X-Git-Url: http://plrg.eecs.uci.edu/git/?p=model-checker.git;a=blobdiff_plain;f=model.cc;h=1ec72738ba3d0622bb27c8dedb3eab4c875aa90c;hp=e394865e26c01d75b05853a55a4b2b7a23c3e853;hb=202542965363285e68bb33654a62fe816c69b176;hpb=18f3e39e72b1b31594acb10842e61f90109876e0 diff --git a/model.cc b/model.cc index e394865..1ec7273 100644 --- a/model.cc +++ b/model.cc @@ -1,5 +1,6 @@ #include #include +#include #include "model.h" #include "action.h" @@ -11,7 +12,6 @@ #include "cyclegraph.h" #include "promise.h" #include "datarace.h" -#include "mutex.h" #include "threads-model.h" #define INITIAL_THREAD_ID 0 @@ -31,6 +31,7 @@ ModelChecker::ModelChecker(struct model_params params) : thread_map(new HashTable()), obj_map(new HashTable()), lock_waiters_map(new HashTable()), + condvar_waiters_map(new HashTable()), obj_thrd_map(new HashTable, uintptr_t, 4 >()), promises(new std::vector< Promise *, SnapshotAlloc >()), futurevalues(new std::vector< struct PendingFutureValue, SnapshotAlloc >()), @@ -63,6 +64,7 @@ ModelChecker::~ModelChecker() delete obj_thrd_map; delete obj_map; delete lock_waiters_map; + delete condvar_waiters_map; delete action_trace; for (unsigned int i = 0; i < promises->size(); i++) @@ -116,6 +118,10 @@ modelclock_t ModelChecker::get_next_seq_num() return ++priv->used_sequence_numbers; } +Node * ModelChecker::get_curr_node() { + return node_stack->get_head(); +} + /** * @brief Choose the next thread to execute. * @@ -158,7 +164,11 @@ Thread * ModelChecker::get_next_thread(ModelAction *curr) scheduler->update_sleep_set(prevnode); /* Reached divergence point */ - if (nextnode->increment_promise()) { + if (nextnode->increment_misc()) { + /* The next node will try to satisfy a different misc_index values. */ + tid = next->get_tid(); + node_stack->pop_restofstack(2); + } else if (nextnode->increment_promise()) { /* The next node will try to satisfy a different set of promises. */ tid = next->get_tid(); node_stack->pop_restofstack(2); @@ -208,7 +218,8 @@ void ModelChecker::execute_sleep_set() { for(unsigned int i=0;iget_enabled(thr) == THREAD_SLEEP_SET ) { + if ( scheduler->get_enabled(thr) == THREAD_SLEEP_SET && + thr->get_pending() == NULL ) { thr->set_state(THREAD_RUNNING); scheduler->next_thread(thr); Thread::swap(&system_context, thr); @@ -225,7 +236,7 @@ void ModelChecker::wake_up_sleeping_actions(ModelAction * curr) { Thread *thr=get_thread(tid); if ( scheduler->get_enabled(thr) == THREAD_SLEEP_SET ) { ModelAction *pending_act=thr->get_pending(); - if (pending_act->could_synchronize_with(curr)) { + if ((!curr->is_rmwr())&&pending_act->could_synchronize_with(curr)) { //Remove this thread from sleep set scheduler->remove_sleep(thr); } @@ -261,8 +272,10 @@ bool ModelChecker::next_execution() pending_rel_seqs->size()); - if (isfinalfeasible() || (params.bound != 0 && priv->used_sequence_numbers > params.bound ) || DBG_ENABLED() ) + if (isfinalfeasible() || (params.bound != 0 && priv->used_sequence_numbers > params.bound ) || DBG_ENABLED() ) { + checkDataRaces(); print_summary(); + } if ((diverge = get_next_backtrack()) == NULL) return false; @@ -315,6 +328,32 @@ ModelAction * ModelChecker::get_last_conflict(ModelAction *act) } break; } + case ATOMIC_WAIT: { + /* linear search: from most recent to oldest */ + action_list_t *list = obj_map->get_safe_ptr(act->get_location()); + action_list_t::reverse_iterator rit; + for (rit = list->rbegin(); rit != list->rend(); rit++) { + ModelAction *prev = *rit; + if (!act->same_thread(prev)&&prev->is_failed_trylock()) + return prev; + if (!act->same_thread(prev)&&prev->is_notify()) + return prev; + } + break; + } + + case ATOMIC_NOTIFY_ALL: + case ATOMIC_NOTIFY_ONE: { + /* linear search: from most recent to oldest */ + action_list_t *list = obj_map->get_safe_ptr(act->get_location()); + action_list_t::reverse_iterator rit; + for (rit = list->rbegin(); rit != list->rend(); rit++) { + ModelAction *prev = *rit; + if (!act->same_thread(prev)&&prev->is_wait()) + return prev; + } + break; + } default: break; } @@ -347,8 +386,12 @@ void ModelChecker::set_backtracking(ModelAction *act) for(int i = low_tid; i < high_tid; i++) { thread_id_t tid = int_to_id(i); + /* Make sure this thread can be enabled here. */ + if (i >= node->get_num_threads()) + break; + /* Don't backtrack into a point where the thread is disabled or sleeping. */ - if (node->get_enabled_array()[i]!