X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/2938350ef873d235860bee051062edcfd2596da6..3f9b311ec56db95ec539001a860ae3c838c48312:/src/mc/explo/DFSExplorer.cpp diff --git a/src/mc/explo/DFSExplorer.cpp b/src/mc/explo/DFSExplorer.cpp index 451920da63..b328d15773 100644 --- a/src/mc/explo/DFSExplorer.cpp +++ b/src/mc/explo/DFSExplorer.cpp @@ -8,13 +8,10 @@ #include "src/mc/mc_exit.hpp" #include "src/mc/mc_private.hpp" #include "src/mc/mc_record.hpp" +#include "src/mc/remote/mc_protocol.h" #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/asserts.h" #include "xbt/log.h" #include "xbt/string.hpp" #include "xbt/sysdep.h" @@ -44,30 +41,6 @@ xbt::signal DFSExplorer::on_transition_execute_si 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()->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 ***"); - XBT_INFO("******************************************"); - XBT_INFO("Counter-example execution trace:"); - for (auto const& s : get_textual_trace()) - XBT_INFO(" %s", s.c_str()); - XBT_INFO("You can debug the problem (and see the whole details) by rerunning out of simgrid-mc with " - "--cfg=model-check/replay:'%s'", - get_record_trace().to_string().c_str()); - log_state(); - - throw McError(ExitStatus::NON_TERMINATION); - } - } -#endif -} - RecordTrace DFSExplorer::get_record_trace() // override { RecordTrace res; @@ -94,12 +67,9 @@ void DFSExplorer::restore_stack(std::shared_ptr state) } XBT_DEBUG("Replaced stack by %s", get_record_trace().to_string().c_str()); if (reduction_mode_ == ReductionMode::sdpor || reduction_mode_ == ReductionMode::odpor) { - // NOTE: The outgoing transition for the top-most - // state of the stack refers to that which was taken - // as part of the last trace explored by the algorithm. - // Thus, only the sequence of transitions leading up to, - // but not including, the last state must be included - // when reconstructing the Exploration for SDPOR. + // NOTE: The outgoing transition for the top-most state of the stack refers to that which was taken + // as part of the last trace explored by the algorithm. Thus, only the sequence of transitions leading up to, + // but not including, the last state must be included when reconstructing the Exploration for SDPOR. for (auto iter = std::next(stack_.begin()); iter != stack_.end(); ++iter) { execution_seq_.push_transition((*iter)->get_transition_in()); } @@ -113,7 +83,7 @@ void DFSExplorer::log_state() // override XBT_INFO("DFS exploration ended. %ld unique states visited; %lu backtracks (%lu transition replays, %lu states " "visited overall)", State::get_expanded_states(), backtrack_count_, Transition::get_replayed_transitions(), - visited_states_count_); + visited_states_count_); Exploration::log_state(); } @@ -152,29 +122,13 @@ void DFSExplorer::run() continue; } -#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_); - - visited_state_ = nullptr; - this->backtrack(); - continue; - } -#endif - if (reduction_mode_ == ReductionMode::odpor) { - // In the case of ODPOR, the wakeup tree for this - // state may be empty if we're exploring new territory - // (rather than following the partial execution of a - // wakeup tree). This corresponds to lines 9 to 13 of + // In the case of ODPOR, the wakeup tree for this state may be empty if we're exploring new territory + // (rather than following the partial execution of a wakeup tree). This corresponds to lines 9 to 13 of // the ODPOR pseudocode // - // INVARIANT: The execution sequence should be consistent - // with the state when seeding the tree. If the sequence - // gets out of sync with the state, selection will not - // work as we intend + // INVARIANT: The execution sequence should be consistent with the state when seeding the tree. If the sequence + // gets out of sync with the state, selection will not work as we intend state->seed_wakeup_tree_if_needed(execution_seq_); } @@ -184,7 +138,21 @@ void DFSExplorer::run() const aid_t next = reduction_mode_ == ReductionMode::odpor ? state->next_odpor_transition() : std::get<0>(state->next_transition_guided()); - if (next < 0) { // If there is no more transition in the current state, backtrack. + if (next < 0 || not state->is_actor_enabled(next)) { + if (next >= 0) { // Actor is not enabled, then + XBT_DEBUG( + "Reduction %s wants to execute a disabled transition %s. If it's ODPOR, ReversibleRace is suboptimal.", + to_c_str(reduction_mode_), state->get_actors_list().at(next).get_transition()->to_string(true).c_str()); + if (reduction_mode_ == ReductionMode::odpor) { + // Remove the disabled transition from the wakeup tree so that ODPOR doesn't try it again + state->remove_subtree_at_aid(next); + state->add_sleep_set(state->get_actors_list().at(next).get_transition()); + } else { + xbt_assert(false, "Only ODPOR should be confident enought in itself to try executing a disabled transition"); + } + } + // If there is no more transition in the current state (or if ODPOR picked an actor that is not enabled -- + // ReversibleRace is an overapproximation), backtrace XBT_VERB("%lu actors remain, but none of them need to be interleaved (depth %zu).", state->get_actor_count(), stack_.size() + 1); @@ -204,13 +172,16 @@ void DFSExplorer::run() XBT_VERB(" <%ld,%s>", aid, transition->to_string().c_str()); } + auto todo = state->get_actors_list().at(next).get_transition(); + XBT_DEBUG("wanna execute %ld: %.60s", next, todo->to_string().c_str()); + /* Actually answer the request: let's execute the selected request (MCed does one step) */ auto executed_transition = state->execute_next(next, get_remote_app()); on_transition_execute_signal(state->get_transition_out().get(), get_remote_app()); // If there are processes to interleave and the maximum depth has not been // reached then perform one step of the exploration algorithm. - XBT_VERB("Execute %ld: %.60s (stack depth: %zu, state: %ld, %zu interleaves)", state->get_transition_out()->aid_, + XBT_VERB("Executed %ld: %.60s (stack depth: %zu, state: %ld, %zu interleaves)", state->get_transition_out()->aid_, state->get_transition_out()->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) */ @@ -218,13 +189,10 @@ void DFSExplorer::run() on_state_creation_signal(next_state.get(), get_remote_app()); if (reduction_mode_ == ReductionMode::odpor) { - // With ODPOR, after taking a step forward, we must - // assign a copy of that subtree to the next state. + // With ODPOR, after taking a step forward, we must assign a copy of that subtree to the next state. // - // NOTE: We only add actions to the sleep set AFTER - // we've regenerated states. We must perform the search - // fully down a single path before we consider adding - // any elements to the sleep set according to the pseudocode + // NOTE: We only add actions to the sleep set AFTER we've regenerated states. We must perform the search + // fully down a single path before we consider adding any elements to the sleep set according to the pseudocode next_state->sprout_tree_from_parent_state(); } else { /* Sleep set procedure: @@ -253,8 +221,10 @@ void DFSExplorer::run() continue; } else if (prev_state->get_transition_out()->depends(state->get_transition_out().get())) { XBT_VERB("Dependent Transitions:"); - XBT_VERB(" %s (state=%ld)", prev_state->get_transition_out()->to_string().c_str(), prev_state->get_num()); - XBT_VERB(" %s (state=%ld)", state->get_transition_out()->to_string().c_str(), state->get_num()); + XBT_VERB(" #%ld %s (state=%ld)", prev_state->get_transition_out()->aid_, + prev_state->get_transition_out()->to_string().c_str(), prev_state->get_num()); + XBT_VERB(" #%ld %s (state=%ld)", state->get_transition_out()->aid_, + state->get_transition_out()->to_string().c_str(), state->get_num()); if (prev_state->is_actor_enabled(issuer_id)) { if (not prev_state->is_actor_done(issuer_id)) { @@ -273,8 +243,10 @@ void DFSExplorer::run() break; } else { XBT_VERB("INDEPENDENT Transitions:"); - XBT_VERB(" %s (state=%ld)", prev_state->get_transition_out()->to_string().c_str(), prev_state->get_num()); - XBT_VERB(" %s (state=%ld)", state->get_transition_out()->to_string().c_str(), state->get_num()); + XBT_VERB(" #%ld %s (state=%ld)", prev_state->get_transition_out()->aid_, + prev_state->get_transition_out()->to_string().c_str(), prev_state->get_num()); + XBT_VERB(" #%ld %s (state=%ld)", state->get_transition_out()->aid_, + state->get_transition_out()->to_string().c_str(), state->get_num()); } tmp_stack.pop_back(); } @@ -282,15 +254,13 @@ void DFSExplorer::run() /** * SDPOR Source Set Procedure: * - * Find "reversible races" in the current execution `E` with respect - * to the latest action `p`. For each such race, determine one thread - * not contained in the backtrack set at the "race point" `r` which - * "represents" the trace formed by first executing everything after - * `r` that doesn't depend on it (`v := notdep(r, E)`) and then `p` to + * Find "reversible races" in the current execution `E` with respect to the latest action `p`. For each such race, + * determine one thread not contained in the backtrack set at the "race point" `r` which "represents" the trace + * formed by first executing everything after `r` that doesn't depend on it (`v := notdep(r, E)`) and then `p` to * flip the race. * - * The intuition is that some subsequence of `v` may enable `p`, so - * we want to be sure that search "in that direction" + * The intuition is that some subsequence of `v` may enable `p`, so we want to be sure that search "in that + * direction" */ execution_seq_.push_transition(std::move(executed_transition)); xbt_assert(execution_seq_.get_latest_event_handle().has_value(), "No events are contained in the SDPOR execution " @@ -301,12 +271,10 @@ void DFSExplorer::run() State* prev_state = stack_[e_race].get(); const auto choices = execution_seq_.get_missing_source_set_actors_from(e_race, prev_state->get_backtrack_set()); if (not choices.empty()) { - // NOTE: To incorporate the idea of attempting to select the "best" - // backtrack point into SDPOR, instead of selecting the `first` initial, - // we should instead compute all choices and decide which is best + // NOTE: To incorporate the idea of attempting to select the "best" backtrack point into SDPOR, instead of + // selecting the `first` initial, we should instead compute all choices and decide which is best // - // Here, we choose the actor with the lowest ID to ensure - // we get deterministic results + // Here, we choose the actor with the lowest ID to ensure we get deterministic results const auto q = std::min_element(choices.begin(), choices.end(), [](const aid_t a1, const aid_t a2) { return a1 < a2; }); prev_state->consider_one(*q); @@ -314,8 +282,7 @@ void DFSExplorer::run() } } } else if (reduction_mode_ == ReductionMode::odpor) { - // In the case of ODPOR, we simply observe the transition that was executed - // until we've reached a maximal trace + // In the case of ODPOR, we simply observe the transition that was executed until we've reached a maximal trace execution_seq_.push_transition(std::move(executed_transition)); } @@ -324,36 +291,18 @@ void DFSExplorer::run() if (stack_.back()->count_todo_multiples() > 0) opened_states_.emplace_back(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_.emplace_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_out()->dot_string().c_str()); -#if SIMGRID_HAVE_STATEFUL_MC - } 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_out()->dot_string().c_str()); -#endif + /* 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_out()->dot_string().c_str()); } log_state(); } @@ -415,24 +364,25 @@ void DFSExplorer::backtrack() /** * ODPOR Race Detection Procedure: * - * For each reversible race in the current execution, we - * note if there are any continuations `C` equivalent to that which - * would reverse the race that have already either a) been searched by ODPOR or - * b) been *noted* to be searched by the wakeup tree at the - * appropriate reversal point, either as `C` directly or - * an as equivalent to `C` ("eventually looks like C", viz. the `~_E` - * relation) + * For each reversible race in the current execution, we note if there are any continuations `C` equivalent to that + * which would reverse the race that have already either a) been searched by ODPOR or b) been *noted* to be searched + * by the wakeup tree at the appropriate reversal point, either as `C` directly or an as equivalent to `C` + * ("eventually looks like C", viz. the `~_E` relation) */ for (auto e_prime = static_cast(0); e_prime <= last_event.value(); ++e_prime) { + XBT_DEBUG("ODPOR: Now considering all possible race with `%u`", e_prime); for (const auto e : execution_seq_.get_reversible_races_of(e_prime)) { XBT_DEBUG("ODPOR: Reversible race detected between events `%u` and `%u`", e, e_prime); State& prev_state = *stack_[e]; if (const auto v = execution_seq_.get_odpor_extension_from(e, e_prime, prev_state); v.has_value()) { switch (prev_state.insert_into_wakeup_tree(v.value(), execution_seq_.get_prefix_before(e))) { case odpor::WakeupTree::InsertionResult::root: { - XBT_DEBUG("ODPOR: Reversible race with `%u` unaccounted for in the wakeup tree for " - "the execution prior to event `%u`:", - e_prime, e); + XBT_DEBUG("ODPOR: Reversible race with `%u`(%ld: %.20s) unaccounted for in the wakeup tree for " + "the execution prior to event `%u`(%ld: %.20s):", + e_prime, stack_[e_prime]->get_transition_out()->aid_, + stack_[e_prime]->get_transition_out()->to_string(true).c_str(), e, + prev_state.get_transition_out()->aid_, + prev_state.get_transition_out()->to_string(true).c_str()); break; } case odpor::WakeupTree::InsertionResult::interior_node: { @@ -481,41 +431,16 @@ void DFSExplorer::backtrack() 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 - // Search how to restore the backtracking point - State* init_state = nullptr; std::deque replay_recipe; - for (auto* s = backtracking_point.get(); s != nullptr; s = s->get_parent_state().get()) { -#if SIMGRID_HAVE_STATEFUL_MC - if (s->get_system_state() != nullptr) { // Found a state that I can restore - init_state = s; - break; - } -#endif + for (const auto* s = backtracking_point.get(); s != nullptr; s = s->get_parent_state().get()) { if (s->get_transition_in() != nullptr) // The root has no transition_in replay_recipe.push_front(s->get_transition_in().get()); } - // Restore the init_state, if any - if (init_state != nullptr) { -#if SIMGRID_HAVE_STATEFUL_MC - const auto* system_state = init_state->get_system_state(); - system_state->restore(*get_remote_app().get_remote_process_memory()); - on_restore_system_state_signal(init_state, get_remote_app()); -#endif - } else { // Restore the initial state if no intermediate state was found - get_remote_app().restore_initial_state(); - on_restore_initial_state_signal(get_remote_app()); - } + // Restore the initial state if no intermediate state was found + get_remote_app().restore_initial_state(); + on_restore_initial_state_signal(get_remote_app()); /* if no snapshot, we need to restore the initial state and replay the transitions */ /* Traverse the stack from the state at position start and re-execute the transitions */ @@ -527,23 +452,9 @@ void DFSExplorer::backtrack() this->restore_stack(backtracking_point); } -DFSExplorer::DFSExplorer(const std::vector& args, ReductionMode mode, bool need_memory_info) - : Exploration(args, need_memory_info || _sg_mc_termination -#if SIMGRID_HAVE_STATEFUL_MC - || _sg_mc_checkpoint > 0 -#endif - ) - , reduction_mode_(mode) +DFSExplorer::DFSExplorer(const std::vector& args, ReductionMode mode) : Exploration(args), reduction_mode_(mode) { - if (_sg_mc_termination) { - if (mode != ReductionMode::none) { - XBT_INFO("Check non progressive cycles (turning DPOR off)"); - reduction_mode_ = ReductionMode::none; - } else { - XBT_INFO("Check non progressive cycles"); - } - } else - XBT_INFO("Start a DFS exploration. Reduction is: %s.", to_c_str(reduction_mode_)); + XBT_INFO("Start a DFS exploration. Reduction is: %s.", to_c_str(reduction_mode_)); auto initial_state = std::make_shared(get_remote_app());