+/* Coordinator => Machine that initiates the transaction request call for commiting a transaction
+ * Participant => Machines that host the objects involved in a transaction commit */
+
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int dstmInit(void)
{
- //Initialize main object store
+ /* Initialize main object store */
mainobjstore = objstrCreate(DEFAULT_OBJ_STORE_SIZE);
+ /* Create machine lookup table and location lookup table */
if (mhashCreate(HASH_SIZE, LOADFACTOR))
return 1; //failure
}
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 fd_flags = fcntl((int)acceptfd, F_GETFD), size;
printf("Recieved connection: fd = %d\n", (int)acceptfd);
+ /* 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;
}
+
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;
+ return NULL;
}
srcObj = mhashSearch(oid);
h = (objheader_t *) srcObj;
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;
}
} 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");
+ perror("Error sending size of object to coordinator\n");
+ return NULL;
}
if(send((int)acceptfd, h, size, MSG_NOSIGNAL) < size) {
- perror("Error in sending object\n");
+ perror("Error in sending object\n");
+ return NULL;
}
}
break;
break;
case TRANS_REQUEST:
+ /* Read transaction request */
printf("DEBUG -> Recv TRANS_REQUEST\n");
- if((val = readClientReq((int)acceptfd, &transinfo)) != 0) {
+ if((val = readClientReq(&transinfo, (int)acceptfd)) != 0) {
printf("Error in readClientReq\n");
+ return;
}
break;
default:
printf("DEBUG -> dstmAccept: Error Unknown opcode %d\n", control);
}
+
+ /* Close connection */
if (close((int)acceptfd) == -1)
perror("close");
else
pthread_exit(NULL);
}
-// Reads transaction request per thread
-int readClientReq(int acceptfd, trans_commit_data_t *transinfo) {
- char *ptr, control, prevctrl, sendctrl, newctrl;
- void *modptr, *header;
- objheader_t *tmp_header;
+/* This function reads the information available in a transaction request
+ * and makes a function call to process the request */
+int readClientReq(trans_commit_data_t *transinfo, int acceptfd) {
+ char *ptr;
+ void *modptr;
fixed_data_t fixed;
- int sum = 0, i, N, n, val, retval;
+ int sum = 0, i, N, n, val;
- //Reads to process the TRANS_REQUEST protocol further
- // Read fixed_data
+ /* Read fixed_data_t data structure */
N = sizeof(fixed) - 1;
ptr = (char *)&fixed;;
fixed.control = TRANS_REQUEST;
sum += n;
} while(sum < N && n != 0);
- // Read list of mids
+ /* Read list of mids */
int mcount = fixed.mcount;
N = mcount * sizeof(unsigned int);
unsigned int listmid[mcount];
sum += n;
} while(sum < N && n != 0);
- // Read oid and version tuples
+ /* 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];
} while(sum < N && n != 0);
}
- // Read modified objects
+ /* 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
if ((modptr = objstrAlloc(mainobjstore, fixed.sum_bytes)) == NULL) {
printf("objstrAlloc error for modified objects %s, %d\n", __FILE__, __LINE__);
return 1;
}
sum = 0;
- do { // Recv the objs that are modified at Coordinator
+ do { // Recv the objs that are modified by the Coordinator
n = recv((int)acceptfd, modptr+sum, fixed.sum_bytes-sum, 0);
sum += n;
} while (sum < fixed.sum_bytes && n != 0);
}
- // Process the information available in the TRANS_REQUEST control
- //Send control message as per all votes from all oids in the machine
- if((prevctrl = handleTransReq(acceptfd, &fixed, transinfo, listmid, objread, modptr)) == 0 ) {
+ /*Process the information read */
+ if((val = processClientReq(&fixed, transinfo, listmid, objread, modptr, acceptfd)) != 0) {
+ printf("Error in processClientReq %s, %d\n", __FILE__, __LINE__);
+ return 1;
+ }
+
+ return 0;
+}
+
+/* This function processes the Coordinator's transaction request using "handleTransReq"
+ * function and sends a reply to the co-ordinator.
