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constraint_solver.cc
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// Copyright 2010-2021 Google LLC
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// This file implements the core objects of the constraint solver:
// Solver, Search, Queue, ... along with the main resolution loop.
#include "ortools/constraint_solver/constraint_solver.h"
#include <csetjmp>
#include <cstdint>
#include <deque>
#include <iosfwd>
#include <limits>
#include <memory>
#include <string>
#include <utility>
#include "absl/memory/memory.h"
#include "absl/time/clock.h"
#include "absl/time/time.h"
#include "ortools/base/commandlineflags.h"
#include "ortools/base/file.h"
#include "ortools/base/integral_types.h"
#include "ortools/base/logging.h"
#include "ortools/base/macros.h"
#include "ortools/base/map_util.h"
#include "ortools/base/recordio.h"
#include "ortools/base/stl_util.h"
#include "ortools/base/sysinfo.h"
#include "ortools/constraint_solver/constraint_solveri.h"
#include "ortools/util/tuple_set.h"
#include "zlib.h"
// These flags are used to set the fields in the DefaultSolverParameters proto.
ABSL_FLAG(bool, cp_trace_propagation, false,
"Trace propagation events (constraint and demon executions,"
" variable modifications).");
ABSL_FLAG(bool, cp_trace_search, false, "Trace search events");
ABSL_FLAG(bool, cp_print_added_constraints, false,
"show all constraints added to the solver.");
ABSL_FLAG(bool, cp_print_model, false,
"use PrintModelVisitor on model before solving.");
ABSL_FLAG(bool, cp_model_stats, false,
"use StatisticsModelVisitor on model before solving.");
ABSL_FLAG(bool, cp_disable_solve, false,
"Force failure at the beginning of a search.");
ABSL_FLAG(std::string, cp_profile_file, "",
"Export profiling overview to file.");
ABSL_FLAG(bool, cp_print_local_search_profile, false,
"Print local search profiling data after solving.");
ABSL_FLAG(bool, cp_name_variables, false, "Force all variables to have names.");
ABSL_FLAG(bool, cp_name_cast_variables, false,
"Name variables casted from expressions");
ABSL_FLAG(bool, cp_use_small_table, true,
"Use small compact table constraint when possible.");
ABSL_FLAG(bool, cp_use_cumulative_edge_finder, true,
"Use the O(n log n) cumulative edge finding algorithm described "
"in 'Edge Finding Filtering Algorithm for Discrete Cumulative "
"Resources in O(kn log n)' by Petr Vilim, CP 2009.");
ABSL_FLAG(bool, cp_use_cumulative_time_table, true,
"Use a O(n^2) cumulative time table propagation algorithm.");
ABSL_FLAG(bool, cp_use_cumulative_time_table_sync, false,
"Use a synchronized O(n^2 log n) cumulative time table propagation "
"algorithm.");
ABSL_FLAG(bool, cp_use_sequence_high_demand_tasks, true,
"Use a sequence constraints for cumulative tasks that have a "
"demand greater than half of the capacity of the resource.");
ABSL_FLAG(bool, cp_use_all_possible_disjunctions, true,
"Post temporal disjunctions for all pairs of tasks sharing a "
"cumulative resource and that cannot overlap because the sum of "
"their demand exceeds the capacity.");
ABSL_FLAG(int, cp_max_edge_finder_size, 50,
"Do not post the edge finder in the cumulative constraints if "
"it contains more than this number of tasks");
ABSL_FLAG(bool, cp_diffn_use_cumulative, true,
"Diffn constraint adds redundant cumulative constraint");
ABSL_FLAG(bool, cp_use_element_rmq, true,
"If true, rmq's will be used in element expressions.");
ABSL_FLAG(int, cp_check_solution_period, 1,
"Number of solutions explored between two solution checks during "
"local search.");
ABSL_FLAG(int64_t, cp_random_seed, 12345,
"Random seed used in several (but not all) random number "
"generators used by the CP solver. Use -1 to auto-generate an"
"undeterministic random seed.");
void ConstraintSolverFailsHere() { VLOG(3) << "Fail"; }
#if defined(_MSC_VER) // WINDOWS
#pragma warning(disable : 4351 4355)
#endif
namespace operations_research {
namespace {
// Calls the given method with the provided arguments on all objects in the
// collection.
