control message */
 369         switch(control) {
 370                 case TRANS_ABORT:
 371                         if (fixed->nummod > 0)
 372                                 free(modptr);
 373                         /* Unlock objects that was locked due to this transaction */
 374                         for(i = 0; i< transinfo->numlocked; i++) {
 375                                 if((header = mhashSearch(transinfo->objlocked[i])) == NULL) {
 376                                         printf("mhashSearch returns NULL at %s, %d\n", __FILE__, __LINE__);// find the header address
 377                                         return 1;
 378                                 }
 379                                 STATUS(((objheader_t *)header)) &= ~(LOCK);
 380                         }
 381
 382                         /* Send ack to Coordinator */
 383                         sendctrl = TRANS_UNSUCESSFUL;
 384                         send_data((int)acceptfd, &sendctrl, sizeof(char));
 385                         break;
 386
 387                 case TRANS_COMMIT:
 388                         /* Invoke the transCommit process() */
 389                         if((val = transCommitProcess(modptr, oidmod, transinfo->objlocked, fixed->nummod, transinfo->numlocked, (int)acceptfd)) != 0) {
 390                                 printf("Error: In transCommitProcess() %s, %d\n", __FILE__, __LINE__);
 391                                 /* Free memory */
 392                                 if (transinfo->objlocked != NULL) {
 393                                         free(transinfo->objlocked);
 394                                 }
 395                                 if (transinfo->objnotfound != NULL) {
 396                                         free(transinfo->objnotfound);
 397                                 }
 398                                 return 1;
 399                         }
 400                         break;
 401
 402                 case TRANS_ABORT_BUT_RETRY_COMMIT_WITH_RELOCATING:
 403                         break;
 404                 default:
 405                         printf("Error: No response to TRANS_AGREE OR DISAGREE protocol %s, %d\n", __FILE__, __LINE__);
 406                         //TODO Use fixed.trans_id  TID since Client may have died
 407                         break;
 408         }
 409
 410         /* Free memory */
 411         if (transinfo->objlocked != NULL) {
 412                 free(transinfo->objlocked);
 413         }
 414         if (transinfo->objnotfound != NULL) {
 415                 free(transinfo->objnotfound);
 416         }
 417
 418         return 0;
 419 }
 420
 421 /* This function increments counters while running a voting decision on all objects involved
 422  * in TRANS_REQUEST and If a TRANS_DISAGREE sends the response immediately back to the coordinator */
 423 char handleTransReq(fixed_data_t *fixed, trans_commit_data_t *transinfo, unsigned int *listmid, char *objread, void *modptr, int acceptfd) {
 424         int val, i = 0, j;
 425         unsigned short version;
 426         char control = 0, *ptr;
 427         unsigned int oid;
 428         unsigned int *oidnotfound, *oidlocked;
 429         void *mobj;
 430         objheader_t *headptr;
 431
 432         /* Counters and arrays to formulate decision on control message to be sent */
 433         oidnotfound = (unsigned int *) calloc(fixed->numread + fixed->nummod, sizeof(unsigned int));
 434         oidlocked = (unsigned int *) calloc(fixed->numread + fixed->nummod, sizeof(unsigned int));
 435         int objnotfound = 0, objlocked = 0;
 436         int v_nomatch = 0, v_matchlock = 0, v_matchnolock = 0;
 437
 438         /* modptr points to the beginning of the object store
 439          * created at the Pariticipant.
