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Add parallel_tactical2.cpp: portfolio parallel solver using the solver API (#9515)

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* add parallel_tactical2.cpp: portfolio parallel solver using solver API

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Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>

* address code review: cap conflict growth, clarify cube/split comments, use mk_or for conflict clause

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Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
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1
src/solver/CMakeLists.txt
View file

@ -5,6 +5,7 @@ z3_add_component(solver
combined_solver.cpp
mus.cpp
parallel_tactical.cpp
parallel_tactical2.cpp
simplifier_solver.cpp
slice_solver.cpp
smt_logics.cpp

906
src/solver/parallel_tactical2.cpp Normal file
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@ -0,0 +1,906 @@
/*++
Copyright (c) 2024 Microsoft Corporation
Module Name:
parallel_tactical2.cpp
Abstract:
Parallel portfolio solver using the solver API.
Models the internals after smt/smt_parallel.cpp but operates on generic
solver objects (smt_solver, inc_sat_solver, etc.) via the solver interface
instead of accessing smt::context internals directly.
Key features compared to parallel_tactical.cpp:
- Search tree for coordinated non-chronological backtracking (from smt_parallel).
- Shared clause pool: learned conflict clauses are broadcast to all workers.
- Shared backbone/unit pool: base-level units propagated by one worker are
asserted as facts on every other worker's solver.
- Workers reuse their solver state across multiple cube checks, accumulating
learned clauses (same pattern as smt_parallel workers).
Key differences from smt_parallel:
- Uses the solver API throughout (translate, check_sat, get_trail, cube,
get_model, get_unsat_core, assert_expr, push, pop, updt_params, …)
rather than accessing smt::context members directly.
- Works with any conforming solver implementation.
Cube path management follows the assumption-based pattern from smt_parallel:
- The worker's solver base assertion set is fixed at construction (the full
problem is translated into the worker's own ast_manager once).
- Shared clauses discovered by other workers are appended to the base set via
assert_expr at any time.
- The current cube path is passed as extra assumptions on every check_sat call,
so the solver can reuse learned clauses across different cube checks.
Split atom selection is performed by temporarily pushing the cube path onto
the solver, calling solver::cube(), retrieving the first proposed literal, and
then popping, so that the base state is preserved.
Author:
(based on smt_parallel.cpp by nbjorner / Ilana Shapiro, and
parallel_tactical.cpp by nbjorner / Miguel Neves)
--*/
#include "util/scoped_ptr_vector.h"
#include "util/uint_set.h"
#include "ast/ast_pp.h"
#include "ast/ast_ll_pp.h"
#include "ast/ast_util.h"
#include "ast/ast_translation.h"
#include "solver/solver.h"
#include "solver/parallel_tactical2.h"
#include "solver/parallel_params.hpp"
#include "solver/solver_preprocess.h"
#include "util/search_tree.h"
#include "tactic/tactic.h"
#include "tactic/tactical.h"
#include "solver/solver2tactic.h"
#include <cmath>
#include <mutex>
/* ------------------------------------------------------------------ */
/* Single-threaded stub */
/* ------------------------------------------------------------------ */
class non_parallel_tactic2 : public tactic {
public:
non_parallel_tactic2(solver*, params_ref const&) {}
char const* name() const override { return "parallel_tactic2"; }
void operator()(const goal_ref&, goal_ref_buffer&) override {
throw default_exception("parallel_tactic2 is disabled in single-threaded mode");
}
tactic* translate(ast_manager&) override { return nullptr; }
void cleanup() override {}
};
#ifdef SINGLE_THREAD
tactic* mk_parallel_tactic2(solver* s, params_ref const& p) {
return alloc(non_parallel_tactic2, s, p);
}
#else
#include <atomic>
#include <thread>
#include <condition_variable>
/* ------------------------------------------------------------------ */
/* Search-tree literal configuration */
/* ------------------------------------------------------------------ */
struct solver_cube_config {
using literal = expr_ref;
static bool literal_is_null(expr_ref const& l) { return l == nullptr; }
static std::ostream& display_literal(std::ostream& out, expr_ref const& l) {
if (l) return out << mk_bounded_pp(l, l.get_manager());
return out << "(null)";
}
};
/* ------------------------------------------------------------------ */
/* parallel_solver – the core portfolio engine */
/* ------------------------------------------------------------------ */
class parallel_solver {
/* ---- forward declarations ---- */
class worker;
/* ---- node lease (mirrors smt_parallel) ---- */
struct node_lease {
search_tree::node<solver_cube_config>* leased_node = nullptr;
unsigned cancel_epoch = 0;
bool cancel_signaled = false;
};
/* ---- shared clause entry ---- */
struct shared_clause {
unsigned source_worker_id;
expr_ref clause;
};
/* ================================================================
* batch_manager
* Coordinates workers: distributes cubes, collects clauses/units,
* stores the final result (sat model / unsat core / exception).
