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                         /* Read oid requested and search if available */
 154                         recv_data((int)acceptfd, &oid, sizeof(unsigned int));
 155                         if((srcObj = mhashSearch(oid)) == NULL) {
 156                                 printf("Error: Object 0x%x is not found in Main Object Store %s, %d\n", oid, __FILE__, __LINE__);
 157                                 pthread_exit(NULL);
 158                         }
 159                         h = (objheader_t *) srcObj;
 160                         GETSIZE(size, h);
 161                         size += sizeof(objheader_t);
 162                         sockid = (int) acceptfd;
 163
 164                         if (h == NULL) {
 165                                 ctrl = OBJECT_NOT_FOUND;
 166                                 send_data(sockid, &ctrl, sizeof(char));
 167                         } else {
 168                                 /* Type */
 169                                 char msg[]={OBJECT_FOUND, 0, 0, 0, 0};
 170                                 *((int *)&msg[1])=size;
 171                                 send_data(sockid, &msg, sizeof(msg));
 172                                 send_data(sockid, h, size);
 173                         }
 174                         break;
 175
 176                 case READ_MULT_REQUEST:
 177                         break;
 178
 179                 case MOVE_REQUEST:
 180                         break;
 181
 182                 case MOVE_MULT_REQUEST:
 183                         break;
 184
 185                 case TRANS_REQUEST:
 186                         /* Read transaction request */
 187                         if((val = readClientReq(&transinfo, (int)acceptfd)) != 0) {
 188                                 printf("Error: In readClientReq() %s, %d\n", __FILE__, __LINE__);
 189                                 pthread_exit(NULL);
 190                         }
 191                         break;
 192                 case TRANS_PREFETCH:
 193                         do {
 194                                 if((val = prefetchReq((int)acceptfd)) != 0) {
 195                                         printf("Error: In prefetchReq() %s, %d\n", __FILE__, __LINE__);
 196                                         break;
 197                                 }
 198                                 recv_data((int)acceptfd, &control, sizeof(char));
 199                         } while (control == TRANS_PREFETCH);
 200                         break;
 201                 case TRANS_PREFETCH_RESPONSE:
 202                         //do {
 203                                 if((val = getPrefetchResponse((int) acceptfd)) != 0) {
 204                                         printf("Error: In getPrefetchResponse() %s, %d\n", __FILE__, __LINE__);
 205                                         pthread_exit(NULL);
 206                                 }
 207                         //} while (control == TRANS_PREFETCH_RESPONSE);
 208                         break;
 209                 case START_REMOTE_THREAD:
 210                         recv_data((int)acceptfd, &oid, sizeof(unsigned int));
 211                         objType = getObjType(oid);
 212                         startDSMthread(oid, objType);
 213                         break;
 214
 215                 case THREAD_NOTIFY_REQUEST:
 216                         recv_data((int)acceptfd, &numoid, sizeof(unsigned int));
 217                         size = (sizeof(unsigned int) + sizeof(unsigned short)) * numoid + 2 * sizeof(unsigned int);
 218                         if((buffer = calloc(1,size)) == NULL) {
 219                                 printf("%s() Calloc error at %s, %d\n", __func__, __FILE__, __LINE__);
 220                                 pthread_exit(NULL);
 221                         }
 222
 223                         recv_data((int)acceptfd, buffer, size);
 224
 225                         oidarry = calloc(numoid, sizeof(unsigned int));
 226                         memcpy(oidarry, buffer, sizeof(unsigned int) * numoid);
 227                         size = sizeof(unsigned int) * numoid;
 228                         versionarry = calloc(numoid, sizeof(unsigned short));
 229                         memcpy(versionarry, buffer+size, sizeof(unsigned short) * numoid);
 230                         size += sizeof(unsigned short) * numoid;
 231                         mid = *((unsigned int *)(buffer+size));
 232                         size += sizeof(unsigned int);
 233                         threadid = *((unsigned int *)(buffer+size));
 234                         processReqNotify(numoid, oidarry, versionarry, mid, threadid);
