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