int DRNG::random (ULONGLONG max, ULONGLONG *rand)
{
UINT bits;
int retries= 1000; // A big enough number make failure extremely unlikely.
if ( ! HAVE_RDRAND ) return 0;
if ( max == 0 ) {
*rand= 0;
return 1;
}
bits= ceiling_log2(max);
if ( bits > 32 ) {
ULONG64 val;
while (retries--) {
if ( ! rand64(&val) ) return 0;
val>>= (64-bits);
if ( val < max ) {
*rand= (ULONGLONG) val;
return 1;
}
}
} else {
}
/* XXX Write random data to make it harder for fake chips to become "smarter".
* There would be a random seed.
* Buffer cannot be all 0x00 or all 0xFF.
*/
static void fill_buffer(char *buf, int len)
{
memset(buf, 0xAA, len);
}
int probe_device_max_blocks(struct device *dev)
{
uint64_t num_blocks = dev_get_size_byte(dev) >>
dev_get_block_order(dev);
int n = ceiling_log2(num_blocks);
/* Make sure that there is no overflow in the formula below.
* The number 10 is arbitrary here, that is, it's not tight.
*/
assert(MAX_N_BLOCK_ORDER < sizeof(int) - 10);
return
/* search_wrap() */
1 +
/* Search_edge()
*
* The number of used blocks is (p * w); see comments in
* estimate_best_n_block() for the definition of the variables.
*
* p * w = n/m * (2^m - 1) < n/m * 2^m = n * (2^m / m)
int hs_random(int argc, char *argv[]) {
if (argc != 2 && argc != 3) {
printf("Usage: ./hs-random [ -v ] <Process number>\n");
exit(1);
}
int lnum_sent = 0, lnum_recv = 0;
int tnum_sent = 0, tnum_recv = 0;
int pnum;
int verbose = 0;
if (argc == 3) {
if (!strcmp(argv[1], "-v")) pnum = atoi(argv[2]), verbose = 1;
else if (!strcmp(argv[2], "-v")) pnum = atoi(argv[1]), verbose = 1;
} else if (argc == 2)
pnum = atoi(argv[1]);
int rank, size;
MPI_Init (&argc, &argv);
MPI_Comm_rank (MPI_COMM_WORLD, &rank); // get my pid
MPI_Comm_size (MPI_COMM_WORLD, &size); // get number of processes
MPI_Status status;
MPI_Request request;
if (pnum <= size || pnum/size < 7 || gcd(size, pnum) != 1) {
printf("Usage: pnum must be at least 7 times larger than and relatively coprime to size.\n");
exit(1);
}
int election_sendbuf[SIZE_MSG];
srand(time(NULL) + rank);
int uid = (rand() % pnum);
// int uid = ((rank+1)*pnum) % size;
int max_so_far = uid;
int k = 0, d = 0;
election_sendbuf[0] = uid, election_sendbuf[1] = k, election_sendbuf[2] = d;
int left = rank-1;
if (!rank) left = size-1;
int right = (rank+1)%size;
int recvbuf[SIZE_MSG];
int left_recv_tag, right_recv_tag;
int endLoopFlag = 0;
int recvReplies[2][2] = {{0, 0}, {0, 0}}; // left, right; j, k
int left_sendbuf[SIZE_MSG] = { max_so_far, k, d }, left_send_tag = TAG_ELECTION, left_send_dest = right;
int right_sendbuf[SIZE_MSG] = { max_so_far, k, d }, right_send_tag = TAG_ELECTION, right_send_dest = left;
int last = ceiling_log2((unsigned long long) size);
int initiator = (((rand()+uid) % size) > (size - 1)/2);
int participant = 0;
if (initiator) {
participant = 1;
if (verbose) printf("Process %d is an initiator\n", rank);
MPI_Isend(election_sendbuf, SIZE_MSG, MPI_INT, left, TAG_ELECTION, MPI_COMM_WORLD, &request);
