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

   1 #include "dstm.h"
   2 #include "ip.h"
   3 #include "clookup.h"
   4 #include "machinepile.h"
   5 #include "mlookup.h"
   6 #include "llookup.h"
   7 #include "plookup.h"
   8 #include "prelookup.h"
   9 #include "queue.h"
  10 #include <pthread.h>
  11 #include <sys/types.h>
  12 #include <sys/socket.h>
  13 #include <netdb.h>
  14 #include <netinet/in.h>
  15 #include <sys/types.h>
  16 #include <unistd.h>
  17 #include <errno.h>
  18 #include <time.h>
  19 #include <string.h>
  20 #include <pthread.h>
  21
  22 #define LISTEN_PORT 2156
  23 #define RECEIVE_BUFFER_SIZE 2048
  24 #define NUM_THREADS 10
  25 #define PREFETCH_CACHE_SIZE 1048576 //1MB
  26
  27 /* Global Variables */
  28 extern int classsize[];
  29 extern primarypfq_t pqueue; // shared prefetch queue
  30 extern mcpileq_t mcqueue;  //Shared queue containing prefetch requests sorted by remote machineids
  31 objstr_t *prefetchcache; //Global Prefetch cache
  32 extern prehashtable_t pflookup; //Global Prefetch cache's lookup table
  33 pthread_t wthreads[NUM_THREADS]; //Worker threads for working on the prefetch queue
  34 pthread_t tPrefetch;
  35 extern objstr_t *mainobjstore;
  36
  37 plistnode_t *createPiles(transrecord_t *);
  38 inline int arrayLength(int *array) {
  39         int i;
  40         for(i=0 ;array[i] != -1; i++)
  41                 ;
  42         return i;
  43 }
  44 inline int findmax(int *array, int arraylength) {
  45         int max, i;
  46         max = array[0];
  47         for(i = 0; i < arraylength; i++){
  48                 if(array[i] > max) {
  49                         max = array[i];
  50                 }
  51         }
  52         return max;
  53 }
  54 /* This function is a prefetch call generated by the compiler that
  55  * populates the shared primary prefetch queue*/
  56 void prefetch(int ntuples, unsigned int *oids, short *endoffsets, short *arrayfields) {
  57         int qnodesize;
  58         int len = 0;
  59
  60         /* Allocate for the queue node*/
  61         char *node;
  62         qnodesize = sizeof(prefetchqelem_t) + sizeof(int) + ntuples * (sizeof(short) + sizeof(unsigned int)) + endoffsets[ntuples - 1] * sizeof(short);
  63         if((node = calloc(1, qnodesize)) == NULL) {
  64                 printf("Calloc Error %s, %d\n", __FILE__, __LINE__);
  65                 return;
  66         }
  67         /* Set queue node values */
  68         len = sizeof(prefetchqelem_t);
  69         memcpy(node + len, &ntuples, sizeof(int));
  70         len += sizeof(int);
  71         memcpy(node + len, oids, ntuples*sizeof(unsigned int));
  72         len += ntuples * sizeof(unsigned int);
  73         memcpy(node + len, endoffsets, ntuples*sizeof(short));
  74         len += ntuples * sizeof(short);
  75         memcpy(node + len, arrayfields, endoffsets[ntuples-1]*sizeof(short));
  76         /* Lock and insert into primary prefetch queue */
  77         pthread_mutex_lock(&pqueue.qlock);
  78         pre_enqueue((prefetchqelem_t *)node);
  79         pthread_cond_signal(&pqueue.qcond);
  80         pthread_mutex_unlock(&pqueue.qlock);
  81 }
  82
  83 /* This function initiates the prefetch thread
  84  * A queue is shared between the main thread of execution
  85  * and the prefetch thread to process the prefetch call
  86  * Call from compiler populates the shared queue with prefetch requests while prefetch thread
  87  * processes the prefetch requests */
  88 void transInit() {
  89         int t, rc;
  90         //Create and initialize prefetch cache structure
  91         prefetchcache = objstrCreate(PREFETCH_CACHE_SIZE);
  92         //Create prefetch cache lookup table
  93         if(prehashCreate(HASH_SIZE, LOADFACTOR))
  94                 return; //Failure
  95         //Initialize primary shared queue
  96         queueInit();
  97         //Initialize machine pile w/prefetch oids and offsets shared queue
  98         mcpileqInit();
  99         //Create the primary prefetch thread
 100         pthread_create(&tPrefetch, NULL, transPrefetch, NULL);
 101         //Create and Initialize a pool of threads
 102         /* Threads are active for the entire period runtime is running */
 103         for(t = 0; t< NUM_THREADS; t++) {
 104                 rc = pthread_create(&wthreads[t], NULL, mcqProcess, (void *)t);
 105                 if (rc) {
 106                         printf("Thread create error %s, %d\n", __FILE__, __LINE__);
 107                         return;
 108                 }
 109         }
 110 }
 111
 112 /* This function stops the threads spawned */
 113 void transExit() {
 114         int t;
 115         pthread_cancel(tPrefetch);
 116         for(t = 0; t < NUM_THREADS; t++)
 117                 pthread_cancel(wthreads[t]);
 118
 119         return;
 120 }
 121
 122 /* This functions inserts randowm wait delays in the order of msec
 123  * Mostly used when transaction commits retry*/
 124 void randomdelay(void)
 125 {
 126         struct timespec req, rem;
 127         time_t t;
 128
 129         t = time(NULL);
 130         req.tv_sec = 0;
 131         req.tv_nsec = (long)(1000000 + (t%10000000)); //1-11 msec
 132         nanosleep(&req, &rem);
 133         return;
 134 }
 135
 136 /* This function initializes things required in the transaction start*/
 137 transrecord_t *transStart()
 138 {
 139         transrecord_t *tmp = malloc(sizeof(transrecord_t));
 140         tmp->cache = objstrCreate(1048576);
 141         tmp->lookupTable = chashCreate(HASH_SIZE, LOADFACTOR);
 142 #ifdef COMPILER
 143         tmp->revertlist=NULL;
 144 #endif
 145         return tmp;
 146 }
 147
 148 /* This function finds the location of the objects involved in a transaction
 149  * and returns the pointer to the object if found in a remote location */
 150 objheader_t *transRead(transrecord_t *record, unsigned int oid) {
 151         printf("Inside transaction read call\n");
 152         unsigned int machinenumber;
 153         objheader_t *tmp, *objheader;
 154         void *objcopy;
 155         int size, rc, found = 0;
 156         void *buf;
 157         struct timespec ts;
 158         struct timeval tp;
 159
 160         rc = gettimeofday(&tp, NULL);
 161
 162         /* Convert from timeval to timespec */
 163         ts.tv_nsec = tp.tv_usec * 1000;
 164
 165         /* Search local transaction cache */
 166         if((objheader = (objheader_t *)chashSearch(record->lookupTable, oid)) != NULL){
 167                 printf("Inside transaction cache \n");
 168                 return(objheader);
 169         } else if ((objheader = (objheader_t *) mhashSearch(oid)) != NULL) {
 170                 /* Look up in machine lookup table  and copy  into cache*/
 171                 printf("Inside mainobject store \n");
 172                 tmp = mhashSearch(oid);
 173                 size = sizeof(objheader_t)+classsize[TYPE(tmp)];
 174                 objcopy = objstrAlloc(record->cache, size);
 175                 memcpy(objcopy, (void *)objheader, size);
 176                 /* Insert into cache's lookup table */
 177                 chashInsert(record->lookupTable, OID(objheader), objcopy);
 178                 return(objcopy);
 179         } else if((tmp = (objheader_t *) prehashSearch(oid)) != NULL) { /* Look up in prefetch cache */
 180                 printf("Inside prefetch cache \n");
 181                 found = 1;
 182                 size = sizeof(objheader_t)+classsize[TYPE(tmp)];
 183                 objcopy = objstrAlloc(record->cache, size);
 184                 memcpy(objcopy, (void *)tmp, size);
 185                 /* Insert into cache's lookup table */
 186                 chashInsert(record->lookupTable, OID(tmp), objcopy);
 187                 return(objcopy);
 188         } else { /* If not found anywhere, then block until object appears in prefetch cache */
 189                 printf("Inside remote machine\n");
 190                 pthread_mutex_lock(&pflookup.lock);
 191                 while(!found) {
 192                         rc = pthread_cond_timedwait(&pflookup.cond, &pflookup.lock, &ts);
 193                         if(rc == ETIMEDOUT) {
 194                                 printf("Wait timed out\n");
 195                                 /* Check Prefetch cache again */
 196                                 if((tmp = (objheader_t *) prehashSearch(oid)) != NULL) { /* Look up in prefetch cache */
 197                                         found = 1;
 198                                         size = sizeof(objheader_t)+classsize[TYPE(tmp)];
 199                                         objcopy = objstrAlloc(record->cache, size);
 200                                         memcpy(objcopy, (void *)tmp, size);
 201                                         /* Insert into cache's lookup table */
 202                                         chashInsert(record->lookupTable, OID(tmp), objcopy);
 203                                         return(objcopy);
 204                                 } else {
 205                                         pthread_mutex_unlock(&pflookup.lock);
 206                                         break;
 207                                 }
 208                                 pthread_mutex_unlock(&pflookup.lock);
 209                         }
 210                 }
 211                 /* Get the object from the remote location */
 212                 machinenumber = lhashSearch(oid);
 213                 objcopy = getRemoteObj(record, machinenumber, oid);
 214                 if(objcopy == NULL) {
 215                         //If object is not found in Remote location
 216                         //printf("Object oid = %d not found in Machine %d\n", oid, machinenumber);
 217                         return NULL;
 218                 }
 219                 else {
 220                         //printf("Object oid = %d found in Machine %d\n", oid, machinenumber);
