box naive_icp::solve(box b, contractor & ctc,
scoped_vec<shared_ptr<constraint>> const & ctrs,
SMTConfig & config, BranchHeuristic& brancher) {
thread_local static unordered_set<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();
prune(b, ctc, config, used_constraints);
if (!b.is_empty()) {
if (config.nra_use_stat) { config.nra_stat.increase_branch(); }
vector<int> sorted_dims = brancher.sort_branches(b, ctrs, config);
if (sorted_dims.size() > 0) {
int const i = sorted_dims[0];
tuple<int, box, box> splits = b.bisect_at(sorted_dims[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;
}
}
// 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 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 multiheuristic_icp::solve(box bx, contractor & ctc,
scoped_vec<shared_ptr<constraint>> const & ctrs,
SMTConfig & config, vector<reference_wrapper<BranchHeuristic>> heuristics) {
// don't use yet, since contractor is not yet threadsafe
static vector<box> solns;
solns.clear();
mutex mu;
box hull = bx;
// hull is a shared box, that's used by all dothreads,
// contains the intersection of the unions of the possible regions for each heuristic.
// Therefore, any solution must be in hull.
atomic_bool solved;
unordered_set<shared_ptr<constraint>> all_used_constraints;
prune(hull, ctc, config, all_used_constraints);
vector<thread> threads;
auto dothread = [&](BranchHeuristic & heuristic) {
#define PRUNEBOX(x) prune((x), ctc, config, used_constraints)
thread_local static unordered_set<shared_ptr<constraint>> used_constraints;
thread_local static vector<box> box_stack;
thread_local static vector<box> hull_stack; // nth box in hull_stack contains hull of first n boxes in box_stack
box_stack.clear();
hull_stack.clear();
used_constraints.clear();
auto pushbox = [&](box b) {
box_stack.push_back(b); // copies hull into vector
if (hull_stack.size() > 0) { b.hull(hull_stack.back()); } // maintain hull_stack invariant
hull_stack.push_back(b);
};
auto popbox = [&] {
box b = box_stack.back();
box_stack.pop_back();
hull_stack.pop_back();
return b;
};
mu.lock();
box b = hull;
mu.unlock();
pushbox(b);
do {
b = popbox();
mu.lock();
b.intersect(hull);
// TODO(clhuang): is contractor threadsafe???
PRUNEBOX(b);
mu.unlock();
if (!b.is_empty()) {
vector<int> sorted_dims = heuristic.sort_branches(b, ctrs, config);
if (config.nra_use_stat) { config.nra_stat.increase_branch(); }
if (sorted_dims.size() > 0) {
int bisectdim = sorted_dims[0];
auto splits = b.bisect_at(bisectdim);
box first = get<1>(splits);
box second = get<2>(splits);
assert(bisectdim != -1);
assert(first.get_idx_last_branched() == bisectdim);
assert(second.get_idx_last_branched() == bisectdim);
if (second.is_bisectable()) {
pushbox(second);
pushbox(first);
} else {
pushbox(first);
pushbox(second);
}
if (config.nra_proof) {
config.nra_proof_out << "[branched on "
<< b.get_name(bisectdim)
<< "]" << endl;
}
} else {
mu.lock();
config.nra_found_soln++;
solns.push_back(b);
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) {
solved = true;
mu.unlock();
break;
}
mu.unlock();
}
}
// hull_stack, hopefully shrunk
if (!hull_stack.empty()) {
mu.lock();
hull.intersect(hull_stack.back());
mu.unlock();
}
} while (box_stack.size() > 0 && !solved);
mu.lock();
if (config.nra_found_soln == 0) {
solved = true; // needed if unsat
solns.push_back(b); // would be empty
}
// update all_used_constraints
for (auto x : used_constraints) {
all_used_constraints.insert(x);
}
mu.unlock();
#undef PRUNEBOX
};
for (auto& heuristic : heuristics) {
threads.push_back(thread(dothread, heuristic));
}
for (auto& t : threads) {
t.join();
}
ctc.set_used_constraints(all_used_constraints);
return solns.back();
}
box multiprune_icp::solve(box b, contractor & ctc,
scoped_vec<shared_ptr<constraint>> const & ctrs,
SMTConfig & config, BranchHeuristic& brancher, unsigned num_try) {
#define PRUNEBOX(x) prune((x), ctc, config, used_constraints)
thread_local static unordered_set<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();
PRUNEBOX(b);
box_stack.push_back(b);
do {
DREAL_LOG_INFO << "multiprune_icp::solve - loop"
<< "\t" << "box stack Size = " << box_stack.size();
b = box_stack.back();
box_stack.pop_back();
if (!b.is_empty()) {
vector<int> sorted_dims = brancher.sort_branches(b, ctrs, config);
if (sorted_dims.size() > num_try) {
sorted_dims = vector<int>(sorted_dims.begin(), sorted_dims.begin()+num_try);
}
if (config.nra_use_stat) { config.nra_stat.increase_branch(); }
if (sorted_dims.size() > 0) {
int bisectdim = -1;
box first = b;
box second = b;
double score = -INFINITY;
for (int dim : sorted_dims) {
tuple<int, box, box> splits = b.bisect_at(dim);
box a1 = get<1>(splits);
box a2 = get<2>(splits);
PRUNEBOX(a1);
PRUNEBOX(a2);
double cscore = -a1.volume() * a2.volume();
if (cscore > score || bisectdim == -1) {
first.hull(second);
a1.intersect(first);
a2.intersect(first);
first = a1;
second = a2;
bisectdim = dim;
score = cscore;
} else {
a1.hull(a2);
first.intersect(a1);
second.intersect(a1);
}
}
assert(bisectdim != -1);
assert(first.get_idx_last_branched() == bisectdim);
assert(second.get_idx_last_branched() == bisectdim);
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(bisectdim)
<< "]" << 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;
}
#undef PRUNEBOX
}
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;
}
}