* ================================================================ */
class batch_manager {
enum state {
is_running,
is_sat,
is_unsat,
is_exception_msg,
is_exception_code
};
struct stats {
unsigned m_num_cubes = 0;
unsigned m_max_cube_depth = 0;
unsigned m_backbones_found = 0;
};
ast_manager& m;
parallel_solver& p;
std::mutex mux;
state m_state = state::is_running;
stats m_stats;
search_tree::tree<solver_cube_config> m_search_tree;
vector<node_lease> m_worker_leases;
/* shared clause pool (guarded by mux) */
vector<shared_clause> shared_clause_trail;
obj_hashtable<expr> shared_clause_set;
/* shared backbone / unit pool (guarded by mux) */
obj_hashtable<expr> m_global_backbones;
/* result storage (guarded by mux) */
unsigned m_exception_code = 0;
std::string m_exception_msg;
model_ref m_model; /* sat model translated to m */
expr_ref_vector m_unsat_core; /* unsat core translated to m */
/* ---- cancellation helpers (called under mux) ---- */
void cancel_workers_unlocked() {
IF_VERBOSE(1, verbose_stream() << "par2: canceling workers\n");
for (auto* w : p.m_workers)
w->cancel();
}
void release_lease_unlocked(unsigned worker_id,
search_tree::node<solver_cube_config>* n) {
if (worker_id >= m_worker_leases.size()) return;
auto& lease = m_worker_leases[worker_id];
if (!lease.leased_node || lease.leased_node != n) return;
m_search_tree.dec_active_workers(lease.leased_node);
lease = {};
}
void cancel_closed_leases_unlocked(unsigned source_worker_id) {
unsigned n = std::min(m_worker_leases.size(), p.m_workers.size());
for (unsigned id = 0; id < n; ++id) {
if (id == source_worker_id) continue;
auto const& lease = m_worker_leases[id];
if (lease.leased_node && !lease.cancel_signaled &&
m_search_tree.is_lease_canceled(lease.leased_node, lease.cancel_epoch)) {
p.m_workers[id]->cancel_lease();
m_worker_leases[id].cancel_signaled = true;
}
}
}
void collect_clause_unlocked(ast_translation& l2g,
unsigned source_worker_id,
expr* clause) {
expr* g_clause = l2g(clause);
if (!shared_clause_set.contains(g_clause)) {
shared_clause_set.insert(g_clause);
shared_clause sc{source_worker_id, expr_ref(g_clause, m)};
shared_clause_trail.push_back(std::move(sc));
}
}
bool is_global_backbone_unlocked(ast_translation& l2g,
expr* bb_cand) {
expr_ref cand(l2g(bb_cand), m);
return m_global_backbones.contains(cand.get());
}
public:
batch_manager(ast_manager& m, parallel_solver& p)
: m(m), p(p),
m_search_tree(expr_ref(m)),
m_unsat_core(m) {}
/* ---- initialisation ---- */
void initialize(unsigned num_workers,
unsigned initial_max_thread_conflicts = 1000) {
m_state = state::is_running;
m_search_tree.reset();
m_search_tree.set_effort_unit(initial_max_thread_conflicts);
m_worker_leases.reset();
m_worker_leases.resize(num_workers);
shared_clause_trail.reset();
shared_clause_set.reset();
m_global_backbones.reset();
m_model = nullptr;
m_unsat_core.reset();
}
/* ---- result setters (called by workers, guarded by mux) ---- */
void set_sat(ast_translation& l2g, model& mdl) {
std::scoped_lock lock(mux);
IF_VERBOSE(1, verbose_stream() << "par2: batch_manager SAT\n");
if (m_state != state::is_running) return;
m_state = state::is_sat;
m_model = mdl.translate(l2g);
cancel_workers_unlocked();
}
void set_unsat(ast_translation& l2g,
expr_ref_vector const& core) {
std::scoped_lock lock(mux);
IF_VERBOSE(1, verbose_stream() << "par2: batch_manager UNSAT\n");
if (m_state != state::is_running) return;