=THREAD_ENABLED) + if (node->enabled_status(tid)!=THREAD_ENABLED) continue; /* Check if this has been explored already */ @@ -405,7 +448,7 @@ ModelAction * ModelChecker::get_next_backtrack() */ bool ModelChecker::process_read(ModelAction *curr, bool second_part_of_rmw) { - uint64_t value; + uint64_t value = VALUE_NONE; bool updated = false; while (true) { const ModelAction *reads_from = curr->get_node()->get_read_from(); @@ -462,8 +505,17 @@ bool ModelChecker::process_read(ModelAction *curr, bool second_part_of_rmw) * @return True if synchronization was updated; false otherwise */ bool ModelChecker::process_mutex(ModelAction *curr) { - std::mutex *mutex = (std::mutex *)curr->get_location(); - struct std::mutex_state *state = mutex->get_state(); + std::mutex *mutex=NULL; + struct std::mutex_state *state=NULL; + + if (curr->is_trylock() || curr->is_lock() || curr->is_unlock()) { + mutex = (std::mutex *)curr->get_location(); + state = mutex->get_state(); + } else if(curr->is_wait()) { + mutex = (std::mutex *)curr->get_value(); + state = mutex->get_state(); + } + switch (curr->get_type()) { case ATOMIC_TRYLOCK: { bool success = !state->islocked; @@ -501,6 +553,43 @@ bool ModelChecker::process_mutex(ModelAction *curr) { waiters->clear(); break; } + case ATOMIC_WAIT: { + //unlock the lock + state->islocked = false; + //wake up the other threads + action_list_t *waiters = lock_waiters_map->get_safe_ptr((void *) curr->get_value()); + //activate all the waiting threads + for (action_list_t::iterator rit = waiters->begin(); rit != waiters->end(); rit++) { + scheduler->wake(get_thread(*rit)); + } + waiters->clear(); + //check whether we should go to sleep or not...simulate spurious failures + if (curr->get_node()->get_misc()==0) { + condvar_waiters_map->get_safe_ptr(curr->get_location())->push_back(curr); + //disable us + scheduler->sleep(get_current_thread()); + } + break; + } + case ATOMIC_NOTIFY_ALL: { + action_list_t *waiters = condvar_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->wake(get_thread(*rit)); + } + waiters->clear(); + break; + } + case ATOMIC_NOTIFY_ONE: { + action_list_t *waiters = condvar_waiters_map->get_safe_ptr(curr->get_location()); + int wakeupthread=curr->get_node()->get_misc(); + action_list_t::iterator it = waiters->begin(); + advance(it, wakeupthread); + scheduler->wake(get_thread(*it)); + waiters->erase(it); + break; + } + default: ASSERT(0); } @@ -662,41 +751,46 @@ void ModelChecker::process_relseq_fixup(ModelAction *curr, work_queue_t *work_qu * initializing clock vectors, and computing the promises to fulfill. * * @param curr The current action, as passed from the user context; may be - * freed/invalidated after the execution of this function - * @return The current action, as processed by the ModelChecker. Is only the - * same as the parameter @a curr if this is a newly-explored action. + * freed/invalidated after the execution of this function, with a different + * action "returned" its place (pass-by-reference) + * @return True if curr is a newly-explored action; false otherwise */ -ModelAction * ModelChecker::initialize_curr_action(ModelAction *curr) +bool ModelChecker::initialize_curr_action(ModelAction **curr) { ModelAction *newcurr; - if (curr->is_rmwc() || curr->is_rmw()) { - newcurr = process_rmw(curr); - delete curr; + if ((*curr)->is_rmwc() || (*curr)->is_rmw()) { + newcurr = process_rmw(*curr); + delete *curr; if (newcurr->is_rmw()) compute_promises(newcurr); - return newcurr; + + *curr = newcurr; + return false; } - curr->set_seq_number(get_next_seq_num()); + (*curr)->set_seq_number(get_next_seq_num()); - newcurr = node_stack->explore_action(curr, scheduler->get_enabled()); + newcurr = node_stack->explore_action(*curr, scheduler->get_enabled()); if (newcurr) { /* First restore type and order in case of RMW operation */ - if (curr->is_rmwr()) - newcurr->copy_typeandorder(curr); + if ((*curr)->is_rmwr()) + newcurr->copy_typeandorder(*curr); - ASSERT(curr->get_location() == newcurr->get_location()); - newcurr->copy_from_new(curr); + ASSERT((*curr)->get_location() == newcurr->get_location()); + newcurr->copy_from_new(*curr); /* Discard duplicate ModelAction; use action from NodeStack */ - delete curr; + delete *curr; /* Always compute new clock vector */ newcurr->create_cv(get_parent_action(newcurr->get_tid())); + + *curr = newcurr; + return false; /* Action was explored previously */ } else { - newcurr = curr; + newcurr = *curr; /* Always compute new clock vector */ newcurr->create_cv(get_parent_action(newcurr->get_tid())); @@ -708,8 +802,13 @@ ModelAction * ModelChecker::initialize_curr_action(ModelAction *curr) compute_promises(newcurr); else if (newcurr->is_relseq_fixup()) compute_relseq_breakwrites(newcurr); + else if (newcurr->is_wait()) + newcurr->get_node()->set_misc_max(2); + else if (newcurr->is_notify_one()) { + newcurr->get_node()->set_misc_max(condvar_waiters_map->get_safe_ptr(newcurr->get_location())->size()); + } + return true; /* This was a new ModelAction */ } - return newcurr; } /** @@ -767,18 +866,17 @@ Thread * ModelChecker::check_current_action(ModelAction *curr) return get_next_thread(NULL); } - ModelAction *newcurr = initialize_curr_action(curr); + bool newly_explored = initialize_curr_action(&curr); wake_up_sleeping_actions(curr); /* Add the action to lists before any other model-checking tasks */ if (!second_part_of_rmw) - add_action_to_lists(newcurr); + add_action_to_lists(curr); /* Build may_read_from set for newly-created actions */ - if (curr == newcurr && curr->is_read()) + if (newly_explored && curr->is_read()) build_reads_from_past(curr); - curr = newcurr; /* Initialize work_queue with the "current action" work */ work_queue_t work_queue(1, CheckCurrWorkEntry(curr)); @@ -852,6 +950,7 @@ void ModelChecker::check_curr_backtracking(ModelAction * curr) { Node *parnode = currnode->get_parent(); if ((!parnode->backtrack_empty() || + !currnode->misc_empty() || !currnode->read_from_empty() || !currnode->future_value_empty() || !currnode->promise_empty() || @@ -875,7 +974,7 @@ bool ModelChecker::promises_expired() { /** @return whether the current partial trace must be a prefix of a * feasible trace. */ bool ModelChecker::isfeasibleprefix() { - return promises->size() == 0 && pending_rel_seqs->size() == 0; + return promises->size() == 0 && pending_rel_seqs->size() == 0 && isfeasible(); } /** @return whether the current partial trace is feasible. */ @@ -998,7 +1097,7 @@ void ModelChecker::check_recency(ModelAction *curr, const ModelAction *rf) { ModelAction *act=*rit; bool foundvalue = false; for (int j = 0; jget_node()->get_read_from_size(); j++) { - if (act->get_node()->get_read_from_at(i)==write) { + if (act->get_node()->get_read_from_at(j)==write) { foundvalue = true; break; } @@ -1278,33 +1377,44 @@ bool ModelChecker::thin_air_constraint_may_allow(const ModelAction * writer, con return true; } -/** Arbitrary reads from the future are not allowed. Section 29.3 - * part 9 places some constraints. This method checks one result of constraint - * constraint. Others require compiler support. */ -bool ModelChecker::mo_may_allow(const ModelAction * writer, const ModelAction *reader) { +/** + * Arbitrary reads from the future are not allowed. Section 29.3 part 9 places + * some constraints. This method checks one the following constraint (others + * require compiler support): + * + * If X --hb-> Y --mo-> Z, then X should not read from Z. + */ +bool ModelChecker::mo_may_allow(const ModelAction *writer, const ModelAction *reader) +{ std::vector *thrd_lists = obj_thrd_map->get_safe_ptr(reader->get_location()); + unsigned int i; - //Get write that follows reader action - action_list_t *list = &(*thrd_lists)[id_to_int(reader->get_tid())]; - action_list_t::reverse_iterator rit; - ModelAction *first_write_after_read=NULL; + /* Iterate over all threads */ + for (i = 0; i < thrd_lists->size(); i++) { + const ModelAction *write_after_read = NULL; - for (rit = list->rbegin(); rit != list->rend(); rit++) { - ModelAction *act = *rit; - if (act==reader) - break; - if (act->is_write()) - first_write_after_read=act; - } + /* Iterate over actions in thread, starting from most recent */ + action_list_t *list = &(*thrd_lists)[i]; + action_list_t::reverse_iterator rit; + for (rit = list->rbegin(); rit != list->rend(); rit++) { + ModelAction *act = *rit; - if (first_write_after_read==NULL) - return true; + if (!reader->happens_before(act)) + break; + else if (act->is_write()) + write_after_read = act; + else if (act->is_read()&&act->get_reads_from()!