void solve_tsp(int A[SIZE][SIZE]){
// pick the 1st node of the tour
list_node* tmp_p = (list_node*) scalable_malloc (sizeof (list_node));
tmp_p->next = NULL;
tmp_p->val = 0;
solve_tsp_rec(A, tmp_p, 1, 0);
}
void solve_tsp_rec(int A[SIZE][SIZE], int partial_solution[SIZE], int position, int partial_weight)
{
int i,j;
int used;
int myweight;
#ifdef DEBUG
printf("Calling tsp_rec with pos=%d and partial_weight=%d\n", position, partial_weight);
#endif
#ifdef PARTIAL_WEIGHT_CUTOFF
if (partial_weight >= solution_weight) return;
#endif
for(i=0; i<SIZE; i++) {
// 1. check if i was already used in the solution so far.
// if so, skip it.
used = 0;
for(j=0; j<position; j++) {
if (partial_solution[j]==i) {
used = 1;
break;
}
}
if (used) continue;
partial_solution[position] = i;
myweight = partial_weight + A[partial_solution[position-1]][i];
if (position==SIZE-1) {
// 2a. termination
myweight += A[i][0];
#ifdef DEBUG
for(j=0; j<SIZE; j++) {
printf("%d,", partial_solution[j]);
}
printf(" weight = %d\n\n", myweight);
#endif
if (myweight < solution_weight) {
solution_weight = myweight;
// Save solution
for(j=0; j<SIZE; j++) solution[j] = partial_solution[j];
}
} else {
// 2b. recursion
solve_tsp_rec(A, partial_solution, position+1, myweight);
}
}
}
void solve_tsp(int A[SIZE][SIZE]){
partial_solution[0] = 0;
solve_tsp_rec(A, partial_solution, 1, 0);
}
void ser_solve_tsp_rec(const int (*A)[SIZE], list_node* partial_solution, int position, int partial_weight)
{
#ifdef PARTIAL_WEIGHT_CUTOFF
#ifdef NO_LOCKS
if (partial_weight >= my_weight.local() ) return;
#else
if (partial_weight >= solution_weight) return;
#endif
#endif
int i;
for(i=0; i<SIZE; i++){
// 1. check if i was already used in the solution so far.
// if so, skip it.
int used = 0;
int j = position;
list_node* tmp_p = partial_solution;
while(tmp_p != NULL) {
if (tmp_p->val == i) {
used = 1;
break;
}
tmp_p = tmp_p->next;
}
if (!used) {
//partial_solution[position] = i;
// allocate a node
tmp_p = (list_node*) scalable_malloc(sizeof(list_node));
#ifdef DEBUG
if(tmp_p==NULL) {out_of_memory++;//atomic}
#endif
if (tmp_p != NULL) {
int myweight;
tmp_p->next = partial_solution;
tmp_p->val = i;
myweight = partial_weight + A[partial_solution->val][i];
if (position==SIZE-1) {
// 2a. termination
#ifdef NO_LOCKS
myweight += A[i][0];
if (myweight < my_weight.local() ) {
my_weight.local() = myweight;
}
#else
myweight += A[i][0];
#ifdef DOUBLE_CHECK
if (myweight < solution_weight) {
#endif
// acquire lock
tbb::mutex::scoped_lock myLock(solution_lock);
if (myweight < solution_weight) {
// update solution
solution_weight = myweight;
solution = tmp_p;
}
// implicit lock release
#ifdef DOUBLE_CHECK
}
#endif
#endif
} else {
// 2b. recursion
ser_solve_tsp_rec(A, tmp_p, position+1, myweight);
}
scalable_free (tmp_p);
}
} // end if(!used)
} // end spawn
}
void solve_tsp_rec(const int (*A)[SIZE], list_node* partial_solution, int position, int partial_weight);
class tspBody {
public:
//int* A[SIZE];
const int (*A)[SIZE];
list_node* partial_solution;
int position;
int partial_weight;
void operator () (const tbb::blocked_range<int> &range) const {
int i;
for (i=range.begin(); i<range.end(); i++) {
// 1. check if node i was already used in the solution so far.
// if so, skip it.
int used = 0;
int j = position;
list_node* tmp_p = partial_solution;
while(tmp_p != NULL) {
if (tmp_p->val == i) {
used = 1;
break;
}
tmp_p = tmp_p->next;
}
if (!used) {
//partial_solution[position] = i;
// allocate a node
tmp_p = (list_node*) scalable_malloc( sizeof(list_node) );
#ifdef DEBUG
if(tmp_p==NULL) {out_of_memory++;//atomic}
#endif
if (tmp_p != NULL) {
int myweight;
tmp_p->next = partial_solution;
tmp_p->val = i;
myweight = partial_weight + A[partial_solution->val][i];
if (position==SIZE-1) {
// 2a. termination
#ifdef NO_LOCKS
myweight += A[i][0];
if (myweight < my_weight.local() ) {
my_weight.local() = myweight;
}
#else
myweight += A[i][0];
#ifdef DOUBLE_CHECK
if (myweight < solution_weight) {
#endif
tbb::mutex::scoped_lock myLock(solution_lock);
if (myweight < solution_weight) {
// lock solution
solution_weight = myweight;
solution = tmp_p;
}
// implicit lock release
#ifdef DOUBLE_CHECK
}
#endif
#endif
} else {
// 2b. recursion
#ifdef CUTOFF
if (position+1>=CUTOFF_LEVEL)
ser_solve_tsp_rec(A, tmp_p, position+1, myweight);
else
solve_tsp_rec(A, tmp_p, position+1, myweight);
#else
solve_tsp_rec(A, tmp_p, position+1, myweight);
#endif
}
scalable_free (tmp_p);
}
} // end if(!used)
} // end for loop
}
// Constructor
tspBody(const int A[SIZE][SIZE], list_node* partial_solution, int position, int partial_weight):
A(A), partial_solution(partial_solution), position(position), partial_weight(partial_weight) {}
};
