bug fix for OBJECT_NOT_FOUND error in prefetch cache due to unknown oid
[IRC.git] / Robust / src / Runtime / DSTM / interface / dstmserver.c
index 5928799c780694b28b17ce4ab84ff96090424741..672a955c6644129f2aa68786ba907b1be50f7cf9 100644 (file)
 #define LISTEN_PORT 2156
 #define BACKLOG 10 //max pending connections
 #define RECEIVE_BUFFER_SIZE 2048
-#define PRE_BUF_SIZE 2048
 
 extern int classsize[];
 
 objstr_t *mainobjstore;
 pthread_mutex_t mainobjstore_mutex;
 pthread_mutexattr_t mainobjstore_mutex_attr; /* Attribute for lock to make it a recursive lock */
+/**********************************************************
+ * Global variables to map socketid and remote mid
+ * to  resuse sockets
+ **************************************************/
+midSocketInfo_t sockArray[NUM_MACHINES];
+int sockCount; //number of connections with all remote machines(one socket per mc)
+int sockIdFound; //track if socket file descriptor is already established
+pthread_mutex_t sockLock = PTHREAD_MUTEX_INITIALIZER; //lock to prevent global sock variables to be inconsistent
 
 /* This function initializes the main objects store and creates the 
  * global machine and location lookup table */
@@ -48,6 +55,14 @@ int dstmInit(void)
        if (notifyhashCreate(N_HASH_SIZE, N_LOADFACTOR))
                return 1; //failure
        
+       //Initialize mid to socketid mapping array
+       int t;
+       sockCount = 0;
+       for(t = 0; t < NUM_MACHINES; t++) {
+               sockArray[t].mid = 0;
+               sockArray[t].sockid = 0;
+       }
+
        return 0;
 }
 
@@ -113,16 +128,17 @@ void *dstmListen()
  * and accordingly calls other functions to process new requests */
 void *dstmAccept(void *acceptfd)
 {
-       int val, retval, size;
+       int val, retval, size, sum, sockid;
        unsigned int oid;
-       char buffer[RECEIVE_BUFFER_SIZE], control,ctrl;
+       char *buffer;
+       char control,ctrl;
        char *ptr;
        void *srcObj;
        objheader_t *h;
        trans_commit_data_t transinfo;
        unsigned short objType, *versionarry, version;
        unsigned int *oidarry, numoid, mid, threadid;
-
+       
        transinfo.objlocked = NULL;
        transinfo.objnotfound = NULL;
        transinfo.modptr = NULL;
@@ -130,136 +146,121 @@ void *dstmAccept(void *acceptfd)
        transinfo.numnotfound = 0;
 
        /* Receive control messages from other machines */
-       if((retval = recv((int)acceptfd, &control, sizeof(char), 0)) <= 0) {
-               if (retval == 0) {
-                       pthread_exit(NULL); // Testing connection
-               }
-               perror("Error in receiving control from coordinator\n");
-               pthread_exit(NULL);
-       }
-       
+       recv_data((int)acceptfd, &control, sizeof(char));
+
        switch(control) {
                case READ_REQUEST:
                        /* Read oid requested and search if available */
-                       if((retval = recv((int)acceptfd, &oid, sizeof(unsigned int), 0)) <= 0) {
-                               perror("Error receiving object from cooridnator\n");
-                               pthread_exit(NULL);
-                       }
+                       recv_data((int)acceptfd, &oid, sizeof(unsigned int));
                        if((srcObj = mhashSearch(oid)) == NULL) {
-                               printf("Object not found in Main Object Store %s %d\n", __FILE__, __LINE__);
+                               printf("Error: Object 0x%x is not found in Main Object Store %s, %d\n", oid, __FILE__, __LINE__);
                                pthread_exit(NULL);
                        }
                        h = (objheader_t *) srcObj;
                        GETSIZE(size, h);
                        size += sizeof(objheader_t);
+                       sockid = (int) acceptfd;
 
                        if (h == NULL) {
                                ctrl = OBJECT_NOT_FOUND;
-                               if(send((int)acceptfd, &ctrl, sizeof(char), MSG_NOSIGNAL) < sizeof(char)) {
-                                       perror("Error sending control msg to coordinator\n");
-                                       pthread_exit(NULL);
-                               }
+                               send_data(sockid, &ctrl, sizeof(char));
                        } else {
                                /* Type */
                                char msg[]={OBJECT_FOUND, 0, 0, 0, 0};
                                *((int *)&msg[1])=size;
-                               if(send((int)acceptfd, &msg, sizeof(msg), MSG_NOSIGNAL) < sizeof(msg)) {
-                                       perror("Error sending size of object to coordinator\n");
-                                       pthread_exit(NULL);
-                               }
-                               if(send((int)acceptfd, h, size, MSG_NOSIGNAL) < size) {
-                                       perror("Error in sending object\n");
-                                       pthread_exit(NULL);
-                               }
+                               send_data(sockid, &msg, sizeof(msg));
+                               send_data(sockid, h, size);
                        }
                        break;
                
                case READ_MULT_REQUEST:
-                       printf("DEBUG-> READ_MULT_REQUEST\n");
                        break;
        
                case MOVE_REQUEST:
-                       printf("DEBUG -> MOVE_REQUEST\n");
                        break;
 
                case MOVE_MULT_REQUEST:
-                       printf("DEBUG -> MOVE_MULT_REQUEST\n");
                        break;
 