 221                         return(objcopy);
 222                 }
 223         }
 224 }
 225
 226 /* This function creates objects in the transaction record */
 227 objheader_t *transCreateObj(transrecord_t *record, unsigned short type)
 228 {
 229         objheader_t *tmp = (objheader_t *) objstrAlloc(record->cache, (sizeof(objheader_t) + classsize[type]));
 230         OID(tmp) = getNewOID();
 231         TYPE(tmp) = type;
 232         tmp->version = 1;
 233         tmp->rcount = 0; //? not sure how to handle this yet
 234         STATUS(tmp) = NEW;
 235         chashInsert(record->lookupTable, OID(tmp), tmp);
 236         return tmp;
 237 }
 238
 239 /* This function creates machine piles based on all machines involved in a
 240  * transaction commit request */
 241 plistnode_t *createPiles(transrecord_t *record) {
 242         int i = 0;
 243         unsigned int size;/* Represents number of bins in the chash table */
 244         chashlistnode_t *curr, *ptr, *next;
 245         plistnode_t *pile = NULL;
 246         unsigned int machinenum;
 247         void *localmachinenum;
 248         objheader_t *headeraddr;
 249
 250         ptr = record->lookupTable->table;
 251         size = record->lookupTable->size;
 252
 253         for(i = 0; i < size ; i++) {
 254                 curr = &ptr[i];
 255                 /* Inner loop to traverse the linked list of the cache lookupTable */
 256                 while(curr != NULL) {
 257                         //if the first bin in hash table is empty
 258                         if(curr->key == 0) {
 259                                 break;
 260                         }
 261                         next = curr->next;
 262                         //Get machine location for object id
 263
 264                         if ((machinenum = lhashSearch(curr->key)) == 0) {
 265                                 printf("Error: No such machine %s, %d\n", __FILE__, __LINE__);
 266                                 return NULL;
 267                         }
 268
 269                         if ((headeraddr = chashSearch(record->lookupTable, curr->key)) == NULL) {
 270                                 printf("Error: No such oid %s, %d\n", __FILE__, __LINE__);
 271                                 return NULL;
 272                         }
 273                         //Make machine groups
 274                         if ((pile = pInsert(pile, headeraddr, machinenum, record->lookupTable->numelements)) == NULL) {
 275                                 printf("pInsert error %s, %d\n", __FILE__, __LINE__);
 276                                 return NULL;
 277                         }
 278
 279                         /* Check if local or not */
 280                         if((localmachinenum = mhashSearch(curr->key)) != NULL) {
 281                                 /* Set the pile->local flag*/
 282                                 pile->local = 1; //True i.e. local
 283                         }
 284
 285                         curr = next;
 286                 }
 287         }
 288         return pile;
 289 }
 290
 291 /* This function initiates the transaction commit process
 292  * Spawns threads for each of the new connections with Participants
 293  * and creates new piles by calling the createPiles(),
 294  * Fills the piles with necesaary information and
 295  * Sends a transrequest() to each pile*/
 296 int transCommit(transrecord_t *record) {
 297         unsigned int tot_bytes_mod, *listmid;
 298         plistnode_t *pile;
 299         int i, rc, val;
 300         int pilecount = 0, offset, threadnum = 0, trecvcount = 0, tmachcount = 0;
 301         char buffer[RECEIVE_BUFFER_SIZE],control;
 302         char transid[TID_LEN];
 303         trans_req_data_t *tosend;
 304         trans_commit_data_t transinfo;
 305         static int newtid = 0;
 306         char treplyctrl = 0, treplyretry = 0; /* keeps track of the common response that needs to be sent */
 307         char localstat = 0;
 308
 309
 310         /* Look through all the objects in the transaction record and make piles
 311          * for each machine involved in the transaction*/
 312         pile = createPiles(record);
 313
 314         /* Create the packet to be sent in TRANS_REQUEST */
 315
 316         /* Count the number of participants */
 317         pilecount = pCount(pile);
 318
 319         /* Create a list of machine ids(Participants) involved in transaction   */
 320         if((listmid = calloc(pilecount, sizeof(unsigned int))) == NULL) {
 321                 printf("Calloc error %s, %d\n", __FILE__, __LINE__);
 322                 return 1;
 323         }
 324         pListMid(pile, listmid);
 325
 326
 327         /* Initialize thread variables,
 328          * Spawn a thread for each Participant involved in a transaction */
 329         pthread_t thread[pilecount];
 330         pthread_attr_t attr;
 331         pthread_cond_t tcond;
 332         pthread_mutex_t tlock;
 333         pthread_mutex_t tlshrd;
 334
 335         thread_data_array_t *thread_data_array;
 336         thread_data_array = (thread_data_array_t *) malloc(sizeof(thread_data_array_t)*pilecount);
 337         local_thread_data_array_t *ltdata;
 338         if((ltdata = calloc(1, sizeof(local_thread_data_array_t))) == NULL) {
 339                 printf("Calloc error %s, %d\n", __FILE__, __LINE__);
 340                 return 1;
 341         }
 342
 343         thread_response_t rcvd_control_msg[pilecount];  /* Shared thread array that keeps track of responses of participants */
 344
 345         /* Initialize and set thread detach attribute */
 346         pthread_attr_init(&attr);
 347         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
 348         pthread_mutex_init(&tlock, NULL);
 349         pthread_cond_init(&tcond, NULL);
 350
 351         /* Process each machine pile */
 352         while(pile != NULL) {
 353                 //Create transaction id
 354                 newtid++;
 355                 //trans_req_data_t *tosend;
 356                 if ((tosend = calloc(1, sizeof(trans_req_data_t))) == NULL) {
 357                         printf("Calloc error %s, %d\n", __FILE__, __LINE__);
 358                         return 1;
 359                 }
 360                 tosend->f.control = TRANS_REQUEST;
 361                 sprintf(tosend->f.trans_id, "%x_%d", pile->mid, newtid);
 362                 tosend->f.mcount = pilecount;
 363                 tosend->f.numread = pile->numread;
 364                 tosend->f.nummod = pile->nummod;
 365                 tosend->f.sum_bytes = pile->sum_bytes;
 366                 tosend->listmid = listmid;
 367                 tosend->objread = pile->objread;
 368                 tosend->oidmod = pile->oidmod;
 369                 thread_data_array[threadnum].thread_id = threadnum;
 370                 thread_data_array[threadnum].mid = pile->mid;
 371                 thread_data_array[threadnum].pilecount = pilecount;
 372                 thread_data_array[threadnum].buffer = tosend;
 373                 thread_data_array[threadnum].recvmsg = rcvd_control_msg;
 374                 thread_data_array[threadnum].threshold = &tcond;
 375                 thread_data_array[threadnum].lock = &tlock;
 376                 thread_data_array[threadnum].count = &trecvcount;
 377                 thread_data_array[threadnum].replyctrl = &treplyctrl;
 378                 thread_data_array[threadnum].replyretry = &treplyretry;
 379                 thread_data_array[threadnum].rec = record;
 380                 /* If local do not create any extra connection */
 381                 if(pile->local != 1) { /* Not local */
 382                         rc = pthread_create(&thread[threadnum], NULL, transRequest, (void *) &thread_data_array[threadnum]);
 383                         if (rc) {
 384                                 perror("Error in pthread create\n");
 385                                 return 1;
 386                         }
 387                 } else { /*Local*/
 388                         /*Unset the pile->local flag*/
 389                         pile->local = 0;
 390                         /*Set flag to identify that Local machine is involved*/
 391                         ltdata->tdata = &thread_data_array[threadnum];
 392                         ltdata->transinfo = &transinfo;
 393                         val = pthread_create(&thread[threadnum], NULL, handleLocalReq, (void *) ltdata);
 394                         if (val) {
 395                                 perror("Error in pthread create\n");
 396                                 return 1;
 397                         }
 398                 }
 399                 threadnum++;
 400                 pile = pile->next;
 401         }
 402
 403         /* Free attribute and wait for the other threads */
 404         pthread_attr_destroy(&attr);
 405         for (i = 0 ;i < pilecount ; i++) {
 406                 rc = pthread_join(thread[i], NULL);
 407                 if (rc)
 408                 {
 409                         printf("ERROR return code from pthread_join() is %d\n", rc);
 410                         return 1;
 411                 }
 412         }
 413
 414         /* Free resources */
 415         pthread_cond_destroy(&tcond);
 416         pthread_mutex_destroy(&tlock);
 417         free(tosend);
 418         free(listmid);
 419         pDelete(pile);
 420         free(thread_data_array);
 421         free(ltdata);
 422
 423         /* Retry trans commit procedure if not sucessful in the first try */
 424         if(treplyretry == 1) {
 425                 /* wait a random amount of time */
 426                 randomdelay();
 427                 /* Retry the commiting transaction again */
 428                 transCommit(record);
 429         }
 430
 431         return 0;
 432 }
 433
 434 /* This function sends information involved in the transaction request and
 435  * accepts a response from particpants.
