box icp_loop_with_nc_bt(box b, contractor const & ctc, SMTConfig & config) {
static unsigned prune_count = 0;
stack<box> box_stack;
stack<int> bisect_var_stack;
box_stack.push(b);
bisect_var_stack.push(-1); // Dummy var
do {
// Loop Invariant
assert(box_stack.size() == bisect_var_stack.size());
DREAL_LOG_INFO << "new_icp_loop()"
<< "\t" << "box stack Size = " << box_stack.size();
b = box_stack.top();
try {
b = ctc.prune(b, config);
} catch (contractor_exception & e) {
// Do nothing
}
prune_count++;
box_stack.pop();
bisect_var_stack.pop();
if (!b.is_empty()) {
// SAT
if (b.max_diam() > config.nra_precision) {
tuple<int, box, box> splits = b.bisect();
unsigned const index = get<0>(splits);
box const & first = get<1>(splits);
box const & second = get<2>(splits);
if (second.is_bisectable()) {
box_stack.push(second);
box_stack.push(first);
} else {
box_stack.push(first);
box_stack.push(second);
}
bisect_var_stack.push(index);
bisect_var_stack.push(index);
} else {
break;
}
} else {
// UNSAT
while (box_stack.size() > 0) {
assert(box_stack.size() == bisect_var_stack.size());
int bisect_var = bisect_var_stack.top();
ibex::BitSet const & input = ctc.input();
DREAL_LOG_DEBUG << ctc;
if (!input[bisect_var]) {
box_stack.pop();
bisect_var_stack.pop();
} else {
break;
}
}
}
} while (box_stack.size() > 0);
DREAL_LOG_DEBUG << "prune count = " << prune_count;
return b;
}
box naive_icp::solve(box b, contractor const & ctc, SMTConfig & config) {
vector<box> solns;
vector<box> box_stack;
box_stack.push_back(b);
do {
DREAL_LOG_INFO << "icp_loop()"
<< "\t" << "box stack Size = " << box_stack.size();
b = box_stack.back();
box_stack.pop_back();
try {
b = ctc.prune(b, config);
if (config.nra_use_stat) { config.nra_stat.increase_prune(); }
} catch (contractor_exception & e) {
// Do nothing
}
if (!b.is_empty()) {
tuple<int, box, box> splits = b.bisect(config.nra_precision);
if (config.nra_use_stat) { config.nra_stat.increase_branch(); }
int const i = get<0>(splits);
if (i >= 0) {
box const & first = get<1>(splits);
box const & second = get<2>(splits);
if (second.is_bisectable()) {
box_stack.push_back(second);
box_stack.push_back(first);
} else {
box_stack.push_back(first);
box_stack.push_back(second);
}
if (config.nra_proof) {
config.nra_proof_out << "[branched on "
<< b.get_name(i)
<< "]" << endl;
}
} else {
config.nra_found_soln++;
if (config.nra_found_soln >= config.nra_multiple_soln) {
break;
}
if (config.nra_multiple_soln > 1) {
// If --multiple_soln is used
output_solution(b, config, config.nra_found_soln);
}
solns.push_back(b);
}
}
} while (box_stack.size() > 0);
if (config.nra_multiple_soln > 1 && solns.size() > 0) {
return solns.back();
} else {
assert(!b.is_empty() || box_stack.size() == 0);
// cerr << "BEFORE ADJUST_BOUND\n==================\n" << b << "=========================\n\n\n";
b.adjust_bound(box_stack);
// cerr << "AFTER ADJUST_BOUND\n==================\n" << b << "=========================\n\n\n";
return b;
}
}
void prune(box & b, contractor & ctc, SMTConfig & config, unordered_set<shared_ptr<constraint>> & used_constraints) {
try {
ctc.prune(b, config);
auto this_used_constraints = ctc.used_constraints();
used_constraints.insert(this_used_constraints.begin(), this_used_constraints.end());
if (config.nra_use_stat) { config.nra_stat.increase_prune(); }
} catch (contractor_exception & e) {
// Do nothing
}
}
// Prune a given box b using ctc, but keep the old state of ctc
void test_prune(box & b, contractor & ctc, SMTConfig & config) {
try {
auto const old_output = ctc.output();
auto const old_used_constraints = ctc.used_constraints();
ctc.prune(b, config);
ctc.set_output(old_output);
ctc.set_used_constraints(old_used_constraints);
} catch (contractor_exception & e) {
// Do nothing
}
}
box icp_loop(box b, contractor const & ctc, SMTConfig & config) {
vector<box> solns;
stack<box> box_stack;
box_stack.push(b);
do {
DREAL_LOG_INFO << "icp_loop()"
<< "\t" << "box stack Size = " << box_stack.size();
b = box_stack.top();