 440          * Object store holds the modified objects involved in the transaction request */
 441         ptr = (char *) modptr;
 442
 443         /* Process each oid in the machine pile/ group per thread */
 444         for (i = 0; i < fixed->numread + fixed->nummod; i++) {
 445                 if (i < fixed->numread) {//Objs only read and not modified
 446                         int incr = sizeof(unsigned int) + sizeof(unsigned short);// Offset that points to next position in the objread array
 447                         incr *= i;
 448                         oid = *((unsigned int *)(objread + incr));
 449                         incr += sizeof(unsigned int);
 450                         version = *((unsigned short *)(objread + incr));
 451                 } else {//Objs modified
 452                   int tmpsize;
 453                   headptr = (objheader_t *) ptr;
 454                   oid = OID(headptr);
 455                   version = headptr->version;
 456                   GETSIZE(tmpsize, headptr);
 457                   ptr += sizeof(objheader_t) + tmpsize;
 458                 }
 459
 460                 /* Check if object is still present in the machine since the beginning of TRANS_REQUEST */
 461
 462                 if ((mobj = mhashSearch(oid)) == NULL) {/* Obj not found */
 463                         /* Save the oids not found and number of oids not found for later use */
 464                         oidnotfound[objnotfound] = oid;
 465                         objnotfound++;
 466                 } else { /* If Obj found in machine (i.e. has not moved) */
 467                         /* Check if Obj is locked by any previous transaction */
 468                         if ((STATUS(((objheader_t *)mobj)) & LOCK) == LOCK) {
 469                                 if (version == ((objheader_t *)mobj)->version) {      /* If locked then match versions */
 470                                         v_matchlock++;
 471                                 } else {/* If versions don't match ...HARD ABORT */
 472                                         v_nomatch++;
 473                                         /* Send TRANS_DISAGREE to Coordinator */
 474                                         control = TRANS_DISAGREE;
 475                                         if (objlocked > 0) {
 476                                           for(j = 0; j < objlocked; j++) {
 477                                                         if((headptr = mhashSearch(oidlocked[j])) == NULL) {
 478                                                                 printf("mhashSearch returns NULL at %s, %d\n", __FILE__, __LINE__);
 479                                                                 return 0;
 480                                                         }
 481                                                         STATUS(headptr) &= ~(LOCK);
 482                                                 }
 483                                                 free(oidlocked);
 484                                         }
 485                                         send_data(acceptfd, &control, sizeof(char));
 486                                         return control;
 487                                 }
 488                         } else {/* If Obj is not locked then lock object */
 489                                 STATUS(((objheader_t *)mobj)) |= LOCK;
 490                                 /* Save all object oids that are locked on this machine during this transaction request call */
 491                                 oidlocked[objlocked] = OID(((objheader_t *)mobj));
 492                                 objlocked++;
 493                                 if (version == ((objheader_t *)mobj)->version) { /* Check if versions match */
 494                                         v_matchnolock++;
 495                                 } else { /* If versions don't match ...HARD ABORT */
 496                                         v_nomatch++;
 497                                         control = TRANS_DISAGREE;
 498                                         if (objlocked > 0) {
 499                                                 for(j = 0; j < objlocked; j++) {
 500                                                         if((headptr = mhashSearch(oidlocked[j])) == NULL) {
 501                                                                 printf("mhashSearch returns NULL at %s, %d\n", __FILE__, __LINE__);
 502                                                                 return 0;
 503                                                         }
 504                                                         STATUS(headptr) &= ~(LOCK);
 505                                                 }
 506                                                 free(oidlocked);
 507                                         }
 508
 509                                         /* Send TRANS_DISAGREE to Coordinator */
 510                                         send_data(acceptfd, &control, sizeof(char));
 511                                         return control;
 512                                 }