 436  * It calls decideresponse() to decide on what control message
 437  * to send next and sends the message using sendResponse()*/
 438 void *transRequest(void *threadarg) {
 439         int sd, i, n;
 440         struct sockaddr_in serv_addr;
 441         struct hostent *server;
 442         thread_data_array_t *tdata;
 443         objheader_t *headeraddr;
 444         char buffer[RECEIVE_BUFFER_SIZE], control, recvcontrol;
 445         char machineip[16], retval;
 446
 447         tdata = (thread_data_array_t *) threadarg;
 448
 449         /* Send Trans Request */
 450         if ((sd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
 451                 perror("Error in socket for TRANS_REQUEST\n");
 452                 return NULL;
 453         }
 454         bzero((char*) &serv_addr, sizeof(serv_addr));
 455         serv_addr.sin_family = AF_INET;
 456         serv_addr.sin_port = htons(LISTEN_PORT);
 457         midtoIP(tdata->mid,machineip);
 458         machineip[15] = '\0';
 459         serv_addr.sin_addr.s_addr = inet_addr(machineip);
 460         /* Open Connection */
 461         if (connect(sd, (struct sockaddr *) &serv_addr, sizeof(struct sockaddr)) < 0) {
 462                 perror("Error in connect for TRANS_REQUEST\n");
 463                 return NULL;
 464         }
 465
 466         printf("DEBUG-> trans.c Sending TRANS_REQUEST to mid %s\n", machineip);
 467         /* Send bytes of data with TRANS_REQUEST control message */
 468         if (send(sd, &(tdata->buffer->f), sizeof(fixed_data_t),MSG_NOSIGNAL) < sizeof(fixed_data_t)) {
 469                 perror("Error sending fixed bytes for thread\n");
 470                 return NULL;
 471         }
 472         /* Send list of machines involved in the transaction */
 473         {
 474                 int size=sizeof(unsigned int)*tdata->pilecount;
 475                 if (send(sd, tdata->buffer->listmid, size, MSG_NOSIGNAL) < size) {
 476                         perror("Error sending list of machines for thread\n");
 477                         return NULL;
 478                 }
 479         }
 480         /* Send oids and version number tuples for objects that are read */
 481         {
 482                 int size=(sizeof(unsigned int)+sizeof(short))*tdata->buffer->f.numread;
 483                 if (send(sd, tdata->buffer->objread, size, MSG_NOSIGNAL) < size) {
 484                         perror("Error sending tuples for thread\n");
 485                         return NULL;
 486                 }
 487         }
 488         /* Send objects that are modified */
 489         for(i = 0; i < tdata->buffer->f.nummod ; i++) {
 490                 int size;
 491                 headeraddr = chashSearch(tdata->rec->lookupTable, tdata->buffer->oidmod[i]);
 492                 size=sizeof(objheader_t)+classsize[TYPE(headeraddr)];
 493                 if (send(sd, headeraddr, size, MSG_NOSIGNAL)  < size) {
 494                         perror("Error sending obj modified for thread\n");
 495                         return NULL;
 496                 }
 497         }
 498
 499         /* Read control message from Participant */
 500         if((n = read(sd, &control, sizeof(char))) <= 0) {
 501                 perror("Error in reading control message from Participant\n");
 502                 return NULL;
 503         }
 504         recvcontrol = control;
 505
 506         /* Update common data structure and increment count */
 507         tdata->recvmsg[tdata->thread_id].rcv_status = recvcontrol;
 508
 509         /* Lock and update count */
 510         //Thread sleeps until all messages from pariticipants are received by coordinator
 511         pthread_mutex_lock(tdata->lock);
 512
 513         (*(tdata->count))++; /* keeps track of no of messages received by the coordinator */
 514
 515         /* Wake up the threads and invoke decideResponse (once) */
 516         if(*(tdata->count) == tdata->pilecount) {
 517                 if (decideResponse(tdata) != 0) {
 518                         printf("decideResponse returned error %s,%d\n", __FILE__, __LINE__);
 519                         pthread_mutex_unlock(tdata->lock);
 520                         close(sd);
 521                         return NULL;
 522                 }
 523                 pthread_cond_broadcast(tdata->threshold);
 524         } else {
 525                 pthread_cond_wait(tdata->threshold, tdata->lock);
 526         }
 527         pthread_mutex_unlock(tdata->lock);
 528
 529         /* Send the final response such as TRANS_COMMIT or TRANS_ABORT t
 530          * to all participants in their respective socket */
 531         if (sendResponse(tdata, sd) == 0) {
 532                 printf("sendResponse returned error %s,%d\n", __FILE__, __LINE__);
 533                 pthread_mutex_unlock(tdata->lock);
 534                 close(sd);
 535                 return NULL;
 536         }
 537
 538         /* Close connection */
 539         close(sd);
 540         pthread_exit(NULL);
 541 }
 542
 543 /* This function decides the reponse that needs to be sent to
 544  * all Participant machines involved in the transaction commit */
 545 int decideResponse(thread_data_array_t *tdata) {
 546         char control;
 547         int i, transagree = 0, transdisagree = 0, transsoftabort = 0; /* Counters to formulate decision of what
 548                                                                          message to send */
 549
 550         //Check common data structure
 551         for (i = 0 ; i < tdata->pilecount ; i++) {
 552                 /*Switch on response from Participant */
 553                 control = tdata->recvmsg[i].rcv_status; /* tdata: keeps track of all participant responses
 554                                                            written onto the shared array */
 555                 switch(control) {
 556                         case TRANS_DISAGREE:
 557                                 printf("DEBUG-> trans.c Recv TRANS_DISAGREE\n");
 558                                 transdisagree++;
 559                                 break;
 560
 561                         case TRANS_AGREE:
 562                                 printf("DEBUG-> trans.c Recv TRANS_AGREE\n");
 563                                 transagree++;
 564                                 break;
 565
 566                         case TRANS_SOFT_ABORT:
 567                                 printf("DEBUG-> trans.c Recv TRANS_SOFT_ABORT\n");
 568                                 transsoftabort++;
 569                                 break;
 570                         default:
 571                                 printf("Participant sent unknown message in %s, %d\n", __FILE__, __LINE__);
 572                                 return -1;
 573                 }
 574         }
 575
 576         /* Decide what control message to send to Participant */
 577         if(transdisagree > 0) {
 578                 /* Send Abort */
