X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/515cd2622ad1000f5f3ba58ecfaf488ac922b963..824740eb0df1dedddb86035ff3730d87e037f356:/src/mc/explo/DFSExplorer.cpp diff --git a/src/mc/explo/DFSExplorer.cpp b/src/mc/explo/DFSExplorer.cpp index d2aa4f48b5..eb3b8e7ac1 100644 --- a/src/mc/explo/DFSExplorer.cpp +++ b/src/mc/explo/DFSExplorer.cpp @@ -4,13 +4,16 @@ * under the terms of the license (GNU LGPL) which comes with this package. */ #include "src/mc/explo/DFSExplorer.hpp" -#include "src/mc/VisitedState.hpp" #include "src/mc/mc_config.hpp" #include "src/mc/mc_exit.hpp" #include "src/mc/mc_private.hpp" #include "src/mc/mc_record.hpp" #include "src/mc/transition/Transition.hpp" +#if SIMGRID_HAVE_STATEFUL_MC +#include "src/mc/VisitedState.hpp" +#endif + #include "src/xbt/mmalloc/mmprivate.h" #include "xbt/log.h" #include "xbt/string.hpp" @@ -41,8 +44,10 @@ xbt::signal DFSExplorer::on_log_state_signal; void DFSExplorer::check_non_termination(const State* current_state) { +#if SIMGRID_HAVE_STATEFUL_MC for (auto const& state : stack_) { - if (*state->get_system_state() == *current_state->get_system_state()) { + if (state->get_system_state()->equals_to(*current_state->get_system_state(), + *get_remote_app().get_remote_process_memory())) { XBT_INFO("Non-progressive cycle: state %ld -> state %ld", state->get_num(), current_state->get_num()); XBT_INFO("******************************************"); XBT_INFO("*** NON-PROGRESSIVE CYCLE DETECTED ***"); @@ -58,26 +63,43 @@ void DFSExplorer::check_non_termination(const State* current_state) throw TerminationError(); } } +#endif } RecordTrace DFSExplorer::get_record_trace() // override { RecordTrace res; - for (auto const& state : stack_) - res.push_back(state->get_transition()); + for (auto const& transition : stack_.back()->get_recipe()) + res.push_back(transition); + res.push_back(stack_.back()->get_transition()); return res; } std::vector DFSExplorer::get_textual_trace() // override { std::vector trace; - for (auto const& state : stack_) { - const auto* t = state->get_transition(); - trace.push_back(xbt::string_printf("%ld: %s", t->aid_, t->to_string().c_str())); + for (auto const& transition : stack_.back()->get_recipe()) { + trace.push_back(xbt::string_printf("%ld: %s", transition->aid_, transition->to_string().c_str())); } + trace.push_back(xbt::string_printf("%ld: %s", stack_.back()->get_transition()->aid_, + stack_.back()->get_transition()->to_string().c_str())); return trace; } +void DFSExplorer::restore_stack(std::shared_ptr state) +{ + + stack_ = std::list>(); + std::shared_ptr current_state(state); + stack_.push_front(std::shared_ptr(current_state)); + // condition corresponds to reaching initial state + while (current_state->get_parent_state() != nullptr) { + current_state = current_state->get_parent_state(); + stack_.push_front(std::shared_ptr(current_state)); + } + XBT_DEBUG("Replaced stack by %s", get_record_trace().to_string().c_str()); +} + void DFSExplorer::log_state() // override { on_log_state_signal(get_remote_app()); @@ -97,7 +119,7 @@ void DFSExplorer::run() while (not stack_.empty()) { /* Get current state */ - State* state = stack_.back().get(); + std::shared_ptr state(stack_.back()); XBT_DEBUG("**************************************************"); XBT_DEBUG("Exploration depth=%zu (state:#%ld; %zu interleaves todo)", stack_.size(), state->get_num(), @@ -117,7 +139,8 @@ void DFSExplorer::run() continue; } - // Backtrack if we are revisiting a state we saw previously +#if SIMGRID_HAVE_STATEFUL_MC + // Backtrack if we are revisiting a state we saw previously while applying state-equality reduction if (visited_state_ != nullptr) { XBT_DEBUG("State already visited (equal to state %ld), exploration stopped on this path.", visited_state_->original_num_ == -1 ? visited_state_->num_ : visited_state_->original_num_); @@ -126,21 +149,22 @@ void DFSExplorer::run() this->backtrack(); continue; } +#endif // Search for the next transition - aid_t next = state->next_transition(); + // next_transition returns a pair in case we want to consider multiple state (eg. during backtrack) + auto [next, _] = state->next_transition_guided(); if (next < 0) { // If there is no more transition in the current state, backtrack. - XBT_DEBUG("There remains %lu actors, but none to interleave (depth %zu).", state->get_actor_count(), - stack_.size() + 1); - + XBT_VERB("%lu actors remain, but none of them need to be interleaved (depth %zu).", state->get_actor_count(), + stack_.size() + 1); + if (state->get_actor_count() == 0) { - mc_model_checker->finalize_app(); + get_remote_app().finalize_app(); XBT_VERB("Execution came to an end at %s (state: %ld, depth: %zu)", get_record_trace().to_string().c_str(), state->get_num(), stack_.size()); - } - + this->backtrack(); continue; } @@ -152,7 +176,7 @@ void DFSExplorer::run() } /* Actually answer the request: let's execute the selected request (MCed does one step) */ - state->execute_next(next); + state->execute_next(next, get_remote_app()); on_transition_execute_signal(state->get_transition(), get_remote_app()); // If there are processes to interleave and the maximum depth has not been @@ -161,83 +185,30 @@ void DFSExplorer::run() state->get_transition()->to_string().c_str(), stack_.size(), state->get_num(), state->count_todo()); /* Create the new expanded state (copy the state of MCed into our MCer data) */ - std::unique_ptr next_state; - - /* If we want sleep set reduction, pass the old state to the new state so it can - * both copy the sleep set and eventually removes things from it locally */ - if (_sg_mc_sleep_set) - next_state = std::make_unique(get_remote_app(), state); - else - next_state = std::make_unique(get_remote_app()); - + std::shared_ptr next_state = std::make_shared(get_remote_app(), state); on_state_creation_signal(next_state.get(), get_remote_app()); - - if (_sg_mc_termination) - this->check_non_termination(next_state.get()); - - /* Check whether we already explored next_state in the past (but only if interested in state-equality reduction) */ - if (_sg_mc_max_visited_states > 0) - visited_state_ = visited_states_.addVisitedState(next_state->get_num(), next_state.get(), get_remote_app()); - - /* If this is a new state (or if we don't care about state-equality reduction) */ - if (visited_state_ == nullptr) { - /* Get an enabled process and insert it in the interleave set of the next state */ - for (auto const& [aid, _] : next_state->get_actors_list()) { - if (next_state->is_actor_enabled(aid) and not next_state->is_actor_done(aid)) { - next_state->mark_todo(aid); - if (reduction_mode_ == ReductionMode::dpor) - break; // With DPOR, we take the first enabled transition - } - } - - dot_output("\"%ld\" -> \"%ld\" [%s];\n", state->get_num(), next_state->get_num(), - state->get_transition()->dot_string().c_str()); - } else - dot_output("\"%ld\" -> \"%ld\" [%s];\n", state->get_num(), - visited_state_->original_num_ == -1 ? visited_state_->num_ : visited_state_->original_num_, - state->get_transition()->dot_string().c_str()); - - stack_.push_back(std::move(next_state)); - } - - log_state(); -} - -void DFSExplorer::backtrack() -{ - backtrack_count_++; - XBT_VERB("Backtracking from %s", get_record_trace().to_string().c_str()); - on_backtracking_signal(get_remote_app()); - get_remote_app().check_deadlock(); - - /* We may backtrack from somewhere either because it's leaf, or because every enabled process are in done/sleep set. - * In the first case, we need to remove the last transition corresponding to the Finalize */ - if (stack_.back()->get_transition()->aid_ == 0) - stack_.pop_back(); - - /* Traverse the stack backwards until a state with a non empty interleave set is found, deleting all the states that - * have it empty in the way. For each deleted state, check if the request that has generated it (from its - * predecessor state) depends on any other previous request executed before it on another process. If there exists one, - * find the more recent, and add its process to the interleave set. If the process is not enabled at this point, - * then add every enabled process to the interleave */ - bool found_backtracking_point = false; - while (not stack_.empty() && not found_backtracking_point) { - std::unique_ptr state = std::move(stack_.back()); - - stack_.pop_back(); - + /* Sleep set procedure: + * adding the taken transition to the sleep set of the original state. + * Since the parent sleep set is used to compute the child sleep set, this need to be + * done after next_state creation */ XBT_DEBUG("Marking Transition >>%s<< of process %ld done and adding it to the sleep set", state->get_transition()->to_string().c_str(), state->get_transition()->aid_); state->add_sleep_set(state->get_transition()); // Actors are marked done when they are considerd in ActorState + /* DPOR persistent set procedure: + * for each new transition considered, check