m_state = state::is_unsat;
SASSERT(m_unsat_core.empty());
for (expr* c : core)
m_unsat_core.push_back(l2g(c));
cancel_workers_unlocked();
}
void set_exception(std::string const& msg) {
std::scoped_lock lock(mux);
IF_VERBOSE(1, verbose_stream() << "par2: batch_manager exception: " << msg << "\n");
if (m_state != state::is_running) return;
m_state = state::is_exception_msg;
m_exception_msg = msg;
cancel_workers_unlocked();
}
void set_exception(unsigned error_code) {
std::scoped_lock lock(mux);
if (m_state != state::is_running) return;
m_state = state::is_exception_code;
m_exception_code = error_code;
cancel_workers_unlocked();
}
/* ---- cube distribution (called by workers) ---- */
bool get_cube(ast_translation& g2l, unsigned id,
expr_ref_vector& cube, bool is_first_run,
node_lease& lease) {
std::scoped_lock lock(mux);
cube.reset();
if (m_search_tree.is_closed()) return false;
if (m_state != state::is_running) return false;
auto* t = is_first_run
? m_search_tree.activate_root()
: m_search_tree.activate_best_node();
if (!t) return false;
lease.leased_node = t;
lease.cancel_epoch = t->get_cancel_epoch();
if (id >= m_worker_leases.size())
m_worker_leases.resize(id + 1);
m_worker_leases[id] = lease;
/* build cube from path root → t */
for (auto* cur = t; cur; cur = cur->parent()) {
if (solver_cube_config::literal_is_null(cur->get_literal()))
break;
expr_ref lit(g2l.to());
lit = g2l(cur->get_literal().get());
cube.push_back(std::move(lit));
}
return true;
}
/* ---- backtrack on conflict (called by workers) ---- */
void backtrack(ast_translation& l2g, unsigned worker_id,
expr_ref_vector const& core,
node_lease const& lease) {
std::scoped_lock lock(mux);
if (m_state != state::is_running) return;
vector<solver_cube_config::literal> g_core;
for (auto c : core)
g_core.push_back(expr_ref(l2g(c), m));
if (!m_search_tree.is_lease_canceled(
lease.leased_node, lease.cancel_epoch)) {
release_lease_unlocked(worker_id, lease.leased_node);
m_search_tree.backtrack(lease.leased_node, g_core);
}
cancel_closed_leases_unlocked(worker_id);
IF_VERBOSE(2, m_search_tree.display(verbose_stream() << "\n"););
if (m_search_tree.is_closed()) {
IF_VERBOSE(1, verbose_stream() << "par2: search tree closed → UNSAT\n");
m_state = state::is_unsat;
for (auto& e : m_search_tree.get_core_from_root())
m_unsat_core.push_back(e.get());
cancel_workers_unlocked();
}
}
/* ---- try to split (called on undef) ---- */
void try_split(ast_translation& l2g, unsigned worker_id,
node_lease const& lease,
expr* atom, unsigned effort) {
std::scoped_lock lock(mux);
if (m_state != state::is_running) return;
if (m_search_tree.is_lease_canceled(
lease.leased_node, lease.cancel_epoch)) return;
expr_ref lit(m), nlit(m);
lit = l2g(atom);
nlit = mk_not(m, lit);
bool did_split = m_search_tree.try_split(
lease.leased_node, lease.cancel_epoch,
lit, nlit, effort);
release_lease_unlocked(worker_id, lease.leased_node);
if (did_split) {
++m_stats.m_num_cubes;
m_stats.m_max_cube_depth = std::max(
m_stats.m_max_cube_depth,
lease.leased_node->depth() + 1);
IF_VERBOSE(1, verbose_stream() << "par2: split on "
<< mk_bounded_pp(lit, m, 3) << "\n");
}
}
void release_lease(unsigned worker_id, node_lease const& lease) {
std::scoped_lock lock(mux);
release_lease_unlocked(worker_id, lease.leased_node);
}
bool lease_canceled(node_lease const& lease) {
std::scoped_lock lock(mux);
return m_state == state::is_running &&
m_search_tree.is_lease_canceled(