 579                 *(tdata->replyctrl) = TRANS_ABORT;
 580                 printf("DEBUG-> trans.c Sending TRANS_ABORT\n");
 581                 /* Free resources */
 582                 objstrDelete(tdata->rec->cache);
 583                 chashDelete(tdata->rec->lookupTable);
 584                 free(tdata->rec);
 585         } else if(transagree == tdata->pilecount){
 586                 /* Send Commit */
 587                 *(tdata->replyctrl) = TRANS_COMMIT;
 588                 printf("DEBUG-> trans.c Sending TRANS_COMMIT\n");
 589                 /* Free resources */
 590                 objstrDelete(tdata->rec->cache);
 591                 chashDelete(tdata->rec->lookupTable);
 592                 free(tdata->rec);
 593         } else if(transsoftabort > 0 && transdisagree == 0) {
 594                 /* Send Abort in soft abort case followed by retry commiting transaction again*/
 595                 *(tdata->replyctrl) = TRANS_ABORT;
 596                 *(tdata->replyretry) = 1;
 597                 printf("DEBUG-> trans.c Sending TRANS_ABORT\n");
 598         } else {
 599                 printf("DEBUG -> %s, %d: Error: undecided response\n", __FILE__, __LINE__);
 600                 return -1;
 601         }
 602
 603         return 0;
 604 }
 605 /* This function sends the final response to remote machines per thread in their respective socket id */
 606 char sendResponse(thread_data_array_t *tdata, int sd) {
 607         int n, N, sum, oidcount = 0;
 608         char *ptr, retval = 0;
 609         unsigned int *oidnotfound;
 610
 611         /* If the decided response is due to a soft abort and missing objects at the Participant's side */
 612         if(tdata->recvmsg[tdata->thread_id].rcv_status == TRANS_SOFT_ABORT) {
 613                 /* Read list of objects missing */
 614                 if((read(sd, &oidcount, sizeof(int)) != 0) && (oidcount != 0)) {
 615                         N = oidcount * sizeof(unsigned int);
 616                         if((oidnotfound = calloc(oidcount, sizeof(unsigned int))) == NULL) {
 617                                 printf("Calloc error %s, %d\n", __FILE__, __LINE__);
 618                         }
 619                         ptr = (char *) oidnotfound;
 620                         do {
 621                                 n = read(sd, ptr+sum, N-sum);
 622                                 sum += n;
 623                         } while(sum < N && n !=0);
 624                 }
 625                 retval =  TRANS_SOFT_ABORT;
 626         }
 627         /* If the decided response is TRANS_ABORT */
 628         if(*(tdata->replyctrl) == TRANS_ABORT) {
 629                 retval = TRANS_ABORT;
 630         } else if(*(tdata->replyctrl) == TRANS_COMMIT) { /* If the decided response is TRANS_COMMIT */
 631                 retval = TRANS_COMMIT;
 632         }
 633         /* Send response to the Participant */
 634         if (send(sd, tdata->replyctrl, sizeof(char),MSG_NOSIGNAL) < sizeof(char)) {
 635                 perror("Error sending ctrl message for participant\n");
 636         }
 637
 638         return retval;
 639 }
 640
 641 /* This function opens a connection, places an object read request to the
 642  * remote machine, reads the control message and object if available  and
 643  * copies the object and its header to the local cache.
 644  * TODO replace mnum and midtoIP() with MACHINE_IP address later */
 645
 646 void *getRemoteObj(transrecord_t *record, unsigned int mnum, unsigned int oid) {
 647         int sd, size, val;
 648         struct sockaddr_in serv_addr;
 649         struct hostent *server;
 650         char control;
 651         char machineip[16];
 652         objheader_t *h;
 653         void *objcopy;
 654
 655         if ((sd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
 656                 perror("Error in socket\n");
 657                 return NULL;
 658         }
 659         bzero((char*) &serv_addr, sizeof(serv_addr));
 660         serv_addr.sin_family = AF_INET;
 661         serv_addr.sin_port = htons(LISTEN_PORT);
 662         //serv_addr.sin_addr.s_addr = inet_addr(MACHINE_IP);
 663         midtoIP(mnum,machineip);
 664         machineip[15] = '\0';
 665         serv_addr.sin_addr.s_addr = inet_addr(machineip);
 666         /* Open connection */
 667         if (connect(sd, (struct sockaddr *) &serv_addr, sizeof(struct sockaddr)) < 0) {
 668                 perror("Error in connect\n");
 669                 return NULL;
 670         }
 671         char readrequest[sizeof(char)+sizeof(unsigned int)];
 672         readrequest[0] = READ_REQUEST;
 673         *((unsigned int *)(&readrequest[1])) = oid;
 674         if (send(sd, &readrequest, sizeof(readrequest), MSG_NOSIGNAL) < sizeof(readrequest)) {
 675                 perror("Error sending message\n");
 676                 return NULL;
 677         }
 678
 679 #ifdef DEBUG1
 680         printf("DEBUG -> ready to rcv ...\n");
 681 #endif
 682         /* Read response from the Participant */
 683         if((val = read(sd, &control, sizeof(char))) <= 0) {
 684                 perror("No control response for getRemoteObj sent\n");
 685                 return NULL;
 686         }
 687         switch(control) {
 688                 case OBJECT_NOT_FOUND:
 689                         printf("DEBUG -> Control OBJECT_NOT_FOUND received\n");
 690                         return NULL;
 691                 case OBJECT_FOUND:
 692                         /* Read object if found into local cache */
 693                         if((val = read(sd, &size, sizeof(int))) <= 0) {
 694                                 perror("No size is read from the participant\n");
 695                                 return NULL;
 696                         }
 697                         objcopy = objstrAlloc(record->cache, size);
 698                         if((val = read(sd, objcopy, size)) <= 0) {
 699                                 perror("No objects are read from the remote participant\n");
 700                                 return NULL;
 701                         }
 702                         /* Insert into cache's lookup table */
 703                         chashInsert(record->lookupTable, oid, objcopy);
 704                         break;
 705                 default:
 706                         printf("Error in recv request from participant on a READ_REQUEST %s, %d\n",__FILE__, __LINE__);
 707                         return NULL;
 708         }
 709         /* Close connection */
 710         close(sd);
 711         return objcopy;
 712 }
 713
 714 /*This function handles the local trans requests involved in a transaction commiting process
 715  * makes a decision if the local machine sends AGREE or DISAGREE or SOFT_ABORT
 716  * Activates the other nonlocal threads that are waiting for the decision and the
 717  * based on common decision by all groups involved in the transaction it
 718  * either commits or aborts the transaction.