template <typename T, typename MethodPointer, typename... Args>
void ForAll(const std::vector<T*>& objects, MethodPointer method,
const Args&... args) {
for (T* const object : objects) {
DCHECK(object != nullptr);
(object->*method)(args...);
}
}
} // namespace
// ----- ConstraintSolverParameters -----
ConstraintSolverParameters Solver::DefaultSolverParameters() {
ConstraintSolverParameters params;
params.set_compress_trail(ConstraintSolverParameters::NO_COMPRESSION);
params.set_trail_block_size(8000);
params.set_array_split_size(16);
params.set_store_names(true);
params.set_profile_propagation(!absl::GetFlag(FLAGS_cp_profile_file).empty());
params.set_trace_propagation(absl::GetFlag(FLAGS_cp_trace_propagation));
params.set_trace_search(absl::GetFlag(FLAGS_cp_trace_search));
params.set_name_all_variables(absl::GetFlag(FLAGS_cp_name_variables));
params.set_profile_file(absl::GetFlag(FLAGS_cp_profile_file));
params.set_profile_local_search(
absl::GetFlag(FLAGS_cp_print_local_search_profile));
params.set_print_local_search_profile(
absl::GetFlag(FLAGS_cp_print_local_search_profile));
params.set_print_model(absl::GetFlag(FLAGS_cp_print_model));
params.set_print_model_stats(absl::GetFlag(FLAGS_cp_model_stats));
params.set_disable_solve(absl::GetFlag(FLAGS_cp_disable_solve));
params.set_name_cast_variables(absl::GetFlag(FLAGS_cp_name_cast_variables));
params.set_print_added_constraints(
absl::GetFlag(FLAGS_cp_print_added_constraints));
params.set_use_small_table(absl::GetFlag(FLAGS_cp_use_small_table));
params.set_use_cumulative_edge_finder(
absl::GetFlag(FLAGS_cp_use_cumulative_edge_finder));
params.set_use_cumulative_time_table(
absl::GetFlag(FLAGS_cp_use_cumulative_time_table));
params.set_use_cumulative_time_table_sync(
absl::GetFlag(FLAGS_cp_use_cumulative_time_table_sync));
params.set_use_sequence_high_demand_tasks(
absl::GetFlag(FLAGS_cp_use_sequence_high_demand_tasks));
params.set_use_all_possible_disjunctions(
absl::GetFlag(FLAGS_cp_use_all_possible_disjunctions));
params.set_max_edge_finder_size(absl::GetFlag(FLAGS_cp_max_edge_finder_size));
params.set_diffn_use_cumulative(absl::GetFlag(FLAGS_cp_diffn_use_cumulative));
params.set_use_element_rmq(absl::GetFlag(FLAGS_cp_use_element_rmq));
params.set_check_solution_period(
absl::GetFlag(FLAGS_cp_check_solution_period));
return params;
}
// ----- Forward Declarations and Profiling Support -----
extern DemonProfiler* BuildDemonProfiler(Solver* const solver);
extern void DeleteDemonProfiler(DemonProfiler* const monitor);
extern void InstallDemonProfiler(DemonProfiler* const monitor);
extern LocalSearchProfiler* BuildLocalSearchProfiler(Solver* solver);
extern void DeleteLocalSearchProfiler(LocalSearchProfiler* monitor);
extern void InstallLocalSearchProfiler(LocalSearchProfiler* monitor);
// TODO(user): remove this complex logic.
// We need the double test because parameters are set too late when using
// python in the open source. This is the cheapest work-around.
