X-Git-Url: http://bilbo.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/14bddad6ad3fcf94b0bcdeb69ef68350efb5b213..bc2253e2c879ee28ae5153f1d56497ab802aeea9:/src/mc/explo/DFSExplorer.cpp diff --git a/src/mc/explo/DFSExplorer.cpp b/src/mc/explo/DFSExplorer.cpp index 304130173f..ee49e31d9b 100644 --- a/src/mc/explo/DFSExplorer.cpp +++ b/src/mc/explo/DFSExplorer.cpp @@ -65,12 +65,9 @@ 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()); } @@ -84,7 +81,7 @@ 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(); } @@ -124,16 +121,12 @@ void DFSExplorer::run() } 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_); } @@ -143,7 +136,29 @@ 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) { + // If there is no more transition in the current state ), backtrace + 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) { + 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; + } + if (not state->is_actor_enabled(next)) { + // if ODPOR picked an actor that is not enabled -- ReversibleRace is an overapproximation + xbt_assert(reduction_mode_ == ReductionMode::odpor, + "Only ODPOR should be fool enough to try to execute a disabled transition"); + XBT_VERB("Preventing ODPOR exploration from executing a disabled transition. The reversibility of the race " + "must have been overapproximated"); + + state->remove_subtree_at_aid(next); + state->add_sleep_set(state->get_actors_list().at(next).get_transition()); XBT_VERB("%lu actors remain, but none of them need to be interleaved (depth %zu).", state->get_actor_count(), stack_.size() + 1); @@ -180,13 +195,10 @@ 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: @@ -248,15 +260,13 @@ 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 " @@ -267,12 +277,10 @@ 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); @@ -280,8 +288,7 @@ 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)); } @@ -349,9 +356,6 @@ std::shared_ptr DFSExplorer::next_odpor_state() XBT_DEBUG("\tPerformed ODPOR 'clean-up'. Sleep set has:"); for (const auto& [aid, transition] : state->get_sleep_set()) XBT_DEBUG("\t <%ld,%s>", aid, transition->to_string().c_str()); - if (not state->has_empty_tree()) { - return state; - } } return nullptr; } @@ -363,24 +367,25 @@ 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: {