 719  * It also frees the calloced memory resources
 720  */
 721
 722 void *handleLocalReq(void *threadarg) {
 723         int val, i = 0;
 724         short version;
 725         char control = 0, *ptr;
 726         unsigned int oid;
 727         unsigned int *oidnotfound = NULL, *oidlocked = NULL, *oidmod = NULL;
 728         void *mobj, *modptr;
 729         objheader_t *headptr;
 730         local_thread_data_array_t *localtdata;
 731
 732         localtdata = (local_thread_data_array_t *) threadarg;
 733
 734         /* Counters and arrays to formulate decision on control message to be sent */
 735         oidnotfound = (unsigned int *) calloc((localtdata->tdata->buffer->f.numread + localtdata->tdata->buffer->f.nummod), sizeof(unsigned int));
 736         oidlocked = (unsigned int *) calloc((localtdata->tdata->buffer->f.numread + localtdata->tdata->buffer->f.nummod), sizeof(unsigned int));
 737         oidmod = (unsigned int *) calloc(localtdata->tdata->buffer->f.nummod, sizeof(unsigned int));
 738         int objnotfound = 0, objlocked = 0, objmod =0, v_nomatch = 0, v_matchlock = 0, v_matchnolock = 0;
 739         int objmodnotfound = 0, nummodfound = 0;
 740
 741         /* modptr points to the beginning of the object store
 742          * created at the Pariticipant */
 743         if ((modptr = objstrAlloc(mainobjstore, localtdata->tdata->buffer->f.sum_bytes)) == NULL) {
 744                 printf("objstrAlloc error for modified objects %s, %d\n", __FILE__, __LINE__);
 745                 return NULL;
 746         }
 747
 748         ptr = modptr;
 749
 750         /* Process each oid in the machine pile/ group per thread */
 751         for (i = 0; i < localtdata->tdata->buffer->f.numread + localtdata->tdata->buffer->f.nummod; i++) {
 752                 if (i < localtdata->tdata->buffer->f.numread) {//Objs only read and not modified
 753                         int incr = sizeof(unsigned int) + sizeof(short);// Offset that points to next position in the objread array
 754                         incr *= i;
 755                         oid = *((unsigned int *)(localtdata->tdata->buffer->objread + incr));
 756                         incr += sizeof(unsigned int);
 757                         version = *((short *)(localtdata->tdata->buffer->objread + incr));
 758                 } else {//Objs modified
 759                         headptr = (objheader_t *) ptr;
 760                         oid = OID(headptr);
 761                         oidmod[objmod] = oid;//Array containing modified oids
 762                         objmod++;
 763                         version = headptr->version;
 764                         ptr += sizeof(objheader_t) + classsize[TYPE(headptr)];
 765                 }
 766
 767                 /* Check if object is still present in the machine since the beginning of TRANS_REQUEST */
 768
 769                 /* Save the oids not found and number of oids not found for later use */
 770                 if ((mobj = mhashSearch(oid)) == NULL) {/* Obj not found */
 771                         /* Save the oids not found and number of oids not found for later use */
 772
 773                         oidnotfound[objnotfound] = OID(((objheader_t *)mobj));
 774                         objnotfound++;
 775                 } else { /* If Obj found in machine (i.e. has not moved) */
 776                         /* Check if Obj is locked by any previous transaction */
 777                         if (STATUS(((objheader_t *)mobj)) & LOCK) {
 778                                 if (version == ((objheader_t *)mobj)->version) {      /* If not locked then match versions */
 779                                         v_matchlock++;
 780                                 } else {/* If versions don't match ...HARD ABORT */
 781                                         v_nomatch++;
 782                                         /* Send TRANS_DISAGREE to Coordinator */
 783                                         localtdata->tdata->recvmsg[localtdata->tdata->thread_id].rcv_status = TRANS_DISAGREE;
 784                                         printf("DEBUG -> Sending TRANS_DISAGREE\n");
 785                                         //return tdata->recvmsg[tdata->thread_id].rcv_status;
 786                                 }
 787                         } else {/* If Obj is not locked then lock object */
 788                                 STATUS(((objheader_t *)mobj)) |= LOCK;
 789                                 //TODO Remove this for Testing
 790                                 randomdelay();
 791
 792                                 /* Save all object oids that are locked on this machine during this transaction request call */
 793                                 oidlocked[objlocked] = OID(((objheader_t *)mobj));
 794                                 objlocked++;
 795                                 if (version == ((objheader_t *)mobj)->version) { /* Check if versions match */
 796                                         v_matchnolock++;
 797                                 } else { /* If versions don't match ...HARD ABORT */
 798                                         v_nomatch++;
 799                                         /* Send TRANS_DISAGREE to Coordinator */
 800                                         localtdata->tdata->recvmsg[localtdata->tdata->thread_id].rcv_status = TRANS_DISAGREE;
 801                                         printf("DEBUG -> Sending TRANS_DISAGREE\n");
 802                                         //      return tdata->recvmsg[tdata->thread_id].rcv_status;
 803                                 }
 804                         }
 805                 }
 806         }
 807
 808         /*Decide the response to be sent to the Coordinator( the local machine in this case)*/
 809
 810         /* Condition to send TRANS_AGREE */
 811         if(v_matchnolock == localtdata->tdata->buffer->f.numread + localtdata->tdata->buffer->f.nummod) {
 812                 localtdata->tdata->recvmsg[localtdata->tdata->thread_id].rcv_status = TRANS_AGREE;
 813                 printf("DEBUG -> Sending TRANS_AGREE\n");
 814         }
 815         /* Condition to send TRANS_SOFT_ABORT */
 816         if((v_matchlock > 0 && v_nomatch == 0) || (objnotfound > 0 && v_nomatch == 0)) {
 817                 localtdata->tdata->recvmsg[localtdata->tdata->thread_id].rcv_status = TRANS_SOFT_ABORT;
 818                 printf("DEBUG -> Sending TRANS_SOFT_ABORT\n");
 819                 //TODO  currently the only soft abort case that is supported is when object locked by previous
 820                 //transaction => v_matchlock > 0
 821                 //The other case for SOFT ABORT i.e. when object is not found but versions match is not supported
 822                 /* Send number of oids not found and the missing oids if objects are missing in the machine */
 823                 /* TODO Remember to store the oidnotfound for later use
 824                    if(objnotfound != 0) {
 825                    int size = sizeof(unsigned int)* objnotfound;
 826                    }
 827                    */
 828         }
 829
 830         /* Fill out the trans_commit_data_t data structure. This is required for a trans commit process
 831          * if Participant receives a TRANS_COMMIT */
 832         localtdata->transinfo->objmod = oidmod;
 833         localtdata->transinfo->objlocked = oidlocked;
 834         localtdata->transinfo->objnotfound = oidnotfound;
 835         localtdata->transinfo->modptr = modptr;
 836         localtdata->transinfo->nummod = localtdata->tdata->buffer->f.nummod;
 837         localtdata->transinfo->numlocked = objlocked;
 838         localtdata->transinfo->numnotfound = objnotfound;
 839
 840         /*Set flag to show that common data structure for this individual thread has been written to */
 841         //*(tdata->localstatus) |= LM_UPDATED;
 842
 843         /* Lock and update count */
 844         //Thread sleeps until all messages from pariticipants are received by coordinator
 845         pthread_mutex_lock(localtdata->tdata->lock);
 846         (*(localtdata->tdata->count))++; /* keeps track of no of messages received by the coordinator */
 847
 848         /* Wake up the threads and invoke decideResponse (once) */
 849         if(*(localtdata->tdata->count) == localtdata->tdata->pilecount) {
 850                 if (decideResponse(localtdata->tdata) != 0) {
 851                         printf("decideResponse returned error %s,%d\n", __FILE__, __LINE__);
 852                         pthread_mutex_unlock(localtdata->tdata->lock);
 853                         return NULL;
 854                 }
 855                 pthread_cond_broadcast(localtdata->tdata->threshold);
 856         } else {
 857                 pthread_cond_wait(localtdata->tdata->threshold, localtdata->tdata->lock);
 858         }
 859         pthread_mutex_unlock(localtdata->tdata->lock);
 860
 861         /*Based on DecideResponse(), Either COMMIT or ABORT the operation*/
 862         if(*(localtdata->tdata->replyctrl) == TRANS_ABORT){
 863                 if(transAbortProcess(modptr,oidlocked, localtdata->transinfo->numlocked, localtdata->transinfo->nummod, localtdata->tdata->buffer->f.numread) != 0) {
 864                         printf("Error in transAbortProcess() %s,%d\n", __FILE__, __LINE__);
 865                         return NULL;
 866                 }
 867         }else if(*(localtdata->tdata->replyctrl) == TRANS_COMMIT){
 868                 if(transComProcess(localtdata->transinfo) != 0) {
 869                         printf("Error in transComProcess() %s,%d\n", __FILE__, __LINE__);
 870                         return NULL;
 871                 }
 872         }
 873
 874         /* Free memory */
 875         printf("DEBUG -> Freeing...\n");
 876         fflush(stdout);
 877         if (localtdata->transinfo->objmod != NULL) {
 878                 free(localtdata->transinfo->objmod);
 879                 localtdata->transinfo->objmod = NULL;
 880         }
 881         if (localtdata->transinfo->objlocked != NULL) {
 882                 free(localtdata->transinfo->objlocked);
 883                 localtdata->transinfo->objlocked = NULL;
 884         }
 885         if (localtdata->transinfo->objnotfound != NULL) {
 886                 free(localtdata->transinfo->objnotfound);
 887                 localtdata->transinfo->objnotfound = NULL;
 888         }
 889
 890         pthread_exit(NULL);
 891 }
 892 /* This function completes the ABORT process if the transaction is aborting
 893 */
 894 int transAbortProcess(void *modptr, unsigned int *objlocked, int numlocked, int nummod, int numread) {
 895         char *ptr;
 896         int i;
 897         objheader_t *tmp_header;
 898         void *header;
 899
 900         printf("DEBUG -> Recv TRANS_ABORT\n");
 901         /* Set all ref counts as 1 and do garbage collection */
