bug fixes
[IRC.git] / Robust / src / Runtime / DSTM / interface / dstmserver.c
index 2d2935779bd7617dfab20172796f6e8248b7db94..99f48f070727b627bf42f88a2230f3122d89e79d 100644 (file)
@@ -7,9 +7,12 @@
 #include <pthread.h>
 #include <netdb.h>
 #include <fcntl.h>
+#include <errno.h>
+#include <string.h>
 #include "dstm.h"
 #include "mlookup.h"
 #include "llookup.h"
+#include "threadnotify.h"
 #ifdef COMPILER
 #include "thread.h"
 #endif
@@ -24,6 +27,8 @@ 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 */
+pthread_mutex_t threadnotify_mutex = PTHREAD_MUTEX_INITIALIZER;
 
 /* This function initializes the main objects store and creates the 
  * global machine and location lookup table */
@@ -31,12 +36,18 @@ pthread_mutex_t mainobjstore_mutex;
 int dstmInit(void)
 {
        mainobjstore = objstrCreate(DEFAULT_OBJ_STORE_SIZE);
-       pthread_mutex_init(&mainobjstore_mutex, NULL);
+       /* Initialize attribute for mutex */
+       pthread_mutexattr_init(&mainobjstore_mutex_attr);
+       pthread_mutexattr_settype(&mainobjstore_mutex_attr, PTHREAD_MUTEX_RECURSIVE_NP);
+       pthread_mutex_init(&mainobjstore_mutex, &mainobjstore_mutex_attr);
        if (mhashCreate(HASH_SIZE, LOADFACTOR))
                return 1; //failure
        
        if (lhashCreate(HASH_SIZE, LOADFACTOR))
                return 1; //failure
+
+       if (notifyhashCreate(N_HASH_SIZE, N_LOADFACTOR))
+               return 1; //failure
        
        return 0;
 }
@@ -91,44 +102,52 @@ void *dstmListen()
        printf("Listening on port %d, fd = %d\n", LISTEN_PORT, listenfd);
        while(1)
        {
-               acceptfd = accept(listenfd, (struct sockaddr *)&client_addr, &addrlength);
-               pthread_create(&thread_dstm_accept, NULL, dstmAccept, (void *)acceptfd);
+         int retval;
+         acceptfd = accept(listenfd, (struct sockaddr *)&client_addr, &addrlength);
+         do {
+           retval=pthread_create(&thread_dstm_accept, NULL, dstmAccept, (void *)acceptfd);
+         } while(retval!=0);
+         pthread_detach(thread_dstm_accept);
        }
-       pthread_exit(NULL);
 }
 /* This function accepts a new connection request, decodes the control message in the connection 
  * and accordingly calls other functions to process new requests */
 void *dstmAccept(void *acceptfd)
 {
-       int numbytes,i, val, retval;
+       int val, retval, size;
        unsigned int oid;
        char buffer[RECEIVE_BUFFER_SIZE], control,ctrl;
        char *ptr;
        void *srcObj;
        objheader_t *h;
        trans_commit_data_t transinfo;
-       unsigned short objType;
+       unsigned short objType, *versionarry, version;
+       unsigned int *oidarry, numoid, mid, threadid;
        
-       int fd_flags = fcntl((int)acceptfd, F_GETFD), size;
+       int i;
+
+       transinfo.objlocked = NULL;
+       transinfo.objnotfound = NULL;
+       transinfo.modptr = NULL;
+       transinfo.numlocked = 0;
+       transinfo.numnotfound = 0;
 
        /* Receive control messages from other machines */
        if((retval = recv((int)acceptfd, &control, sizeof(char), 0)) <= 0) {
-               if (retval == 0) {
-                       return; // Testing connection
-               }
-               perror("Error in receiving control from coordinator\n");
-               return;
+               perror("Error: in receiving control from coordinator\n");
+               pthread_exit(NULL);
        }
        