 513                         }
 514                 }
 515         }
 516
 517         /* Decide what control message to send to Coordinator */
 518         if ((control = decideCtrlMessage(fixed, transinfo, &v_matchnolock, &v_matchlock, &v_nomatch, &objnotfound, &objlocked,
 519                                         modptr, oidnotfound, oidlocked, acceptfd)) == 0) {
 520                 printf("Error: In decideCtrlMessage() %s, %d\n", __FILE__, __LINE__);
 521                 return 0;
 522         }
 523
 524         return control;
 525
 526 }
 527 /* This function decides what control message such as TRANS_AGREE, TRANS_DISAGREE or TRANS_SOFT_ABORT
 528  * to send to Coordinator based on the votes of oids involved in the transaction */
 529 char decideCtrlMessage(fixed_data_t *fixed, trans_commit_data_t *transinfo, int *v_matchnolock, int *v_matchlock,
 530                 int *v_nomatch, int *objnotfound, int *objlocked, void *modptr,
 531                 unsigned int *oidnotfound, unsigned int *oidlocked, int acceptfd) {
 532         int val;
 533         char control = 0;
 534
 535         /* Condition to send TRANS_AGREE */
 536         if(*(v_matchnolock) == fixed->numread + fixed->nummod) {
 537                 control = TRANS_AGREE;
 538                 /* Send control message */
 539                 send_data(acceptfd, &control, sizeof(char));
 540         }
 541         /* Condition to send TRANS_SOFT_ABORT */
 542         if((*(v_matchlock) > 0 && *(v_nomatch) == 0) || (*(objnotfound) > 0 && *(v_nomatch) == 0)) {
 543                 control = TRANS_SOFT_ABORT;
 544
 545                 /* Send control message */
 546                 send_data(acceptfd, &control, sizeof(char));
 547
 548                 /* Send number of oids not found and the missing oids if objects are missing in the machine */
 549                 if(*(objnotfound) != 0) {
 550                         int msg[1];
 551                         msg[0] = *(objnotfound);
 552                         send_data(acceptfd, &msg, sizeof(int));
 553                         int size = sizeof(unsigned int)* *(objnotfound);
 554                         send_data(acceptfd, oidnotfound, size);
 555                 }
 556         }
 557
 558         /* Fill out the trans_commit_data_t data structure. This is required for a trans commit process
 559          * if Participant receives a TRANS_COMMIT */
 560         transinfo->objlocked = oidlocked;
 561         transinfo->objnotfound = oidnotfound;
 562         transinfo->modptr = modptr;
 563         transinfo->numlocked = *(objlocked);
 564         transinfo->numnotfound = *(objnotfound);
 565
 566         return control;
 567 }
 568
 569 /* This function processes all modified objects involved in a TRANS_COMMIT and updates pointer
 570  * addresses in lookup table and also changes version number
 571  * Sends an ACK back to Coordinator */
 572 int transCommitProcess(void *modptr, unsigned int *oidmod, unsigned int *oidlocked, int nummod, int numlocked, int acceptfd) {
 573         objheader_t *header;
 574         objheader_t *newheader;
 575         int i = 0, offset = 0;
 576         char control;
 577         int tmpsize;
 578
 579         /* Process each modified object saved in the mainobject store */
 580         for(i = 0; i < nummod; i++) {
 581                 if((header = (objheader_t *) mhashSearch(oidmod[i])) == NULL) {
 582                         printf("Error: mhashsearch returns NULL at %s, %d\n", __FILE__, __LINE__);
 583                         return 1;
 584                 }
 585                 GETSIZE(tmpsize,header);
 586                 pthread_mutex_lock(&mainobjstore_mutex);
 587                 memcpy((char*)header + sizeof(objheader_t), ((char *)modptr + sizeof(objheader_t) + offset), tmpsize);
 588                 header->version += 1;
 589                 /* If threads are waiting on this object to be updated, notify them */
 590                 if(header->notifylist != NULL) {
 591                         notifyAll(&header->notifylist, OID(header), header->version);
 592                 }
 593                 pthread_mutex_unlock(&mainobjstore_mutex);
 594                 offset += sizeof(objheader_t) + tmpsize;
 595         }
 596
 597         if (nummod > 0)
 598                 free(modptr);
 599
 600         /* Unlock locked objects */
 601         for(i = 0; i < numlocked; i++) {
 602                 if((header = (objheader_t *) mhashSearch(oidlocked[i])) == NULL) {
 603                         printf("Error: mhashsearch returns NULL at %s, %d\n", __FILE__, __LINE__);
 604                         return 1;
 605                 }
 606                 STATUS(header) &= ~(LOCK);
 607         }
 608         //TODO Update location lookup table
 609
 610         /* Send ack to coordinator */
 611         control = TRANS_SUCESSFUL;
 612         send_data((int)acceptfd, &control, sizeof(char));
 613         return 0;
 614 }
 615
 616 /* This function recevies the oid and offset tuples from the Coordinator's prefetch call.
 617  * Looks for the objects to be prefetched in the main object store.