 902         ptr = modptr;
 903         for(i = 0; i< nummod; i++) {
 904                 tmp_header = (objheader_t *)ptr;
 905                 tmp_header->rcount = 1;
 906                 ptr += sizeof(objheader_t) + classsize[TYPE(tmp_header)];
 907         }
 908         /* Unlock objects that was locked due to this transaction */
 909         for(i = 0; i< numlocked; i++) {
 910                 header = mhashSearch(objlocked[i]);// find the header address
 911                 STATUS(((objheader_t *)header)) &= ~(LOCK);
 912         }
 913
 914         /* Send ack to Coordinator */
 915         printf("DEBUG-> TRANS_SUCCESSFUL\n");
 916
 917         /*Free the pointer */
 918         ptr = NULL;
 919         return 0;
 920 }
 921
 922 /*This function completes the COMMIT process is the transaction is commiting
 923 */
 924 int transComProcess(trans_commit_data_t *transinfo) {
 925         objheader_t *header;
 926         int i = 0, offset = 0;
 927         char control;
 928
 929         printf("DEBUG -> Recv TRANS_COMMIT\n");
 930         /* Process each modified object saved in the mainobject store */
 931         for(i=0; i<transinfo->nummod; i++) {
 932                 if((header = (objheader_t *) mhashSearch(transinfo->objmod[i])) == NULL) {
 933                         printf("mhashsearch returns NULL at %s, %d\n", __FILE__, __LINE__);
 934                 }
 935                 /* Change reference count of older address and free space in objstr ?? */
 936                 header->rcount = 1; //TODO Not sure what would be the val
 937
 938                 /* Change ptr address in mhash table */
 939                 mhashRemove(transinfo->objmod[i]);
 940                 mhashInsert(transinfo->objmod[i], (transinfo->modptr + offset));
 941                 offset += sizeof(objheader_t) + classsize[TYPE(header)];
 942
 943                 /* Update object version number */
 944                 header = (objheader_t *) mhashSearch(transinfo->objmod[i]);
 945                 header->version += 1;
 946         }
 947
 948         /* Unlock locked objects */
 949         for(i=0; i<transinfo->numlocked; i++) {
 950                 header = (objheader_t *) mhashSearch(transinfo->objlocked[i]);
 951                 STATUS(header) &= ~(LOCK);
 952         }
 953
 954         //TODO Update location lookup table
 955
 956         /* Send ack to Coordinator */
 957         printf("DEBUG-> TRANS_SUCESSFUL\n");
 958         return 0;
 959 }
 960
 961 /* This function checks if the prefetch oids are same and have same offsets
 962  * for case x.a.b and y.a.b where x and y have same oid's
 963  * or if a.b.c is a subset of x.b.c.d*/
 964 /* check for case where the generated request a.y.z or x.y.z.g then
 965  * prefetch needs to be generated for x.y.z.g  if oid of a and x are same*/
 966 void checkPrefetchTuples(prefetchqelem_t *node) {
 967         int i,j, count,k, sindex, index;
 968         char *ptr, *tmp;
 969         int ntuples, slength;
 970         unsigned int *oid;
 971         short *endoffsets, *arryfields;
 972
 973         /* Check for the case x.y.z and a.b.c are same oids */
 974         ptr = (char *) node;
 975         ntuples = *(GET_NTUPLES(ptr));
 976         oid = GET_PTR_OID(ptr);
 977         endoffsets = GET_PTR_EOFF(ptr, ntuples);
 978         arryfields = GET_PTR_ARRYFLD(ptr, ntuples);
 979         /* Find offset length for each tuple */
 980         int numoffset[ntuples];
 981         numoffset[0] = endoffsets[0];
 982         for(i = 1; i<ntuples; i++) {
 983                 numoffset[i] = endoffsets[i] - endoffsets[i-1];
 984         }
 985         /* Check for redundant tuples by comparing oids of each tuple */
 986         for(i = 0; i < ntuples; i++) {
 987                 if(oid[i] == -1)
 988                         continue;
 989                 for(j = i+1 ; j < ntuples; j++) {
 990                         if(oid[j] == -1)
 991                                 continue;
 992                         /*If oids of tuples match */
 993                         if (oid[i] == oid[j]) {
 994                                 /* Find the smallest offset length of two tuples*/
 995                                 if(numoffset[i] >  numoffset[j]){
 996                                         slength = numoffset[j];
 997                                         sindex = j;
 998                                 }
 999                                 else {
1000                                         slength = numoffset[i];
1001                                         sindex = i;
1002                                 }
1003
1004                                 /* Compare the offset values based on the current indices
1005                                  * break if they do not match
1006                                  * if all offset values match then pick the largest tuple*/
1007
1008                                 if(i == 0) {
1009                                         k = 0;
1010                                         index = endoffsets[j -1];
1011                                         for(count = 0; count < slength; count ++) {
1012                                                 if (arryfields[k] != arryfields[index]) {
1013                                                         break;
1014                                                 }
1015                                                 index++;
1016                                                 k++;
1017                                         }
1018                                 } else {
1019                                         k = endoffsets[i-1];
1020                                         index = endoffsets[j-1];
1021                                         printf("Value of slength = %d\n", slength);
1022                                         for(count = 0; count < slength; count++) {
1023                                                 if(arryfields[k] != arryfields[index]) {
1024                                                         break;
1025                                                 }
1026                                                 index++;
1027                                                 k++;
1028                                         }
1029                                 }
1030
1031                                 if(slength == count) {
1032                                         oid[sindex] = -1;
1033                                 }
1034                         }
1035                 }
1036         }
1037 }
1038
1039 void checkPreCache(prefetchqelem_t *node, int *numoffset, int counter, int loopcount, unsigned int objoid, int index, int iter, int oidnfound) {
1040         char *ptr, *tmp;
1041         int ntuples, i, k, flag;
1042         unsigned int * oid;
1043         short *endoffsets, *arryfields;
1044         objheader_t *header;
1045
1046         ptr = (char *) node;
1047         ntuples = *(GET_NTUPLES(ptr));
1048         oid = GET_PTR_OID(ptr);
1049         endoffsets = GET_PTR_EOFF(ptr, ntuples);
1050         arryfields = GET_PTR_ARRYFLD(ptr, ntuples);
1051
1052         if(oidnfound == 1) {
1053                 if((header = (objheader_t *) prehashSearch(objoid)) == NULL) {
1054                         return;
1055                 } else { //Found in Prefetch Cache
1056                         //TODO Decide if object is too old, if old remove from cache
1057                         tmp = (char *) header;
1058                         /* Check if any of the offset oid is available in the Prefetch cache */
1059                         for(i = counter; i < loopcount; i++) {
1060                                 objoid = *(tmp + sizeof(objheader_t) + arryfields[counter]);
1061                                 if((header = (objheader_t *)prehashSearch(objoid)) != NULL) {
1062                                         flag = 0;
1063                                 } else {
1064                                         flag = 1;
1065                                         break;
1066                                 }
1067                         }
1068                 }
1069         } else {
1070                 for(i = counter; i<loopcount; i++) {
1071                         if((header = (objheader_t *)prehashSearch(objoid)) != NULL) {
1072                                 tmp = (char *) header;
1073                                 objoid = *(tmp + sizeof(objheader_t) + arryfields[index]);
1074                                 flag = 0;
1075                                 index++;
1076                         } else {
1077                                 flag = 1;
1078                                 break;
1079                         }
1080                 }
1081         }
1082
1083         /* If oid not found locally or in prefetch cache then
1084          * assign the latest oid found as the new oid
1085          * and copy left over offsets into the arrayoffsetfieldarray*/
1086         oid[iter] = objoid;
1087         numoffset[iter] = numoffset[iter] - (i+1);
1088         for(k = 0; k < numoffset[iter] ; k++) {
1089                 arryfields[endoffsets[counter]+k] = arryfields[endoffsets[counter]+k+1];
1090         }
1091
1092         if(flag == 0) {
1093                 oid[iter] = -1;
1094                 numoffset[iter] = 0;
1095         }
1096 }
1097
1098 /* This function makes machine piles to be added into the machine pile queue for each prefetch call */
1099 prefetchpile_t *makePreGroups(prefetchqelem_t *node, int *numoffset) {
1100         char *ptr, *tmp;
1101         int ntuples, slength, i, machinenum;
1102         int maxoffset;
1103         unsigned int *oid;
1104         short *endoffsets, *arryfields, *offset;
1105         prefetchpile_t *head = NULL;
1106
1107         /* Check for the case x.y.z and a.b.c are same oids */
1108         ptr = (char *) node;
1109         ntuples = *(GET_NTUPLES(ptr));
1110         oid = GET_PTR_OID(ptr);
1111         endoffsets = GET_PTR_EOFF(ptr, ntuples);
1112         arryfields = GET_PTR_ARRYFLD(ptr, ntuples);
1113
1114         /* Check for redundant tuples by comparing oids of each tuple */
1115         for(i = 0; i < ntuples; i++) {
1116                 if(oid[i] == -1)
1117                         continue;
1118                 /* For each tuple make piles */
1119                 if ((machinenum = lhashSearch(oid[i])) == 0) {
1120                         printf("Error: No such Machine %s, %d\n", __FILE__, __LINE__);
1121                         return NULL;
1122                 }
1123                 /* Insert into machine pile */
1124                 offset = &arryfields[endoffsets[i-1]];
1125                 insertPile(machinenum, oid[i], numoffset[i], offset, head);
1126         }
1127
1128         return head;
1129 }
1130
1131
1132 /* This function checks if the oids within the prefetch tuples are available locally.