bool Solver::InstrumentsDemons() const {
return IsProfilingEnabled() || InstrumentsVariables();
}
bool Solver::IsProfilingEnabled() const {
return parameters_.profile_propagation() ||
!parameters_.profile_file().empty();
}
bool Solver::IsLocalSearchProfilingEnabled() const {
return parameters_.profile_local_search() ||
parameters_.print_local_search_profile();
}
bool Solver::InstrumentsVariables() const {
return parameters_.trace_propagation();
}
bool Solver::NameAllVariables() const {
return parameters_.name_all_variables();
}
// ------------------ Demon class ----------------
Solver::DemonPriority Demon::priority() const {
return Solver::NORMAL_PRIORITY;
}
std::string Demon::DebugString() const { return "Demon"; }
void Demon::inhibit(Solver* const s) {
if (stamp_ < std::numeric_limits<uint64_t>::max()) {
s->SaveAndSetValue(&stamp_, std::numeric_limits<uint64_t>::max());
}
}
void Demon::desinhibit(Solver* const s) {
if (stamp_ == std::numeric_limits<uint64_t>::max()) {
s->SaveAndSetValue(&stamp_, s->stamp() - 1);
}
}
// ------------------ Queue class ------------------
extern void CleanVariableOnFail(IntVar* const var);
class Queue {
public:
static constexpr int64_t kTestPeriod = 10000;
explicit Queue(Solver* const s)
: solver_(s),
stamp_(1),
freeze_level_(0),
in_process_(false),
clean_action_(nullptr),
clean_variable_(nullptr),
in_add_(false),
instruments_demons_(s->InstrumentsDemons()) {}
~Queue() {}
void Freeze() {
freeze_level_++;
stamp_++;
}
void Unfreeze() {
if (--freeze_level_ == 0) {
Process();
}
}
void ProcessOneDemon(Demon* const demon) {
demon->set_stamp(stamp_ - 1);
if (!instruments_demons_) {
if (++solver_->demon_runs_[demon->priority()] % kTestPeriod == 0) {
solver_->TopPeriodicCheck();
}
demon->Run(solver_);
solver_->CheckFail();
} else {
solver_->GetPropagationMonitor()->BeginDemonRun(demon);
if (++solver_->demon_runs_[demon->priority()] % kTestPeriod == 0) {
solver_->TopPeriodicCheck();
}
demon->Run(solver_);
solver_->CheckFail();
solver_->GetPropagationMonitor()->EndDemonRun(demon);
}
}
void Process() {
if (!in_process_) {
in_process_ = true;
while (!var_queue_.empty() || !delayed_queue_.empty()) {
if (!var_queue_.empty()) {
Demon* const demon = var_queue_.front();
var_queue_.pop_front();
ProcessOneDemon(demon);
} else {
DCHECK(!delayed_queue_.empty());
Demon* const demon = delayed_queue_.front();
delayed_queue_.pop_front();
ProcessOneDemon(demon);
}
}
in_process_ = false;
}
}
void ExecuteAll(const SimpleRevFIFO<Demon*>& demons) {
if (!instruments_demons_) {
for (SimpleRevFIFO<Demon*>::Iterator it(&demons); it.ok(); ++it) {
Demon* const demon = *it;
if (demon->stamp() < stamp_) {
DCHECK_EQ(demon->priority(), Solver::NORMAL_PRIORITY);
if (++solver_->demon_runs_[Solver::NORMAL_PRIORITY] % kTestPeriod ==
0) {
solver_->TopPeriodicCheck();
}
demon->Run(solver_);
solver_->CheckFail();
}
}
} else {
for (SimpleRevFIFO<Demon*>::Iterator it(&demons); it.ok(); ++it) {
Demon* const demon = *it;
if (demon->stamp() < stamp_) {
DCHECK_EQ(demon->priority(), Solver::NORMAL_PRIORITY);
solver_->GetPropagationMonitor()->BeginDemonRun(demon);
if (++solver_->demon_runs_[Solver::NORMAL_PRIORITY] % kTestPeriod ==
0) {
solver_->TopPeriodicCheck();
}
demon->Run(solver_);
solver_->CheckFail();
solver_->GetPropagationMonitor()->EndDemonRun(demon);
}
}
}
}
void EnqueueAll(const SimpleRevFIFO<Demon*>& demons) {
for (SimpleRevFIFO<Demon*>::Iterator it(&demons); it.ok(); ++it) {
EnqueueDelayedDemon(*it);
}
}
void EnqueueVar(Demon* const demon) {
DCHECK(demon->priority() == Solver::VAR_PRIORITY);
if (demon->stamp() < stamp_) {
demon->set_stamp(stamp_);
var_queue_.push_back(demon);
if (freeze_level_ == 0) {
Process();
}
}
}
void EnqueueDelayedDemon(Demon* const demon) {
DCHECK(demon->priority() == Solver::DELAYED_PRIORITY);
if (demon->stamp() < stamp_) {
demon->set_stamp(stamp_);
delayed_queue_.push_back(demon);
}
}
void AfterFailure() {
// Clean queue.