if it depends on any other previous transition executed before it + * on another process. If there exists one, find the more recent, and add its process to the interleave set. + * If the process is not enabled at this point, then add every enabled process to the interleave */ if (reduction_mode_ == ReductionMode::dpor) { - aid_t issuer_id = state->get_transition()->aid_; - for (auto i = stack_.rbegin(); i != stack_.rend(); ++i) { - State* prev_state = i->get(); + aid_t issuer_id = state->get_transition()->aid_; + stack_t tmp_stack = std::list(stack_); + while (not tmp_stack.empty()) { + State* prev_state = tmp_stack.back().get(); if (state->get_transition()->aid_ == prev_state->get_transition()->aid_) { XBT_DEBUG("Simcall >>%s<< and >>%s<< with same issuer %ld", state->get_transition()->to_string().c_str(), prev_state->get_transition()->to_string().c_str(), issuer_id); + tmp_stack.pop_back(); continue; } else if (prev_state->get_transition()->depends(state->get_transition())) { XBT_VERB("Dependent Transitions:"); @@ -245,15 +216,18 @@ void DFSExplorer::backtrack() XBT_VERB(" %s (state=%ld)", state->get_transition()->to_string().c_str(), state->get_num()); if (prev_state->is_actor_enabled(issuer_id)) { - if (not prev_state->is_actor_done(issuer_id)) - prev_state->mark_todo(issuer_id); - else + if (not prev_state->is_actor_done(issuer_id)) { + prev_state->consider_one(issuer_id); + opened_states_.push(std::shared_ptr(tmp_stack.back())); + } else XBT_DEBUG("Actor %ld is already in done set: no need to explore it again", issuer_id); } else { XBT_DEBUG("Actor %ld is not enabled: DPOR may be failing. To stay sound, we are marking every enabled " "transition as todo", issuer_id); - prev_state->mark_all_enabled_todo(); + // If we ended up marking at least a transition, explore it at some point + if (prev_state->consider_all() > 0) + opened_states_.push(std::shared_ptr(tmp_stack.back())); } break; } else { @@ -261,45 +235,102 @@ void DFSExplorer::backtrack() XBT_VERB(" %s (state=%ld)", prev_state->get_transition()->to_string().c_str(), prev_state->get_num()); XBT_VERB(" %s (state=%ld)", state->get_transition()->to_string().c_str(), state->get_num()); } + tmp_stack.pop_back(); } } - if (state->count_todo() == 0) { // Empty interleaving set: exploration at this level is over - XBT_DEBUG("Delete state %ld at depth %zu", state->get_num(), stack_.size() + 1); + // Before leaving that state, if the transition we just took can be taken multiple times, we + // need to give it to the opened states + if (stack_.back()->count_todo_multiples() > 0) + opened_states_.push(std::shared_ptr(stack_.back())); + + if (_sg_mc_termination) + this->check_non_termination(next_state.get()); + +#if SIMGRID_HAVE_STATEFUL_MC + /* Check whether we already explored next_state in the past (but only if interested in state-equality reduction) */ + if (_sg_mc_max_visited_states > 0) + visited_state_ = visited_states_.addVisitedState(next_state->get_num(), next_state.get(), get_remote_app()); +#endif + + stack_.push_back(std::move(next_state)); + /* If this is a new state (or if we don't care about state-equality reduction) */ + if (visited_state_ == nullptr) { + /* Get an enabled process and insert it in the interleave set of the next state */ + if (reduction_mode_ == ReductionMode::dpor) + stack_.back()->consider_best(); // Take only one transition if DPOR: others may be considered later if required + else { + stack_.back()->consider_all(); + } + + dot_output("\"%ld\" -> \"%ld\" [%s];\n", state->get_num(), stack_.back()->get_num(), + state->get_transition()->dot_string().c_str()); +#if SIMGRID_HAVE_STATEFUL_MC } else { - XBT_DEBUG("Back-tracking to state %ld at depth %zu: %lu transitions left to be explored", state->get_num(), - stack_.size() + 1, state->count_todo()); - stack_.push_back(std::move(state)); // Put it back on the stack so we can explore the next transition of the interleave - found_backtracking_point = true; + dot_output("\"%ld\" -> \"%ld\" [%s];\n", state->get_num(), + visited_state_->original_num_ == -1 ? visited_state_->num_ : visited_state_->original_num_, + state->get_transition()->dot_string().c_str()); +#endif } } + log_state(); +} - if (found_backtracking_point) { - /* If asked to rollback on a state that has a snapshot, restore it */ - State* last_state = stack_.back().get(); - if (const auto* system_state = last_state->get_system_state()) { - system_state->restore(&get_remote_app().get_remote_process_memory()); - on_restore_system_state_signal(last_state, get_remote_app()); - return; - } +void DFSExplorer::backtrack() +{ + XBT_VERB("Backtracking from %s", get_record_trace().to_string().c_str()); + XBT_DEBUG("%lu alternatives are yet to be explored:", opened_states_.size()); - /* if no snapshot, we need to restore the initial state and replay the transitions */ - get_remote_app().restore_initial_state(); - on_restore_initial_state_signal(get_remote_app()); - - /* Traverse the stack from the state at position start and re-execute the transitions */ - for (std::unique_ptr const& state : stack_) { - if (state == stack_.back()) /* If we are arrived on the target state, don't replay the outgoing transition */ - break; - state->get_transition()->replay(); - on_transition_replay_signal(state->get_transition(), get_remote_app()); - visited_states_count_++; - } - } // If no backtracing point, then the stack is empty and the exploration is over + on_backtracking_signal(get_remote_app()); + get_remote_app().check_deadlock(); + + // if no backtracking point, then set the stack_ to empty so we can end the exploration + if (opened_states_.empty()) { + XBT_DEBUG("No more opened point of exploration, the search will end"); + stack_ = std::list>(); + return; + } + + std::shared_ptr backtracking_point = opened_states_.top(); // Take the point with smallest distance + opened_states_.pop(); + + // if the smallest distance corresponded to no enable actor, remove this and let the + // exploration ask again for a backtrack + if (backtracking_point->next_transition_guided().first == -1) { + XBT_DEBUG("Best backtracking candidates has already been explored. Let's backtrack again"); + this->backtrack(); + return; + } + + // We found a real backtracking point, let's go to it + backtrack_count_++; + XBT_DEBUG("Backtracking to state#%ld", backtracking_point->get_num()); + +#if SIMGRID_HAVE_STATEFUL_MC + /* If asked to rollback on a state that has a snapshot, restore it */ + if (const auto* system_state = backtracking_point->get_system_state()) { + system_state->restore(*get_remote_app().get_remote_process_memory()); + on_restore_system_state_signal(backtracking_point.get(), get_remote_app()); + this->restore_stack(backtracking_point); + return; + } +#endif + + /* if no snapshot, we need to restore the initial state and replay the transitions */ + get_remote_app().restore_initial_state(); + on_restore_initial_state_signal(get_remote_app()); + /* Traverse the stack from the state at position start and re-execute the transitions */ + for (auto& state : backtracking_point->get_recipe()) { + state->replay(get_remote_app()); + on_transition_replay_signal(state, get_remote_app()); + visited_states_count_++; + } + this->restore_stack(backtracking_point); } -DFSExplorer::DFSExplorer(const std::vector& args, bool with_dpor) : Exploration(args) +DFSExplorer::DFSExplorer(const std::vector& args, bool with_dpor, bool need_memory_info) + : Exploration(args, need_memory_info || _sg_mc_termination) { if (with_dpor) reduction_mode_ = ReductionMode::dpor; @@ -316,24 +347,21 @@ DFSExplorer::DFSExplorer(const std::vector& args, bool with_dpor) : Explo } else XBT_INFO("Start a DFS exploration. Reduction is: %s.", to_c_str(reduction_mode_)); - auto initial_state = std::make_unique(get_remote_app()); + auto initial_state = std::make_shared(get_remote_app()); XBT_DEBUG("**************************************************"); + stack_.push_back(std::move(initial_state)); + /* Get an enabled actor and insert it in the interleave set of the initial state */ - XBT_DEBUG("Initial state. %lu actors to consider", initial_state->get_actor_count()); - for (auto const& [aid, _] : initial_state->get_actors_list()) { - if (initial_state->is_actor_enabled(aid)) { - initial_state->mark_todo(aid); - if (reduction_mode_ == ReductionMode::dpor) { - XBT_DEBUG("Actor %ld is TODO, DPOR is ON so let's go for this one.", aid); - break; - } - XBT_DEBUG("Actor %ld is TODO", aid); - } + XBT_DEBUG("Initial state. %lu actors to consider", stack_.back()->get_actor_count()); + if (reduction_mode_ == ReductionMode::dpor) + stack_.back()->consider_best(); + else { + stack_.back()->consider_all(); } - - stack_.push_back(std::move(initial_state)); + if (stack_.back()->count_todo_multiples() > 1) + opened_states_.push(std::shared_ptr(stack_.back())); } Exploration* create_dfs_exploration(const std::vector& args, bool with_dpor)