+ * 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, int acceptfd) {
+ char *ptr, control, sendctrl;
+ objheader_t *tmp_header;
+ void *header;
+ int i = 0, val, retval;
+
+ /* 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 for new control message from Coordiator
+ /* 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;
}
+ /* Process the new control message */
switch(control) {
case TRANS_ABORT:
- //Mark all ref counts as 1 and do garbage collection
+ /* Set all ref counts as 1 and do garbage collection */
ptr = modptr;
- for(i = 0; i< fixed.nummod; i++) {
+ for(i = 0; i< fixed->nummod; i++) {
tmp_header = (objheader_t *)ptr;
tmp_header->rcount = 1;
ptr += sizeof(objheader_t) + classsize[tmp_header->type];
}
- //Unlock objects that was locked in this machine due to this transaction
+ /* Unlock objects that was locked due to this transaction */
for(i = 0; i< transinfo->numlocked; i++) {
- printf("DEBUG-> Unlocking objects\n");
header = mhashSearch(transinfo->objlocked[i]);// find the header address
((objheader_t *)header)->status &= ~(LOCK);
}
- //send ack to coordinator
+ /* Send ack to Coordinator */
printf("DEBUG -> Recv TRANS_ABORT\n");
sendctrl = TRANS_SUCESSFUL;
if(send((int)acceptfd, &sendctrl, sizeof(char), MSG_NOSIGNAL) < sizeof(char)) {
perror("Error sending ACK to coordinator\n");
return 1;
}
-
ptr = NULL;
- return 0;
+ // return 0;
+ break;
+
case TRANS_COMMIT:
+ /* Invoke the transCommit process() */
printf("DEBUG -> Recv TRANS_COMMIT \n");
if((val = transCommitProcess(transinfo, (int)acceptfd)) != 0) {
printf("Error in transCommitProcess %s, %d\n", __FILE__, __LINE__);
+ return 1;
}
break;
//TODO Use fixed.trans_id TID since Client may have died
break;
}
- //Free memory
+ /* Free memory */
printf("DEBUG -> Freeing...\n");
fflush(stdout);
if (transinfo->objmod != NULL) {
return 0;
}
-//This function runs a decision after all objects involved in TRANS_REQUEST
-//and returns the appropriate control message such as TRANS_AGREE, TRANS_DISAGREE or TRANS_SOFT_ABORT to the Ccordinator
-char handleTransReq(int acceptfd, fixed_data_t *fixed, trans_commit_data_t *transinfo, unsigned int *listmid, char *objread, void *modptr) {
- int val;
+/* This function increments counters while running a voting decision on all objects involved
+ * in TRANS_REQUEST */
+
+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;
- char control = 0, ctrlmissoid, *ptr;
- int i, j = 0;
+ char control = 0, *ptr;
unsigned int oid;
unsigned int *oidnotfound, *oidlocked, *oidmod;
+ void *mobj;
+ objheader_t *headptr;
+ /* Counters and arrays to formulate decision on control message to be sent */
oidnotfound = (unsigned int *) calloc(fixed->numread + fixed->nummod, sizeof(unsigned int));
oidlocked = (unsigned int *) calloc(fixed->numread + fixed->nummod, sizeof(unsigned int));
oidmod = (unsigned int *) calloc(fixed->nummod, sizeof(unsigned int));
- // Counters and arrays to formulate decision on control message to be sent
- // version match or no match
int objnotfound = 0, objlocked = 0, objmod =0, v_nomatch = 0, v_matchlock = 0, v_matchnolock = 0;
int objmodnotfound = 0, nummodfound = 0;
- void *mobj;
- objheader_t *headptr;
-
- //Process each object present in the pile
+
+ /* modptr points to the beginning of the object store
+ * created at the Pariticipant.
+ * Object store holds the modified objects involved in the transaction request */
ptr = modptr;
- //Process each oid in the machine pile/ group per thread
- //Should be a new function
+ /* Process each oid in the machine pile/ group per thread */
for (i = 0; i < fixed->numread + fixed->nummod; i++) {
- if (i < fixed->numread) {//Object is read
+ 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
incr *= i;
oid = *((unsigned int *)(objread + incr));
incr += sizeof(unsigned int);
version = *((short *)(objread + incr));
- } else {//Obj is modified
+ } else {//Objs modified
headptr = (objheader_t *) ptr;
oid = headptr->oid;
oidmod[objmod] = oid;//Array containing modified oids
version = headptr->version;
ptr += sizeof(objheader_t) + classsize[headptr->type];
}
- //Check if object is still present in the machine since the beginning of TRANS_REQUEST
- if ((mobj = mhashSearch(oid)) == NULL) {// Obj not found
- //Save the oids not found for later use
+
+ /* Check if object is still present in the machine since the beginning of TRANS_REQUEST */
+
+ if ((mobj = mhashSearch(oid)) == NULL) {/* Obj not found */
+ /* Save the oids not found and number of oids not found for later use */
oidnotfound[objnotfound] = ((objheader_t *)mobj)->oid;
objnotfound++;
- } else { // If obj found in machine (i.e. has not moved)
- //Check if obj is locked
+ } else { /* If Obj found in machine (i.e. has not moved) */
+ /* Check if Obj is locked by any previous transaction */
if ((((objheader_t *)mobj)->status & LOCK) == LOCK) {
- if (version == ((objheader_t *)mobj)->version) { // If version match
- printf("DEBUG -> obj = %d locked\n", ((objheader_t *)mobj)->oid);
+ if (version == ((objheader_t *)mobj)->version) { /* If not locked then match versions */