var_queue_.clear();
delayed_queue_.clear();
// Call cleaning actions on variables.
if (clean_action_ != nullptr) {
clean_action_(solver_);
clean_action_ = nullptr;
} else if (clean_variable_ != nullptr) {
CleanVariableOnFail(clean_variable_);
clean_variable_ = nullptr;
}
freeze_level_ = 0;
in_process_ = false;
in_add_ = false;
to_add_.clear();
}
void increase_stamp() { stamp_++; }
uint64_t stamp() const { return stamp_; }
void set_action_on_fail(Solver::Action a) {
DCHECK(clean_variable_ == nullptr);
clean_action_ = std::move(a);
}
void set_variable_to_clean_on_fail(IntVar* var) {
DCHECK(clean_action_ == nullptr);
clean_variable_ = var;
}
void reset_action_on_fail() {
DCHECK(clean_variable_ == nullptr);
clean_action_ = nullptr;
}
void AddConstraint(Constraint* const c) {
to_add_.push_back(c);
ProcessConstraints();
}
void ProcessConstraints() {
if (!in_add_) {
in_add_ = true;
// We cannot store to_add_.size() as constraints can add other
// constraints. For the same reason a range-based for loop cannot be used.
// TODO(user): Make to_add_ a queue to make the behavior more obvious.
for (int counter = 0; counter < to_add_.size(); ++counter) {
Constraint* const constraint = to_add_[counter];
// TODO(user): Add profiling to initial propagation
constraint->PostAndPropagate();
}
in_add_ = false;
to_add_.clear();
}
}
private:
Solver* const solver_;
std::deque<Demon*> var_queue_;
std::deque<Demon*> delayed_queue_;
uint64_t stamp_;
// The number of nested freeze levels. The queue is frozen if and only if
// freeze_level_ > 0.
uint32_t freeze_level_;
bool in_process_;
Solver::Action clean_action_;
IntVar* clean_variable_;
std::vector<Constraint*> to_add_;
bool in_add_;
const bool instruments_demons_;
};
// ------------------ StateMarker / StateInfo struct -----------
struct StateInfo { // This is an internal structure to store
// additional information on the choice point.
public:
StateInfo()
: ptr_info(nullptr),
int_info(0),
depth(0),
left_depth(0),
reversible_action(nullptr) {}
StateInfo(void* pinfo, int iinfo)
: ptr_info(pinfo),
int_info(iinfo),
depth(0),
left_depth(0),
reversible_action(nullptr) {}
StateInfo(void* pinfo, int iinfo, int d, int ld)
: ptr_info(pinfo),
int_info(iinfo),
depth(d),
left_depth(ld),
reversible_action(nullptr) {}
StateInfo(Solver::Action a, bool fast)
: ptr_info(nullptr),
int_info(static_cast<int>(fast)),
depth(0),
left_depth(0),
reversible_action(std::move(a)) {}
void* ptr_info;
int int_info;
int depth;
int left_depth;
Solver::Action reversible_action;
};
struct StateMarker {
public:
StateMarker(Solver::MarkerType t, const StateInfo& info);
friend class Solver;
friend struct Trail;
private:
Solver::MarkerType type_;
int rev_int_index_;
int rev_int64_index_;
int rev_uint64_index_;
int rev_double_index_;
int rev_ptr_index_;
int rev_boolvar_list_index_;
int rev_bools_index_;
int rev_int_memory_index_;
int rev_int64_memory_index_;
int rev_double_memory_index_;
int rev_object_memory_index_;
int rev_object_array_memory_index_;
int rev_memory_index_;
int rev_memory_array_index_;
StateInfo info_;
};
StateMarker::StateMarker(Solver::MarkerType t, const StateInfo& info)
: type_(t),
rev_int_index_(0),
rev_int64_index_(0),
rev_uint64_index_(0),
rev_double_index_(0),
rev_ptr_index_(0),
rev_boolvar_list_index_(0),
rev_bools_index_(0),
rev_int_memory_index_(0),
rev_int64_memory_index_(0),
rev_double_memory_index_(0),
rev_object_memory_index_(0),
rev_object_array_memory_index_(0),
info_(info) {}
// ---------- Trail and Reversibility ----------
namespace {
// ----- addrval struct -----
// This template class is used internally to implement reversibility.