                case TRANS_REQUEST:
                        /* Read transaction request */
-                       printf("DEBUG -> Recv TRANS_REQUEST\n");
                        if((val = readClientReq(&transinfo, (int)acceptfd)) != 0) {
-                               printf("Error in readClientReq\n");
+                               printf("Error: In readClientReq() %s, %d\n", __FILE__, __LINE__);
                                pthread_exit(NULL);
                        }
                        break;
                case TRANS_PREFETCH:
-                       printf("DEBUG -> Recv TRANS_PREFETCH\n");
-                       if((val = prefetchReq((int)acceptfd)) != 0) {
-                               printf("Error in transPrefetch\n");
-                               pthread_exit(NULL);
-                       }
+                       do {
+                               if((val = prefetchReq((int)acceptfd)) != 0) {
+                                       printf("Error: In prefetchReq() %s, %d\n", __FILE__, __LINE__);
+                                       break;
+                               }
+                               recv_data((int)acceptfd, &control, sizeof(char));
+                       } while (control == TRANS_PREFETCH);
+                       break;
+               case TRANS_PREFETCH_RESPONSE:
+                       //do {
+                               if((val = getPrefetchResponse((int) acceptfd)) != 0) {
+                                       printf("Error: In getPrefetchResponse() %s, %d\n", __FILE__, __LINE__);
+                                       pthread_exit(NULL);
+                               }
+                       //} while (control == TRANS_PREFETCH_RESPONSE);
                        break;
                case START_REMOTE_THREAD:
-                       retval = recv((int)acceptfd, &oid, sizeof(unsigned int), 0);
-                       if (retval <= 0)
-                               perror("dstmAccept(): error receiving START_REMOTE_THREAD msg");
-                       else if (retval != sizeof(unsigned int))
-                               printf("dstmAccept(): incorrect msg size %d for START_REMOTE_THREAD\n",
-                                       retval);
-                       else
-                       {
-                               objType = getObjType(oid);
-                               startDSMthread(oid, objType);
-                       }
+                       recv_data((int)acceptfd, &oid, sizeof(unsigned int));
+                       objType = getObjType(oid);
+                       startDSMthread(oid, objType);
                        break;
 
                case THREAD_NOTIFY_REQUEST:
-                       size = sizeof(unsigned int);
-                       retval = recv((int)acceptfd, ptr, size, 0);
-                       numoid = *((unsigned int *) ptr);
+                       recv_data((int)acceptfd, &numoid, sizeof(unsigned int));
                        size = (sizeof(unsigned int) + sizeof(unsigned short)) * numoid + 2 * sizeof(unsigned int);
-                       retval = recv((int)acceptfd, ptr, size, 0);
+                       if((buffer = calloc(1,size)) == NULL) {
+                               printf("%s() Calloc error at %s, %d\n", __func__, __FILE__, __LINE__);
+                               pthread_exit(NULL);
+                       }
+
+                       recv_data((int)acceptfd, buffer, size);
+
                        oidarry = calloc(numoid, sizeof(unsigned int)); 
-                       memcpy(oidarry, ptr, sizeof(unsigned int) * numoid);
+                       memcpy(oidarry, buffer, sizeof(unsigned int) * numoid);
                        size = sizeof(unsigned int) * numoid;
                        versionarry = calloc(numoid, sizeof(unsigned short));
-                       memcpy(versionarry, ptr+size, sizeof(unsigned short) * numoid);
+                       memcpy(versionarry, buffer+size, sizeof(unsigned short) * numoid);
                        size += sizeof(unsigned short) * numoid;
-                       mid = *((unsigned int *)(ptr+size));
+                       mid = *((unsigned int *)(buffer+size));
                        size += sizeof(unsigned int);
-                       threadid = *((unsigned int *)(ptr+size));
+                       threadid = *((unsigned int *)(buffer+size));
                        processReqNotify(numoid, oidarry, versionarry, mid, threadid);
+                       free(buffer);
 
                        break;
 
                case THREAD_NOTIFY_RESPONSE:
                        size = sizeof(unsigned short) + 2 * sizeof(unsigned int);
-                       retval = recv((int)acceptfd, ptr, size, 0);
-                       if(retval <= 0) 
-                               perror("dstmAccept(): error receiving THREAD_NOTIFY_RESPONSE msg");
-                       else if( retval != 2*sizeof(unsigned int) + sizeof(unsigned short))
-                               printf("dstmAccept(): incorrect smsg size %d for THREAD_NOTIFY_RESPONSE msg\n", retval);
-                       else {
-                               oid = *((unsigned int *)ptr);
-                               size = sizeof(unsigned int);
-                               version = *((unsigned short *)(ptr+size));
-                               size += sizeof(unsigned short);
-                               threadid = *((unsigned int *)(ptr+size));
-                               threadNotify(oid,version,threadid);
+                       if((buffer = calloc(1,size)) == NULL) {
+                               printf("%s() Calloc error at %s, %d\n", __func__, __FILE__, __LINE__);
+                               pthread_exit(NULL);
                        }
 
-                       break;
+                       recv_data((int)acceptfd, buffer, size);
+
+                       oid = *((unsigned int *)buffer);
+                       size = sizeof(unsigned int);
+                       version = *((unsigned short *)(buffer+size));
+                       size += sizeof(unsigned short);
+                       threadid = *((unsigned int *)(buffer+size));
+                       threadNotify(oid,version,threadid);
+                       free(buffer);
 
+                       break;
                default:
-                       printf("DEBUG -> dstmAccept: Error Unknown opcode %d\n", control);
+                       printf("Error: dstmAccept() Unknown opcode %d at %s, %d\n", control, __FILE__, __LINE__);
        }
 
        /* Close connection */
        if (close((int)acceptfd) == -1)
                perror("close");
-       
        pthread_exit(NULL);
 }
 
@@ -271,41 +272,30 @@ int readClientReq(trans_commit_data_t *transinfo, int acceptfd) {
        unsigned int *oidmod, oid;
        fixed_data_t fixed;
        objheader_t *headaddr;
-       int sum = 0, i, N, n, val;
+       int sum, i, size, n, val;
 
        oidmod = NULL;
 