        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");
-                               return NULL;
+                               perror("Error: receiving 0x0 object from cooridnator\n");
+                               pthread_exit(NULL);
                        }
                        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);
@@ -138,7 +157,7 @@ void *dstmAccept(void *acceptfd)
                                ctrl = OBJECT_NOT_FOUND;
                                if(send((int)acceptfd, &ctrl, sizeof(char), MSG_NOSIGNAL) < sizeof(char)) {
                                        perror("Error sending control msg to coordinator\n");
-                                       return NULL;
+                                       pthread_exit(NULL);
                                }
                        } else {
                                /* Type */
@@ -146,40 +165,35 @@ void *dstmAccept(void *acceptfd)
                                *((int *)&msg[1])=size;
                                if(send((int)acceptfd, &msg, sizeof(msg), MSG_NOSIGNAL) < sizeof(msg)) {
                                        perror("Error sending size of object to coordinator\n");
-                                       return NULL;
+                                       pthread_exit(NULL);
                                }
                                if(send((int)acceptfd, h, size, MSG_NOSIGNAL) < size) {
                                        perror("Error in sending object\n");
-                                       return NULL;
+                                       pthread_exit(NULL);
                                }
                        }
                        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");
-                               return;
+                               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 readClientReq\n");
-                               return;
+                               printf("Error: In prefetchReq() %s, %d\n", __FILE__, __LINE__);
+                               pthread_exit(NULL);
                        }
                        break;
                case START_REMOTE_THREAD:
@@ -187,21 +201,65 @@ void *dstmAccept(void *acceptfd)
                        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);
+                               printf("dstmAccept(): incorrect msg size %d for START_REMOTE_THREAD %s, %d\n",
+                                       retval, __FILE__, __LINE__);
                        else
-                       { //TODO: execute run method on this global thread object
-                               printf("dstmAccept(): received START_REMOTE_THREAD msg, oid=0x%x\n", oid);
+                       {
                                objType = getObjType(oid);
-                               printf("dstmAccept(): type of object 0x%x is %d\n", oid, objType);
                                startDSMthread(oid, objType);
+                       }
+                       break;
+
+               case THREAD_NOTIFY_REQUEST:
+                       size = sizeof(unsigned int);
+                       bzero(&buffer, RECEIVE_BUFFER_SIZE);
+                       retval = recv((int)acceptfd, &buffer, size, 0);
+                       numoid = *((unsigned int *) &buffer);
+                       size = (sizeof(unsigned int) + sizeof(unsigned short)) * numoid + 2 * sizeof(unsigned int);
+                       bzero(&buffer, RECEIVE_BUFFER_SIZE);
+                       retval = recv((int)acceptfd, &buffer, size, 0);
+                       if(retval <=0)
+                               perror("dstmAccept(): error receiving THREAD_NOTIFY_REQUEST");
+                       else if( retval != (2* sizeof(unsigned int) + (sizeof(unsigned int) + sizeof(unsigned short)) * numoid))
+                               printf("dstmAccept(): incorrect msg size %d for THREAD_NOTIFY_REQUEST %s, %d\n", retval, 
+                                               __FILE__, __LINE__);
+                       else {
+                               oidarry = calloc(numoid, sizeof(unsigned int)); 
+                               memcpy(oidarry, buffer, sizeof(unsigned int) * numoid);
+                               size = sizeof(unsigned int) * numoid;
+                               versionarry = calloc(numoid, sizeof(unsigned short));
+                               memcpy(versionarry, buffer+size, sizeof(unsigned short) * numoid);
+                               size += sizeof(unsigned short) * numoid;
+                               mid = *((unsigned int *)(buffer+size));
+                               size += sizeof(unsigned int);
+                               threadid = *((unsigned int *)(buffer+size));
+                               processReqNotify(numoid, oidarry, versionarry, mid, threadid);
+                       }
 
+                       break;
 
+               case THREAD_NOTIFY_RESPONSE:
+                       size = sizeof(unsigned short) + 2 * sizeof(unsigned int);
+                       bzero(&buffer, RECEIVE_BUFFER_SIZE);
+                       retval = recv((int)acceptfd, &buffer, size, 0);
+                       if(retval <= 0) 
+                               perror("dstmAccept(): error receiving THREAD_NOTIFY_RESPONSE");
+                       else if( retval != 2*sizeof(unsigned int) + sizeof(unsigned short))
+                               printf("dstmAccept(): incorrect msg size %d for THREAD_NOTIFY_RESPONSE msg %s, %d\n", 
+                                               retval, __FILE__, __LINE__);
+                       else {
+                               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);
                        }
+
                        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 */
@@ -221,6 +279,8 @@ int readClientReq(trans_commit_data_t *transinfo, int acceptfd) {
        objheader_t *headaddr;
        int sum = 0, i, N, n, val;
 
+       oidmod = NULL;
+
        /* Read fixed_data_t data structure */ 
        N = sizeof(fixed) - 1;
        ptr = (char *)&fixed;;
@@ -255,16 +315,11 @@ int readClientReq(trans_commit_data_t *transinfo, int acceptfd) {
        }
        