 235                         free(buffer);
 236
 237                         break;
 238
 239                 case THREAD_NOTIFY_RESPONSE:
 240                         size = sizeof(unsigned short) + 2 * sizeof(unsigned int);
 241                         if((buffer = calloc(1,size)) == NULL) {
 242                                 printf("%s() Calloc error at %s, %d\n", __func__, __FILE__, __LINE__);
 243                                 pthread_exit(NULL);
 244                         }
 245
 246                         recv_data((int)acceptfd, buffer, size);
 247
 248                         oid = *((unsigned int *)buffer);
 249                         size = sizeof(unsigned int);
 250                         version = *((unsigned short *)(buffer+size));
 251                         size += sizeof(unsigned short);
 252                         threadid = *((unsigned int *)(buffer+size));
 253                         threadNotify(oid,version,threadid);
 254                         free(buffer);
 255
 256                         break;
 257                 default:
 258                         printf("Error: dstmAccept() Unknown opcode %d at %s, %d\n", control, __FILE__, __LINE__);
 259         }
 260
 261         /* Close connection */
 262         if (close((int)acceptfd) == -1)
 263                 perror("close");
 264         pthread_exit(NULL);
 265 }
 266
 267 /* This function reads the information available in a transaction request
 268  * and makes a function call to process the request */
 269 int readClientReq(trans_commit_data_t *transinfo, int acceptfd) {
 270         char *ptr;
 271         void *modptr;
 272         unsigned int *oidmod, oid;
 273         fixed_data_t fixed;
 274         objheader_t *headaddr;
 275         int sum, i, size, n, val;
 276
 277         oidmod = NULL;
 278
 279         /* Read fixed_data_t data structure */
 280         size = sizeof(fixed) - 1;
 281         ptr = (char *)&fixed;;
 282         fixed.control = TRANS_REQUEST;
 283         recv_data((int)acceptfd, ptr+1, size);
 284
 285         /* Read list of mids */
 286         int mcount = fixed.mcount;
 287         size = mcount * sizeof(unsigned int);
 288         unsigned int listmid[mcount];
 289         ptr = (char *) listmid;
 290         recv_data((int)acceptfd, ptr, size);
 291
 292         /* Read oid and version tuples for those objects that are not modified in the transaction */
 293         int numread = fixed.numread;
 294         size = numread * (sizeof(unsigned int) + sizeof(unsigned short));
 295         char objread[size];
 296         if(numread != 0) { //If pile contains more than one object to be read,
 297                           // keep reading all objects
 298                 recv_data((int)acceptfd, objread, size);
 299         }
 300
 301         /* Read modified objects */
 302         if(fixed.nummod != 0) {
 303                 if ((modptr = calloc(1, fixed.sum_bytes)) == NULL) {
 304                         printf("calloc error for modified objects %s, %d\n", __FILE__, __LINE__);
 305                         return 1;
 306                 }
 307                 size = fixed.sum_bytes;
 308                 recv_data((int)acceptfd, modptr, size);
 309         }
 310
 311         /* Create an array of oids for modified objects */
 312         oidmod = (unsigned int *) calloc(fixed.nummod, sizeof(unsigned int));
 313         if (oidmod == NULL)
 314         {
 315                 printf("calloc error %s, %d\n", __FILE__, __LINE__);
 316                 return 1;
 317         }
 318         ptr = (char *) modptr;
 319         for(i = 0 ; i < fixed.nummod; i++) {
 320           int tmpsize;
 321           headaddr = (objheader_t *) ptr;
 322           oid = OID(headaddr);
 323           oidmod[i] = oid;
 324           GETSIZE(tmpsize, headaddr);
 325           ptr += sizeof(objheader_t) + tmpsize;
 326         }
 327
 328         /*Process the information read */
 329         if((val = processClientReq(&fixed, transinfo, listmid, objread, modptr, oidmod, acceptfd)) != 0) {
 330                 printf("Error: In processClientReq() %s, %d\n", __FILE__, __LINE__);
 331                 /* Free resources */
 332                 if(oidmod != NULL) {
 333                         free(oidmod);
 334                 }
 335                 return 1;
 336         }
 337
 338         /* Free resources */
 339         if(oidmod != NULL) {
 340                 free(oidmod);
 341         }
 342
 343         return 0;
 344 }
 345
 346 /* This function processes the Coordinator's transaction request using "handleTransReq"
 347  * function and sends a reply to the co-ordinator.