1133  * If yes then makes the tuple invalid. If no then rearranges oid and offset values in
1134  * the prefetchqelem_t node to represent a new prefetch tuple */
1135 prefetchpile_t *foundLocal(prefetchqelem_t *node) {
1136         int ntuples,i, j, k, oidnfound = 0, index, flag;
1137         unsigned int *oid;
1138         unsigned int  objoid;
1139         char *ptr, *tmp;
1140         objheader_t *objheader;
1141         short *endoffsets, *arryfields;
1142         prefetchpile_t *head = NULL;
1143
1144         ptr = (char *) node;
1145         ntuples = *(GET_NTUPLES(ptr));
1146         oid = GET_PTR_OID(ptr);
1147         endoffsets = GET_PTR_EOFF(ptr, ntuples);
1148         arryfields = GET_PTR_ARRYFLD(ptr, ntuples);
1149         /* Find offset length for each tuple */
1150         int numoffset[ntuples];//Number of offsets for each tuple
1151         numoffset[0] = endoffsets[0];
1152         for(i = 1; i<ntuples; i++) {
1153                 numoffset[i] = endoffsets[i] - endoffsets[i-1];
1154         }
1155         for(i = 0; i < ntuples; i++) {
1156                 if(oid[i] == -1)
1157                         continue;
1158                 /* If object found locally */
1159                 if((objheader = (objheader_t*) mhashSearch(oid[i])) != NULL) {
1160                         oidnfound = 0;
1161                         tmp = (char *) objheader;
1162                         /* Find the oid of its offset value */
1163                         if(i == 0)
1164                                 index = 0;
1165                         else
1166                                 index = endoffsets[i - 1];
1167                         for(j = 0 ; j < numoffset[i] ; j++) {
1168                                 objoid = *(tmp + sizeof(objheader_t) + arryfields[index]);
1169                                 /*If oid found locally then
1170                                  *assign the latest oid found as the new oid
1171                                  *and copy left over offsets into the arrayoffsetfieldarray*/
1172                                 oid[i] = objoid;
1173                                 numoffset[i] = numoffset[i] - (j+1);
1174                                 for(k = 0; k < numoffset[i]; k++)
1175                                         arryfields[endoffsets[j]+ k] = arryfields[endoffsets[j]+k+1];
1176                                 index++;
1177                                 /*New offset oid not found */
1178                                 if((objheader = (objheader_t*) mhashSearch(objoid)) == NULL) {
1179                                         flag = 1;
1180                                         checkPreCache(node, numoffset, j, numoffset[i], objoid, index, i, oidnfound);
1181                                         break;
1182                                 } else
1183                                         flag = 0;
1184                         }
1185
1186                         /*If all offset oids are found locally,make the prefetch tuple invalid */
1187                         if(flag == 0) {
1188                                 oid[i] = -1;
1189                                 numoffset[i] = 0;
1190                         }
1191                 } else {
1192                         oidnfound = 1;
1193                         /* Look in Prefetch cache */
1194                         checkPreCache(node, numoffset, 0, numoffset[i], oid[i], 0, i, oidnfound);
1195                 }
1196
1197         }
1198         /* Make machine groups */
1199         head = makePreGroups(node, numoffset);
1200         return head;
1201 }
1202
1203 /* This function is called by the thread calling transPrefetch */
1204 void *transPrefetch(void *t) {
1205         //int *offstarray = NULL;
1206         prefetchqelem_t *qnode;
1207         prefetchpile_t *pilehead = NULL;
1208
1209         while(1) {
1210                 /* lock mutex of primary prefetch queue */
1211                 pthread_mutex_lock(&pqueue.qlock);
1212                 /* while primary queue is empty, then wait */
1213                 while((pqueue.front == NULL) && (pqueue.rear == NULL)) {
1214                         pthread_cond_wait(&pqueue.qcond, &pqueue.qlock);
1215                 }
1216
1217                 /* dequeue node to create a machine piles and  finally unlock mutex */
1218                 if((qnode = pre_dequeue()) == NULL) {
1219                         printf("Error: No node returned %s, %d\n", __FILE__, __LINE__);
1220                         return NULL;
1221                 }
1222                 pthread_mutex_unlock(&pqueue.qlock);
1223                 /* Reduce redundant prefetch requests */
1224                 checkPrefetchTuples(qnode);
1225                 /* Check if the tuples are found locally, if yes then reduce them further*/
1226                 /* and group requests by remote machine ids by calling the makePreGroups() */
1227                 pilehead = foundLocal(qnode);
1228
1229                 /* Lock mutex of pool queue */
1230                 pthread_mutex_lock(&mcqueue.qlock);
1231                 /* Update the pool queue with the new remote machine piles generated per prefetch call */
1232                 mcpileenqueue(pilehead);
1233                 /* Broadcast signal on machine pile queue */
1234                 pthread_cond_broadcast(&mcqueue.qcond);
1235                 /* Unlock mutex of  machine pile queue */
1236                 pthread_mutex_unlock(&mcqueue.qlock);
1237                 /* Deallocate the prefetch queue pile node */
1238                 predealloc(qnode);
1239
1240         }
1241 }
1242
1243 /* Each thread in the  pool of threads calls this function to establish connection with
1244  * remote machines, send the prefetch requests and process the reponses from
1245  * the remote machines .