// It stores an address and the value that was at the address.
template <class T>
struct addrval {
public:
addrval() : address_(nullptr) {}
explicit addrval(T* adr) : address_(adr), old_value_(*adr) {}
void restore() const { (*address_) = old_value_; }
private:
T* address_;
T old_value_;
};
// ----- Compressed trail -----
// ---------- Trail Packer ---------
// Abstract class to pack trail blocks.
template <class T>
class TrailPacker {
public:
explicit TrailPacker(int block_size) : block_size_(block_size) {}
virtual ~TrailPacker() {}
int input_size() const { return block_size_ * sizeof(addrval<T>); }
virtual void Pack(const addrval<T>* block, std::string* packed_block) = 0;
virtual void Unpack(const std::string& packed_block, addrval<T>* block) = 0;
private:
const int block_size_;
DISALLOW_COPY_AND_ASSIGN(TrailPacker);
};
template <class T>
class NoCompressionTrailPacker : public TrailPacker<T> {
public:
explicit NoCompressionTrailPacker(int block_size)
: TrailPacker<T>(block_size) {}
~NoCompressionTrailPacker() override {}
void Pack(const addrval<T>* block, std::string* packed_block) override {
DCHECK(block != nullptr);
DCHECK(packed_block != nullptr);
absl::string_view block_str(reinterpret_cast<const char*>(block),
this->input_size());
packed_block->assign(block_str.data(), block_str.size());
}
void Unpack(const std::string& packed_block, addrval<T>* block) override {
DCHECK(block != nullptr);
memcpy(block, packed_block.c_str(), packed_block.size());
}
private:
DISALLOW_COPY_AND_ASSIGN(NoCompressionTrailPacker<T>);
};
template <class T>
class ZlibTrailPacker : public TrailPacker<T> {
public:
explicit ZlibTrailPacker(int block_size)
: TrailPacker<T>(block_size),
tmp_size_(compressBound(this->input_size())),
tmp_block_(new char[tmp_size_]) {}
~ZlibTrailPacker() override {}
void Pack(const addrval<T>* block, std::string* packed_block) override {
DCHECK(block != nullptr);
DCHECK(packed_block != nullptr);
uLongf size = tmp_size_;
const int result =
compress(reinterpret_cast<Bytef*>(tmp_block_.get()), &size,
reinterpret_cast<const Bytef*>(block), this->input_size());
CHECK_EQ(Z_OK, result);
absl::string_view block_str;
block_str = absl::string_view(tmp_block_.get(), size);
packed_block->assign(block_str.data(), block_str.size());
}
void Unpack(const std::string& packed_block, addrval<T>* block) override {
DCHECK(block != nullptr);
uLongf size = this->input_size();
const int result =
uncompress(reinterpret_cast<Bytef*>(block), &size,
reinterpret_cast<const Bytef*>(packed_block.c_str()),
packed_block.size());
CHECK_EQ(Z_OK, result);
}
private:
const uint64_t tmp_size_;
std::unique_ptr<char[]> tmp_block_;
DISALLOW_COPY_AND_ASSIGN(ZlibTrailPacker<T>);
};
template <class T>
class CompressedTrail {
public:
CompressedTrail(
int block_size,
ConstraintSolverParameters::TrailCompression compression_level)
: block_size_(block_size),
blocks_(nullptr),
free_blocks_(nullptr),
data_(new addrval<T>[block_size]),
buffer_(new addrval<T>[block_size]),
buffer_used_(false),
current_(0),
size_(0) {
switch (compression_level) {
case ConstraintSolverParameters::NO_COMPRESSION: {
packer_.reset(new NoCompressionTrailPacker<T>(block_size));
break;
}
case ConstraintSolverParameters::COMPRESS_WITH_ZLIB: {
packer_.reset(new ZlibTrailPacker<T>(block_size));
break;
}
default: {
LOG(ERROR) << "Should not be here";
}
}
// We zero all memory used by addrval arrays.
