X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=model.cc;h=c9353db71c5bc15c77e802c32285f64f0c697681;hb=3ca736f95f5a2ade69700fb2c148f348a0a683f9;hp=1711e1a002b6d105cb413efec6c20e644f51f0f8;hpb=9c02def96200170715f28557ba36ab94b4f956a6;p=c11tester.git diff --git a/model.cc b/model.cc index 1711e1a0..c9353db7 100644 --- a/model.cc +++ b/model.cc @@ -25,6 +25,7 @@ ModelChecker::ModelChecker(struct model_params params) : num_executions(0), num_feasible_executions(0), diverge(NULL), + earliest_diverge(NULL), action_trace(new action_list_t()), thread_map(new HashTable()), obj_map(new HashTable()), @@ -38,7 +39,8 @@ ModelChecker::ModelChecker(struct model_params params) : mo_graph(new CycleGraph()), failed_promise(false), too_many_reads(false), - asserted(false) + asserted(false), + bad_synchronization(false) { /* Allocate this "size" on the snapshotting heap */ priv = (struct model_snapshot_members *)calloc(1, sizeof(*priv)); @@ -80,6 +82,7 @@ void ModelChecker::reset_to_initial_state() node_stack->reset_execution(); failed_promise = false; too_many_reads = false; + bad_synchronization = false; reset_asserted(); snapshotObject->backTrackBeforeStep(0); } @@ -136,6 +139,9 @@ Thread * ModelChecker::get_next_thread(ModelAction *curr) ModelAction *next = node_stack->get_next()->get_action(); if (next == diverge) { + if (earliest_diverge == NULL || *diverge < *earliest_diverge) + earliest_diverge=diverge; + Node *nextnode = next->get_node(); /* Reached divergence point */ if (nextnode->increment_promise()) { @@ -155,8 +161,12 @@ Thread * ModelChecker::get_next_thread(ModelAction *curr) Node *node = nextnode->get_parent(); tid = node->get_next_backtrack(); node_stack->pop_restofstack(1); + if (diverge==earliest_diverge) { + earliest_diverge=node->get_action(); + } } DEBUG("*** Divergence point ***\n"); + diverge = NULL; } else { tid = next->get_tid(); @@ -178,8 +188,20 @@ bool ModelChecker::next_execution() DBG(); num_executions++; - if (isfinalfeasible()) + + if (isfinalfeasible()) { + printf("Earliest divergence point since last feasible execution:\n"); + if (earliest_diverge) + earliest_diverge->print(false); + else + printf("(Not set)\n"); + + earliest_diverge = NULL; num_feasible_executions++; + } + + DEBUG("Number of acquires waiting on pending release sequences: %lu\n", + pending_acq_rel_seq->size()); if (isfinalfeasible() || DBG_ENABLED()) print_summary(); @@ -412,7 +434,7 @@ bool ModelChecker::process_mutex(ModelAction *curr) { action_list_t *waiters = lock_waiters_map->get_safe_ptr(curr->get_location()); //activate all the waiting threads for (action_list_t::iterator rit = waiters->begin(); rit != waiters->end(); rit++) { - scheduler->add_thread(get_thread((*rit)->get_tid())); + scheduler->wake(get_thread(*rit)); } waiters->clear(); break; @@ -457,11 +479,11 @@ bool ModelChecker::process_write(ModelAction *curr) * (e.g., ATOMIC_{READ,WRITE,RMW,LOCK}, etc.) * * @param curr The current action - * @return True if synchronization was updated + * @return True if synchronization was updated or a thread completed */ bool ModelChecker::process_thread_action(ModelAction *curr) { - bool synchronized = false; + bool updated = false; switch (curr->get_type()) { case THREAD_CREATE: { @@ -478,7 +500,7 @@ bool ModelChecker::process_thread_action(ModelAction *curr) scheduler->sleep(waiting); } else { do_complete_join(curr); - synchronized = true; + updated = true; /* trigger rel-seq checks */ } break; } @@ -489,9 +511,10 @@ bool ModelChecker::process_thread_action(ModelAction *curr) Thread *wake = get_thread(act); scheduler->wake(wake); do_complete_join(act); - synchronized = true; + updated = true; /* trigger rel-seq checks */ } th->complete(); + updated = true; /* trigger rel-seq checks */ break; } case THREAD_START: { @@ -502,7 +525,7 @@ bool ModelChecker::process_thread_action(ModelAction *curr) break; } - return synchronized; + return updated; } /** @@ -523,10 +546,14 @@ ModelAction * ModelChecker::initialize_curr_action(ModelAction *curr) if (curr->is_rmwc() || curr->is_rmw()) { newcurr = process_rmw(curr); delete curr; - compute_promises(newcurr); + + if (newcurr->is_rmw()) + compute_promises(newcurr); return