1246  * The thread is active throughout the period of runtime */
1247
1248 void *mcqProcess(void *threadid) {
1249         int tid;
1250         prefetchpile_t *mcpilenode;
1251
1252         tid = (int) threadid;
1253         while(1) {
1254                 /* Lock mutex of mc pile queue */
1255                 pthread_mutex_lock(&mcqueue.qlock);
1256                 /* When mc pile queue is empty, wait */
1257                 while((mcqueue.front == NULL) && (mcqueue.rear == NULL)) {
1258                         pthread_cond_wait(&mcqueue.qcond, &mcqueue.qlock);
1259                 }
1260                 /* Dequeue node to send remote machine connections*/
1261                 if((mcpilenode = mcpiledequeue()) == NULL) {
1262                         printf("Dequeue Error: No node returned %s %d\n", __FILE__, __LINE__);
1263                         return NULL;
1264                 }
1265                 /* Unlock mutex */
1266                 pthread_mutex_unlock(&mcqueue.qlock);
1267
1268                 /*Initiate connection to remote host and send request */
1269                 /* Process Request */
1270                 sendPrefetchReq(mcpilenode, tid);
1271
1272                 /* Deallocate the machine queue pile node */
1273                 mcdealloc(mcpilenode);
1274         }
1275 }
1276
1277 void sendPrefetchReq(prefetchpile_t *mcpilenode, int threadid) {
1278         int sd, i, offset, off, len, endpair, numoffsets, count = 0;
1279         struct sockaddr_in serv_addr;
1280         struct hostent *server;
1281         char machineip[16], control;
1282         objpile_t *tmp;
1283
1284
1285         /* Send Trans Prefetch Request */
1286         if ((sd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
1287                 perror("Error in socket for TRANS_REQUEST\n");
1288                 return;
1289         }
1290         bzero((char*) &serv_addr, sizeof(serv_addr));
1291         serv_addr.sin_family = AF_INET;
1292         serv_addr.sin_port = htons(LISTEN_PORT);
1293         //serv_addr.sin_addr.s_addr = inet_addr(MACHINE_IP);
1294         midtoIP(mcpilenode->mid ,machineip);
1295         machineip[15] = '\0';
1296         serv_addr.sin_addr.s_addr = inet_addr(machineip);
1297
1298         /* Open Connection */
1299         if (connect(sd, (struct sockaddr *) &serv_addr, sizeof(struct sockaddr)) < 0) {
1300                 perror("Error in connect for TRANS_REQUEST\n");
1301                 return;
1302         }
1303
1304         /* Send TRANS_PREFETCH control message */
1305         control = TRANS_PREFETCH;
1306         if(send(sd, &control, sizeof(char), MSG_NOSIGNAL) < sizeof(char)) {
1307                 perror("Error in sending prefetch control\n");
1308                 return;
1309         }
1310
1311         /* Send Oids and offsets in pairs */
1312         tmp = mcpilenode->objpiles;
1313         while(tmp != NULL) {
1314                 off = offset = 0;
1315                 count++;  // Keeps track of the number of oid and offset tuples sent per remote machine
1316                 len = sizeof(int) + sizeof(unsigned int) + ((tmp->numoffset) * sizeof(short));
1317                 char oidnoffset[len];
1318                 memcpy(oidnoffset, &len, sizeof(int));
1319                 off = sizeof(int);
1320                 memcpy(oidnoffset + off, &tmp->oid, sizeof(unsigned int));
1321                 off += sizeof(unsigned int);
1322                 for(i = 0; i < numoffsets; i++) {
1323                         offset = off +  (i * sizeof(short));
1324                         memcpy(oidnoffset + offset, tmp->offset, sizeof(short));
1325                 }
1326                 if (send(sd, &oidnoffset, sizeof(oidnoffset),MSG_NOSIGNAL) < sizeof(oidnoffset)) {
1327                         perror("Error sending fixed bytes for thread\n");
1328                         return;
1329                 }
1330                 tmp = tmp->next;
1331         }
1332
1333         /* Send a special char -1 to represent the end of sending oids + offset pair to remote machine */
1334         endpair = -1;
1335         if (send(sd, &endpair, sizeof(int), MSG_NOSIGNAL) < sizeof(int)) {
1336                 perror("Error sending fixed bytes for thread\n");
1337                 return;
1338         }
1339
1340         /* Get Response from the remote machine */
1341         getPrefetchResponse(count,sd);
1342         close(sd);
1343         return;
1344 }
1345
1346 void getPrefetchResponse(int count, int sd) {
1347         int i = 0, val, n, N, sum, index, objsize;
1348         unsigned int bufsize,oid;
1349         char buffer[RECEIVE_BUFFER_SIZE], control;
1350         char *ptr;
1351         void *modptr, *oldptr;
1352
1353         /* Read  prefetch response from the Remote machine */
1354         if((val = read(sd, &control, sizeof(char))) <= 0) {
1355                 perror("No control response for Prefetch request sent\n");
1356                 return;
1357         }
1358
1359         if(control == TRANS_PREFETCH_RESPONSE) {
1360                 /*For each oid and offset tuple sent as prefetch request to remote machine*/
1361                 while(i < count) {
1362                         /* Clear contents of buffer */
1363                         memset(buffer, 0, RECEIVE_BUFFER_SIZE);
1364                         sum = 0;
1365                         index = 0;
1366                         /* Read the size of buffer to be received */
1367                         if((N = read(sd, buffer, sizeof(unsigned int))) <= 0) {
1368                                 perror("Size of buffer not recv\n");
1369                                 return;
1370                         }
1371                         memcpy(&bufsize, buffer, sizeof(unsigned int));
1372                         ptr = buffer + sizeof(unsigned int);
1373                         /* Keep receiving the buffer containing oid info */
1374                         do {
1375                                 n = recv((int)sd, (void *)ptr+sum, bufsize-sum, 0);
1376                                 sum +=n;
1377                         } while(sum < bufsize && n != 0);
1378                         /* Decode the contents of the buffer */
1379                         index = sizeof(unsigned int);
1380                         while(index < (bufsize - sizeof(unsigned int))) {
1381                                 if(buffer[index] == OBJECT_FOUND) {
1382                                         /* Increment it to get the object */
1383                                         index += sizeof(char);
1384                                         memcpy(&oid, buffer + index, sizeof(unsigned int));
1385                                         index += sizeof(unsigned int);
1386                                         /* Lock the Prefetch Cache look up table*/
1387                                         pthread_mutex_lock(&pflookup.lock);
1388                                         /* For each object found add to Prefetch Cache */
1389                                         memcpy(&objsize, buffer + index, sizeof(int));
1390                                         if ((modptr = objstrAlloc(prefetchcache, objsize)) == NULL) {
1391                                                 printf("objstrAlloc error for copying into prefetch cache %s, %d\n", __FILE__, __LINE__);
1392                                                 return;
1393                                         }
1394                                         memcpy(modptr, buffer+index, objsize);
1395                                         index += sizeof(int);
1396                                         /* Insert the oid and its address into the prefetch hash lookup table */
1397                                         /* Do a version comparison if the oid exists */
1398                                         if((oldptr = prehashSearch(oid)) != NULL) {
1399                                                 /* If older version then update with new object ptr */
1400                                                 if(((objheader_t *)oldptr)->version < ((objheader_t *)modptr)->version) {
1401                                                         prehashRemove(oid);
1402                                                         prehashInsert(oid, modptr);
1403                                                 } else if(((objheader_t *)oldptr)->version == ((objheader_t *)modptr)->version) {
1404                                                         /* Add the new object ptr to hash table */
1405                                                         prehashInsert(oid, modptr);
1406                                                 } else { /* Do nothing */
1407                                                         ;
1408                                                 }
1409                                         } else {/*If doesn't no match found in hashtable, add the object ptr to hash table*/
1410                                                 prehashInsert(oid, modptr);
1411                                         }
1412                                         /* Broadcast signal on prefetch cache condition variable */
1413                                         pthread_cond_broadcast(&pflookup.cond);
1414                                         /* Unlock the Prefetch Cache look up table*/
1415                                         pthread_mutex_unlock(&pflookup.lock);
1416                                 } else if(buffer[index] == OBJECT_NOT_FOUND) {
1417                                         /* Increment it to get the object */
1418                                         /* TODO: For each object not found query DHT for new location and retrieve the object */
1419                                         index += sizeof(char);
1420                                         memcpy(&oid, buffer + index, sizeof(unsigned int));
1421                                         index += sizeof(unsigned int);
1422                                         /* Throw an error */
1423                                         printf("OBJECT NOT FOUND.... THIS SHOULD NOT HAPPEN...TERMINATE PROGRAM\n");
1424                                         exit(-1);
1425                                 } else
1426                                         printf("Error in decoding the index value %s, %d\n",__FILE__, __LINE__);
1427                         }
1428
1429                         i++;
1430                 }
1431         } else
1432                 printf("Error in receving response for prefetch request %s, %d\n",__FILE__, __LINE__);
1433         return;
1434 }