        /* Read fixed_data_t data structure */ 
-       N = sizeof(fixed) - 1;
+       size = sizeof(fixed) - 1;
        ptr = (char *)&fixed;;
        fixed.control = TRANS_REQUEST;
-       do {
-               n = recv((int)acceptfd, (void *) ptr+1+sum, N-sum, 0);
-               sum += n;
-       } while(sum < N && n != 0); 
+       recv_data((int)acceptfd, ptr+1, size);
 
        /* Read list of mids */
        int mcount = fixed.mcount;
-       N = mcount * sizeof(unsigned int);
+       size = mcount * sizeof(unsigned int);
        unsigned int listmid[mcount];
        ptr = (char *) listmid;
-       sum = 0;
-       do {
-               n = recv((int)acceptfd, (void *) ptr+sum, N-sum, 0);
-               sum += n;
-       } while(sum < N && n != 0);
-
+       recv_data((int)acceptfd, ptr, size);
+       
        /* Read oid and version tuples for those objects that are not modified in the transaction */
        int numread = fixed.numread;
-       N = numread * (sizeof(unsigned int) + sizeof(short));
-       char objread[N];
+       size = numread * (sizeof(unsigned int) + sizeof(unsigned short));
+       char objread[size];
        if(numread != 0) { //If pile contains more than one object to be read, 
                          // keep reading all objects
-               sum = 0;
-               do {
-                       n = recv((int)acceptfd, (void *) objread, N, 0);
-                       sum += n;
-               } while(sum < N && n != 0);
+               recv_data((int)acceptfd, objread, size);        
        }
        
        /* Read modified objects */
@@ -314,11 +304,8 @@ int readClientReq(trans_commit_data_t *transinfo, int acceptfd) {
                        printf("calloc error for modified objects %s, %d\n", __FILE__, __LINE__);
                        return 1;
                }
-               sum = 0;
-               do { // Recv the objs that are modified by the Coordinator
-                       n = recv((int)acceptfd, (char *) modptr+sum, fixed.sum_bytes-sum, 0);
-                       sum += n;
-               } while (sum < fixed.sum_bytes && n != 0);
+               size = fixed.sum_bytes;
+               recv_data((int)acceptfd, modptr, size); 
        }
 
        /* Create an array of oids for modified objects */
@@ -340,7 +327,7 @@ int readClientReq(trans_commit_data_t *transinfo, int acceptfd) {
        
        /*Process the information read */
        if((val = processClientReq(&fixed, transinfo, listmid, objread, modptr, oidmod, acceptfd)) != 0) {
-               printf("Error in processClientReq %s, %d\n", __FILE__, __LINE__);
+               printf("Error: In processClientReq() %s, %d\n", __FILE__, __LINE__);
                /* Free resources */
                if(oidmod != NULL) {
                        free(oidmod);
@@ -361,23 +348,19 @@ int readClientReq(trans_commit_data_t *transinfo, int acceptfd) {
  * Following this it also receives a new control message from the co-ordinator and processes this message*/
 int processClientReq(fixed_data_t *fixed, trans_commit_data_t *transinfo,
                unsigned int *listmid, char *objread, void *modptr, unsigned int *oidmod, int acceptfd) {
-       char *ptr, control, sendctrl;
+       char control, sendctrl, retval;
        objheader_t *tmp_header;
        void *header;
-       int  i = 0, val, retval;
+       int  i = 0, val;
 
        /* Send reply to the Coordinator */
        if((retval = handleTransReq(fixed, transinfo, listmid, objread, modptr,acceptfd)) == 0 ) {
-               printf("Handle Trans Req error %s, %d\n", __FILE__, __LINE__);
-               return 1;
-       }
-
-       /* Read new control message from Coordiator */
-       if((retval = recv((int)acceptfd, &control, sizeof(char), 0)) <= 0 ) {
-               perror("Error in receiving control message\n");
+               printf("Error: In handleTransReq() %s, %d\n", __FILE__, __LINE__);
                return 1;
        }
 
+       recv_data((int)acceptfd, &control, sizeof(char));
+       
        /* Process the new control message */
        switch(control) {
                case TRANS_ABORT:
@@ -385,30 +368,22 @@ int processClientReq(fixed_data_t *fixed, trans_commit_data_t *transinfo,
                                free(modptr);
                        /* Unlock objects that was locked due to this transaction */
                        for(i = 0; i< transinfo->numlocked; i++) {
-                               header = mhashSearch(transinfo->objlocked[i]);// find the header address
+                               if((header = mhashSearch(transinfo->objlocked[i])) == NULL) {
+                                       printf("mhashSearch returns NULL at %s, %d\n", __FILE__, __LINE__);// find the header address
+                                       return 1;
+                               }
                                STATUS(((objheader_t *)header)) &= ~(LOCK);             
                        }
 
                        /* Send ack to Coordinator */
-                       sendctrl = TRANS_SUCESSFUL;
-                       if(send((int)acceptfd, &sendctrl, sizeof(char), MSG_NOSIGNAL) < sizeof(char)) {
-                               perror("Error sending ACK to coordinator\n");
-                               if (transinfo->objlocked != NULL) {
-                                       free(transinfo->objlocked);
-                               }
-                               if (transinfo->objnotfound != NULL) {
-                                       free(transinfo->objnotfound);
-                               }
-
-                               return 1;
-                       }
-                       ptr = NULL;
+                       sendctrl = TRANS_UNSUCESSFUL;
+                       send_data((int)acceptfd, &sendctrl, sizeof(char));
                        break;
 