 618  * If objects are not found then record those and if objects are found
 619  * then use offset values to prefetch references to other objects */
 620
 621 int prefetchReq(int acceptfd) {
 622         int i, size, objsize, numbytes = 0, isArray = 0, numoffset = 0;
 623         int length, sd = -1;
 624         char *recvbuffer, *sendbuffer, control;
 625         unsigned int oid, mid;
 626         short *offsetarry;
 627         objheader_t *header;
 628         struct sockaddr_in remoteAddr;
 629
 630         do {
 631                 recv_data((int)acceptfd, &length, sizeof(int));
 632                 if(length != -1) {
 633                         size = length - sizeof(int);
 634                         if((recvbuffer = calloc(1, size)) == NULL) {
 635                                 printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
 636                                 return -1;
 637                         }
 638                         recv_data((int)acceptfd, recvbuffer, size);
 639                         oid = *((unsigned int *) recvbuffer);
 640                         mid = *((unsigned int *) (recvbuffer + sizeof(unsigned int)));
 641                         size = size - (2 * sizeof(unsigned int));
 642                         numoffset = size / sizeof(short);
 643                         if((offsetarry = calloc(numoffset, sizeof(short))) == NULL) {
 644                                 printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
 645                                 free(recvbuffer);
 646                                 return -1;
 647                         }
 648                         memcpy(offsetarry, recvbuffer + (2 * sizeof(unsigned int)), size);
 649                         free(recvbuffer);
 650                         pthread_mutex_lock(&sockLock);
 651                         sockIdFound = 0;
 652                         pthread_mutex_unlock(&sockLock);
 653             /* If socket is already established then send data reusing socket */
 654                         for(i = 0; i < NUM_MACHINES; i++) {
 655                                 if(sockArray[i].mid == mid) {
 656                                         sd = sockArray[i].sockid;
 657                                         pthread_mutex_lock(&sockLock);
 658                                         sockIdFound = 1;
 659                                         pthread_mutex_unlock(&sockLock);
 660                                         break;
 661                                 }
 662                         }
 663
 664                         if(sockIdFound == 0) {
 665                                 if(sockCount < NUM_MACHINES) {
 666                                         /* Create socket to send information */
 667                                         if ((sd = socket(AF_INET, SOCK_STREAM, 0)) < 0){
 668                                                 perror("prefetchReq():socket()");
 669                                                 return -1;
 670                                         }
 671                                         bzero(&remoteAddr, sizeof(remoteAddr));
 672                                         remoteAddr.sin_family = AF_INET;
 673                                         remoteAddr.sin_port = htons(LISTEN_PORT);
 674                                         remoteAddr.sin_addr.s_addr = htonl(mid);
 675
 676                                         if (connect(sd, (struct sockaddr *)&remoteAddr, sizeof(remoteAddr)) < 0){
 677                                                 perror("connect");
 678                                                 printf("Error: prefetchReq():error %d connecting to %s:%d\n", errno,
 679                                                                 inet_ntoa(remoteAddr.sin_addr), LISTEN_PORT);
 680                                                 close(sd);
 681                                                 return -1;
 682                                         }
 683                                         sockArray[sockCount].mid = mid;
 684                                         sockArray[sockCount].sockid = sd;
 685                                         pthread_mutex_lock(&sockLock);
 686                                         sockCount++;
 687                                         pthread_mutex_unlock(&sockLock);
 688                                 } else {
 689                                         //TODO Fix for connecting to more than 2 machines && close socket
 690                                         printf("%s(): Error: Currently works for only 2 machines\n", __func__);
 691                                         return -1;
 692                                 }
 693                         }
 694
 695                         /*Process each oid */
 696                         if ((header = mhashSearch(oid)) == NULL) {/* Obj not found */
 697                                 /* Save the oids not found in buffer for later use */
 698                                 size = sizeof(int) + sizeof(char) + sizeof(unsigned int) ;
 699                                 if((sendbuffer = calloc(1, size)) == NULL) {
 700                                         printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
 701                                         free(offsetarry);
 702                                         close(sd);
 703                                         return -1;
 704                                 }
 705                                 *((int *) sendbuffer) = size;
 706                                 *((char *)(sendbuffer + sizeof(int))) = OBJECT_NOT_FOUND;
 707                                 *((unsigned int *)(sendbuffer + sizeof(int) + sizeof(char))) = oid;
 708
 709                                 control = TRANS_PREFETCH_RESPONSE;
 710                                 if(sendPrefetchResponse(sd, &control, sendbuffer, &size) != 0) {
 711                                         free(offsetarry);
 712                                         printf("Error: %s() in sending prefetch response at %s, %d\n",
 713                                                         __func__, __FILE__, __LINE__);
