/* first_avail()
* - Pick first avail output port w/ at least 1 unallocated VC
*/
int ocin_router_sel_noturn::first_avail(ocin_msg *msg) {
map <int, set <int> >::iterator routes_itr;
routes_itr = msg->routes.begin();
int p_out = (*routes_itr).first;
if (msg->routes.size() > 1) {
for (; routes_itr != msg->routes.end(); routes_itr++) {
p_out = (*routes_itr).first;
// If an avail VC has been found, terminate the search
if (is_avail(p_out, msg))
break;
} // for each valid output port
} // if (routes > 1)
return p_out;
}
/* select()
* - Oblivious selector implementing the "no turn" policy.
* - Tries to keep the packet from turning as long as the
* buffer space in the current dimension is avail.
*/
int ocin_router_sel_noturn::select(ocin_msg *msg) {
map <int, set <int> >::iterator routes_itr;
if (msg->routes.size() > 1) {
int prev_pout = msg->p_out;
// is the port we routed to on the prev node
// available at this node?
routes_itr = msg->routes.find(prev_pout);
if (routes_itr != msg->routes.end()) {
if (is_avail(prev_pout, msg))
return prev_pout;
}
}
// If can't route in the same dim as before for whatever reason
// (dim is not valid or no free buffers), route in the first
// available dimension.
return first_avail(msg);
}
void solve(int depth) {
if (depth >= N) return;
for (int j = 0; j < N; ++j) {
// detect if available
if (is_avail(depth, j)) {
grid[depth][j] = 'Q';
// output solution
if (depth == N-1) {
sol.push_back(grid);
} else {
solve(depth+1);
}
// reset
grid[depth][j] = '.';
}
}
}