                case TRANS_COMMIT:
                        /* Invoke the transCommit process() */
                        if((val = transCommitProcess(modptr, oidmod, transinfo->objlocked, fixed->nummod, transinfo->numlocked, (int)acceptfd)) != 0) {
-                               printf("Error in transCommitProcess %s, %d\n", __FILE__, __LINE__);
+                               printf("Error: In transCommitProcess() %s, %d\n", __FILE__, __LINE__);
                                /* Free memory */
                                if (transinfo->objlocked != NULL) {
                                        free(transinfo->objlocked);
@@ -421,11 +396,9 @@ int processClientReq(fixed_data_t *fixed, trans_commit_data_t *transinfo,
                        break;
 
                case TRANS_ABORT_BUT_RETRY_COMMIT_WITH_RELOCATING:
-                       //TODO expect another transrequest from client
-                       printf("DEBUG -> Recv TRANS_ABORT_BUT_RETRY_COMMIT_WITH_RELOCATING\n");
                        break;
                default:
-                       printf("No response to TRANS_AGREE OR DISAGREE protocol\n");
+                       printf("Error: No response to TRANS_AGREE OR DISAGREE protocol %s, %d\n", __FILE__, __LINE__);
                        //TODO Use fixed.trans_id  TID since Client may have died
                        break;
        }
@@ -444,7 +417,7 @@ int processClientReq(fixed_data_t *fixed, trans_commit_data_t *transinfo,
 /* This function increments counters while running a voting decision on all objects involved 
  * in TRANS_REQUEST and If a TRANS_DISAGREE sends the response immediately back to the coordinator */
 char handleTransReq(fixed_data_t *fixed, trans_commit_data_t *transinfo, unsigned int *listmid, char *objread, void *modptr, int acceptfd) {
-       int val, i = 0;
+       int val, i = 0, j;
        unsigned short version;
        char control = 0, *ptr;
        unsigned int oid;
@@ -466,7 +439,7 @@ char handleTransReq(fixed_data_t *fixed, trans_commit_data_t *transinfo, unsigne
        /* Process each oid in the machine pile/ group per thread */
        for (i = 0; i < fixed->numread + fixed->nummod; i++) {
                if (i < fixed->numread) {//Objs only read and not modified
-                       int incr = sizeof(unsigned int) + sizeof(short);// Offset that points to next position in the objread array
+                       int incr = sizeof(unsigned int) + sizeof(unsigned short);// Offset that points to next position in the objread array
                        incr *= i;
                        oid = *((unsigned int *)(objread + incr));
                        incr += sizeof(unsigned int);
@@ -495,10 +468,17 @@ char handleTransReq(fixed_data_t *fixed, trans_commit_data_t *transinfo, unsigne
                                        v_nomatch++;
                                        /* Send TRANS_DISAGREE to Coordinator */
                                        control = TRANS_DISAGREE;
-                                       if((val = send(acceptfd, &control, sizeof(char), MSG_NOSIGNAL)) < sizeof(char)) {
-                                               perror("Error in sending control to the Coordinator\n");
-                                               return 0;
+                                       if (objlocked > 0) {
+                                         for(j = 0; j < objlocked; j++) {
+                                                       if((headptr = mhashSearch(oidlocked[j])) == NULL) {
+                                                               printf("mhashSearch returns NULL at %s, %d\n", __FILE__, __LINE__);
+                                                               return 0;
+                                                       }
+                                                       STATUS(headptr) &= ~(LOCK);
+                                               }
+                                               free(oidlocked);
                                        }
+                                       send_data(acceptfd, &control, sizeof(char));
                                        return control;
                                }
                        } else {/* If Obj is not locked then lock object */
@@ -511,15 +491,19 @@ char handleTransReq(fixed_data_t *fixed, trans_commit_data_t *transinfo, unsigne
                                } else { /* If versions don't match ...HARD ABORT */
                                        v_nomatch++;
                                        control = TRANS_DISAGREE;
-                                       /* Send TRANS_DISAGREE to Coordinator */
-                                       if((val = send(acceptfd, &control, sizeof(char), MSG_NOSIGNAL)) < sizeof(char)) {
-                                               perror("Error in sending control to the Coordinator\n");
-                                               return 0;
-                                       }
                                        if (objlocked > 0) {
-                                               STATUS(((objheader_t *)mobj)) &= ~(LOCK);
+                                               for(j = 0; j < objlocked; j++) {
+                                                       if((headptr = mhashSearch(oidlocked[j])) == NULL) {
+                                                               printf("mhashSearch returns NULL at %s, %d\n", __FILE__, __LINE__);
+                                                               return 0;
+                                                       }
+                                                       STATUS(headptr) &= ~(LOCK);
+                                               }
                                                free(oidlocked);
                                        }
+
+                                       /* Send TRANS_DISAGREE to Coordinator */
+                                       send_data(acceptfd, &control, sizeof(char));
                                        return control;
                                }
                        }
@@ -527,49 +511,43 @@ char handleTransReq(fixed_data_t *fixed, trans_commit_data_t *transinfo, unsigne
        }
        
        /* Decide what control message to send to Coordinator */
-       if ((val = decideCtrlMessage(fixed, transinfo, &v_matchnolock, &v_matchlock, &v_nomatch, &objnotfound, &objlocked,
+       if ((control = decideCtrlMessage(fixed, transinfo, &v_matchnolock, &v_matchlock, &v_nomatch, &objnotfound, &objlocked,
                                        modptr, oidnotfound, oidlocked, acceptfd)) == 0) {
-               printf("Error in decideCtrlMessage %s, %d\n", __FILE__, __LINE__);
+               printf("Error: In decideCtrlMessage() %s, %d\n", __FILE__, __LINE__);
                return 0;
        }
        
-       return val;
+       return control;
 