lease.leased_node, lease.cancel_epoch);
}
/* ---- clause sharing ---- */
void collect_clause(ast_translation& l2g,
unsigned source_worker_id,
expr* clause) {
std::scoped_lock lock(mux);
collect_clause_unlocked(l2g, source_worker_id, clause);
}
expr_ref_vector return_shared_clauses(ast_translation& g2l,
unsigned& worker_limit,
unsigned worker_id) {
std::scoped_lock lock(mux);
expr_ref_vector result(g2l.to());
for (unsigned i = worker_limit; i < shared_clause_trail.size(); ++i) {
if (shared_clause_trail[i].source_worker_id != worker_id)
result.push_back(g2l(shared_clause_trail[i].clause.get()));
}
worker_limit = shared_clause_trail.size();
return result;
}
/* ---- backbone / unit sharing ---- */
bool collect_global_backbone(ast_translation& l2g,
expr_ref const& backbone,
unsigned source_worker_id = UINT_MAX) {
std::scoped_lock lock(mux);
if (is_global_backbone_unlocked(l2g, backbone.get()))
return false;
expr_ref g_bb(l2g(backbone.get()), m);
m_global_backbones.insert(g_bb.get());
++m_stats.m_backbones_found;
IF_VERBOSE(2, verbose_stream() << "par2: new backbone "
<< mk_bounded_pp(g_bb, m, 3) << "\n");
/* share it as a unit clause so other workers pick it up */
collect_clause_unlocked(l2g, source_worker_id, backbone.get());
return true;
}
/* ---- result accessors ---- */
lbool get_result() const {
if (m.limit().is_canceled()) return l_undef;
switch (m_state) {
case state::is_running:
throw default_exception("par2: inconsistent end state");
case state::is_sat: return l_true;
case state::is_unsat: return l_false;
case state::is_exception_msg:
throw default_exception(m_exception_msg.c_str());
case state::is_exception_code:
throw z3_error(m_exception_code);
default:
UNREACHABLE();
return l_undef;
}
}
model_ref& get_model() { return m_model; }
expr_ref_vector const& get_unsat_core() const { return m_unsat_core; }
void collect_statistics(statistics& st) const {
st.update("par2-cubes", m_stats.m_num_cubes);
st.update("par2-cube-depth", m_stats.m_max_cube_depth);
st.update("par2-backbones", m_stats.m_backbones_found);
}
}; // class batch_manager
/* ================================================================
* worker
* Each worker owns a translated copy of the original solver plus
* its own ast_manager. Workers communicate only through the
* batch_manager (mutex-protected).
* ================================================================ */
class worker {
struct config {
unsigned m_threads_max_conflicts = 1000;
double m_max_conflict_mul = 1.5;
unsigned m_max_conflicts = UINT_MAX;
bool m_share_units = true;
bool m_share_conflicts = true;
unsigned m_max_cube_depth = 20;
};
unsigned id;
parallel_solver& p;
batch_manager& b;
ast_manager m; /* worker-local manager */
ref<solver> s; /* translated solver copy */
expr_ref_vector asms; /* translated assumptions */
ast_translation m_g2l, m_l2g; /* global↔local translations */
config m_config;
expr_mark m_known_units; /* units already shared by this worker */
unsigned m_shared_clause_limit = 0;
void update_max_conflicts() {
m_config.m_threads_max_conflicts = static_cast<unsigned>(
m_config.m_max_conflict_mul * m_config.m_threads_max_conflicts);
/* cap at the configured global maximum to prevent runaway cube checks */
if (m_config.m_threads_max_conflicts > m_config.m_max_conflicts)
m_config.m_threads_max_conflicts = m_config.m_max_conflicts;
}
/* Check the current cube (passed as additional assumptions).