v_matchlock++;
- } else {//If versions don't match ..HARD ABORT
+ } else {/* If versions don't match ...HARD ABORT */
v_nomatch++;
- //send TRANS_DISAGREE to Coordinator
+ /* Send TRANS_DISAGREE to Coordinator */
control = TRANS_DISAGREE;
- if((val = send(acceptfd, &control, sizeof(char),MSG_NOSIGNAL)) < sizeof(char)) {
+ 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 accept_fd = %d\n", acceptfd);
+ printf("DEBUG -> Sending TRANS_DISAGREE\n");
return control;
}
- } else {//Obj is not locked , so lock object
+ } else {/* If Obj is not locked then lock object */
((objheader_t *)mobj)->status |= LOCK;
- // TESTING Add sleep to make transactions run for a long time such that
- // we can test for soft abort case
- sleep(1);
- //Save all object oids that are locked on this machine during this transaction request call
+
+ /*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] = ((objheader_t *)mobj)->oid;
objlocked++;
- if (version == ((objheader_t *)mobj)->version) { //If versions match
+ if (version == ((objheader_t *)mobj)->version) { /* Check if versions match */
v_matchnolock++;
- } else { //If versions don't match
+ } else { /* If versions don't match ...HARD ABORT */
v_nomatch++;
- //send TRANS_DISAGREE to Coordinator
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;
}
}
- //Decide what control message(s) to send
- // Should be a new function
- if(v_matchnolock == fixed->numread + fixed->nummod) {
- //send TRANS_AGREE to Coordinator
+ /* Decide what control message to send to Coordinator */
+ if ((val = decideCtrlMessage(fixed, transinfo, &v_matchnolock, &v_matchlock, &v_nomatch, &objnotfound, &objlocked,
+ modptr, oidnotfound, oidlocked, oidmod, acceptfd)) == 0) {
+ printf("Error in decideCtrlMessage %s, %d\n", __FILE__, __LINE__);
+ return 0;
+ }
+
+ return val;
+
+}
+/* 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,
+ int *v_nomatch, int *objnotfound, int *objlocked, void *modptr,
+ unsigned int *oidnotfound, unsigned int *oidlocked, unsigned int *oidmod,
+ int acceptfd) {
+ int val;
+ char control = 0;
+ /* Condition to send TRANS_AGREE */
+ if(*(v_matchnolock) == fixed->numread + fixed->nummod) {
control = TRANS_AGREE;
if((val = send(acceptfd, &control, sizeof(char), MSG_NOSIGNAL)) < sizeof(char)) {
perror("Error in sending control to Coordinator\n");
}
printf("DEBUG -> Sending TRANS_AGREE\n");
}
- //Condition to send TRANS_SOFT_ABORT
- if((v_matchlock > 0 && v_nomatch == 0) || (objnotfound > 0 && v_nomatch == 0)) {
+ /* 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;
+ *((int*)&msg[1])= *(objnotfound);
printf("DEBUG -> Sending TRANS_SOFT_ABORT\n");
- //Sending control message
+ /* 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 number of oids not found and the missing oids if objects are missing in the machine
- if(objnotfound != 0) {
- int size = sizeof(unsigned int)*objnotfound;
- if((val = send(acceptfd, oidnotfound, size ,MSG_NOSIGNAL)) < size) {
+ /* Send number of oids not found and the missing oids if objects are missing in the machine */
+ if(*(objnotfound) != 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");
return 0;
}
}
}
-
- //Do the following when TRANS_DISAGREE is sent
- if(control == TRANS_DISAGREE) {
- //Set the reference count of the object to 1 in mainstore for garbage collection
- ptr = modptr;
- for(i = 0; i< fixed->nummod; i++) {
- headptr = (objheader_t *) ptr;
- headptr->rcount = 1;
- ptr += sizeof(objheader_t) + classsize[headptr->type];
- }
- //Unlock objects that was locked in the trans
- for(i = 0; i< objlocked ; i++) {
- mobj = mhashSearch(oidlocked[i]);// find the header address
- ((objheader_t *)mobj)->status &= ~(LOCK);
- }
- }
-
- //Fill out the structure required for a trans commit process if pile receives a TRANS_COMMIT
+
+ /* Fill out the trans_commit_data_t data structure. This is required for a trans commit process
+ * if Participant receives a TRANS_COMMIT */
transinfo->objmod = oidmod;
transinfo->objlocked = oidlocked;
transinfo->objnotfound = oidnotfound;
transinfo->modptr = modptr;
transinfo->nummod = fixed->nummod;
- transinfo->numlocked = objlocked;
- transinfo->numnotfound = objnotfound;
+ transinfo->numlocked = *(objlocked);
+ transinfo->numnotfound = *(objnotfound);
return control;
}
-//Process oids in the TRANS_COMMIT requested by the participant and sends an ACK back to Coordinator
+/* This function processes all modified objects involved in a TRANS_COMMIT and updates pointer
+ * addresses in lookup table and also changes version number
+ * Sends an ACK back to Coordinator */
int transCommitProcess(trans_commit_data_t *transinfo, int acceptfd) {
objheader_t *header;
int i = 0, offset = 0;
char control;
- //Process each modified object saved in the mainobject store
+ /* Process each modified object saved in the mainobject store */
for(i=0; i<transinfo->nummod; i++) {
if((header = (objheader_t *) mhashSearch(transinfo->objmod[i])) == NULL) {
printf("mhashsearch returns NULL at %s, %d\n", __FILE__, __LINE__);
}
- //change reference count of older address and free space in objstr ??
