X-Git-Url: http://bilbo.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/e92731a85139d9ebe033deb0827a8a4deaf3651e..d68e1c39ec0832cb2391aedd17a868c597dd399e:/src/mc/explo/UdporChecker.hpp diff --git a/src/mc/explo/UdporChecker.hpp b/src/mc/explo/UdporChecker.hpp index a629aec8a2..02f2a8e1d1 100644 --- a/src/mc/explo/UdporChecker.hpp +++ b/src/mc/explo/UdporChecker.hpp @@ -7,10 +7,16 @@ #ifndef SIMGRID_MC_UDPOR_CHECKER_HPP #define SIMGRID_MC_UDPOR_CHECKER_HPP +#include "src/mc/api/State.hpp" #include "src/mc/explo/Exploration.hpp" +#include "src/mc/explo/udpor/Configuration.hpp" +#include "src/mc/explo/udpor/EventSet.hpp" +#include "src/mc/explo/udpor/Unfolding.hpp" +#include "src/mc/explo/udpor/UnfoldingEvent.hpp" #include "src/mc/mc_record.hpp" -#include "src/mc/udpor_global.hpp" +#include +#include #include namespace simgrid::mc::udpor { @@ -24,7 +30,7 @@ namespace simgrid::mc::udpor { * current implementation of `tiny_simgrid`: * * 1. "Unfolding-based Partial Order Reduction" by Rodriguez et al. - * 2. Quasi-Optimal Partial Order Reduction by Nguyen et al. + * 2. "Quasi-Optimal Partial Order Reduction" by Nguyen et al. * 3. The Anh Pham's Thesis "Exploration efficace de l'espace ..." */ class XBT_PRIVATE UdporChecker : public Exploration { @@ -33,51 +39,49 @@ public: void run() override; RecordTrace get_record_trace() override; - std::vector get_textual_trace() override; + std::unique_ptr get_current_state() { return std::make_unique(get_remote_app()); } private: - /** - * The total number of events created whilst exploring the unfolding - */ - uint32_t nb_events = 0; - uint32_t nb_traces = 0; + Unfolding unfolding = Unfolding(); + + // The current sequence of states that the checker has + // visited in order to reach the current configuration + std::list> state_stack; /** - * @brief The "relevant" portions of the unfolding that must be kept around to ensure that - * UDPOR properly searches the state space + * @brief Explores the unfolding of the concurrent system + * represented by the ModelChecker instance "mcmodel_checker" * - * The set `U` is a global variable which is maintained by UDPOR - * to keep track of "just enough" information about the unfolding - * to compute *alternatives* (see the paper for more details). + * This function performs the actual search following the + * UDPOR algorithm according to [1]. * - * @invariant: When a new event is created by UDPOR, it is inserted into - * this set. All new events that are created by UDPOR have causes that - * also exist in U and are valid for the duration of the search. + * @param C the current configuration from which UDPOR will be used + * to explore expansions of the concurrent system being modeled + * @param D the set of events that should not be considered by UDPOR + * while performing its searches, in order to avoid sleep-set blocked + * executions. See [1] for more details + * @param A the set of events to "guide" UDPOR in the correct direction + * when it returns back to a node in the unfolding and must decide among + * events to select from `ex(C)`. See [1] for more details * - * If an event is discarded instead of moved from set `U` to set `G`, - * the event and its contents will be discarded. + * TODO: Add the optimization where we can check if e == e_prior + * to prevent repeated work when computing ex(C) */ - EventSet U; + void explore(const Configuration& C, EventSet D, EventSet A, EventSet prev_exC); /** - * @brief The "irrelevant" portions of the unfolding that do not need to be kept - * around to ensure that UDPOR functions correctly + * @brief Identifies the next event from the unfolding of the concurrent system + * that should next be explored as an extension of a configuration with + * enabled events `enC` * - * The set `G` is another global variable maintained by the UDPOR algorithm which - * is used to keep track of all events which used to be important to UDPOR - */ - EventSet G; - -private: - /** - * @brief Explores the unfolding of the concurrent system - * represented by the model checker instance - * "model_checker" + * @param A The set of events `A` maintained by the UDPOR algorithm to help + * determine how events should be selected. See the original paper [1] for more details * - * TODO: Explain what this means here + * @param enC The set `enC` of enabled events from the extension set `exC` used + * by the UDPOR algorithm to select new events to search. See the original + * paper [1] for more details */ - void explore(Configuration C, std::list max_evt_history, EventSet D, EventSet A, UnfoldingEvent* cur_event, - EventSet prev_exC); + UnfoldingEvent* select_next_unfolding_event(const EventSet& A, const EventSet& enC); /** * @brief Computes the sets `ex(C)` and `en(C)` of the given configuration @@ -94,39 +98,55 @@ private: * SimGrid is apart, which allow for `ex(C)` to be computed much more efficiently. * Intuitively, the idea is to take advantage of the fact that you can avoid a lot * of repeated computation by exploiting the aforementioned properties (in [3]) in - * what is effectively a dynamic programming optimization. See [3] for more details + * what is akin to a dynamic programming optimization. See [3] for more details * * @param C the configuration based on which the two sets `ex(C)` and `en(C)` are * computed - * @param cur_event the event where UDPOR currently "rests", viz. the event UDPOR - * is now currently considering + * @param stateC the state of the program after having executed C (viz. `state(C)`) * @param prev_exC the previous value of `ex(C)`, viz. that which was computed for - * the configuration `C' := C - {cur_event}` - * @returns a tuple containing the pair of sets `ex(C)` and `en(C)` respectively + * the configuration `C' := C - {e}` + * @returns the extension set `ex(C)` of `C` */ - std::tuple extend(const Configuration& C, const std::list& max_evt_history, - const UnfoldingEvent& cur_event, const EventSet& prev_exC) const; + EventSet compute_exC(const Configuration& C, const State& stateC, const EventSet& prev_exC); + EventSet compute_enC(const Configuration& C, const EventSet& exC) const; /** - * @brief Identifies the next event from the unfolding of the concurrent system - * that should next be explored as an extension of a configuration with - * enabled events `enC` * - * @param A The set of events `A` maintained by the UDPOR algorithm to help - * determine how events should be selected. See the original paper [1] for more details - * - * @param enC The set `enC` of enabled events from the extension set `exC` used - * by the UDPOR algorithm to select new events to search. See the original - * paper [1] for more details */ - UnfoldingEvent* select_next_unfolding_event(const EventSet& A, const EventSet& enC); + void move_to_stateCe(State* stateC, UnfoldingEvent* e); - EventSet compute_partial_alternative(const EventSet& D, const EventSet& C, const unsigned k) const; + /** + * @brief Creates a new snapshot of the state of the application + * as it currently looks + */ + std::unique_ptr record_current_state(); /** + * @brief Move the application side into the state at the top of the + * state stack provided + * + * As UDPOR performs its search, it moves the application-side along with + * it so that the application is always providing the checker with + * the correct information about what each actor is running (and whether + * those actors are enabled) at the state reached by the configuration it + * decides to search. * + * When UDPOR decides to "backtrack" (e.g. after reaching a configuration + * whose en(C) is empty), before it attempts to continue the search by taking + * a different path from a configuration it visited in the past, it must ensure + * that the application-side has moved back into `state(C)`. + * + * The search may have moved the application arbitrarily deep into its execution, + * and the search may backtrack arbitrarily closer to the beginning of the execution. + * The UDPOR implementation in SimGrid ensures that the stack is updated appropriately, + * but the process must still be regenerated. + */ + void restore_program_state_with_current_stack(); + + /** + * @brief Perform the functionality of the `Remove(e, C, D)` function in [1] */ - void clean_up_explore(const UnfoldingEvent* e, const EventSet& C, const EventSet& D); + void clean_up_explore(const UnfoldingEvent* e, const Configuration& C, const EventSet& D); }; } // namespace simgrid::mc::udpor