* The solver's conflict budget is set via updt_params before
* each call so that long-running cubes are interrupted. */
lbool check_cube(expr_ref_vector const& cube) {
params_ref p;
p.set_uint("max_conflicts",
std::min(m_config.m_threads_max_conflicts,
m_config.m_max_conflicts));
s->updt_params(p);
expr_ref_vector combined(m);
combined.append(asms);
combined.append(cube);
IF_VERBOSE(2, verbose_stream() << "par2 worker " << id
<< ": checking cube of size " << cube.size() << "\n");
lbool r = l_undef;
try {
r = s->check_sat(combined);
}
catch (z3_error& err) {
if (!m.limit().is_canceled())
b.set_exception(err.error_code());
}
catch (z3_exception& ex) {
if (!m.limit().is_canceled())
b.set_exception(ex.what());
}
IF_VERBOSE(2, verbose_stream() << "par2 worker " << id
<< ": cube result " << r << "\n");
return r;
}
/* Assert shared clauses discovered by other workers into the
* base assertion set of this worker's solver. The solver
* automatically re-uses them on the next check_sat call. */
void collect_shared_clauses() {
expr_ref_vector nc = b.return_shared_clauses(
m_g2l, m_shared_clause_limit, id);
for (expr* e : nc) {
IF_VERBOSE(4, verbose_stream() << "par2 worker " << id
<< ": asserting shared clause "
<< mk_bounded_pp(e, m, 3) << "\n");
s->assert_expr(e);
}
}
/* Propagate any new base-level units (backbone literals) this
* worker has learned to the shared backbone pool.
*
* Uses solver::get_trail(0) which returns all literals
* propagated at decision level 0. */
void share_units() {
if (!m_config.m_share_units) return;
expr_ref_vector trail = s->get_trail(0);
for (expr* e : trail) {
/* get_trail may include ground terms; skip complex ones */
expr* atom = e;
m.is_not(e, atom);
if (!is_uninterp_const(atom)) continue;
if (m_known_units.is_marked(e)) continue;
m_known_units.mark(e);
expr_ref lit(e, m);
b.collect_global_backbone(m_l2g, lit, id);
}
}
/* Select a split atom using solver::cube() on a temporary
* solver state that includes the current cube path.
*
* We push the cube literals, call cube(), take the first
* literal, then pop to restore the base state. */
expr_ref get_split_atom(expr_ref_vector const& cube) {
if (cube.size() >= m_config.m_max_cube_depth)
return expr_ref(nullptr, m);
s->push();
for (expr* c : cube)
s->assert_expr(c);
expr_ref_vector vars(m);
expr_ref_vector c = s->cube(vars, UINT_MAX);
s->pop(1);
/* solver::cube() convention: an empty result means done; a result
* whose last element is true means the problem is trivially sat;
* a result whose last element is false means unsat was detected.