- header->rcount = 1; //Not sure what would be th val
- //change ptr address in mhash table
+ /* Change reference count of older address and free space in objstr ?? */
+ header->rcount = 1; //Not sure what would be the val
+
+ /* Change ptr address in mhash table */
printf("DEBUG -> removing object oid = %d\n", transinfo->objmod[i]);
mhashRemove(transinfo->objmod[i]);
mhashInsert(transinfo->objmod[i], (transinfo->modptr + offset));
offset += sizeof(objheader_t) + classsize[header->type];
- //update object version
+
+ /* Update object version number */
header = (objheader_t *) mhashSearch(transinfo->objmod[i]);
header->version += 1;
}
+ /* Unlock locked objects */
for(i=0; i<transinfo->numlocked; i++) {
- //unlock objects
header = (objheader_t *) mhashSearch(transinfo->objlocked[i]);
header->status &= ~(LOCK);
}
//TODO Update location lookup table
- //send ack to coordinator
+ /* Send ack to coordinator */
control = TRANS_SUCESSFUL;
printf("DEBUG-> TRANS_SUCESSFUL\n");
if(send((int)acceptfd, &control, sizeof(char), MSG_NOSIGNAL) < sizeof(char)) {
#define RECEIVE_BUFFER_SIZE 2048
extern int classsize[];
-
+plistnode_t *createPiles(transrecord_t *);
+/* This functions inserts randowm wait delays in the order of msec */
void randomdelay(void)
{
struct timespec req, rem;
return tmp;
}
+/* This function finds the location of the objects involved in a transaction
+ * and returns the pointer to the object if found in a remote location */
objheader_t *transRead(transrecord_t *record, unsigned int oid)
{
unsigned int machinenumber;
void *objcopy;
int size;
void *buf;
- //check cache
+ /* Search local cache */
if((objheader =(objheader_t *)chashSearch(record->lookupTable, oid)) != NULL){
//printf("DEBUG -> transRead oid %d found local\n", oid);
return(objheader);
} else if ((objheader = (objheader_t *) mhashSearch(oid)) != NULL) {
- //Look up in Machine lookup table and found
-
+ /* Look up in machine lookup table and copy into cache*/
//printf("oid is found in Local machinelookup\n");
tmp = mhashSearch(oid);
size = sizeof(objheader_t)+classsize[tmp->type];
- //Copy into cache
objcopy = objstrAlloc(record->cache, size);
memcpy(objcopy, (void *)tmp, size);
- //Insert into cache's lookup table
+ /* Insert into cache's lookup table */
chashInsert(record->lookupTable, objheader->oid, objcopy);
return(objcopy);
- } else {
- //Get the object from the remote location
- //printf("oid is found in remote machine\n");
+ } else { /* If not found in machine look up */
+ /* Get the object from the remote location */
machinenumber = lhashSearch(oid);
objcopy = getRemoteObj(record, machinenumber, oid);
if(objcopy == NULL) {
}
}
}
-
+/* This function creates objects in the transaction record */
objheader_t *transCreateObj(transrecord_t *record, unsigned short type)
{
objheader_t *tmp = (objheader_t *) objstrAlloc(record->cache, (sizeof(objheader_t) + classsize[type]));
return tmp;
}
-//This function decides the reponse that needs to be sent to all other machines involved in a
-//transaction by the machine that initiated the transaction request
-
-int decideResponse(thread_data_array_t *tdata) {
- char control;
- int i, transagree = 0, transdisagree = 0, transsoftabort = 0;
+plistnode_t *createPiles(transrecord_t *record) {
+ int i = 0;
+ unsigned int size;/* Represents number of bins in the chash table */
+ chashlistnode_t *curr, *ptr, *next;
+ plistnode_t *pile = NULL;
+ unsigned int machinenum;
+ objheader_t *headeraddr;
- //Check common data structure
- for (i = 0 ; i < tdata->pilecount ; i++) {
- //Switch case
- control = tdata->recvmsg[i].rcv_status;
- switch(control) {
- case TRANS_DISAGREE:
- printf("DEBUG-> trans.c Recv TRANS_DISAGREE\n");
- transdisagree++;
- break;
+ ptr = record->lookupTable->table;
+ size = record->lookupTable->size;
- case TRANS_AGREE:
- printf("DEBUG-> trans.c Recv TRANS_AGREE\n");
- transagree++;
- break;
-
- case TRANS_SOFT_ABORT:
- printf("DEBUG-> trans.c Recv TRANS_SOFT_ABORT\n");
- transsoftabort++;
+ for(i = 0; i < size ; i++) {
+ curr = &ptr[i];
+ /* Inner loop to traverse the linked list of the cache lookupTable */
+ while(curr != NULL) {
+ //if the first bin in hash table is empty
+ if(curr->key == 0) {
break;
- default:
- printf("Participant sent unknown message in %s, %d\n", __FILE__, __LINE__);
- return -1;
+ }
+ next = curr->next;
+ //Get machine location for object id
+
+ if ((machinenum = lhashSearch(curr->key)) == 0) {
+ printf("Error: No such machine %s, %d\n", __FILE__, __LINE__);
+ return NULL;
+ }
+
+ if ((headeraddr = chashSearch(record->lookupTable, curr->key)) == NULL) {
+ printf("Error: No such oid %s, %d\n", __FILE__, __LINE__);
+ return NULL;
+ }
+ //Make machine groups
+ if ((pile = pInsert(pile, headeraddr, machinenum, record->lookupTable->numelements)) == NULL) {
+ printf("pInsert error %s, %d\n", __FILE__, __LINE__);
+ return NULL;
+ }
+ curr = next;
}
}
+
+ return pile;
+}
+/* This function initiates the transaction commit process
+ * Spawns threads for each of the new connections with Participants
+ * by creating new piles,
+ * Fills the piles with necesaary information and
+ * Sends a transrequest() to each pile*/
+int transCommit(transrecord_t *record) {
+ unsigned int tot_bytes_mod, *listmid;
+ plistnode_t *pile;
+ int i, rc;
+ int pilecount = 0, offset, numthreads = 0, trecvcount = 0, tmachcount = 0;
+ char buffer[RECEIVE_BUFFER_SIZE],control;
+ char transid[TID_LEN];
+ trans_req_data_t *tosend;
+ static int newtid = 0;
+ char treplyctrl = 0, treplyretry = 0; /* keeps track of the common response that needs to be sent */
+