 }
 /* This function decides what control message such as TRANS_AGREE, TRANS_DISAGREE or TRANS_SOFT_ABORT
  * to send to Coordinator based on the votes of oids involved in the transaction */
-int decideCtrlMessage(fixed_data_t *fixed, trans_commit_data_t *transinfo, int *v_matchnolock, int *v_matchlock, 
+char decideCtrlMessage(fixed_data_t *fixed, trans_commit_data_t *transinfo, int *v_matchnolock, int *v_matchlock, 
                int *v_nomatch, int *objnotfound, int *objlocked, void *modptr, 
                unsigned int *oidnotfound, unsigned int *oidlocked, int acceptfd) {
        int val;
        char control = 0;
+
        /* Condition to send TRANS_AGREE */
        if(*(v_matchnolock) == fixed->numread + fixed->nummod) {
                control = TRANS_AGREE;
                /* Send control message */
-               if((val = send(acceptfd, &control, sizeof(char), MSG_NOSIGNAL)) < sizeof(char)) {
-                       perror("Error in sending control to Coordinator\n");
-                       return 0;
-               }
+               send_data(acceptfd, &control, sizeof(char));
        }
        /* Condition to send TRANS_SOFT_ABORT */
        if((*(v_matchlock) > 0 && *(v_nomatch) == 0) || (*(objnotfound) > 0 && *(v_nomatch) == 0)) {
                control = TRANS_SOFT_ABORT;
-               char msg[]={TRANS_SOFT_ABORT, 0,0,0,0};
-               *((int*)&msg[1])= *(objnotfound);
 
                /* Send control message */
-               if((val = send(acceptfd, &msg, sizeof(msg),MSG_NOSIGNAL)) < sizeof(msg)) {
-                       perror("Error in sending no of objects that are not found\n");
-                       return 0;
-               }
+               send_data(acceptfd, &control, sizeof(char));
+       
                /* Send number of oids not found and the missing oids if objects are missing in the machine */
                if(*(objnotfound) != 0) { 
+                       int msg[1];
+                       msg[0] = *(objnotfound);
+                       send_data(acceptfd, &msg, sizeof(int));
                        int size = sizeof(unsigned int)* *(objnotfound);
-                       if((val = send(acceptfd, oidnotfound, size ,MSG_NOSIGNAL)) < size) {
-                               perror("Error in sending objects that are not found\n");
-                               return 0;
-                       }
+                       send_data(acceptfd, oidnotfound, size);
                }
        }
 
@@ -597,12 +575,12 @@ int transCommitProcess(void *modptr, unsigned int *oidmod, unsigned int *oidlock
        /* Process each modified object saved in the mainobject store */
        for(i = 0; i < nummod; i++) {
                if((header = (objheader_t *) mhashSearch(oidmod[i])) == NULL) {
-                       printf("mhashsearch returns NULL at %s, %d\n", __FILE__, __LINE__);
+                       printf("Error: mhashsearch returns NULL at %s, %d\n", __FILE__, __LINE__);
                        return 1;
                }
                GETSIZE(tmpsize,header);
                pthread_mutex_lock(&mainobjstore_mutex);
-               memcpy(header, (char *)modptr + offset, tmpsize + sizeof(objheader_t));
+               memcpy((char*)header + sizeof(objheader_t), ((char *)modptr + sizeof(objheader_t) + offset), tmpsize);
                header->version += 1; 
                /* If threads are waiting on this object to be updated, notify them */
                if(header->notifylist != NULL) {
@@ -618,7 +596,7 @@ int transCommitProcess(void *modptr, unsigned int *oidmod, unsigned int *oidlock
        /* Unlock locked objects */
        for(i = 0; i < numlocked; i++) {
                if((header = (objheader_t *) mhashSearch(oidlocked[i])) == NULL) {
-                       printf("mhashsearch returns NULL at %s, %d\n", __FILE__, __LINE__);
+                       printf("Error: mhashsearch returns NULL at %s, %d\n", __FILE__, __LINE__);
                        return 1;
                }
                STATUS(header) &= ~(LOCK);
@@ -627,10 +605,7 @@ int transCommitProcess(void *modptr, unsigned int *oidmod, unsigned int *oidlock
 
        /* Send ack to coordinator */
        control = TRANS_SUCESSFUL;
-       if(send((int)acceptfd, &control, sizeof(char), MSG_NOSIGNAL) < sizeof(char)) {
-               perror("Error sending ACK to coordinator\n");
-       }
-       
+       send_data((int)acceptfd, &control, sizeof(char));
        return 0;
 }
 
@@ -640,146 +615,252 @@ int transCommitProcess(void *modptr, unsigned int *oidmod, unsigned int *oidlock
  * then use offset values to prefetch references to other objects */
 