 348  * Following this it also receives a new control message from the co-ordinator and processes this message*/
 349 int processClientReq(fixed_data_t *fixed, trans_commit_data_t *transinfo,
 350                 unsigned int *listmid, char *objread, void *modptr, unsigned int *oidmod, int acceptfd) {
 351         char control, sendctrl, retval;
 352         objheader_t *tmp_header;
 353         void *header;
 354         int  i = 0, val;
 355
 356         /* Send reply to the Coordinator */
 357         if((retval = handleTransReq(fixed, transinfo, listmid, objread, modptr,acceptfd)) == 0 ) {
 358                 printf("Error: In handleTransReq() %s, %d\n", __FILE__, __LINE__);
 359                 return 1;
 360         }
 361
 362         recv_data((int)acceptfd, &control, sizeof(char));
 363
 364         /* Process the new control message */
 365         switch(control) {
 366                 case TRANS_ABORT:
 367                         if (fixed->nummod > 0)
 368                                 free(modptr);
 369                         /* Unlock objects that was locked due to this transaction */
 370                         for(i = 0; i< transinfo->numlocked; i++) {
 371                                 if((header = mhashSearch(transinfo->objlocked[i])) == NULL) {
 372                                         printf("mhashSearch returns NULL at %s, %d\n", __FILE__, __LINE__);// find the header address
 373                                         return 1;
 374                                 }
 375                                 STATUS(((objheader_t *)header)) &= ~(LOCK);
 376                         }
 377
 378                         /* Send ack to Coordinator */
 379                         sendctrl = TRANS_UNSUCESSFUL;
 380                         send_data((int)acceptfd, &sendctrl, sizeof(char));
 381                         break;
 382
 383                 case TRANS_COMMIT:
 384                         /* Invoke the transCommit process() */
 385                         if((val = transCommitProcess(modptr, oidmod, transinfo->objlocked, fixed->nummod, transinfo->numlocked, (int)acceptfd)) != 0) {
 386                                 printf("Error: In transCommitProcess() %s, %d\n", __FILE__, __LINE__);
 387                                 /* Free memory */
 388                                 if (transinfo->objlocked != NULL) {
 389                                         free(transinfo->objlocked);
 390                                 }
 391                                 if (transinfo->objnotfound != NULL) {
 392                                         free(transinfo->objnotfound);
 393                                 }
 394                                 return 1;
 395                         }
 396                         break;
 397
 398                 case TRANS_ABORT_BUT_RETRY_COMMIT_WITH_RELOCATING:
 399                         break;
 400                 default:
 401                         printf("Error: No response to TRANS_AGREE OR DISAGREE protocol %s, %d\n", __FILE__, __LINE__);
 402                         //TODO Use fixed.trans_id  TID since Client may have died
 403                         break;
 404         }
 405
 406         /* Free memory */
 407         if (transinfo->objlocked != NULL) {
 408                 free(transinfo->objlocked);
 409         }
 410         if (transinfo->objnotfound != NULL) {
 411                 free(transinfo->objnotfound);
 412         }
 413
 414         return 0;
 415 }
 416
 417 /* This function increments counters while running a voting decision on all objects involved
 418  * in TRANS_REQUEST and If a TRANS_DISAGREE sends the response immediately back to the coordinator */
 419 char handleTransReq(fixed_data_t *fixed, trans_commit_data_t *transinfo, unsigned int *listmid, char *objread, void *modptr, int acceptfd) {
 420         int val, i = 0, j;
 421         unsigned short version;
 422         char control = 0, *ptr;
 423         unsigned int oid;
 424         unsigned int *oidnotfound, *oidlocked;
 425         void *mobj;
 426         objheader_t *headptr;
 427
 428         /* Counters and arrays to formulate decision on control message to be sent */
 429         oidnotfound = (unsigned int *) calloc(fixed->numread + fixed->nummod, sizeof(unsigned int));
 430         oidlocked = (unsigned int *) calloc(fixed->numread + fixed->nummod, sizeof(unsigned int));
 431         int objnotfound = 0, objlocked = 0;
 432         int v_nomatch = 0, v_matchlock = 0, v_matchnolock = 0;
 433
 434         /* modptr points to the beginning of the object store
 435          * created at the Pariticipant.