* In all other cases every element (including index 0) is a
* valid literal that can serve as a split atom. */
if (c.empty() || m.is_true(c.back()) || m.is_false(c.back()))
return expr_ref(nullptr, m);
return expr_ref(c.get(0), m);
}
public:
worker(unsigned id, parallel_solver& p,
solver& src, params_ref const& params,
expr_ref_vector const& src_asms)
: id(id), p(p), b(p.m_batch_manager),
asms(m), m_g2l(src.get_manager(), m), m_l2g(m, src.get_manager())
{
/* create translated solver copy */
s = src.translate(m, params);
/* translate assumptions */
for (expr* a : src_asms)
asms.push_back(m_g2l(a));
IF_VERBOSE(1, verbose_stream() << "par2: worker " << id
<< " created (" << asms.size() << " assumptions)\n");
}
void run() {
bool is_first_run = true;
node_lease lease;
expr_ref_vector cube(m);
while (true) {
if (!b.get_cube(m_g2l, id, cube, is_first_run, lease)) {
IF_VERBOSE(1, verbose_stream() << "par2 worker " << id
<< ": no more cubes\n");
return;
}
is_first_run = false;
collect_shared_clauses();
lbool r = check_cube(cube);
if (b.lease_canceled(lease)) {
IF_VERBOSE(1, verbose_stream() << "par2 worker " << id
<< ": lease canceled\n");
lease = {};
m.limit().dec_cancel();
continue;
}
if (!m.inc()) return;
switch (r) {
case l_undef: {
update_max_conflicts();
IF_VERBOSE(1, verbose_stream() << "par2 worker " << id
<< ": undef – attempting split\n");
expr_ref atom = get_split_atom(cube);
if (atom) {
b.try_split(m_l2g, id, lease, atom.get(),
m_config.m_threads_max_conflicts);
}
else {
b.release_lease(id, lease);
}
if (m_config.m_share_units) share_units();
break;
}
case l_true: {
IF_VERBOSE(1, verbose_stream() << "par2 worker " << id
<< ": SAT\n");
model_ref mdl;
s->get_model(mdl);
if (mdl)
b.set_sat(m_l2g, *mdl);
return;
}
case l_false: {
IF_VERBOSE(1, verbose_stream() << "par2 worker " << id
<< ": UNSAT cube\n");
expr_ref_vector core(m);
s->get_unsat_core(core);
/* Filter to only cube literals (exclude base assumptions). */
expr_ref_vector cube_core(m);
for (expr* c : core) {
if (cube.contains(c))
cube_core.push_back(c);
}
/* If core contains none of the cube lits, the whole
* problem is UNSAT independent of the cube path. */
if (cube_core.empty()) {
b.set_unsat(m_l2g, core);
return;
}
b.backtrack(m_l2g, id, cube_core, lease);
if (m_config.m_share_conflicts) {
/* Share the negation of the cube-core conjunction
* as a learned clause: ¬(c₁ ∧ … ∧ cₙ) ≡ ¬c₁ ∨ … ∨ ¬cₙ */
expr_ref_vector neg_lits(m);
for (expr* c : cube_core)
neg_lits.push_back(mk_not(expr_ref(c, m)));
expr_ref clause(mk_or(neg_lits), m);
b.collect_clause(m_l2g, id, clause.get());
}
if (m_config.m_share_units) share_units();
break;
}
} // switch
} // while
} // run()
void cancel() {
m.limit().cancel();
}
void cancel_lease() {
m.limit().inc_cancel();
}
void collect_statistics(statistics& st) const {
s->collect_statistics(st);
}
reslimit& limit() { return m.limit(); }
}; // class worker
/* ---- members ---- */
ref<solver> m_solver;
ast_manager& m_manager;
params_ref m_params;
scoped_ptr_vector<worker> m_workers;
batch_manager m_batch_manager;
statistics m_stats;
public:
parallel_solver(solver* s, params_ref const& p)
: m_solver(s),
m_manager(s->get_manager()),
m_params(p),
m_batch_manager(s->get_manager(), *this) {}
/* Run the portfolio. Returns sat/unsat/undef.
*
* On sat: *mdl is populated (translated into m_manager).
* On unsat: *core is populated (translated into m_manager).