        /* Read modified objects */
-       if(fixed.nummod != 0) { // If pile contains more than one modified object,
-                               // allocate new object store and recv all modified objects
-                               // TODO deallocate this space
-               pthread_mutex_lock(&mainobjstore_mutex);
-               if ((modptr = objstrAlloc(mainobjstore, fixed.sum_bytes)) == NULL) {
-                       printf("objstrAlloc error for modified objects %s, %d\n", __FILE__, __LINE__);
-                       pthread_mutex_unlock(&mainobjstore_mutex);
+       if(fixed.nummod != 0) {
+               if ((modptr = calloc(1, fixed.sum_bytes)) == NULL) {
+                       printf("calloc error for modified objects %s, %d\n", __FILE__, __LINE__);
                        return 1;
                }
-               pthread_mutex_unlock(&mainobjstore_mutex);
                sum = 0;
                do { // Recv the objs that are modified by the Coordinator
                        n = recv((int)acceptfd, (char *) modptr+sum, fixed.sum_bytes-sum, 0);
@@ -274,6 +329,11 @@ int readClientReq(trans_commit_data_t *transinfo, int acceptfd) {
 
        /* Create an array of oids for modified objects */
        oidmod = (unsigned int *) calloc(fixed.nummod, sizeof(unsigned int));
+       if (oidmod == NULL)
+       {
+               printf("calloc error %s, %d\n", __FILE__, __LINE__);
+               return 1;
+       }
        ptr = (char *) modptr;
        for(i = 0 ; i < fixed.nummod; i++) {
          int tmpsize;
@@ -286,11 +346,10 @@ 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);
-                       oidmod = NULL;
                }
                return 1;
        }
@@ -298,7 +357,6 @@ int readClientReq(trans_commit_data_t *transinfo, int acceptfd) {
        /* Free resources */
        if(oidmod != NULL) {
                free(oidmod);
-               oidmod = NULL;
        }
 
        return 0;
@@ -309,101 +367,79 @@ 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__);
+               printf("Error: In handleTransReq() %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");
-               return 1;
-       }
+       do {
+               retval = recv((int)acceptfd, &control, sizeof(char), 0);
+       } while(retval < sizeof(char));
 
        /* Process the new control message */
        switch(control) {
                case TRANS_ABORT:
-                       /* Set all ref counts as 1 and do garbage collection */
-                       ptr = modptr;
-                       for(i = 0; i< fixed->nummod; i++) {
-                         int tmpsize;
-                         tmp_header = (objheader_t *)ptr;
-                         tmp_header->rcount = 0;
-                         GETSIZE(tmpsize, tmp_header);
-                         ptr += sizeof(objheader_t) + tmpsize;
-                       }
+                       if (fixed->nummod > 0)
+                               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 */
-                       printf("DEBUG -> Recv TRANS_ABORT\n");
-                       sendctrl = TRANS_SUCESSFUL;
+                       sendctrl = TRANS_UNSUCESSFUL;
                        if(send((int)acceptfd, &sendctrl, sizeof(char), MSG_NOSIGNAL) < sizeof(char)) {
-                               perror("Error sending ACK to coordinator\n");
+                               perror("Error: In sending ACK to coordinator\n");
                                if (transinfo->objlocked != NULL) {
                                        free(transinfo->objlocked);
-                                       transinfo->objlocked = NULL;
                                }
                                if (transinfo->objnotfound != NULL) {
                                        free(transinfo->objnotfound);
-                                       transinfo->objnotfound = NULL;
                                }
 
                                return 1;
                        }
-                       ptr = NULL;
                        break;
 
                case TRANS_COMMIT:
                        /* Invoke the transCommit process() */
-                       printf("DEBUG -> Recv TRANS_COMMIT \n");
                        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 */
-                               printf("DEBUG -> Freeing...\n");
-                               fflush(stdout);
                                if (transinfo->objlocked != NULL) {
                                        free(transinfo->objlocked);
-                                       transinfo->objlocked = NULL;
                                }
                                if (transinfo->objnotfound != NULL) {
                                        free(transinfo->objnotfound);
-                                       transinfo->objnotfound = NULL;
                                }
                                return 1;
                        }
                        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;
        }
 
        /* Free memory */
-       printf("DEBUG -> Freeing...\n");
-       fflush(stdout);
-
        if (transinfo->objlocked != NULL) {
                free(transinfo->objlocked);
-               transinfo->objlocked = NULL;
        }
        if (transinfo->objnotfound != NULL) {
                free(transinfo->objnotfound);
-               transinfo->objnotfound = NULL;
        }
 
        return 0;
@@ -412,11 +448,11 @@ 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;
-       short version;
+       int val, i = 0, j;
+       unsigned short version;
        char control = 0, *ptr;
        unsigned int oid;
-       unsigned int *oidnotfound, *oidlocked, *oidmod;
+       unsigned int *oidnotfound, *oidlocked;
        void *mobj;
        objheader_t *headptr;
 