 436          * Object store holds the modified objects involved in the transaction request */
 437         ptr = (char *) modptr;
 438
 439         /* Process each oid in the machine pile/ group per thread */
 440         for (i = 0; i < fixed->numread + fixed->nummod; i++) {
 441                 if (i < fixed->numread) {//Objs only read and not modified
 442                         int incr = sizeof(unsigned int) + sizeof(unsigned short);// Offset that points to next position in the objread array
 443                         incr *= i;
 444                         oid = *((unsigned int *)(objread + incr));
 445                         incr += sizeof(unsigned int);
 446                         version = *((unsigned short *)(objread + incr));
 447                 } else {//Objs modified
 448                   int tmpsize;
 449                   headptr = (objheader_t *) ptr;
 450                   oid = OID(headptr);
 451                   version = headptr->version;
 452                   GETSIZE(tmpsize, headptr);
 453                   ptr += sizeof(objheader_t) + tmpsize;
 454                 }
 455
 456                 /* Check if object is still present in the machine since the beginning of TRANS_REQUEST */
 457
 458                 if ((mobj = mhashSearch(oid)) == NULL) {/* Obj not found */
 459                         /* Save the oids not found and number of oids not found for later use */
 460                         oidnotfound[objnotfound] = oid;
 461                         objnotfound++;
 462                 } else { /* If Obj found in machine (i.e. has not moved) */
 463                         /* Check if Obj is locked by any previous transaction */
 464                         if ((STATUS(((objheader_t *)mobj)) & LOCK) == LOCK) {
 465                                 if (version == ((objheader_t *)mobj)->version) {      /* If locked then match versions */
 466                                         v_matchlock++;
 467                                 } else {/* If versions don't match ...HARD ABORT */
 468                                         v_nomatch++;
 469                                         /* Send TRANS_DISAGREE to Coordinator */
 470                                         control = TRANS_DISAGREE;
 471                                         if (objlocked > 0) {
 472                                           for(j = 0; j < objlocked; j++) {
 473                                                         if((headptr = mhashSearch(oidlocked[j])) == NULL) {
 474                                                                 printf("mhashSearch returns NULL at %s, %d\n", __FILE__, __LINE__);
 475                                                                 return 0;
 476                                                         }
 477                                                         STATUS(headptr) &= ~(LOCK);
 478                                                 }
 479                                                 free(oidlocked);
 480                                         }
 481                                         send_data(acceptfd, &control, sizeof(char));
 482                                         return control;
 483                                 }
 484                         } else {/* If Obj is not locked then lock object */
 485                                 STATUS(((objheader_t *)mobj)) |= LOCK;
 486                                 /* Save all object oids that are locked on this machine during this transaction request call */
 487                                 oidlocked[objlocked] = OID(((objheader_t *)mobj));
 488                                 objlocked++;
 489                                 if (version == ((objheader_t *)mobj)->version) { /* Check if versions match */
 490                                         v_matchnolock++;
 491                                 } else { /* If versions don't match ...HARD ABORT */
 492                                         v_nomatch++;
 493                                         control = TRANS_DISAGREE;
 494                                         if (objlocked > 0) {
 495                                                 for(j = 0; j < objlocked; j++) {
 496                                                         if((headptr = mhashSearch(oidlocked[j])) == NULL) {
 497                                                                 printf("mhashSearch returns NULL at %s, %d\n", __FILE__, __LINE__);
 498                                                                 return 0;
 499                                                         }
 500                                                         STATUS(headptr) &= ~(LOCK);
 501                                                 }
 502                                                 free(oidlocked);
 503                                         }
 504
 505                                         /* Send TRANS_DISAGREE to Coordinator */
 506                                         send_data(acceptfd, &control, sizeof(char));
 507                                         return control;