// Because of padding, all bytes may not be initialized, while compression
// will read them all, even if the uninitialized bytes are never used.
// This makes valgrind happy.
memset(data_.get(), 0, sizeof(*data_.get()) * block_size);
memset(buffer_.get(), 0, sizeof(*buffer_.get()) * block_size);
}
~CompressedTrail() {
FreeBlocks(blocks_);
FreeBlocks(free_blocks_);
}
const addrval<T>& Back() const {
// Back of empty trail.
DCHECK_GT(current_, 0);
return data_[current_ - 1];
}
void PopBack() {
if (size_ > 0) {
--current_;
if (current_ <= 0) {
if (buffer_used_) {
data_.swap(buffer_);
current_ = block_size_;
buffer_used_ = false;
} else if (blocks_ != nullptr) {
packer_->Unpack(blocks_->compressed, data_.get());
FreeTopBlock();
current_ = block_size_;
}
}
--size_;
}
}
void PushBack(const addrval<T>& addr_val) {
if (current_ >= block_size_) {
if (buffer_used_) { // Buffer is used.
NewTopBlock();
packer_->Pack(buffer_.get(), &blocks_->compressed);
// O(1) operation.
data_.swap(buffer_);
} else {
data_.swap(buffer_);
buffer_used_ = true;
}
current_ = 0;
}
data_[current_] = addr_val;
++current_;
++size_;
}
int64_t size() const { return size_; }
private:
struct Block {
std::string compressed;
Block* next;
};
void FreeTopBlock() {
Block* block = blocks_;
blocks_ = block->next;
block->compressed.clear();
block->next = free_blocks_;
free_blocks_ = block;
}
void NewTopBlock() {
Block* block = nullptr;
if (free_blocks_ != nullptr) {
block = free_blocks_;
free_blocks_ = block->next;
} else {
block = new Block;
}
block->next = blocks_;
blocks_ = block;
}
void FreeBlocks(Block* blocks) {
while (nullptr != blocks) {
Block* next = blocks->next;
delete blocks;
blocks = next;
}
}
std::unique_ptr<TrailPacker<T> > packer_;
const int block_size_;
Block* blocks_;
Block* free_blocks_;
std::unique_ptr<addrval<T>[]> data_;
std::unique_ptr<addrval<T>[]> buffer_;
bool buffer_used_;
int current_;
int size_;
};
} // namespace
// ----- Trail -----
// Object are explicitly copied using the copy ctor instead of
// passing and storing a pointer. As objects are small, copying is
// much faster than allocating (around 35% on a complete solve).
extern void RestoreBoolValue(IntVar* const var);
struct Trail {
CompressedTrail<int> rev_ints_;
CompressedTrail<int64_t> rev_int64s_;
CompressedTrail<uint64_t> rev_uint64s_;
CompressedTrail<double> rev_doubles_;
CompressedTrail<void*> rev_ptrs_;
std::vector<IntVar*> rev_boolvar_list_;
std::vector<bool*> rev_bools_;
std::vector<bool> rev_bool_value_;
std::vector<int*> rev_int_memory_;
std::vector<int64_t*> rev_int64_memory_;
std::vector<double*> rev_double_memory_;
std::vector<BaseObject*> rev_object_memory_;
std::vector<BaseObject**> rev_object_array_memory_;
std::vector<void*> rev_memory_;
std::vector<void**> rev_memory_array_;
Trail(int block_size,
ConstraintSolverParameters::TrailCompression compression_level)
: rev_ints_(block_size, compression_level),
rev_int64s_(block_size, compression_level),
rev_uint64s_(block_size, compression_level),
rev_doubles_(block_size, compression_level),
rev_ptrs_(block_size, compression_level) {}
void BacktrackTo(StateMarker* m) {
int target = m->rev_int_index_;
for (int curr = rev_ints_.size(); curr > target; --curr) {
const addrval<int>& cell = rev_ints_.Back();
cell.restore();
rev_ints_.PopBack();
}
DCHECK_EQ(rev_ints_.size(), target);
// Incorrect trail size after backtrack.