 714                                         close(sd);
 715                                         return -1;
 716                                 }
 717                         } else { /* Object Found */
 718                                 int incr = 0;
 719                                 GETSIZE(objsize, header);
 720                                 size = sizeof(int) + sizeof(char) + sizeof(unsigned int) + sizeof(objheader_t) + objsize;
 721                                 if((sendbuffer = calloc(1, size)) == NULL) {
 722                                         printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
 723                                         free(offsetarry);
 724                                         close(sd);
 725                                         return -1;
 726                                 }
 727                                 *((int *) (sendbuffer + incr)) = size;
 728                                 incr += sizeof(int);
 729                                 *((char *)(sendbuffer + incr)) = OBJECT_FOUND;
 730                                 incr += sizeof(char);
 731                                 *((unsigned int *)(sendbuffer+incr)) = oid;
 732                                 incr += sizeof(unsigned int);
 733                                 memcpy(sendbuffer + incr, header, objsize + sizeof(objheader_t));
 734
 735                                 control = TRANS_PREFETCH_RESPONSE;
 736                                 if(sendPrefetchResponse(sd, &control, sendbuffer, &size) != 0) {
 737                                         free(offsetarry);
 738                                         printf("Error: %s() in sending prefetch response at %s, %d\n",
 739                                                         __func__, __FILE__, __LINE__);
 740                                         close(sd);
 741                                         return -1;
 742                                 }
 743
 744                                 /* Calculate the oid corresponding to the offset value */
 745                                 for(i = 0 ; i< numoffset ; i++) {
 746                                         /* Check for arrays  */
 747                                         if(TYPE(header) > NUMCLASSES) {
 748                                                 isArray = 1;
 749                                         }
 750                                         if(isArray == 1) {
 751                                                 int elementsize = classsize[TYPE(header)];
 752                                                 struct ArrayObject *ao = (struct ArrayObject *) (((char *)header) + sizeof(objheader_t));
 753                                                 unsigned short length = ao->___length___;
 754                                                 /* Check if array out of bounds */
 755                                                 if(offsetarry[i]< 0 || offsetarry[i] >= length) {
 756                                                         break;
 757                                                 }
 758                                                 oid = *((unsigned int *)(((char *)header) + sizeof(objheader_t) + sizeof(struct ArrayObject) + (elementsize*offsetarry[i])));
 759                                         } else {
 760                                                 oid = *((unsigned int *)(((char *)header) + sizeof(objheader_t) + offsetarry[i]));
 761                                         }
 762
 763                                         if((header = mhashSearch(oid)) == NULL) {
 764                                                 size = sizeof(int) + sizeof(char) + sizeof(unsigned int) ;
 765                                                 if((sendbuffer = calloc(1, size)) == NULL) {
 766                                                         printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
 767                                                         free(offsetarry);
 768                                                         close(sd);
 769                                                         return -1;
 770                                                 }
 771                                                 *((int *) sendbuffer) = size;
 772                                                 *((char *)(sendbuffer + sizeof(int))) = OBJECT_NOT_FOUND;
 773                                                 *((unsigned int *)(sendbuffer + sizeof(int) + sizeof(char))) = oid;
 774
 775                                                 control = TRANS_PREFETCH_RESPONSE;
 776                                                 if(sendPrefetchResponse(sd, &control, sendbuffer, &size) != 0) {
 777                                                         free(offsetarry);
 778                                                         printf("Error: %s() in sending prefetch response at %s, %d\n",
 779                                                                         __FILE__, __LINE__);
 780                                                         close(sd);
 781                                                         return -1;
 782                                                 }
 783                                                 break;
 784                                         } else {/* Obj Found */
 785                                                 int incr = 0;
 786                                                 GETSIZE(objsize, header);
 787                                                 size = sizeof(int) + sizeof(char) + sizeof(unsigned int) + sizeof(objheader_t) + objsize;
 788                                                 if((sendbuffer = calloc(1, size)) == NULL) {
 789                                                         printf("Calloc error at %s,%d\n", __func__, __FILE__, __LINE__);
 790                                                         free(offsetarry);
 791                                                         close(sd);
 792                                                         return -1;
 793                                                 }
 794                                                 *((int *) (sendbuffer + incr)) = size;
