GQueue* prefetch_segments(segmentid id, int prefetch_num) {
static struct backupVersion *opened_bv;
if (id == TEMPORARY_ID) {
assert(id != TEMPORARY_ID);
return NULL;
}
int64_t bnum = id_to_bnum(id);
int64_t off = id_to_off(id);
int64_t size = id_to_size(id);
/* All prefetched segment recipes */
GQueue *segments = g_queue_new();
if(opened_bv == NULL || opened_bv->bv_num != bnum){
/* The required segment locates in another backup */
if(opened_bv && opened_bv->bv_num != jcr.bv->bv_num)
free_backup_version(opened_bv);
if(bnum == jcr.bv->bv_num)
opened_bv = jcr.bv;
else{
opened_bv = open_backup_version(bnum);
assert(opened_bv);
}
}
fseek(opened_bv->recipe_fp, off, SEEK_SET);
VERBOSE("Dedup phase: Read segment %lld in backup %lld of %lld offset and %lld size",
id, bnum, off, size);
struct chunkPointer flag;
int j;
for (j = 0; j < prefetch_num; j++) {
int64_t current_off = ftell(opened_bv->recipe_fp);
fread(&flag.fp, sizeof(flag.fp), 1, opened_bv->recipe_fp);
fread(&flag.id, sizeof(flag.id), 1, opened_bv->recipe_fp);
fread(&flag.size, sizeof(flag.size), 1, opened_bv->recipe_fp);
if(flag.id != -CHUNK_SEGMENT_START){
VERBOSE("Dedup phase: no more segment can be prefetched at offset %lld!", current_off);
assert(j!=0);
break;
}
struct segmentRecipe* sr = new_segment_recipe();
sr->id = make_segment_id(opened_bv->bv_num, current_off, flag.size);
int i;
for (i = 0; i < flag.size; i++) {
struct chunkPointer* cp = (struct chunkPointer*) malloc(
sizeof(struct chunkPointer));
fread(&cp->fp, sizeof(cp->fp), 1, opened_bv->recipe_fp);
fread(&cp->id, sizeof(cp->id), 1, opened_bv->recipe_fp);
fread(&cp->size, sizeof(cp->size), 1, opened_bv->recipe_fp);
if(cp->id <= TEMPORARY_ID){
WARNING("expect > 0, but being %lld", cp->id);
assert(cp->id > TEMPORARY_ID);
}
g_hash_table_replace(sr->kvpairs, &cp->fp, cp);
}
fread(&flag.fp, sizeof(flag.fp), 1, opened_bv->recipe_fp);
fread(&flag.id, sizeof(flag.id), 1, opened_bv->recipe_fp);
fread(&flag.size, sizeof(flag.size), 1, opened_bv->recipe_fp);
assert(flag.id == 0 - CHUNK_SEGMENT_END);
g_queue_push_tail(segments, sr);
}
return segments;
}
void compute(int rank, int size)
{
double *row1a = (double *) malloc(sizeof(double) * size_x);
double *row1b = (double *) malloc(sizeof(double) * size_x);
memset(row1a, 0, sizeof(double *) * size_x);
double *row2a = (double *) malloc(sizeof(double) * size_x);
double *row2b = (double *) malloc(sizeof(double) * size_x);
memset(row2a, 0, sizeof(double *) * size_x);
int position = id_to_position(size_y, size, rank);
int height = id_to_size(size_y, size, rank);
MPI_Request req[2];
MPI_Request req2[2];
DoubleMatrix matrix(size_x, height);
set_fixed_temp(matrix, size_y, position, temp);
matrix.swap();
compute_new_values(matrix, row1a, row2a);
set_fixed_temp(matrix, size_y, position, temp);
matrix.swap();
for (int i = 1; i < iterations; i++) {
MPI_Isend(row1a, size_x, MPI_DOUBLE, (rank + size - 1) % size, TAG_ROW1,
MPI_COMM_WORLD, &req[0]);
MPI_Isend(row2a, size_x, MPI_DOUBLE, (rank + 1) % size, TAG_ROW2,
MPI_COMM_WORLD, &req[1]);
MPI_Irecv(row1b, size_x, MPI_DOUBLE, (rank + size - 1) % size, TAG_ROW2,
MPI_COMM_WORLD, &req2[0]);
MPI_Irecv(row2b, size_x, MPI_DOUBLE, (rank + 1) % size, TAG_ROW1,
MPI_COMM_WORLD, &req2[1]);
MPI_Waitall(2, req2, MPI_STATUSES_IGNORE);
double *tmp;
tmp = row1a; // swap row1a <-> row1b
row1a = row1b;
row1b = tmp;
tmp = row2a; // swap row2a <-> row2b
row2a = row2b;
row2b = tmp;
compute_new_values(matrix, row1a, row2a);
set_fixed_temp(matrix, size_y, position, temp);
matrix.swap();
MPI_Waitall(2, req, MPI_STATUSES_IGNORE);
}
free(row1a);
free(row1b);
free(row2a);
free(row2b);
if (rank == 0) {
DoubleMatrix out(size_x, size_y);
out.set_data(matrix.get_data(), size_x * position, matrix.get_data_size());
for (int rank = 1; rank < size; rank++) {
int position = id_to_position(size_y, size, rank);
int height = id_to_size(size_y, size, rank);
MPI_Recv(out.get_write_pointer(0, position),
size_x * height, MPI_DOUBLE, rank, TAG_MATRIX,
MPI_COMM_WORLD, MPI_STATUSES_IGNORE);
}
out.swap();
out.write_to_file("result2.html");
} else {
MPI_Send(matrix.get_data(),
matrix.get_size_x() * matrix.get_size_y(),
MPI_DOUBLE, 0, TAG_MATRIX, MPI_COMM_WORLD);
}
}