 int prefetchReq(int acceptfd) {
-  int i, length, sum, n, numbytes, numoffset, N, objnotfound = 0, size, count = 0;
-  int isArray = 0;
-  unsigned int oid, index = 0;
-  char *ptr, buffer[PRE_BUF_SIZE];
-  void *mobj;
-  unsigned int objoid;
-  char control;
-  objheader_t * header;
-  int bytesRecvd;
-  
-  /* Repeatedly recv the oid and offset pairs sent for prefetch */
-  while(numbytes = recv((int)acceptfd, &length, sizeof(int), 0) != 0) {
-    count++;
-    if(length == -1)
-      break;
-    sum = 0;
-    index = sizeof(unsigned int); // Index starts with sizeof  unsigned int because the 
-    // first 4 bytes are saved to send the
-    // size of the buffer (that is computed at the end of the loop)
-    bytesRecvd = 0;
-    do {
-      bytesRecvd += recv((int)acceptfd, (char *)&oid +bytesRecvd,
-                        sizeof(unsigned int) - bytesRecvd, 0);
-    } while (bytesRecvd < sizeof(unsigned int));
-    numoffset = (length - (sizeof(int) + sizeof(unsigned int)))/ sizeof(short);
-    N = numoffset * sizeof(short);
-    short offset[numoffset];
-    ptr = (char *)&offset;
-    /* Recv the offset values per oid */ 
-    do {
-      n = recv((int)acceptfd, (void *)ptr+sum, N-sum, 0); 
-      sum += n; 
-    } while(sum < N && n != 0);        
-    
-    /* Process each oid */
-    if ((mobj = mhashSearch(oid)) == NULL) {/* Obj not found */
-      /* Save the oids not found in buffer for later use */
-      *(buffer + index) = OBJECT_NOT_FOUND;
-      index += sizeof(char);
-      memcpy(buffer+index, &oid, sizeof(unsigned int));
-      index += sizeof(unsigned int);
-    } else { /* If Obj found in machine (i.e. has not moved) */
-      /* send the oid, it's size, it's header and data */
-      header = mobj;
-      GETSIZE(size, header);
-      size += sizeof(objheader_t);
-      *(buffer + index) = OBJECT_FOUND;
-      index += sizeof(char);
-      memcpy(buffer+index, &oid, sizeof(unsigned int));
-      index += sizeof(unsigned int);
-      memcpy(buffer+index, &size, sizeof(int));
-      index += sizeof(int);
-      memcpy(buffer + index, header, size);
-      index += size;
-      /* Calculate the oid corresponding to the offset value */
-      for(i = 0 ; i< numoffset ; i++) {
-             /* Check for arrays  */
-             if(TYPE(header) > NUMCLASSES) {
-                     isArray = 1;
-             }
-             if(isArray == 1) {
-                     int elementsize = classsize[TYPE(header)];
-                     objoid = *((unsigned int *)(((char *)header) + sizeof(objheader_t) + sizeof(struct ArrayObject) + (elementsize*offset[i])));
-             } else {
-                     objoid = *((unsigned int *)(((char *)header) + sizeof(objheader_t) + offset[i]));
-             }
-             if((header = mhashSearch(objoid)) == NULL) {
-                     /* Obj not found, send oid */
-                     *(buffer + index) = OBJECT_NOT_FOUND;
-                     index += sizeof(char);
-                     memcpy(buffer+index, &oid, sizeof(unsigned int));
-                     index += sizeof(unsigned int);
-                     break;
-             } else {/* Obj Found */
-                     /* send the oid, it's size, it's header and data */
-                     GETSIZE(size, header);
-                     size+=sizeof(objheader_t);
-                     *(buffer + index) = OBJECT_FOUND;
-                     index += sizeof(char);
-                     memcpy(buffer+index, &oid, sizeof(unsigned int));
-                     index += sizeof(unsigned int);
-                     memcpy(buffer+index, &size, sizeof(int));
-                     index += sizeof(int);
-                     memcpy(buffer+index, header, size);
-                     index += size;
-                     isArray = 0;
-                     continue;
-             }
-      }
-    }
-    /* Check for overflow in the buffer */
-    if (index >= PRE_BUF_SIZE) {
-      printf("Char buffer is overflowing\n");
-      return 1;
-    }
-    /* Send Prefetch response control message only once*/
-    if(count == 1) {
-      control = TRANS_PREFETCH_RESPONSE;
-      if((numbytes = send(acceptfd, &control, sizeof(char), MSG_NOSIGNAL)) < sizeof(char)) {
-       perror("Error in sending PREFETCH RESPONSE to Coordinator\n");
-       return 1;
-      }
-    }
-    
-    /* Add the buffer size into buffer as a parameter */
-    *((unsigned int *)buffer)=index;
-    /* Send the entire buffer with its size and oids found and not found */
-    if(send((int)acceptfd, &buffer, index, MSG_NOSIGNAL) < sizeof(index -1)) {
-      perror("Error sending oids found\n");
-      return 1;
-    }
-  }
-  return 0;
+       int i, size, objsize, numbytes = 0, isArray = 0, numoffset = 0;
+       int length, sd = -1;
+       char *recvbuffer, *sendbuffer, control;
+       unsigned int oid, mid;
+       short *offsetarry;
+       objheader_t *header;
+       struct sockaddr_in remoteAddr;
+
+       do {
+               recv_data((int)acceptfd, &length, sizeof(int));
+               if(length != -1) {
+                       size = length - sizeof(int);
+                       if((recvbuffer = calloc(1, size)) == NULL) {
+                               printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
+                               return -1;
+                       }
+                       recv_data((int)acceptfd, recvbuffer, size);
+                       oid = *((unsigned int *) recvbuffer);
+                       mid = *((unsigned int *) (recvbuffer + sizeof(unsigned int)));
+                       size = size - (2 * sizeof(unsigned int));
+                       numoffset = size / sizeof(short);
+                       if((offsetarry = calloc(numoffset, sizeof(short))) == NULL) {
+                               printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
+                               free(recvbuffer);
+                               return -1;
+                       }
+                       memcpy(offsetarry, recvbuffer + (2 * sizeof(unsigned int)), size);
+                       free(recvbuffer);
+#if 0
+                       pthread_mutex_lock(&sockLock);
+                       sockIdFound = 0;
+                       pthread_mutex_unlock(&sockLock);
+                       for(i = 0; i < NUM_MACHINES; i++) {
+                               if(sockArray[i].mid == mid) {
+                                       sd = sockArray[i].sockid;
+                                       pthread_mutex_lock(&sockLock);
+                                       sockIdFound = 1;
+                                       pthread_mutex_unlock(&sockLock);
+                                       break;
+                               }
+                       }
+
+                       if(sockIdFound == 0) {
+                               if(sockCount < NUM_MACHINES) {
+
+#endif
+                                       /* Create socket to send information */
+                                       if ((sd = socket(AF_INET, SOCK_STREAM, 0)) < 0){
+                                               perror("prefetchReq():socket()");
+                                               return -1;
+                                       }
+                                       bzero(&remoteAddr, sizeof(remoteAddr));
+                                       remoteAddr.sin_family = AF_INET;
+                                       remoteAddr.sin_port = htons(LISTEN_PORT);
+                                       remoteAddr.sin_addr.s_addr = htonl(mid);
+
+                                       if (connect(sd, (struct sockaddr *)&remoteAddr, sizeof(remoteAddr)) < 0){
+                                               printf("Error: prefetchReq():error %d connecting to %s:%d\n", errno,
+                                                               inet_ntoa(remoteAddr.sin_addr), LISTEN_PORT);
+                                               close(sd);
+                                               return -1;
+                                       }
+
+#if 0
+                                       sockArray[sockCount].mid = mid;
+                                       sockArray[sockCount].sockid = sd;
+                                       pthread_mutex_lock(&sockLock);
+                                       sockCount++;
+                                       pthread_mutex_unlock(&sockLock);
+                               } else {
+                                       //TODO Fix for connecting to more than 2 machines && close socket
+                                       printf("%s(): Error: Currently works for only 2 machines\n", __func__);
+                                       return -1;
+                               }
+                       }
+#endif
+
+                       /*Process each oid */
+                       if ((header = mhashSearch(oid)) == NULL) {/* Obj not found */