 508                                 }
 509                         }
 510                 }
 511         }
 512
 513         /* Decide what control message to send to Coordinator */
 514         if ((control = decideCtrlMessage(fixed, transinfo, &v_matchnolock, &v_matchlock, &v_nomatch, &objnotfound, &objlocked,
 515                                         modptr, oidnotfound, oidlocked, acceptfd)) == 0) {
 516                 printf("Error: In decideCtrlMessage() %s, %d\n", __FILE__, __LINE__);
 517                 return 0;
 518         }
 519
 520         return control;
 521
 522 }
 523 /* This function decides what control message such as TRANS_AGREE, TRANS_DISAGREE or TRANS_SOFT_ABORT
 524  * to send to Coordinator based on the votes of oids involved in the transaction */
 525 char decideCtrlMessage(fixed_data_t *fixed, trans_commit_data_t *transinfo, int *v_matchnolock, int *v_matchlock,
 526                 int *v_nomatch, int *objnotfound, int *objlocked, void *modptr,
 527                 unsigned int *oidnotfound, unsigned int *oidlocked, int acceptfd) {
 528         int val;
 529         char control = 0;
 530
 531         /* Condition to send TRANS_AGREE */
 532         if(*(v_matchnolock) == fixed->numread + fixed->nummod) {
 533                 control = TRANS_AGREE;
 534                 /* Send control message */
 535                 send_data(acceptfd, &control, sizeof(char));
 536         }
 537         /* Condition to send TRANS_SOFT_ABORT */
 538         if((*(v_matchlock) > 0 && *(v_nomatch) == 0) || (*(objnotfound) > 0 && *(v_nomatch) == 0)) {
 539                 control = TRANS_SOFT_ABORT;
 540
 541                 /* Send control message */
 542                 send_data(acceptfd, &control, sizeof(char));
 543
 544                 /* Send number of oids not found and the missing oids if objects are missing in the machine */
 545                 if(*(objnotfound) != 0) {
 546                         int msg[1];
 547                         msg[0] = *(objnotfound);
 548                         send_data(acceptfd, &msg, sizeof(int));
 549                         int size = sizeof(unsigned int)* *(objnotfound);
 550                         send_data(acceptfd, oidnotfound, size);
 551                 }
 552         }
 553
 554         /* Fill out the trans_commit_data_t data structure. This is required for a trans commit process
 555          * if Participant receives a TRANS_COMMIT */
 556         transinfo->objlocked = oidlocked;
 557         transinfo->objnotfound = oidnotfound;
 558         transinfo->modptr = modptr;
 559         transinfo->numlocked = *(objlocked);
 560         transinfo->numnotfound = *(objnotfound);
 561
 562         return control;
 563 }
 564
 565 /* This function processes all modified objects involved in a TRANS_COMMIT and updates pointer
 566  * addresses in lookup table and also changes version number
 567  * Sends an ACK back to Coordinator */
 568 int transCommitProcess(void *modptr, unsigned int *oidmod, unsigned int *oidlocked, int nummod, int numlocked, int acceptfd) {
 569         objheader_t *header;
 570         objheader_t *newheader;
 571         int i = 0, offset = 0;
 572         char control;
 573         int tmpsize;
 574
 575         /* Process each modified object saved in the mainobject store */
 576         for(i = 0; i < nummod; i++) {
 577                 if((header = (objheader_t *) mhashSearch(oidmod[i])) == NULL) {
 578                         printf("Error: mhashsearch returns NULL at %s, %d\n", __FILE__, __LINE__);
 579                         return 1;
 580                 }
 581                 GETSIZE(tmpsize,header);
 582                 pthread_mutex_lock(&mainobjstore_mutex);
 583                 memcpy((char*)header + sizeof(objheader_t), ((char *)modptr + sizeof(objheader_t) + offset), tmpsize);
 584                 header->version += 1;
 585                 /* If threads are waiting on this object to be updated, notify them */
 586                 if(header->notifylist != NULL) {
 587                         notifyAll(&header->notifylist, OID(header), header->version);
 588                 }
 589                 pthread_mutex_unlock(&mainobjstore_mutex);
 590                 offset += sizeof(objheader_t) + tmpsize;
 591         }
 592
 593         if (nummod > 0)
 594                 free(modptr);
 595
 596         /* Unlock locked objects */
 597         for(i = 0; i < numlocked; i++) {
 598                 if((header = (objheader_t *) mhashSearch(oidlocked[i])) == NULL) {
 599                         printf("Error: mhashsearch returns NULL at %s, %d\n", __FILE__, __LINE__);
 600                         return 1;
 601                 }
 602                 STATUS(header) &= ~(LOCK);
 603         }
 604         //TODO Update location lookup table
 605
 606         /* Send ack to coordinator */
 607         control = TRANS_SUCESSFUL;
 608         send_data((int)acceptfd, &control, sizeof(char));
 609         return 0;
 610 }
 611
 612 /* This function recevies the oid and offset tuples from the Coordinator's prefetch call.