@@ -438,7 +474,7 @@ char handleTransReq(fixed_data_t *fixed, trans_commit_data_t *transinfo, unsigne
                        incr *= i;
                        oid = *((unsigned int *)(objread + incr));
                        incr += sizeof(unsigned int);
-                       version = *((short *)(objread + incr));
+                       version = *((unsigned short *)(objread + incr));
                } else {//Objs modified
                  int tmpsize;
                  headptr = (objheader_t *) ptr;
@@ -452,33 +488,35 @@ char handleTransReq(fixed_data_t *fixed, trans_commit_data_t *transinfo, unsigne
 
                if ((mobj = mhashSearch(oid)) == NULL) {/* Obj not found */
                        /* Save the oids not found and number of oids not found for later use */
-                       //oidnotfound[objnotfound] = OID(((objheader_t *)mobj));
                        oidnotfound[objnotfound] = oid;
                        objnotfound++;
                } else { /* If Obj found in machine (i.e. has not moved) */
                        /* Check if Obj is locked by any previous transaction */
                        if ((STATUS(((objheader_t *)mobj)) & LOCK) == LOCK) {           
-                               if (version == ((objheader_t *)mobj)->version) {      /* If not locked then match versions */
+                               if (version == ((objheader_t *)mobj)->version) {      /* If locked then match versions */
                                        v_matchlock++;
                                } else {/* If versions don't match ...HARD ABORT */
                                        v_nomatch++;
                                        /* Send TRANS_DISAGREE to Coordinator */
                                        control = TRANS_DISAGREE;
+                                       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);
+                                       }
                                        if((val = send(acceptfd, &control, sizeof(char), MSG_NOSIGNAL)) < sizeof(char)) {
                                                perror("Error in sending control to the Coordinator\n");
                                                return 0;
                                        }
-                                       printf("DEBUG -> Sending TRANS_DISAGREE\n");
                                        return control;
                                }
                        } else {/* If Obj is not locked then lock object */
                                STATUS(((objheader_t *)mobj)) |= LOCK;
-                              
-                               /*TESTING Add random wait to make transactions run for a long time such that
-                                * we can test for soft abort case */
-                       
-                               //randomdelay();
-
                                /* Save all object oids that are locked on this machine during this transaction request call */
                                oidlocked[objlocked] = OID(((objheader_t *)mobj));
                                objlocked++;
@@ -487,12 +525,23 @@ 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;
+                                       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 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;
                                        }
-                                       printf("DEBUG -> Sending TRANS_DISAGREE\n");
+                                       
                                        return control;
                                }
                        }
@@ -500,22 +549,23 @@ 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;
@@ -524,22 +574,25 @@ int decideCtrlMessage(fixed_data_t *fixed, trans_commit_data_t *transinfo, int *
                        perror("Error in sending control to Coordinator\n");
                        return 0;
                }
-               printf("DEBUG -> Sending TRANS_AGREE\n");
        }
        /* 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);
 
-               printf("DEBUG -> Sending TRANS_SOFT_ABORT\n");
                /* 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");
+               if((val = send(acceptfd, &control, sizeof(char),MSG_NOSIGNAL)) < sizeof(char)) {
+                       perror("Error in sending TRANS_SOFT_ABORT control\n");
                        return 0;
                }
+
                /* 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);
+                       if((val = send(acceptfd, msg, sizeof(int) ,MSG_NOSIGNAL)) < sizeof(int)) {
+                               perror("Error in sending objects that are not found\n");
+                               return 0;
+                       }
                        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");
@@ -564,35 +617,36 @@ int decideCtrlMessage(fixed_data_t *fixed, trans_commit_data_t *transinfo, int *
  * Sends an ACK back to Coordinator */
 int transCommitProcess(void *modptr, unsigned int *oidmod, unsigned int *oidlocked, int nummod, int numlocked, int acceptfd) {
        objheader_t *header;
+       objheader_t *newheader;
        int i = 0, offset = 0;
        char control;
+       int tmpsize;
 