+ /* Look through all the objects in the transaction record and make piles
+ * for each machine involved in the transaction*/
+ pile = createPiles(record);
+
+ /* Create the packet to be sent in TRANS_REQUEST */
+
+ /* Count the number of participants */
+ pilecount = pCount(pile);
+
+ /* Create a list of machine ids(Participants) involved in transaction */
+ if((listmid = calloc(pilecount, sizeof(unsigned int))) == NULL) {
+ printf("Calloc error %s, %d\n", __FILE__, __LINE__);
+ return 1;
+ }
+ pListMid(pile, listmid);
- //Decide what control message to send to Participant
- if(transdisagree > 0) {
- //Send Abort
- *(tdata->replyctrl) = TRANS_ABORT;
- printf("DEBUG-> trans.c Sending TRANS_ABORT\n");
- objstrDelete(tdata->rec->cache);
- chashDelete(tdata->rec->lookupTable);
- free(tdata->rec);
- } else if(transagree == tdata->pilecount){
- //Send Commit
- *(tdata->replyctrl) = TRANS_COMMIT;
- printf("DEBUG-> trans.c Sending TRANS_COMMIT\n");
- objstrDelete(tdata->rec->cache);
- chashDelete(tdata->rec->lookupTable);
- free(tdata->rec);
- } else if(transsoftabort > 0 && transdisagree == 0) {
- //Send Abort
- *(tdata->replyctrl) = TRANS_ABORT;
- *(tdata->replyretry) = 1;
- //objstrDelete(tdata->rec->cache);
- //chashDelete(tdata->rec->lookupTable);
- //free(tdata->rec);
- printf("DEBUG-> trans.c Sending TRANS_ABORT\n");
- } else {
- printf("DEBUG -> %s, %d: Error: undecided response\n", __FILE__, __LINE__);
- return -1;
- }
+
+ /* Initialize thread variables,
+ * Spawn a thread for each Participant involved in a transaction */
+ pthread_t thread[pilecount];
+ pthread_attr_t attr;
+ pthread_cond_t tcond;
+ pthread_mutex_t tlock;
+ pthread_mutex_t tlshrd;
- return 0;
-}
-//This function sends the final response to all threads in their respective socket id
-char sendResponse(thread_data_array_t *tdata, int sd) {
- int n, N, sum, oidcount = 0;
- char *ptr, retval = 0;
- unsigned int *oidnotfound;
+ thread_data_array_t *thread_data_array;
+ thread_data_array = (thread_data_array_t *) malloc(sizeof(thread_data_array_t)*pilecount);
+ thread_response_t rcvd_control_msg[pilecount]; /* Shared thread array that keeps track of responses of participants */
- //If the decided response is due to a soft abort and missing objects at the Participant's side
- if(tdata->recvmsg[tdata->thread_id].rcv_status == TRANS_SOFT_ABORT) {
- //Read list of objects missing
- if((read(sd, &oidcount, sizeof(int)) != 0) && (oidcount != 0)) {
- //Break if only objs are locked at the Participant side
- N = oidcount * sizeof(unsigned int);
- if((oidnotfound = calloc(oidcount, sizeof(unsigned int))) == NULL) {
- printf("Calloc error %s, %d\n", __FILE__, __LINE__);
- }
- ptr = (char *) oidnotfound;
- do {
- n = read(sd, ptr+sum, N-sum);
- sum += n;
- } while(sum < N && n !=0);
+ /* Initialize and set thread detach attribute */
+ pthread_attr_init(&attr);
+ pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
+ pthread_mutex_init(&tlock, NULL);
+ pthread_cond_init(&tcond, NULL);
+
+ /* Process each machine pile */
+ while(pile != NULL) {
+ //Create transaction id
+ newtid++;
+ //trans_req_data_t *tosend;
+ if ((tosend = calloc(1, sizeof(trans_req_data_t))) == NULL) {
+ printf("Calloc error %s, %d\n", __FILE__, __LINE__);
+ return 1;
}
- retval = TRANS_SOFT_ABORT;
- }
- //If the decided response is TRANS_ABORT
- if(*(tdata->replyctrl) == TRANS_ABORT) {
- retval = TRANS_ABORT;
- }
- if(*(tdata->replyctrl) == TRANS_COMMIT) {
- retval = TRANS_COMMIT;
+ tosend->f.control = TRANS_REQUEST;
+ sprintf(tosend->f.trans_id, "%x_%d", pile->mid, newtid);
+ tosend->f.mcount = pilecount;
+ tosend->f.numread = pile->numread;
+ tosend->f.nummod = pile->nummod;
+ tosend->f.sum_bytes = pile->sum_bytes;
+ tosend->listmid = listmid;
+ tosend->objread = pile->objread;
+ tosend->oidmod = pile->oidmod;
+ thread_data_array[numthreads].thread_id = numthreads;
+ thread_data_array[numthreads].mid = pile->mid;
+ thread_data_array[numthreads].pilecount = pilecount;
+ thread_data_array[numthreads].buffer = tosend;
+ thread_data_array[numthreads].recvmsg = rcvd_control_msg;
+ thread_data_array[numthreads].threshold = &tcond;
+ thread_data_array[numthreads].lock = &tlock;
+ thread_data_array[numthreads].count = &trecvcount;
+ thread_data_array[numthreads].replyctrl = &treplyctrl;
+ thread_data_array[numthreads].replyretry = &treplyretry;
+ thread_data_array[numthreads].rec = record;
+
+ rc = pthread_create(&thread[numthreads], NULL, transRequest, (void *) &thread_data_array[numthreads]);
+ if (rc) {
+ perror("Error in pthread create");
+ return 1;
+ }
+ numthreads++;
+ //TODO frees
+ pile = pile->next;
}
- // Send response to the Participant
- if (send(sd, tdata->replyctrl, sizeof(char),MSG_NOSIGNAL) < sizeof(char)) {
- perror("Error sending ctrl message for participant\n");
+
+ /* Free attribute and wait for the other threads */
+ pthread_attr_destroy(&attr);
+ for (i = 0 ;i < pilecount ; i++) {
+ rc = pthread_join(thread[i], NULL);
+ if (rc)
+ {
+ printf("ERROR return code from pthread_join() is %d\n", rc);
+ return 1;
+ }
}
+
+ /* Free resources */
+ pthread_cond_destroy(&tcond);
+ pthread_mutex_destroy(&tlock);
+ free(tosend);
+ free(listmid);
+ pDelete(pile);
- return retval;
+ /* Retry trans commit procedure if not sucessful in the first try */
+ if(treplyretry == 1) {
+ /* wait a random amount of time */
+ randomdelay();
+ //sleep(1);
+ /* Retry the commiting transaction again */
+ transCommit(record);
+ }
+
+ return 0;
}
+/* This function sends information involved in the transaction request and
+ * accepts a response from particpants.