 613  * Looks for the objects to be prefetched in the main object store.
 614  * If objects are not found then record those and if objects are found
 615  * then use offset values to prefetch references to other objects */
 616
 617 int prefetchReq(int acceptfd) {
 618         int i, size, objsize, numbytes = 0, isArray = 0, numoffset = 0;
 619         int length, sd = -1;
 620         char *recvbuffer, *sendbuffer, control;
 621         unsigned int oid, mid;
 622         short *offsetarry;
 623         objheader_t *header;
 624         struct sockaddr_in remoteAddr;
 625
 626         do {
 627                 recv_data((int)acceptfd, &length, sizeof(int));
 628                 if(length != -1) {
 629                         size = length - sizeof(int);
 630                         if((recvbuffer = calloc(1, size)) == NULL) {
 631                                 printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
 632                                 return -1;
 633                         }
 634                         recv_data((int)acceptfd, recvbuffer, size);
 635                         oid = *((unsigned int *) recvbuffer);
 636                         mid = *((unsigned int *) (recvbuffer + sizeof(unsigned int)));
 637                         size = size - (2 * sizeof(unsigned int));
 638                         numoffset = size / sizeof(short);
 639                         if((offsetarry = calloc(numoffset, sizeof(short))) == NULL) {
 640                                 printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
 641                                 free(recvbuffer);
 642                                 return -1;
 643                         }
 644                         memcpy(offsetarry, recvbuffer + (2 * sizeof(unsigned int)), size);
 645                         free(recvbuffer);
 646 #if 0
 647                         pthread_mutex_lock(&sockLock);
 648                         sockIdFound = 0;
 649                         pthread_mutex_unlock(&sockLock);
 650                         for(i = 0; i < NUM_MACHINES; i++) {
 651                                 if(sockArray[i].mid == mid) {
 652                                         sd = sockArray[i].sockid;
 653                                         pthread_mutex_lock(&sockLock);
 654                                         sockIdFound = 1;
 655                                         pthread_mutex_unlock(&sockLock);
 656                                         break;
 657                                 }
 658                         }
 659
 660                         if(sockIdFound == 0) {
 661                                 if(sockCount < NUM_MACHINES) {
 662
 663 #endif
 664                                         /* Create socket to send information */
 665                                         if ((sd = socket(AF_INET, SOCK_STREAM, 0)) < 0){
 666                                                 perror("prefetchReq():socket()");
 667                                                 return -1;
 668                                         }
 669                                         bzero(&remoteAddr, sizeof(remoteAddr));
 670                                         remoteAddr.sin_family = AF_INET;
 671                                         remoteAddr.sin_port = htons(LISTEN_PORT);
 672                                         remoteAddr.sin_addr.s_addr = htonl(mid);
 673
 674                                         if (connect(sd, (struct sockaddr *)&remoteAddr, sizeof(remoteAddr)) < 0){
 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
 681 #if 0
 682                                         sockArray[sockCount].mid = mid;
 683                                         sockArray[sockCount].sockid = sd;
 684                                         pthread_mutex_lock(&sockLock);
 685                                         sockCount++;
 686                                         pthread_mutex_unlock(&sockLock);
 687                                 } else {
 688                                         //TODO Fix for connecting to more than 2 machines && close socket
 689                                         printf("%s(): Error: Currently works for only 2 machines\n", __func__);
 690                                         return -1;
 691                                 }
 692                         }
 693 #endif
 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                         close(sd);
 816                 }
 817         } while (length != -1);
 818         return 0;
 819 }
 820