MPI_Isend(election_sendbuf, SIZE_MSG, MPI_INT, right, TAG_ELECTION, MPI_COMM_WORLD, &request);
lnum_sent+= 2;
}
// Current leader is max_so_far
while (k < last+1) {
MPI_Recv(recvbuf, SIZE_MSG, MPI_INT, MPI_ANY_SOURCE, MPI_ANY_TAG, MPI_COMM_WORLD, &status);
lnum_recv++;
k = recvbuf[1], d = recvbuf[2];
if (status.MPI_TAG == TAG_IGNORE) {
if (recvbuf[0] > max_so_far) max_so_far = recvbuf[0];
break;
}
if (k > last) break;
if (status.MPI_SOURCE == left) {
left_recv_tag = status.MPI_TAG;
switch (left_recv_tag) {
case TAG_ELECTION:
if (recvbuf[0] > uid) {
if (recvbuf[2] < (1 << k)) {
left_sendbuf[2] = d + 1, left_sendbuf[0] = recvbuf[0], left_sendbuf[1] = k;
left_send_tag = TAG_ELECTION, left_send_dest = right;
} else if (d >= (1 << k)) {
left_sendbuf[0] = recvbuf[0], left_sendbuf[1] = recvbuf[1];
left_send_tag = TAG_REPLY, left_send_dest = left;
}
} else if (recvbuf[0] == uid) {
if (recvbuf[0] > max_so_far) max_so_far = recvbuf[0];
left_sendbuf[0] = uid, left_sendbuf[1] = k+1, left_sendbuf[2] = 1;
left_send_tag = TAG_ELECTION, left_send_dest = right;
} else {
if (!participant) { // initiate an election if the incoming uid is smaller than mine
participant = 1;
MPI_Isend(election_sendbuf, SIZE_MSG, MPI_INT, left, TAG_ELECTION, MPI_COMM_WORLD, &request);
MPI_Isend(election_sendbuf, SIZE_MSG, MPI_INT, right, TAG_ELECTION, MPI_COMM_WORLD, &request);
lnum_sent+= 2;
}
break;
}
lnum_sent++;
MPI_Isend(left_sendbuf, SIZE_MSG, MPI_INT, left_send_dest, left_send_tag, MPI_COMM_WORLD, &request);
break;
case TAG_REPLY:
if (recvbuf[0] != max_so_far) { // Improvement #1: compare to max_so_far instead of own uid
if (recvbuf[0] > max_so_far) max_so_far = recvbuf[0];
left_sendbuf[0] = recvbuf[0], left_sendbuf[1] = recvbuf[1];
left_send_dest = right, left_send_tag = TAG_REPLY;
recvReplies[0][0] = recvbuf[0], recvReplies[0][1] = recvbuf[1];
} else {
if (recvbuf[0] > max_so_far) max_so_far = recvbuf[0];
left_sendbuf[0] = recvbuf[0], left_sendbuf[1] = k + 1, left_sendbuf[2] = 1;
lnum_sent+=2;
MPI_Isend(left_sendbuf, SIZE_MSG, MPI_INT, left, TAG_ELECTION, MPI_COMM_WORLD, &request);
MPI_Isend(left_sendbuf, SIZE_MSG, MPI_INT, right, TAG_ELECTION, MPI_COMM_WORLD, &request);
}
break;
case TAG_IGNORE: break;
default: endLoopFlag = 1; break;
}
}
// Deal with right received values
else if (status.MPI_SOURCE == right) {
right_recv_tag = status.MPI_TAG;
switch (right_recv_tag) {
case TAG_ELECTION:
if (recvbuf[0] > uid) {
if (recvbuf[0] > max_so_far) max_so_far = recvbuf[0];
if (d < (1 << k)) {
right_sendbuf[2] = recvbuf[2]+1, right_sendbuf[0] = recvbuf[0], right_sendbuf[1] = recvbuf[1];
right_send_tag = TAG_ELECTION, right_send_dest = left;
} else if (d >= (1 << k)) {
right_sendbuf[0] = recvbuf[0], right_sendbuf[1] = recvbuf[1];
right_send_tag = TAG_REPLY, right_send_dest = right;
}
} else if (recvbuf[0] == uid) {
if (recvbuf[0] > max_so_far) max_so_far = recvbuf[0];