+                               /* Save the oids not found in buffer for later use */
+                               size = sizeof(int) + sizeof(char) + sizeof(unsigned int) ;
+                               if((sendbuffer = calloc(1, size)) == NULL) {
+                                       printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
+                                       free(offsetarry);
+                                       close(sd);
+                                       return -1;
+                               }
+                               *((int *) sendbuffer) = size;
+                               *((char *)(sendbuffer + sizeof(int))) = OBJECT_NOT_FOUND;
+                               *((unsigned int *)(sendbuffer + sizeof(int) + sizeof(char))) = oid;
+
+                               control = TRANS_PREFETCH_RESPONSE;
+                               if(sendPrefetchResponse(sd, &control, sendbuffer, &size) != 0) {
+                                       free(offsetarry);
+                                       printf("Error: %s() in sending prefetch response at %s, %d\n",
+                                                       __func__, __FILE__, __LINE__);
+                                       close(sd);
+                                       return -1;
+                               }
+                       } else { /* Object Found */
+                               int incr = 0;
+                               GETSIZE(objsize, header);
+                               size = sizeof(int) + sizeof(char) + sizeof(unsigned int) + sizeof(objheader_t) + objsize;
+                               if((sendbuffer = calloc(1, size)) == NULL) {
+                                       printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
+                                       free(offsetarry);
+                                       close(sd);
+                                       return -1;
+                               }
+                               *((int *) (sendbuffer + incr)) = size;
+                               incr += sizeof(int);
+                               *((char *)(sendbuffer + incr)) = OBJECT_FOUND;
+                               incr += sizeof(char);
+                               *((unsigned int *)(sendbuffer+incr)) = oid;
+                               incr += sizeof(unsigned int);
+                               memcpy(sendbuffer + incr, header, objsize + sizeof(objheader_t));
+
+                               control = TRANS_PREFETCH_RESPONSE;
+                               if(sendPrefetchResponse(sd, &control, sendbuffer, &size) != 0) {
+                                       free(offsetarry);
+                                       printf("Error: %s() in sending prefetch response at %s, %d\n",
+                                                       __func__, __FILE__, __LINE__);
+                                       close(sd);
+                                       return -1;
+                               }
+
+                               /* Calculate the oid corresponding to the offset value */
+                               for(i = 0 ; i< numoffset ; i++) {
+                                       /* Check for arrays  */
+                                       if(TYPE(header) > NUMCLASSES) {
+                                               isArray = 1;
+                                       }
+                                       if(isArray == 1) {
+                                               int elementsize = classsize[TYPE(header)];
+                                               struct ArrayObject *ao = (struct ArrayObject *) (((char *)header) + sizeof(objheader_t));
+                                               unsigned short length = ao->___length___;
+                                               /* Check if array out of bounds */
+                                               if(offsetarry[i]< 0 || offsetarry[i] >= length) {
+                                                       break;
+                                               }
+                                               oid = *((unsigned int *)(((char *)header) + sizeof(objheader_t) + sizeof(struct ArrayObject) + (elementsize*offsetarry[i])));
+                                       } else {
+                                               oid = *((unsigned int *)(((char *)header) + sizeof(objheader_t) + offsetarry[i]));
+                                       }
+
+                                       if((header = mhashSearch(oid)) == NULL) {
+                                               size = sizeof(int) + sizeof(char) + sizeof(unsigned int) ;
+                                               if((sendbuffer = calloc(1, size)) == NULL) {
+                                                       printf("Calloc error at %s,%d\n", __FILE__, __LINE__);
+                                                       free(offsetarry);
+                                                       close(sd);
+                                                       return -1;
+                                               }
+                                               *((int *) sendbuffer) = size;
+                                               *((char *)(sendbuffer + sizeof(int))) = OBJECT_NOT_FOUND;
+                                               *((unsigned int *)(sendbuffer + sizeof(int) + sizeof(char))) = oid;
+
+                                               control = TRANS_PREFETCH_RESPONSE;
+                                               if(sendPrefetchResponse(sd, &control, sendbuffer, &size) != 0) {
+                                                       free(offsetarry);
+                                                       printf("Error: %s() in sending prefetch response at %s, %d\n",
+                                                                       __FILE__, __LINE__);
+                                                       close(sd);
+                                                       return -1;
+                                               }
+                                               break;
+                                       } else {/* Obj Found */
+                                               int incr = 0;
+                                               GETSIZE(objsize, header);
+                                               size = sizeof(int) + sizeof(char) + sizeof(unsigned int) + sizeof(objheader_t) + objsize;
+                                               if((sendbuffer = calloc(1, size)) == NULL) {
+                                                       printf("Calloc error at %s,%d\n", __func__, __FILE__, __LINE__);
+                                                       free(offsetarry);
+                                                       close(sd);
+                                                       return -1;
+                                               }
+                                               *((int *) (sendbuffer + incr)) = size;
+                                               incr += sizeof(int);
+                                               *((char *)(sendbuffer + incr)) = OBJECT_FOUND;
+                                               incr += sizeof(char);
+                                               *((unsigned int *)(sendbuffer+incr)) = oid;
+                                               incr += sizeof(unsigned int);
+                                               memcpy(sendbuffer + incr, header, objsize + sizeof(objheader_t));
+
+                                               control = TRANS_PREFETCH_RESPONSE;
+                                               if(sendPrefetchResponse(sd, &control, sendbuffer, &size) != 0) {
+                                                       free(offsetarry);
+                                                       printf("Error: %s() in sending prefetch response at %s, %d\n",
+                                                                       __func__, __FILE__, __LINE__);
+                                                       close(sd);
+                                                       return -1;
+                                               }
+                                       }
+                                       isArray = 0;
+                               }
+                               free(offsetarry);
+                       }
+                       close(sd);
+               }
+       } while (length != -1);
+       return 0;
+}
+
+int sendPrefetchResponse(int sd, char *control, char *sendbuffer, int *size) {
+       int numbytes = 0;
+
+       send_data(sd, control, sizeof(char));
+       /* Send the buffer with its size */
+       int length = *(size);
+       send_data(sd, sendbuffer, length);
+       free(sendbuffer);
+       return 0;
 }
 