box_stack.pop();
try {
b = ctc.prune(b, config);
} catch (contractor_exception & e) {
// Do nothing
}
if (!b.is_empty()) {
if (b.max_diam() > config.nra_precision) {
tuple<int, box, box> splits = b.bisect();
unsigned const i = get<0>(splits);
box const & first = get<1>(splits);
box const & second = get<2>(splits);
if (second.is_bisectable()) {
box_stack.push(second);
box_stack.push(first);
} else {
box_stack.push(first);
box_stack.push(second);
}
if (config.nra_proof) {
config.nra_proof_out << "[branched on "
<< b.get_name(i)
<< "]" << endl;
}
} else {
config.nra_found_soln++;
if (config.nra_multiple_soln > 1) {
cerr << "Find " << config.nra_found_soln << "-th solution:" << endl;
cerr << b << endl;
}
solns.push_back(b);
if (config.nra_found_soln >= config.nra_multiple_soln) {
break;
}
}
}
} while (box_stack.size() > 0);
if (solns.size() > 0) {
return solns.back();
} else {
return b;
}
}
void parallel_helper_fn(unsigned const id, contractor & c, box & b, SMTConfig & config,
pruning_thread_status & s, mutex & m, condition_variable & cv, int & index,
atomic_int & tasks_to_run) {
s = pruning_thread_status::RUNNING;
PARALLEL_LOG << "parallel_helper: thread " << id << " is running. "
<< tasks_to_run << "tasks to run";
// PARALLEL_LOG << "parallel_helper: thread " << id << " ctc = " << c;
try {
c.prune(b, config);
if (b.is_empty()) {
// do something for UNSAT
s = pruning_thread_status::UNSAT;
PARALLEL_LOG << "parallel_helper: thread " << id << " is UNSAT.";
} else {
s = pruning_thread_status::SAT;
PARALLEL_LOG << "parallel_helper: thread " << id << " is SAT.";
// do something for SAT
}
} catch (contractor_exception & e) {
// handle for exception
s = pruning_thread_status::EXCEPTION;
PARALLEL_LOG << "parallel_helper: thread " << id << " throws an contractor_exception: " << e.what();
} catch (thread_interrupted & e) {
// just killed
s = pruning_thread_status::KILLED;
tasks_to_run--;
PARALLEL_LOG << "parallel_helper: thread " << id << " is KILLED.";
return;
} catch (exception & e) {
tasks_to_run--;
PARALLEL_LOG << "parallel_helper: thread " << id << " throws an unexpected exception: "
<< e.what();
return;
}
PARALLEL_LOG << "parallel_helper: thread " << id << " is waiting for a mutex lock";
unique_lock<mutex> lk(m);
PARALLEL_LOG << "parallel_helper: thread " << id << " get a lock";
index = id;
tasks_to_run--;
PARALLEL_LOG << "parallel_helper: thread " << id << " unlocks";
lk.unlock();
cv.notify_one();
PARALLEL_LOG << "parallel_helper: thread " << id << " notifies CV";
return;
}
box ncbt_icp::solve(box b, contractor & ctc, SMTConfig & config) {
thread_local static unordered_set<shared_ptr<constraint>> used_constraints;
used_constraints.clear();
static unsigned prune_count = 0;
thread_local static vector<box> box_stack;
box_stack.clear();
box_stack.push_back(b);
do {
// Loop Invariant
DREAL_LOG_INFO << "ncbt_icp::solve - loop"
<< "\t" << "box stack Size = " << box_stack.size();
b = box_stack.back();
try {
ctc.prune(b, config);
auto const this_used_constraints = ctc.used_constraints();
used_constraints.insert(this_used_constraints.begin(), this_used_constraints.end());
if (config.nra_use_stat) { config.nra_stat.increase_prune(); }
} catch (contractor_exception & e) {
// Do nothing
}
prune_count++;
box_stack.pop_back();
if (!b.is_empty()) {
// SAT
tuple<int, box, box> splits = b.bisect(config.nra_precision);
if (config.nra_use_stat) { config.nra_stat.increase_branch(); }
int const index = get<0>(splits);
if (index >= 0) {
box const & first = get<1>(splits);
box const & second = get<2>(splits);
assert(first.get_idx_last_branched() == index);
assert(second.get_idx_last_branched() == index);
if (second.is_bisectable()) {
box_stack.push_back(second);
box_stack.push_back(first);
} else {
box_stack.push_back(first);
box_stack.push_back(second);
}
} else {
break;
}
} else {
// UNSAT (b is emptified by pruning operators)
// If this bisect_var is not used in all used
// constraints, this box is safe to be popped.