newcurr; } + curr->set_seq_number(get_next_seq_num()); + newcurr = node_stack->explore_action(curr, scheduler->get_enabled()); if (newcurr) { /* First restore type and order in case of RMW operation */ @@ -539,18 +566,19 @@ ModelAction * ModelChecker::initialize_curr_action(ModelAction *curr) /* Discard duplicate ModelAction; use action from NodeStack */ delete curr; - /* If we have diverged, we need to reset the clock vector. */ - if (diverge == NULL) - newcurr->create_cv(get_parent_action(newcurr->get_tid())); + /* Always compute new clock vector */ + newcurr->create_cv(get_parent_action(newcurr->get_tid())); } else { newcurr = curr; + + /* Always compute new clock vector */ + newcurr->create_cv(get_parent_action(newcurr->get_tid())); /* * Perform one-time actions when pushing new ModelAction onto * NodeStack */ - curr->create_cv(get_parent_action(curr->get_tid())); - if (curr->is_write()) - compute_promises(curr); + if (newcurr->is_write()) + compute_promises(newcurr); } return newcurr; } @@ -598,7 +626,7 @@ Thread * ModelChecker::check_current_action(ModelAction *curr) /* Make the execution look like we chose to run this action * much later, when a lock is actually available to release */ get_current_thread()->set_pending(curr); - remove_thread(get_current_thread()); + scheduler->sleep(get_current_thread()); return get_next_thread(NULL); } @@ -653,7 +681,8 @@ Thread * ModelChecker::check_current_action(ModelAction *curr) bool updated = false; if (act->is_read()) { - if (r_modification_order(act, act->get_reads_from())) + const ModelAction *rf = act->get_reads_from(); + if (rf != NULL && r_modification_order(act, rf)) updated = true; } if (act->is_write()) { @@ -740,10 +769,12 @@ bool ModelChecker::isfeasibleotherthanRMW() { DEBUG("Infeasible: failed promise\n"); if (too_many_reads) DEBUG("Infeasible: too many reads\n"); + if (bad_synchronization) + DEBUG("Infeasible: bad synchronization ordering\n"); if (promises_expired()) DEBUG("Infeasible: promises expired\n"); } - return !mo_graph->checkForCycles() && !failed_promise && !too_many_reads && !promises_expired(); + return !mo_graph->checkForCycles() && !failed_promise && !too_many_reads && !bad_synchronization && !promises_expired(); } /** Returns whether the current completed trace is feasible. */ @@ -903,7 +934,11 @@ bool ModelChecker::r_modification_order(ModelAction *curr, const ModelAction *rf } } else { const ModelAction *prevreadfrom = act->get_reads_from(); - if (prevreadfrom != NULL && rf != prevreadfrom) { + //if the previous read is unresolved, keep going... + if (prevreadfrom == NULL) + continue; + + if (rf != prevreadfrom) { mo_graph->addEdge(prevreadfrom, rf); added = true; } @@ -944,10 +979,10 @@ void ModelChecker::post_r_modification_order(ModelAction *curr, const ModelActio action_list_t::reverse_iterator rit; ModelAction *lastact = NULL; - /* Find last action that happens after curr */ + /* Find last action that happens after curr that is either not curr or a rmw */ for (rit = list->rbegin(); rit != list->rend(); rit++) { ModelAction *act = *rit; - if (curr->happens_before(act)) { + if (curr->happens_before(act) && (curr != act || curr->is_rmw())) { lastact = act; } else break; @@ -955,12 +990,25 @@ void ModelChecker::post_r_modification_order(ModelAction *curr, const ModelActio /* Include at most one act per-thread that "happens before" curr */ if (lastact != NULL) { - if (lastact->is_read()) { + if (lastact==curr) { + //Case 1: The resolved read is a RMW, and we need to make sure + //that the write portion of the RMW mod order after rf + + mo_graph->addEdge(rf, lastact); + } else if (lastact->is_read()) { + //Case 2: The resolved read is a normal read and the next + //operation is a read, and we need to make sure the value read + //is mod ordered after rf + const ModelAction *postreadfrom = lastact->get_reads_from(); if (postreadfrom != NULL&&rf != postreadfrom) mo_graph->addEdge(rf, postreadfrom); - } else if (rf != lastact) { - mo_graph->addEdge(rf, lastact); + } else { + //Case 3: The resolved read is a normal read and the next + //operation is a write, and we need to make sure that the + //write is mod ordered after rf + if (lastact!