target = m->rev_int64_index_;
for (int curr = rev_int64s_.size(); curr > target; --curr) {
const addrval<int64_t>& cell = rev_int64s_.Back();
cell.restore();
rev_int64s_.PopBack();
}
DCHECK_EQ(rev_int64s_.size(), target);
// Incorrect trail size after backtrack.
target = m->rev_uint64_index_;
for (int curr = rev_uint64s_.size(); curr > target; --curr) {
const addrval<uint64_t>& cell = rev_uint64s_.Back();
cell.restore();
rev_uint64s_.PopBack();
}
DCHECK_EQ(rev_uint64s_.size(), target);
// Incorrect trail size after backtrack.
target = m->rev_double_index_;
for (int curr = rev_doubles_.size(); curr > target; --curr) {
const addrval<double>& cell = rev_doubles_.Back();
cell.restore();
rev_doubles_.PopBack();
}
DCHECK_EQ(rev_doubles_.size(), target);
// Incorrect trail size after backtrack.
target = m->rev_ptr_index_;
for (int curr = rev_ptrs_.size(); curr > target; --curr) {
const addrval<void*>& cell = rev_ptrs_.Back();
cell.restore();
rev_ptrs_.PopBack();
}
DCHECK_EQ(rev_ptrs_.size(), target);
// Incorrect trail size after backtrack.
target = m->rev_boolvar_list_index_;
for (int curr = rev_boolvar_list_.size() - 1; curr >= target; --curr) {
IntVar* const var = rev_boolvar_list_[curr];
RestoreBoolValue(var);
}
rev_boolvar_list_.resize(target);
DCHECK_EQ(rev_bools_.size(), rev_bool_value_.size());
target = m->rev_bools_index_;
for (int curr = rev_bools_.size() - 1; curr >= target; --curr) {
*(rev_bools_[curr]) = rev_bool_value_[curr];
}
rev_bools_.resize(target);
rev_bool_value_.resize(target);
target = m->rev_int_memory_index_;
for (int curr = rev_int_memory_.size() - 1; curr >= target; --curr) {
delete[] rev_int_memory_[curr];
}
rev_int_memory_.resize(target);
target = m->rev_int64_memory_index_;
for (int curr = rev_int64_memory_.size() - 1; curr >= target; --curr) {
delete[] rev_int64_memory_[curr];
}
rev_int64_memory_.resize(target);
target = m->rev_double_memory_index_;
for (int curr = rev_double_memory_.size() - 1; curr >= target; --curr) {
delete[] rev_double_memory_[curr];
}
rev_double_memory_.resize(target);
target = m->rev_object_memory_index_;
for (int curr = rev_object_memory_.size() - 1; curr >= target; --curr) {
delete rev_object_memory_[curr];
}
rev_object_memory_.resize(target);
target = m->rev_object_array_memory_index_;
for (int curr = rev_object_array_memory_.size() - 1; curr >= target;
--curr) {
delete[] rev_object_array_memory_[curr];
}
rev_object_array_memory_.resize(target);
target = m->rev_memory_index_;
for (int curr = rev_memory_.size() - 1; curr >= target; --curr) {
// Explicitly call unsized delete
::operator delete(reinterpret_cast<char*>(rev_memory_[curr]));
// The previous cast is necessary to deallocate generic memory
// described by a void* when passed to the RevAlloc procedure
// We cannot do a delete[] there
// This is useful for cells of RevFIFO and should not be used outside
// of the product
}
rev_memory_.resize(target);
target = m->rev_memory_array_index_;
for (int curr = rev_memory_array_.size() - 1; curr >= target; --curr) {
delete[] rev_memory_array_[curr];
// delete [] version of the previous unsafe case.
}
rev_memory_array_.resize(target);
}
};
void Solver::InternalSaveValue(int* valptr) {
trail_->rev_ints_.PushBack(addrval<int>(valptr));
}
void Solver::InternalSaveValue(int64_t* valptr) {
trail_->rev_int64s_.PushBack(addrval<int64_t>(valptr));
}
void Solver::InternalSaveValue(uint64_t* valptr) {
trail_->rev_uint64s_.PushBack(addrval<uint64_t>(valptr));
}
void Solver::InternalSaveValue(double* valptr) {
trail_->rev_doubles_.PushBack(addrval<double>(valptr));
}
void Solver::InternalSaveValue(void** valptr) {
trail_->rev_ptrs_.PushBack(addrval<void*>(valptr));
}
// TODO(user) : this code is unsafe if you save the same alternating
// bool multiple times.