thread_local static unordered_set<Enode *> used_vars;
used_vars.clear();
for (auto used_ctr : used_constraints) {
auto this_used_vars = used_ctr->get_vars();
used_vars.insert(this_used_vars.begin(), this_used_vars.end());
}
while (box_stack.size() > 0) {
int const bisect_var = box_stack.back().get_idx_last_branched();
assert(bisect_var >= 0);
// If this bisect_var is not used in all used
// constraints, this box is safe to be popped.
if (used_vars.find(b.get_vars()[bisect_var]) != used_vars.end()) {
// DREAL_LOG_FATAL << b.get_vars()[bisect_var] << " is used in "
// << *used_ctr << " and it's not safe to skip";
break;
}
// DREAL_LOG_FATAL << b.get_vars()[bisect_var] << " is not used and it's safe to skip this box"
// << " (" << box_stack.size() << ")";
box_stack.pop_back();
}
}
} while (box_stack.size() > 0);
DREAL_LOG_DEBUG << "prune count = " << prune_count;
ctc.set_used_constraints(used_constraints);
return b;
}
box ncbt_icp::solve(box b, contractor const & ctc, SMTConfig & config) {
static unsigned prune_count = 0;
vector<box> box_stack;
vector<int> bisect_var_stack;
box_stack.push_back(b);
bisect_var_stack.push_back(-1); // Dummy var
do {
// Loop Invariant
assert(box_stack.size() == bisect_var_stack.size());
DREAL_LOG_INFO << "new_icp_loop()"
<< "\t" << "box stack Size = " << box_stack.size();
b = box_stack.back();
try {
b = ctc.prune(b, config);
if (config.nra_use_stat) { config.nra_stat.increase_prune(); }
} catch (contractor_exception & e) {
// Do nothing
}
prune_count++;
box_stack.pop_back();
bisect_var_stack.pop_back();
if (!b.is_empty()) {
// SAT
tuple<int, box, box> splits = b.bisect(config.nra_precision);
if (config.nra_use_stat) { config.nra_stat.increase_branch(); }
int const index = get<0>(splits);
if (index >= 0) {
box const & first = get<1>(splits);
box const & second = get<2>(splits);
if (second.is_bisectable()) {
box_stack.push_back(second);
box_stack.push_back(first);
} else {
box_stack.push_back(first);
box_stack.push_back(second);
}
bisect_var_stack.push_back(index);
bisect_var_stack.push_back(index);
} else {
break;
}
} else {
// UNSAT
while (box_stack.size() > 0) {
assert(box_stack.size() == bisect_var_stack.size());
int bisect_var = bisect_var_stack.back();
ibex::BitSet const & input = ctc.input();
DREAL_LOG_DEBUG << ctc;
if (!input[bisect_var]) {
box_stack.pop_back();
bisect_var_stack.pop_back();
} else {
break;
}
}
}
} while (box_stack.size() > 0);
DREAL_LOG_DEBUG << "prune count = " << prune_count;
b.adjust_bound(box_stack);
return b;
}
box naive_icp::solve(box b, contractor & ctc, SMTConfig & config) {
thread_local static std::unordered_set<std::shared_ptr<constraint>> used_constraints;
used_constraints.clear();
thread_local static vector<box> solns;
thread_local static vector<box> box_stack;
solns.clear();
box_stack.clear();
box_stack.push_back(b);
do {
DREAL_LOG_INFO << "naive_icp::solve - loop"
<< "\t" << "box stack Size = " << box_stack.size();
b = box_stack.back();
box_stack.pop_back();
try {
ctc.prune(b, config);
auto this_used_constraints = ctc.used_constraints();
used_constraints.insert(this_used_constraints.begin(), this_used_constraints.end());
if (config.nra_use_stat) { config.nra_stat.increase_prune(); }
} catch (contractor_exception & e) {
// Do nothing
}
if (!b.is_empty()) {
tuple<int, box, box> splits = b.bisect(config.nra_precision);