=rf) + mo_graph->addEdge(rf, lastact); } break; } @@ -1015,14 +1063,22 @@ bool ModelChecker::w_modification_order(ModelAction *curr) ModelAction *act = *rit; if (act == curr) { /* - * If RMW, we already have all relevant edges, - * so just skip to next thread. - * If normal write, we need to look at earlier - * actions, so continue processing list. + * 1) If RMW and it actually read from something, then we + * already have all relevant edges, so just skip to next + * thread. + * + * 2) If RMW and it didn't read from anything, we should + * whatever edge we can get to speed up convergence. + * + * 3) If normal write, we need to look at earlier actions, so + * continue processing list. */ - if (curr->is_rmw()) - break; - else + if (curr->is_rmw()) { + if (curr->get_reads_from()!=NULL) + break; + else + continue; + } else continue; } @@ -1039,8 +1095,12 @@ bool ModelChecker::w_modification_order(ModelAction *curr) */ if (act->is_write()) mo_graph->addEdge(act, curr); - else if (act->is_read() && act->get_reads_from() != NULL) + else if (act->is_read()) { + //if previous read accessed a null, just keep going + if (act->get_reads_from() == NULL) + continue; mo_graph->addEdge(act->get_reads_from(), curr); + } added = true; break; } else if (act->is_read() && !act->is_synchronizing(curr) && @@ -1276,12 +1336,16 @@ bool ModelChecker::resolve_release_sequences(void *location, work_queue_t *work_ complete = release_seq_head(rf, &release_heads); for (unsigned int i = 0; i < release_heads.size(); i++) { if (!act->has_synchronized_with(release_heads[i])) { - updated = true; - act->synchronize_with(release_heads[i]); + if (act->synchronize_with(release_heads[i])) + updated = true; + else + set_bad_synchronization(); } } if (updated) { + /* Re-check all pending release sequences */ + work_queue->push_back(CheckRelSeqWorkEntry(NULL)); /* Re-check act for mo_graph edges */ work_queue->push_back(MOEdgeWorkEntry(act)); @@ -1430,7 +1494,10 @@ bool ModelChecker::resolve_promises(ModelAction *write) //Next fix up the modification order for actions that happened //after the read. post_r_modification_order(read, write); + //Make sure the promise's value matches the write's value + ASSERT(promise->get_value() == write->get_value()); + delete(promise); promises->erase(promises->begin() + promise_index); resolved = true; } else @@ -1564,6 +1631,34 @@ static void print_list(action_list_t *list) printf("---------------------------------------------------------------------\n"); } +#if SUPPORT_MOD_ORDER_DUMP +void ModelChecker::dumpGraph(char *filename) { + char buffer[200]; + sprintf(buffer, "%s.dot",filename); + FILE *file=fopen(buffer, "w"); + fprintf(file, "digraph %s {\n",filename); + mo_graph->dumpNodes(file); + ModelAction ** thread_array=(ModelAction **)model_calloc(1, sizeof(ModelAction *)*get_num_threads()); + + for (action_list_t::iterator it = action_trace->begin(); it != action_trace->end(); it++) { + ModelAction *action=*it; + if (action->is_read()) { + fprintf(file, "N%u [label=\"%u, T%u\"];\n", action->get_seq_number(),action->get_seq_number(), action->get_tid()); + if (action->get_reads_from()!=NULL) + fprintf(file, "N%u -> N%u[label=\"rf\", color=red];\n", action->get_seq_number(), action->get_reads_from()->get_seq_number()); + } + if (thread_array[action->get_tid()] != NULL) { + fprintf(file, "N%u -> N%u[label=\"sb\", color=blue];\n", thread_array[action->get_tid()]->get_seq_number(), action->get_seq_number()); + } + + thread_array[action->get_tid()]=action; + } + fprintf(file,"}\n"); + model_free(thread_array); + fclose(file); +} +#endif + void ModelChecker::print_summary() { printf("\n"); @@ -1576,6 +1671,8 @@ void ModelChecker::print_summary() char buffername[100]; sprintf(buffername, "exec%04u", num_executions); mo_graph->dumpGraphToFile(buffername); + sprintf(buffername, "graph%04u", num_executions); + dumpGraph(buffername); #endif if (!isfinalfeasible()) @@ -1636,6 +1733,7 @@ bool ModelChecker::take_step() { priv->nextThread = check_current_action(priv->current_action); priv->current_action = NULL; + if (curr->is_blocked() || curr->is_complete()) scheduler->remove_thread(curr); } else {