=NULL) { + write_after_read = act->get_reads_from(); + } + } + + if (write_after_read && write_after_read!=writer && mo_graph->checkReachable(write_after_read, writer)) + return false; + } - return !mo_graph->checkReachable(first_write_after_read, writer); + return true; } - - /** * Finds the head(s) of the release sequence(s) containing a given ModelAction. * The ModelAction under consideration is expected to be taking part in @@ -1421,8 +1531,8 @@ bool ModelChecker::release_seq_heads(const ModelAction *rf, continue; } - /* Only writes can break release sequences */ - if (!act->is_write()) + /* Only non-RMW writes can break release sequences */ + if (!act->is_write() || act->is_rmw()) continue; /* Check modification order */ @@ -1578,6 +1688,20 @@ void ModelChecker::add_action_to_lists(ModelAction *act) if ((int)thrd_last_action->size() <= tid) thrd_last_action->resize(get_num_threads()); (*thrd_last_action)[tid] = act; + + if (act->is_wait()) { + void *mutex_loc=(void *) act->get_value(); + obj_map->get_safe_ptr(mutex_loc)->push_back(act); + + std::vector *vec = obj_thrd_map->get_safe_ptr(mutex_loc); + if (tid >= (int)vec->size()) + vec->resize(priv->next_thread_id); + (*vec)[tid].push_back(act); + + if ((int)thrd_last_action->size() <= tid) + thrd_last_action->resize(get_num_threads()); + (*thrd_last_action)[tid] = act; + } } /** @@ -1629,7 +1753,7 @@ ModelAction * ModelChecker::get_last_unlock(ModelAction *curr) const /* Find: max({i in dom(S) | isUnlock(t_i) && samevar(t_i, t)}) */ action_list_t::reverse_iterator rit; for (rit = list->rbegin(); rit != list->rend(); rit++) - if ((*rit)->is_unlock()) + if ((*rit)->is_unlock() || (*rit)->is_wait()) return *rit; return NULL; } @@ -1713,6 +1837,7 @@ void ModelChecker::compute_promises(ModelAction *curr) act->is_read() && !act->could_synchronize_with(curr) && !act->same_thread(curr) && + act->get_location() == curr->get_location() && promise->get_value() == curr->get_value()) { curr->get_node()->set_promise(i); } @@ -1736,6 +1861,16 @@ void ModelChecker::check_promises(thread_id_t tid, ClockVector *old_cv, ClockVec } } +void ModelChecker::check_promises_thread_disabled() { + for (unsigned int i = 0; i < promises->size(); i++) { + Promise *promise = (*promises)[i]; + if (promise->check_promise()) { + failed_promise = true; + return; + } + } +} + /** Checks promises in response to addition to modification order for threads. * Definitions: * pthread is the thread that performed the read that created the promise @@ -1795,7 +1930,7 @@ void ModelChecker::mo_check_promises(thread_id_t tid, const ModelAction *write) if (promise->has_sync_thread(tid)) continue; - if (mo_graph->checkReachable(promise->get_write(), write)) { + if (promise->get_write()&&mo_graph->checkReachable(promise->get_write(), write)) { if (promise->increment_threads(tid)) { failed_promise = true; return; @@ -1891,6 +2026,7 @@ void ModelChecker::build_reads_from_past(ModelAction *curr) if (!initialized) { /** @todo Need a more informative way of reporting errors. */ printf("ERROR: may read from uninitialized atomic\n"); + set_assert(); } if (DBG_ENABLED() || !initialized) { @@ -1900,14 +2036,13 @@ void ModelChecker::build_reads_from_past(ModelAction *curr) curr->get_node()->print_may_read_from(); printf("End printing may_read_from\n"); } - - ASSERT(initialized); } bool ModelChecker::sleep_can_read_from(ModelAction * curr, const ModelAction *write) { while(true) { Node *prevnode=write->get_node()->get_parent(); - bool thread_sleep=prevnode->get_enabled_array()[id_to_int(curr->get_tid())]==THREAD_SLEEP_SET; + + bool thread_sleep=prevnode->enabled_status(curr->get_tid())==THREAD_SLEEP_SET; if (write->is_release()&&thread_sleep) return true; if (!write->is_rmw()) {