+ * It calls decideresponse() to decide on what control message
+ * to send next and sends the message using sendResponse()*/
void *transRequest(void *threadarg) {
int sd, i, n;
struct sockaddr_in serv_addr;
char machineip[16], retval;
tdata = (thread_data_array_t *) threadarg;
- //Send Trans Request
+
+ /* Send Trans Request */
if ((sd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
perror("Error in socket for TRANS_REQUEST\n");
return NULL;
midtoIP(tdata->mid,machineip);
machineip[15] = '\0';
serv_addr.sin_addr.s_addr = inet_addr(machineip);
-
+ /* Open Connection */
if (connect(sd, (struct sockaddr *) &serv_addr, sizeof(struct sockaddr)) < 0) {
perror("Error in connect for TRANS_REQUEST\n");
return NULL;
}
printf("DEBUG-> trans.c Sending TRANS_REQUEST to mid %s\n", machineip);
- //Send bytes of data with TRANS_REQUEST control message
+ /* Send bytes of data with TRANS_REQUEST control message */
if (send(sd, &(tdata->buffer->f), sizeof(fixed_data_t),MSG_NOSIGNAL) < sizeof(fixed_data_t)) {
perror("Error sending fixed bytes for thread\n");
return NULL;
}
- //Send list of machines involved in the transaction
+ /* Send list of machines involved in the transaction */
{
int size=sizeof(unsigned int)*tdata->pilecount;
if (send(sd, tdata->buffer->listmid, size, MSG_NOSIGNAL) < size) {
return NULL;
}
}
- //Send oids and version number tuples for objects that are read
+ /* Send oids and version number tuples for objects that are read */
{
int size=(sizeof(unsigned int)+sizeof(short))*tdata->buffer->f.numread;
if (send(sd, tdata->buffer->objread, size, MSG_NOSIGNAL) < size) {
return NULL;
}
}
- //Send objects that are modified
+ /* Send objects that are modified */
for(i = 0; i < tdata->buffer->f.nummod ; i++) {
int size;
headeraddr = chashSearch(tdata->rec->lookupTable, tdata->buffer->oidmod[i]);
}
}
- //Read message control message from participant side
+ /* Read control message from Participant */
if((n = read(sd, &control, sizeof(char))) <= 0) {
perror("Error in reading control message from Participant\n");
return NULL;
}
recvcontrol = control;
- //Update common data structure and increment count
+ /* Update common data structure and increment count */
tdata->recvmsg[tdata->thread_id].rcv_status = recvcontrol;
- //Lock and update count
+
+ /* Lock and update count */
//Thread sleeps until all messages from pariticipants are received by coordinator
pthread_mutex_lock(tdata->lock);
- (*(tdata->count))++;
-
+ (*(tdata->count))++; /* keeps track of no of messages received by the coordinator */
+
+ /* Wake up the threads and invoke decideResponse (once) */
if(*(tdata->count) == tdata->pilecount) {
if (decideResponse(tdata) != 0) {
printf("decideResponse returned error %s,%d\n", __FILE__, __LINE__);
}
pthread_mutex_unlock(tdata->lock);
-
+
+ /* Send the final response such as TRANS_COMMIT or TRANS_ABORT t
+ * to all participants in their respective socket */
if (sendResponse(tdata, sd) == 0) {
printf("sendResponse returned error %s,%d\n", __FILE__, __LINE__);
pthread_mutex_unlock(tdata->lock);
close(sd);
return NULL;
}
+
+ /* Close connection */
close(sd);
pthread_exit(NULL);
}
-int transCommit(transrecord_t *record) {
- chashlistnode_t *curr, *ptr, *next;
- unsigned int size;//Represents number of bins in the chash table
- unsigned int machinenum, tot_bytes_mod, *listmid;
- objheader_t *headeraddr;
- plistnode_t *tmp, *pile = NULL;
- int i, rc;
- int pilecount = 0, offset, numthreads = 0, trecvcount = 0, tmachcount = 0;
- char buffer[RECEIVE_BUFFER_SIZE],control;
- char transid[TID_LEN];
- static int newtid = 0;
- trans_req_data_t *tosend;
- char treplyctrl = 0, treplyretry = 0; //keep track of the common response that needs to be sent
+/* This function decides the reponse that needs to be sent to
+ * all Participant machines involved in the transaction commit */
+int decideResponse(thread_data_array_t *tdata) {
+ char control;
+ int i, transagree = 0, transdisagree = 0, transsoftabort = 0; /* Counters to formulate decision of what
+ message to send */
- ptr = record->lookupTable->table;
- size = record->lookupTable->size;
- //Look through all the objects in the cache and make piles