 795                                                 incr += sizeof(int);
 796                                                 *((char *)(sendbuffer + incr)) = OBJECT_FOUND;
 797                                                 incr += sizeof(char);
 798                                                 *((unsigned int *)(sendbuffer+incr)) = oid;
 799                                                 incr += sizeof(unsigned int);
 800                                                 memcpy(sendbuffer + incr, header, objsize + sizeof(objheader_t));
 801
 802                                                 control = TRANS_PREFETCH_RESPONSE;
 803                                                 if(sendPrefetchResponse(sd, &control, sendbuffer, &size) != 0) {
 804                                                         free(offsetarry);
 805                                                         printf("Error: %s() in sending prefetch response at %s, %d\n",
 806                                                                         __func__, __FILE__, __LINE__);
 807                                                         close(sd);
 808                                                         return -1;
 809                                                 }
 810                                         }
 811                                         isArray = 0;
 812                                 }
 813                                 free(offsetarry);
 814                         }
 815                 }
 816         } while (length != -1);
 817         return 0;
 818 }
 819
 820 int sendPrefetchResponse(int sd, char *control, char *sendbuffer, int *size) {
 821         int numbytes = 0;
 822
 823         send_data(sd, control, sizeof(char));
 824         /* Send the buffer with its size */
 825         int length = *(size);
 826         send_data(sd, sendbuffer, length);
 827         free(sendbuffer);
 828         return 0;
 829 }
 830
 831 void processReqNotify(unsigned int numoid, unsigned int *oidarry, unsigned short *versionarry, unsigned int mid, unsigned int threadid) {
 832         objheader_t *header;
 833         unsigned int oid;
 834         unsigned short newversion;
 835         char msg[1+  2 * sizeof(unsigned int) + sizeof(unsigned short)];
 836         int sd;
 837         struct sockaddr_in remoteAddr;
 838         int bytesSent;
 839         int size;
 840
 841         int i = 0;
 842         while(i < numoid) {
 843                 oid = *(oidarry + i);
 844                 if((header = (objheader_t *) mhashSearch(oid)) == NULL) {
 845                         printf("Error: mhashsearch returns NULL at %s, %d\n", __FILE__, __LINE__);
 846                         return;
 847                 } else {
 848                         /* Check to see if versions are same */
 849 checkversion:
 850                         if ((STATUS(header) & LOCK) != LOCK) {
 851                                 //FIXME make locking atomic
 852                                 STATUS(header) |= LOCK;
 853                                 newversion = header->version;
 854                                 if(newversion == *(versionarry + i)) {
 855                                         //Add to the notify list
 856                                         if((header->notifylist = insNode(header->notifylist, threadid, mid)) == NULL) {
 857                                                 printf("Error: Obj notify list points to NULL %s, %d\n", __FILE__, __LINE__);
 858                                                 return;
 859                                         }
 860                                         STATUS(header) &= ~(LOCK);
 861                                 } else {
 862                                         STATUS(header) &= ~(LOCK);
 863                                         if ((sd = socket(AF_INET, SOCK_STREAM, 0)) < 0){
 864                                                 perror("processReqNotify():socket()");
 865                                                 return;
 866                                         }
 867                                         bzero(&remoteAddr, sizeof(remoteAddr));
 868                                         remoteAddr.sin_family = AF_INET;
 869                                         remoteAddr.sin_port = htons(LISTEN_PORT);
 870                                         remoteAddr.sin_addr.s_addr = htonl(mid);
 871
 872                                         if (connect(sd, (struct sockaddr *)&remoteAddr, sizeof(remoteAddr)) < 0){
 873                                                 printf("Error: processReqNotify():error %d connecting to %s:%d\n", errno,
 874                                                                 inet_ntoa(remoteAddr.sin_addr), LISTEN_PORT);
 875                                                 close(sd);
 876                                                 return;
 877                                         } else {
 878                                                 //Send Update notification
 879                                                 msg[0] = THREAD_NOTIFY_RESPONSE;
 880                                                 *((unsigned int *)&msg[1]) = oid;
 881                                                 size = sizeof(unsigned int);
 882                                                 *((unsigned short *)(&msg[1]+size)) = newversion;
 883                                                 size += sizeof(unsigned short);
 884                                                 *((unsigned int *)(&msg[1]+size)) = threadid;
 885                                                 size = 1+ 2*sizeof(unsigned int) + sizeof(unsigned short);
 886                                                 send_data(sd, msg, size);
 887                                         }
 888                                         close(sd);
 889                                 }
 890                         } else {
 891                                 randomdelay();
 892                                 goto checkversion;
 893                         }
 894                 }
 895                 i++;
 896         }
 897         free(oidarry);
 898         free(versionarry);
 899 }