        /* 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;
                }
-               /* Change reference count of older address and free space in objstr ?? */
-               header->rcount = 0;
-
-               /* Change ptr address in mhash table */
-               mhashRemove(oidmod[i]);
-               mhashInsert(oidmod[i], (((char *)modptr) + offset));
-               {
-                 int tmpsize;
-                 GETSIZE(tmpsize,header);
-                 offset += sizeof(objheader_t) + tmpsize;
-               }
-               /* Update object version number */
-               header = (objheader_t *) mhashSearch(oidmod[i]);
+               GETSIZE(tmpsize,header);
+               pthread_mutex_lock(&mainobjstore_mutex);
+               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) {
+                       notifyAll(&header->notifylist, OID(header), header->version);
+               }
+               pthread_mutex_unlock(&mainobjstore_mutex);
+               offset += sizeof(objheader_t) + tmpsize;
        }
 
+       if (nummod > 0)
+               free(modptr);
+
        /* 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);
@@ -601,9 +655,9 @@ int transCommitProcess(void *modptr, unsigned int *oidmod, unsigned int *oidlock
 
        /* Send ack to coordinator */
        control = TRANS_SUCESSFUL;
-       printf("DEBUG-> TRANS_SUCESSFUL\n");
        if(send((int)acceptfd, &control, sizeof(char), MSG_NOSIGNAL) < sizeof(char)) {
                perror("Error sending ACK to coordinator\n");
+               return 1;
        }
        
        return 0;
@@ -615,107 +669,201 @@ 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;
-  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++) {
-       objoid = *((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;
-         continue;
+       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 one oid and offset pair sent for prefetch */
+       while(numbytes = recv((int)acceptfd, &length, sizeof(int), 0) != 0) {
+               count++;
+               if(length == -1)
+                       break;
+               index = 0;  
+               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;
+               sum = 0;
+               /* Recv the offset values per oid */ 
+               do {
+                       n = recv((int)acceptfd, (void *)ptr+sum, N-sum, 0); 
+                       sum += n; 
+               } while(sum < N && n != 0);     
+
+               bzero(&buffer, PRE_BUF_SIZE);
+               /* 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);
+                       *((unsigned int *)(buffer+index)) = oid;
+                       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 = (objheader_t *)mobj;
+                       GETSIZE(size, header);
+                       size += sizeof(objheader_t);
+                       *(buffer + index) = OBJECT_FOUND;
+                       index += sizeof(char);
+                       *((unsigned int *)(buffer+index)) = oid;
+                       index += sizeof(unsigned int);
+                       *((int *)(buffer+index)) = size;
+                       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);
+                                       *((unsigned int *)(buffer+index)) = objoid;
+                                       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);
+                                       *((unsigned int *)(buffer+index)) = objoid;
+                                       index += sizeof(unsigned int);
+                                       *((int *)(buffer+index)) = size;
+                                       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("Error: Buffer array overflow %s, %d\n", __FILE__, __LINE__);
+                       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;
+                       }
+               }
+
+               //Send buffer size 
+               if((numbytes = send(acceptfd, &index, sizeof(unsigned int), MSG_NOSIGNAL)) < sizeof(unsigned int)) {
+                       perror("Error: in sending PREFETCH RESPONSE to Coordinator\n");
+                       return 1;
+               }
+
+               /* Send the entire buffer with its size and oids found and not found */
+               if(send((int)acceptfd, &buffer, index, MSG_NOSIGNAL) < sizeof(index)) {
+                       perror("Error: sending oids found\n");
+                       return 1;
+               }
+       }
+       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)];
+       int sd;
+       struct sockaddr_in remoteAddr;
+       int bytesSent;
+       int status, size;
+
+       int i = 0;
+       while(i < numoid) {
+               oid = *(oidarry + i);
+               if((header = (objheader_t *) mhashSearch(oid)) == NULL) {
+                       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;
+                               newversion = header->version;
+                               if(newversion == *(versionarry + i)) {
+                                       //Add to the notify list 
+                                       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;
+                                       }
+                                       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: processReqNotify():error %d connecting to %s:%d\n", errno,
+                                                               inet_ntoa(remoteAddr.sin_addr), LISTEN_PORT);
+                                               status = -1;
+                                       } else {
+                                               //Send Update notification
+                                               msg[0] = THREAD_NOTIFY_RESPONSE;
+                                               *((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("Error: processReqNotify(): error, sent %d bytes %s, %d\n", 
+                                                                       bytesSent, __FILE__, __LINE__);
+                                                       status = -1;
+                                               } else {
+                                                       status = 0;
+                                               }
+
+                                       }
+                                       close(sd);
+                               }
+                       } else {
+                               randomdelay();
+                               goto checkversion;
+                       }
+               }
+               i++;
        }
-      }
-    }
-    /* 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;
+       free(oidarry);
+       free(versionarry);
 }