if (config.nra_use_stat) { config.nra_stat.increase_branch(); }
int const i = get<0>(splits);
if (i >= 0) {
box const & first = get<1>(splits);
box const & second = get<2>(splits);
assert(first.get_idx_last_branched() == i);
assert(second.get_idx_last_branched() == i);
if (second.is_bisectable()) {
box_stack.push_back(second);
box_stack.push_back(first);
} else {
box_stack.push_back(first);
box_stack.push_back(second);
}
if (config.nra_proof) {
config.nra_proof_out << "[branched on "
<< b.get_name(i)
<< "]" << endl;
}
} else {
config.nra_found_soln++;
if (config.nra_multiple_soln > 1) {
// If --multiple_soln is used
output_solution(b, config, config.nra_found_soln);
}
if (config.nra_found_soln >= config.nra_multiple_soln) {
break;
}
solns.push_back(b);
}
}
} while (box_stack.size() > 0);
ctc.set_used_constraints(used_constraints);
if (config.nra_multiple_soln > 1 && solns.size() > 0) {
return solns.back();
} else {
assert(!b.is_empty() || box_stack.size() == 0);
return b;
}
}
box sample_icp::solve(box init_b, contractor const & ctc, SMTConfig & config ) {
vector<box> solns;
vector<box> box_stack;
box b = init_b;
box_stack.push_back(b);
std::map<unsigned int, unsigned int> nempty; // Number of empty boxes at particular depth
int nconflicts = 0;
// Random Restarts
// I need a container for my stack that will allow me to add elements to the end,
// i.e lower depth means its at the end and pop from either end
// std::set<box, BoxComparator> box_stack;
do {
DREAL_LOG_INFO << "icp_loop()"
<< "\t" << "box stack Size = " << box_stack.size();
b = box_stack.back();
box_stack.pop_back();
// std::cout << "Depth: " << b.depth << std::endl;
try {
b = ctc.prune(b, config);
} catch (contractor_exception & e) {
// Do nothing
}
if (!b.is_empty()) {
tuple<int, box, box> splits = b.bisect(config.nra_precision);
int const i = get<0>(splits);
// std::cout << "i is" << i << std::endl;
if (i >= 0) {
box & first = get<1>(splits);
box & second = get<2>(splits);
first.depth = b.depth + 1;
second.depth = b.depth + 1;
bool leftright = random_icp::random_bool();
// std::cout << "left or right? " << leftright << std::endl;
if (leftright) {
box_stack.push_back(second);
box_stack.push_back(first);
} else {
box_stack.push_back(first);
box_stack.push_back(second);
}
if (config.nra_proof) {
config.nra_proof_out << "[branched on "
<< b.get_name(i)
<< "]" << endl;
}
} else {
config.nra_found_soln++;
if (config.nra_found_soln >= config.nra_multiple_soln) {
break;
}
if (config.nra_multiple_soln > 1) {
// If --multiple_soln is used
output_solution(b, config, config.nra_found_soln);
}
solns.push_back(b);
}
}
else {
// std::cout << "Backtracking at Depth: " << b.depth << std::endl;
nempty[b.depth] += 1;
nconflicts += 1;
int nconflicts_before_restart = 200;
if (nconflicts > nconflicts_before_restart) {
std::cout << "Restarting" << std::endl;
box_stack.empty();
box_stack.push_back(init_b);
nempty.empty();
nconflicts = 0;
continue;
}
}
} while (box_stack.size() > 0);
if (config.nra_multiple_soln > 1 && solns.size() > 0) {
return solns.back();
} else {
assert(!b.is_empty() || box_stack.size() == 0);
// cerr << "BEFORE ADJUST_BOUND\n==================\n" << b << "=========================\n\n\n";
b.adjust_bound(box_stack);
// cerr << "AFTER ADJUST_BOUND\n==================\n" << b << "=========================\n\n\n";
double q = proposal_prob(b.depth, nempty);
b.logprob = q;
return b;
}
}