 821 int sendPrefetchResponse(int sd, char *control, char *sendbuffer, int *size) {
 822         int numbytes = 0;
 823
 824         send_data(sd, control, sizeof(char));
 825         /* Send the buffer with its size */
 826         int length = *(size);
 827         send_data(sd, sendbuffer, length);
 828         free(sendbuffer);
 829         return 0;
 830 }
 831
 832 void processReqNotify(unsigned int numoid, unsigned int *oidarry, unsigned short *versionarry, unsigned int mid, unsigned int threadid) {
 833         objheader_t *header;
 834         unsigned int oid;
 835         unsigned short newversion;
 836         char msg[1+  2 * sizeof(unsigned int) + sizeof(unsigned short)];
 837         int sd;
 838         struct sockaddr_in remoteAddr;
 839         int bytesSent;
 840         int size;
 841
 842         int i = 0;
 843         while(i < numoid) {
 844                 oid = *(oidarry + i);
 845                 if((header = (objheader_t *) mhashSearch(oid)) == NULL) {
 846                         printf("Error: mhashsearch returns NULL at %s, %d\n", __FILE__, __LINE__);
 847                         return;
 848                 } else {
 849                         /* Check to see if versions are same */
 850 checkversion:
 851                         if ((STATUS(header) & LOCK) != LOCK) {
 852                                 //FIXME make locking atomic
 853                                 STATUS(header) |= LOCK;
 854                                 newversion = header->version;
 855                                 if(newversion == *(versionarry + i)) {
 856                                         //Add to the notify list
 857                                         if((header->notifylist = insNode(header->notifylist, threadid, mid)) == NULL) {
 858                                                 printf("Error: Obj notify list points to NULL %s, %d\n", __FILE__, __LINE__);
 859                                                 return;
 860                                         }
 861                                         STATUS(header) &= ~(LOCK);
 862                                 } else {
 863                                         STATUS(header) &= ~(LOCK);
 864                                         if ((sd = socket(AF_INET, SOCK_STREAM, 0)) < 0){
 865                                                 perror("processReqNotify():socket()");
 866                                                 return;
 867                                         }
 868                                         bzero(&remoteAddr, sizeof(remoteAddr));
 869                                         remoteAddr.sin_family = AF_INET;
 870                                         remoteAddr.sin_port = htons(LISTEN_PORT);
 871                                         remoteAddr.sin_addr.s_addr = htonl(mid);
 872
 873                                         if (connect(sd, (struct sockaddr *)&remoteAddr, sizeof(remoteAddr)) < 0){
 874                                                 printf("Error: processReqNotify():error %d connecting to %s:%d\n", errno,
 875                                                                 inet_ntoa(remoteAddr.sin_addr), LISTEN_PORT);
 876                                                 close(sd);
 877                                                 return;
 878                                         } else {
 879                                                 //Send Update notification
 880                                                 msg[0] = THREAD_NOTIFY_RESPONSE;
 881                                                 *((unsigned int *)&msg[1]) = oid;
 882                                                 size = sizeof(unsigned int);
 883                                                 *((unsigned short *)(&msg[1]+size)) = newversion;
 884                                                 size += sizeof(unsigned short);
 885                                                 *((unsigned int *)(&msg[1]+size)) = threadid;
 886                                                 size = 1+ 2*sizeof(unsigned int) + sizeof(unsigned short);
 887                                                 send_data(sd, msg, size);
 888                                         }
 889                                         close(sd);
 890                                 }
 891                         } else {
 892                                 randomdelay();
 893                                 goto checkversion;
 894                         }
 895                 }
 896                 i++;
 897         }
 898         free(oidarry);
 899         free(versionarry);
 900 }