 void processReqNotify(unsigned int numoid, unsigned int *oidarry, unsigned short *versionarry, unsigned int mid, unsigned int threadid) {
        objheader_t *header;
        unsigned int oid;
        unsigned short newversion;
-       char msg[1+  2 * sizeof(unsigned int) + sizeof(unsigned short)];
+       char msg[1+  2 * sizeof(unsigned int) + sizeof(unsigned short)];
        int sd;
        struct sockaddr_in remoteAddr;
        int bytesSent;
-       int status, size, retry = 0;
+       int size;
 
        int i = 0;
        while(i < numoid) {
                oid = *(oidarry + i);
                if((header = (objheader_t *) mhashSearch(oid)) == NULL) {
-                       printf("processReqNotify(): Object is not found in mlookup %s, %d\n", __FILE__, __LINE__);
+                       printf("Error: mhashsearch returns NULL at %s, %d\n", __FILE__, __LINE__);
                        return;
                } else {
                        /* Check to see if versions are same */
 checkversion:
                        if ((STATUS(header) & LOCK) != LOCK) {          
+                               //FIXME make locking atomic
                                STATUS(header) |= LOCK;
-                               if(header->version == *(versionarry + i)) {
+                               newversion = header->version;
+                               if(newversion == *(versionarry + i)) {
                                        //Add to the notify list 
-                                       insNode(header->notifylist, threadid, mid); 
+                                       if((header->notifylist = insNode(header->notifylist, threadid, mid)) == NULL) {
+                                               printf("Error: Obj notify list points to NULL %s, %d\n", __FILE__, __LINE__); 
+                                               return;
+                                       }
+                                       STATUS(header) &= ~(LOCK);              
                                } else {
+                                       STATUS(header) &= ~(LOCK);              
                                        if ((sd = socket(AF_INET, SOCK_STREAM, 0)) < 0){
                                                perror("processReqNotify():socket()");
                                                return;
@@ -790,40 +871,30 @@ checkversion:
                                        remoteAddr.sin_addr.s_addr = htonl(mid);
 
                                        if (connect(sd, (struct sockaddr *)&remoteAddr, sizeof(remoteAddr)) < 0){
-                                               printf("processReqNotify():error %d connecting to %s:%d\n", errno,
+                                               printf("Error: processReqNotify():error %d connecting to %s:%d\n", errno,
                                                                inet_ntoa(remoteAddr.sin_addr), LISTEN_PORT);
-                                               status = -1;
+                                               close(sd);
+                                               return;
                                        } else {
                                                //Send Update notification
                                                msg[0] = THREAD_NOTIFY_RESPONSE;
-                                               msg[1] = oid;
+                                               *((unsigned int *)&msg[1]) = oid;
                                                size = sizeof(unsigned int);
                                                *((unsigned short *)(&msg[1]+size)) = newversion;
                                                size += sizeof(unsigned short);
                                                *((unsigned int *)(&msg[1]+size)) = threadid;
-                                               bytesSent = send(sd, msg, 1+ 2*sizeof(unsigned int) + sizeof(unsigned short), 0);
-                                               if (bytesSent < 0){
-                                                       perror("processReqNotify():send()");
-                                                       status = -1;
-                                               } else if (bytesSent != 1 + sizeof(unsigned short) + 2*sizeof(unsigned int)){
-                                                       printf("processReqNotify(): error, sent %d bytes\n", bytesSent);
-                                                       status = -1;
-                                               } else {
-                                                       status = 0;
-                                               }
-
+                                               size = 1+ 2*sizeof(unsigned int) + sizeof(unsigned short);
+                                               send_data(sd, msg, size);
                                        }
                                        close(sd);
                                }
-                               STATUS(header) &= ~(LOCK);              
                        } else {
                                randomdelay();
-                               printf("DEBUG-> processReqNotify() Object is still locked\n");
                                goto checkversion;
                        }
                }
+               i++;
        }
        free(oidarry);
        free(versionarry);
 }
-