// The correct code should use a bitset and a single list.
void Solver::InternalSaveValue(bool* valptr) {
trail_->rev_bools_.push_back(valptr);
trail_->rev_bool_value_.push_back(*valptr);
}
BaseObject* Solver::SafeRevAlloc(BaseObject* ptr) {
check_alloc_state();
trail_->rev_object_memory_.push_back(ptr);
return ptr;
}
int* Solver::SafeRevAllocArray(int* ptr) {
check_alloc_state();
trail_->rev_int_memory_.push_back(ptr);
return ptr;
}
int64_t* Solver::SafeRevAllocArray(int64_t* ptr) {
check_alloc_state();
trail_->rev_int64_memory_.push_back(ptr);
return ptr;
}
double* Solver::SafeRevAllocArray(double* ptr) {
check_alloc_state();
trail_->rev_double_memory_.push_back(ptr);
return ptr;
}
uint64_t* Solver::SafeRevAllocArray(uint64_t* ptr) {
check_alloc_state();
trail_->rev_int64_memory_.push_back(reinterpret_cast<int64_t*>(ptr));
return ptr;
}
BaseObject** Solver::SafeRevAllocArray(BaseObject** ptr) {
check_alloc_state();
trail_->rev_object_array_memory_.push_back(ptr);
return ptr;
}
IntVar** Solver::SafeRevAllocArray(IntVar** ptr) {
BaseObject** in = SafeRevAllocArray(reinterpret_cast<BaseObject**>(ptr));
return reinterpret_cast<IntVar**>(in);
}
IntExpr** Solver::SafeRevAllocArray(IntExpr** ptr) {
BaseObject** in = SafeRevAllocArray(reinterpret_cast<BaseObject**>(ptr));
return reinterpret_cast<IntExpr**>(in);
}
Constraint** Solver::SafeRevAllocArray(Constraint** ptr) {
BaseObject** in = SafeRevAllocArray(reinterpret_cast<BaseObject**>(ptr));
return reinterpret_cast<Constraint**>(in);
}
void* Solver::UnsafeRevAllocAux(void* ptr) {
check_alloc_state();
trail_->rev_memory_.push_back(ptr);
return ptr;
}
void** Solver::UnsafeRevAllocArrayAux(void** ptr) {
check_alloc_state();
trail_->rev_memory_array_.push_back(ptr);
return ptr;
}
void InternalSaveBooleanVarValue(Solver* const solver, IntVar* const var) {
solver->trail_->rev_boolvar_list_.push_back(var);
}
// ------------------ Search class -----------------
class Search {
public:
explicit Search(Solver* const s)
: solver_(s),
marker_stack_(),
fail_buffer_(),
solution_counter_(0),
unchecked_solution_counter_(0),
decision_builder_(nullptr),
created_by_solve_(false),
search_depth_(0),
left_search_depth_(0),
should_restart_(false),
should_finish_(false),
sentinel_pushed_(0),
jmpbuf_filled_(false),
backtrack_at_the_end_of_the_search_(true) {}
// Constructor for a dummy search. The only difference between a dummy search
// and a regular one is that the search depth and left search depth is
// initialized to -1 instead of zero.
Search(Solver* const s, int /* dummy_argument */)
: solver_(s),
marker_stack_(),
fail_buffer_(),
solution_counter_(0),
unchecked_solution_counter_(0),
decision_builder_(nullptr),
created_by_solve_(false),
search_depth_(-1),
left_search_depth_(-1),
should_restart_(false),
should_finish_(false),
sentinel_pushed_(0),
jmpbuf_filled_(false),
backtrack_at_the_end_of_the_search_(true) {}
~Search() { gtl::STLDeleteElements(&marker_stack_); }
void EnterSearch();
void RestartSearch();
void ExitSearch();
void BeginNextDecision(DecisionBuilder* const db);
void EndNextDecision(DecisionBuilder* const db, Decision* const d);
void ApplyDecision(Decision* const d);