- for(i = 0; i < size ;i++) {
- curr = &ptr[i];
- //Inner loop to traverse the linked list of the cache lookupTable
- while(curr != NULL) {
- //if the first bin in hash table is empty
- if(curr->key == 0) {
+ //Check common data structure
+ for (i = 0 ; i < tdata->pilecount ; i++) {
+ /*Switch on response from Participant */
+ control = tdata->recvmsg[i].rcv_status; /* tdata: keeps track of all participant responses
+ written onto the shared array */
+ switch(control) {
+ case TRANS_DISAGREE:
+ printf("DEBUG-> trans.c Recv TRANS_DISAGREE\n");
+ transdisagree++;
break;
- }
- next = curr->next;
- //Get machine location for object id
-
- if ((machinenum = lhashSearch(curr->key)) == 0) {
- printf("Error: No such machine %s, %d\n", __FILE__, __LINE__);
- return 1;
- }
-
- if ((headeraddr = chashSearch(record->lookupTable, curr->key)) == NULL) {
- printf("Error: No such oid %s, %d\n", __FILE__, __LINE__);
- return 1;
- }
- //Make machine groups
- if ((pile = pInsert(pile, headeraddr, machinenum, record->lookupTable->numelements)) == NULL) {
- printf("pInsert error %s, %d\n", __FILE__, __LINE__);
- return 1;
- }
- curr = next;
- }
- }
- //Create the packet to be sent in TRANS_REQUEST
- tmp = pile;
- pilecount = pCount(pile); //Keeps track of the number of participants
-
- //Thread related variables
- pthread_t thread[pilecount]; //Create threads for each participant
- pthread_attr_t attr;
- pthread_cond_t tcond;
- pthread_mutex_t tlock;
- pthread_mutex_t tlshrd;
- //thread_data_array_t thread_data_array[pilecount];
- thread_data_array_t *thread_data_array;
-
- thread_data_array = (thread_data_array_t *) malloc(sizeof(thread_data_array_t)*pilecount);
-
- thread_response_t rcvd_control_msg[pilecount]; //Shared thread array that keeps track of responses of participants
-
- //Initialize and set thread detach attribute
- pthread_attr_init(&attr);
- pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
- pthread_mutex_init(&tlock, NULL);
- pthread_cond_init(&tcond, NULL);
-
- //Keep track of list of machine ids per transaction
- if((listmid = calloc(pilecount, sizeof(unsigned int))) == NULL) {
- printf("Calloc error %s, %d\n", __FILE__, __LINE__);
- return 1;
- }
+ case TRANS_AGREE:
+ printf("DEBUG-> trans.c Recv TRANS_AGREE\n");
+ transagree++;
+ break;
- pListMid(pile, listmid);
- //Process each machine group
- //Should be a new function for while loop
- while(tmp != NULL) {
- //Create transaction id
- newtid++;
- //trans_req_data_t *tosend;
- if ((tosend = calloc(1, sizeof(trans_req_data_t))) == NULL) {
- printf("Calloc error %s, %d\n", __FILE__, __LINE__);
- return 1;
+ case TRANS_SOFT_ABORT:
+ printf("DEBUG-> trans.c Recv TRANS_SOFT_ABORT\n");
+ transsoftabort++;
+ break;
+ default:
+ printf("Participant sent unknown message in %s, %d\n", __FILE__, __LINE__);
+ return -1;
}
- tosend->f.control = TRANS_REQUEST;
- sprintf(tosend->f.trans_id, "%x_%d", tmp->mid, newtid);
- tosend->f.mcount = pilecount;
- tosend->f.numread = tmp->numread;
- tosend->f.nummod = tmp->nummod;
- tosend->f.sum_bytes = tmp->sum_bytes;
- tosend->listmid = listmid;
- tosend->objread = tmp->objread;
- tosend->oidmod = tmp->oidmod;
- thread_data_array[numthreads].thread_id = numthreads;
- thread_data_array[numthreads].mid = tmp->mid;
- thread_data_array[numthreads].pilecount = pilecount;
- thread_data_array[numthreads].buffer = tosend;
- thread_data_array[numthreads].recvmsg = rcvd_control_msg;
- thread_data_array[numthreads].threshold = &tcond;
- thread_data_array[numthreads].lock = &tlock;
- thread_data_array[numthreads].count = &trecvcount;
- thread_data_array[numthreads].replyctrl = &treplyctrl;
- thread_data_array[numthreads].replyretry = &treplyretry;
- thread_data_array[numthreads].rec = record;
-
- rc = pthread_create(&thread[numthreads], NULL, transRequest, (void *) &thread_data_array[numthreads]);
- if (rc) {
- perror("Error in pthread create");
- return 1;
- }
- numthreads++;
- //TODO frees
- tmp = tmp->next;
}
+
+ /* Decide what control message to send to Participant */
+ if(transdisagree > 0) {
+ /* Send Abort */
+ *(tdata->replyctrl) = TRANS_ABORT;
+ printf("DEBUG-> trans.c Sending TRANS_ABORT\n");