right_sendbuf[0] = uid, right_sendbuf[1] = k+1, right_sendbuf[2] = 1;
right_send_tag = TAG_ELECTION, right_send_dest = left;
if (k >= last && recvbuf[0] == max_so_far) endLoopFlag = 1;
} else {
if (!participant) { // initiate an election if the incoming uid is smaller than mine
participant = 1;
MPI_Isend(election_sendbuf, SIZE_MSG, MPI_INT, left, TAG_ELECTION, MPI_COMM_WORLD, &request);
MPI_Isend(election_sendbuf, SIZE_MSG, MPI_INT, right, TAG_ELECTION, MPI_COMM_WORLD, &request);
lnum_sent+= 2;
}
break;
}
lnum_sent++;
MPI_Isend(right_sendbuf, SIZE_MSG, MPI_INT, right_send_dest, right_send_tag, MPI_COMM_WORLD, &request);
break;
case TAG_REPLY:
if (recvbuf[0] != max_so_far) {
if (recvbuf[0] > max_so_far) max_so_far = recvbuf[0];
right_sendbuf[0] = recvbuf[0], right_sendbuf[1] = recvbuf[1];
right_send_tag = TAG_REPLY, right_send_dest = left;
recvReplies[1][0] = recvbuf[0], recvReplies[1][1] = recvbuf[1];
} else {
if (recvbuf[0] > max_so_far) max_so_far = recvbuf[0];
if (recvReplies[1][0] == recvbuf[0] && recvReplies[1][1] == recvbuf[1]) {
left_sendbuf[0] = uid,
left_sendbuf[1] = k+1, right_sendbuf[2] = left_sendbuf[2] = 1;
lnum_sent+=2;
MPI_Isend(left_sendbuf, SIZE_MSG, MPI_INT, left, TAG_ELECTION, MPI_COMM_WORLD, &request);
MPI_Isend(left_sendbuf, SIZE_MSG, MPI_INT, right, TAG_ELECTION, MPI_COMM_WORLD, &request);
} else {
recvReplies[1][0] = recvbuf[0], recvReplies[1][1] = recvbuf[1];
}
break;
}
case TAG_IGNORE: break;
default: endLoopFlag = 1; break;
}
}
if (endLoopFlag) {
break;
}
}
int msgBuf[3] = {max_so_far, 0, 0}, msgRecv[3];
// Election is over - tell the other processes
MPI_Isend(msgBuf, SIZE_MSG, MPI_INT, left, TAG_IGNORE, MPI_COMM_WORLD, &request);
MPI_Isend(msgBuf, SIZE_MSG, MPI_INT, right, TAG_IGNORE, MPI_COMM_WORLD, &request);
MPI_Request_free(&request);
if (participant && verbose)
printf("rank=%d, id=%d, leader=%d, mrcvd=%d, msent=%d\n", rank, uid, (max_so_far == uid), lnum_recv, lnum_sent);
if (max_so_far == uid) {
msgBuf[0] = lnum_recv, msgBuf[1] = lnum_sent, msgBuf[2] = uid;
max_so_far = uid;
MPI_Isend(msgBuf, SIZE_MSG, MPI_INT, right, TAG_MSGNUM, MPI_COMM_WORLD, &request);
} else {
// Non-leaders, do a receive and a send for their message totals as well
MPI_Recv(msgRecv, SIZE_MSG, MPI_INT, left, TAG_MSGNUM, MPI_COMM_WORLD, &status);
// increase its count by 1 for each receive and send
msgBuf[0] = msgRecv[0]+ lnum_recv, msgBuf[1] = msgRecv[1]+ lnum_sent;
max_so_far = msgBuf[2];
if (participant) MPI_Isend(msgBuf, SIZE_MSG, MPI_INT, right, TAG_MSGNUM, MPI_COMM_WORLD, &request);
else MPI_Isend(msgRecv, SIZE_MSG, MPI_INT, right, TAG_MSGNUM, MPI_COMM_WORLD, &request);
}
// Leader receives/prints total number of messages received and sent
if (max_so_far == uid) {
MPI_Recv(msgRecv, SIZE_MSG, MPI_INT, left, TAG_MSGNUM, MPI_COMM_WORLD, &status);
tnum_recv = msgRecv[0];
tnum_sent = msgRecv[1];
printf("Leader: rank=%d, id=%d, trcvd=%d, tsent=%d\n", rank, uid, tnum_recv, tnum_sent);
}
MPI_Finalize();
return 0;
}