* asms: original external assumptions (in m_manager). */
lbool solve(expr_ref_vector const& asms,
model_ref& mdl,
expr_ref_vector& core) {
parallel_params pp(m_params);
unsigned num_threads = std::min(
(unsigned)std::thread::hardware_concurrency(),
pp.threads_max());
if (num_threads < 2) num_threads = 2;
IF_VERBOSE(1, verbose_stream() << "par2: launching " << num_threads
<< " threads\n");
if (m_manager.has_trace_stream())
throw default_exception(
"parallel_tactic2 does not work with trace streams");
/* Build workers – each gets a translated solver copy. */
m_workers.reset();
scoped_limits sl(m_manager.limit());
params_ref worker_params(m_params);
worker_params.set_bool("override_incremental", true);
for (unsigned i = 0; i < num_threads; ++i) {
auto* w = alloc(worker, i, *this, *m_solver, worker_params, asms);
m_workers.push_back(w);
sl.push_child(&(w->limit()));
}
m_batch_manager.initialize(num_threads);
/* Launch threads. */
vector<std::thread> threads;
for (auto* w : m_workers)
threads.push_back(std::thread([w]() { w->run(); }));
for (auto& t : threads)
t.join();
/* Collect per-worker statistics. */
for (auto* w : m_workers)
w->collect_statistics(m_stats);
m_batch_manager.collect_statistics(m_stats);
m_manager.limit().reset_cancel();
lbool result = m_batch_manager.get_result();
if (result == l_true)
mdl = m_batch_manager.get_model();
if (result == l_false) {
for (expr* c : m_batch_manager.get_unsat_core())
core.push_back(c);
}
m_workers.reset();
return result;
}
void collect_statistics(statistics& st) const {
st.copy(m_stats);
}
void reset_statistics() {
m_stats.reset();
}
}; // class parallel_solver
/* ------------------------------------------------------------------ */
/* parallel_tactic2 – wraps parallel_solver as a tactic */
/* ------------------------------------------------------------------ */
class parallel_tactic2 : public tactic {
solver_ref m_solver;
ast_manager& m_manager;
params_ref m_params;
statistics m_stats;
public:
parallel_tactic2(solver* s, params_ref const& p)
: m_solver(s), m_manager(s->get_manager()), m_params(p) {}
char const* name() const override { return "parallel_tactic2"; }
void operator()(const goal_ref& g, goal_ref_buffer& result) override {
fail_if_proof_generation("parallel_tactic2", g);
ast_manager& m = g->m();
if (m.has_trace_stream())
throw default_exception(
"parallel_tactic2 does not work with trace streams");
/* Translate goal into a set of clauses + assumptions. */
solver* s = m_solver->translate(m, m_params);
expr_ref_vector clauses(m);
ptr_vector<expr> assumptions_raw;
obj_map<expr, expr*> bool2dep;
ref<generic_model_converter> fmc;
extract_clauses_and_dependencies(g, clauses, assumptions_raw,
bool2dep, fmc);
for (expr* cl : clauses)
s->assert_expr(cl);
expr_ref_vector asms(m);
asms.append(assumptions_raw.size(), assumptions_raw.data());
parallel_solver ps(s, m_params);
model_ref mdl;
expr_ref_vector core(m);
lbool is_sat = ps.solve(asms, mdl, core);
ps.collect_statistics(m_stats);
switch (is_sat) {
case l_true:
g->reset();
if (g->models_enabled() && mdl) {
if (fmc)
g->add(concat(fmc.get(), model2model_converter(mdl.get())));
else
g->add(model2model_converter(mdl.get()));
}
break;
case l_false: {
SASSERT(!g->proofs_enabled());
expr_dependency* lcore = nullptr;
proof* pr = nullptr;
if (!core.empty()) {
for (expr* c : core) {
expr* dep = nullptr;
if (bool2dep.find(c, dep))
lcore = m.mk_join(lcore, m.mk_leaf(dep));
}
}
g->assert_expr(m.mk_false(), pr, lcore);
break;
}
case l_undef:
if (!m.inc())
throw tactic_exception(Z3_CANCELED_MSG);
break;
}
result.push_back(g.get());
}
void cleanup() override {
m_stats.reset();
}
tactic* translate(ast_manager& m) override {
solver* s = m_solver->translate(m, m_params);
return alloc(parallel_tactic2, s, m_params);
}
void updt_params(params_ref const& p) override {
m_params.copy(p);
}
void collect_statistics(statistics& st) const override {
st.copy(m_stats);
}
void reset_statistics() override {
m_stats.reset();
}
}; // class parallel_tactic2
tactic* mk_parallel_tactic2(solver* s, params_ref const& p) {
return alloc(parallel_tactic2, s, p);
}
#endif /* !SINGLE_THREAD */

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src/solver/parallel_tactical2.h Normal file
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/*++
Copyright (c) 2024 Microsoft Corporation
Module Name:
parallel_tactical2.h
Abstract:
Parallel portfolio solver using the solver API.
Models the internals after smt/smt_parallel.cpp but operates
on generic solver objects instead of smt::context.
Author:
(based on smt_parallel.cpp and parallel_tactical.cpp)
--*/
#pragma once
class tactic;
class solver;
struct params_ref;
tactic * mk_parallel_tactic2(solver* s, params_ref const& p);