+ objstrDelete(tdata->rec->cache);
+ chashDelete(tdata->rec->lookupTable);
+ free(tdata->rec);
+ } else if(transagree == tdata->pilecount){
+ /* Send Commit */
+ *(tdata->replyctrl) = TRANS_COMMIT;
+ printf("DEBUG-> trans.c Sending TRANS_COMMIT\n");
+ objstrDelete(tdata->rec->cache);
+ chashDelete(tdata->rec->lookupTable);
+ free(tdata->rec);
+ } else if(transsoftabort > 0 && transdisagree == 0) {
+ /* Send Abort in soft abort case followed by retry commiting transaction again*/
+ *(tdata->replyctrl) = TRANS_ABORT;
+ *(tdata->replyretry) = 1;
+ printf("DEBUG-> trans.c Sending TRANS_ABORT\n");
+ } else {
+ printf("DEBUG -> %s, %d: Error: undecided response\n", __FILE__, __LINE__);
+ return -1;
+ }
+
+ return 0;
+}
+/* This function sends the final response to all threads in their respective socket id */
+char sendResponse(thread_data_array_t *tdata, int sd) {
+ int n, N, sum, oidcount = 0;
+ char *ptr, retval = 0;
+ unsigned int *oidnotfound;
- // Free attribute and wait for the other threads
- pthread_attr_destroy(&attr);
- for (i = 0 ;i < pilecount ; i++) {
- rc = pthread_join(thread[i], NULL);
- if (rc)
- {
- printf("ERROR return code from pthread_join() is %d\n", rc);
- return 1;
+ /* If the decided response is due to a soft abort and missing objects at the Participant's side */
+ if(tdata->recvmsg[tdata->thread_id].rcv_status == TRANS_SOFT_ABORT) {
+ /* Read list of objects missing */
+ if((read(sd, &oidcount, sizeof(int)) != 0) && (oidcount != 0)) {
+ N = oidcount * sizeof(unsigned int);
+ if((oidnotfound = calloc(oidcount, sizeof(unsigned int))) == NULL) {
+ printf("Calloc error %s, %d\n", __FILE__, __LINE__);
+ }
+ ptr = (char *) oidnotfound;
+ do {
+ n = read(sd, ptr+sum, N-sum);
+ sum += n;
+ } while(sum < N && n !=0);
}
+ retval = TRANS_SOFT_ABORT;
+ }
+ /* If the decided response is TRANS_ABORT */
+ if(*(tdata->replyctrl) == TRANS_ABORT) {
+ retval = TRANS_ABORT;
+ }
+ /* If the decided response is TRANS_COMMIT */
+ if(*(tdata->replyctrl) == TRANS_COMMIT) {
+ retval = TRANS_COMMIT;
+ }
+ /* Send response to the Participant */
+ if (send(sd, tdata->replyctrl, sizeof(char),MSG_NOSIGNAL) < sizeof(char)) {
+ perror("Error sending ctrl message for participant\n");
}
-
- //Free resources
- pthread_cond_destroy(&tcond);
- pthread_mutex_destroy(&tlock);
- free(tosend);
- free(listmid);
- pDelete(pile);
- if(treplyretry == 1) {
- //wait a random amount of time
- randomdelay();
- //sleep(1);
- //Retry the commiting transaction again
- transCommit(record);
- }
-
- return 0;
+ return retval;
}
-//mnun will be used to represent the machine IP address later
+/* This function opens a connection, places an object read request to the
+ * remote machine, reads the control message and object if available and
+ * copies the object and its header to the local cache.
+ * TODO replace mnum and midtoIP() with MACHINE_IP address later */
+
void *getRemoteObj(transrecord_t *record, unsigned int mnum, unsigned int oid) {
int sd, size, val;
struct sockaddr_in serv_addr;
midtoIP(mnum,machineip);
machineip[15] = '\0';
serv_addr.sin_addr.s_addr = inet_addr(machineip);
-
+ /* Open connection */
if (connect(sd, (struct sockaddr *) &serv_addr, sizeof(struct sockaddr)) < 0) {
perror("Error in connect\n");
return NULL;
#ifdef DEBUG1
printf("DEBUG -> ready to rcv ...\n");
#endif
- //Read response from the Participant
+ /* Read response from the Participant */
if((val = read(sd, &control, sizeof(char))) <= 0) {
perror("No control response for getRemoteObj sent\n");
return NULL;
printf("DEBUG -> Control OBJECT_NOT_FOUND received\n");
return NULL;
case OBJECT_FOUND:
+ /* Read object if found into local cache */
if((val = read(sd, &size, sizeof(int))) <= 0) {
perror("No size is read from the participant\n");
return NULL;
perror("No objects are read from the remote participant\n");
return NULL;
}
- //Insert into cache's lookup table
+ /* Insert into cache's lookup table */
chashInsert(record->lookupTable, oid, objcopy);
break;
default:
printf("Error in recv request from participant on a READ_REQUEST %s, %d\n",__FILE__, __LINE__);
return NULL;
}
+ /* Close connection */
close(sd);
return objcopy;
}
projects / IRC.git / commitdiff