X-Git-Url: http://plrg.eecs.uci.edu/git/?p=c11tester.git;a=blobdiff_plain;f=model.cc;h=d6ebfe5abc9f4e60920f9b08bed0112746c3afce;hp=72610f6581e500231941a1613274891556687f3f;hb=43144df37c0f1bb5b4efc4cf1bd2908b6cf440b9;hpb=8f82e4c697b8f4ca7b3d4e79ace1b9cf1dc259d2 diff --git a/model.cc b/model.cc index 72610f65..d6ebfe5a 100644 --- a/model.cc +++ b/model.cc @@ -172,7 +172,7 @@ unsigned int ModelChecker::get_num_threads() const } /** @return The currently executing Thread. */ -Thread * ModelChecker::get_current_thread() +Thread * ModelChecker::get_current_thread() const { return scheduler->get_current_thread(); } @@ -183,7 +183,8 @@ modelclock_t ModelChecker::get_next_seq_num() return ++priv->used_sequence_numbers; } -Node * ModelChecker::get_curr_node() { +Node * ModelChecker::get_curr_node() const +{ return node_stack->get_head(); } @@ -424,7 +425,7 @@ void ModelChecker::print_bugs() const void ModelChecker::record_stats() { stats.num_total++; - if (!isfinalfeasible()) + if (!isfeasibleprefix()) stats.num_infeasible++; else if (have_bug_reports()) stats.num_buggy_executions++; @@ -483,7 +484,7 @@ bool ModelChecker::next_execution() { DBG(); /* Is this execution a feasible execution that's worth bug-checking? */ - bool complete = isfinalfeasible() && (is_complete_execution() || + bool complete = isfeasibleprefix() && (is_complete_execution() || have_bug_reports()); /* End-of-execution bug checks */ @@ -695,7 +696,7 @@ bool ModelChecker::process_read(ModelAction *curr, bool second_part_of_rmw) } - if (!second_part_of_rmw&&!isfeasible()&&(curr->get_node()->increment_read_from()||curr->get_node()->increment_future_value())) { + if (!second_part_of_rmw&&is_infeasible()&&(curr->get_node()->increment_read_from()||curr->get_node()->increment_future_value())) { mo_graph->rollbackChanges(); priv->too_many_reads = false; continue; @@ -1000,7 +1001,7 @@ bool ModelChecker::initialize_curr_action(ModelAction **curr) (*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_array()); if (newcurr) { /* First restore type and order in case of RMW operation */ if ((*curr)->is_rmwr()) @@ -1210,25 +1211,51 @@ bool ModelChecker::promises_expired() const return false; } -/** @return whether the current partial trace must be a prefix of a - * feasible trace. */ +/** + * This is the strongest feasibility check available. + * @return whether the current trace (partial or complete) must be a prefix of + * a feasible trace. + */ bool ModelChecker::isfeasibleprefix() const { - return promises->size() == 0 && pending_rel_seqs->size() == 0 && isfeasible(); + return pending_rel_seqs->size() == 0 && is_feasible_prefix_ignore_relseq(); +} + +/** + * Returns whether the current completed trace is feasible, except for pending + * release sequences. + */ +bool ModelChecker::is_feasible_prefix_ignore_relseq() const +{ + if (DBG_ENABLED() && promises->size() != 0) + DEBUG("Infeasible: unrevolved promises\n"); + + return !is_infeasible() && promises->size() == 0; } -/** @return whether the current partial trace is feasible. */ -bool ModelChecker::isfeasible() const +/** + * Check if the current partial trace is infeasible. Does not check any + * end-of-execution flags, which might rule out the execution. Thus, this is + * useful only for ruling an execution as infeasible. + * @return whether the current partial trace is infeasible. + */ +bool ModelChecker::is_infeasible() const { if (DBG_ENABLED() && mo_graph->checkForRMWViolation()) DEBUG("Infeasible: RMW violation\n"); - return !mo_graph->checkForRMWViolation() && isfeasibleotherthanRMW(); + return mo_graph->checkForRMWViolation() || is_infeasible_ignoreRMW(); } -/** @return whether the current partial trace is feasible other than - * multiple RMW reading from the same store. */ -bool ModelChecker::isfeasibleotherthanRMW() const +/** + * Check If the current partial trace is infeasible, while ignoring + * infeasibility related to 2 RMW's reading from the same store. It does not + * check end-of-execution feasibility. + * @see ModelChecker::is_infeasible + * @return whether the current partial trace is infeasible, ignoring multiple + * RMWs reading from the same store. + * */ +bool ModelChecker::is_infeasible_ignoreRMW() const { if (DBG_ENABLED()) { if (mo_graph->checkForCycles()) @@ -1242,16 +1269,9 @@ bool ModelChecker::isfeasibleotherthanRMW() const if (promises_expired()) DEBUG("Infeasible: promises expired\n"); } - return !mo_graph->checkForCycles() && !priv->failed_promise && !priv->too_many_reads && !priv->bad_synchronization && !promises_expired(); -} - -/** Returns whether the current completed trace is feasible. */ -bool ModelChecker::isfinalfeasible() const -{ - if (DBG_ENABLED() && promises->size() != 0) - DEBUG("Infeasible: unrevolved promises\n"); - - return isfeasible() && promises->size() == 0; + return mo_graph->checkForCycles() || priv->failed_promise || + priv->too_many_reads || priv->bad_synchronization || + promises_expired(); } /** Close out a RMWR by converting previous RMWR into a RMW or READ. */ @@ -1283,7 +1303,7 @@ void ModelChecker::check_recency(ModelAction *curr, const ModelAction *rf) { return; //Must make sure that execution is currently feasible... We could //accidentally clear by rolling back - if (!isfeasible()) + if (is_infeasible()) return; std::vector *thrd_lists = get_safe_ptr_vect_action(obj_thrd_map, curr->get_location()); int tid = id_to_int(curr->get_tid()); @@ -1326,7 +1346,7 @@ void ModelChecker::check_recency(ModelAction *curr, const ModelAction *rf) { /* Test to see whether this is a feasible write to read from*/ mo_graph->startChanges(); r_modification_order(curr, write); - bool feasiblereadfrom = isfeasible(); + bool feasiblereadfrom = !is_infeasible(); mo_graph->rollbackChanges(); if (!feasiblereadfrom) @@ -1515,7 +1535,7 @@ bool ModelChecker::w_modification_order(ModelAction *curr) if (curr->is_seqcst()) { /* We have to at least see the last sequentially consistent write, so we are initialized. */ - ModelAction *last_seq_cst = get_last_seq_cst(curr); + ModelAction *last_seq_cst = get_last_seq_cst_write(curr); if (last_seq_cst != NULL) { mo_graph->addEdge(last_seq_cst, curr); added = true; @@ -1586,8 +1606,8 @@ bool ModelChecker::w_modification_order(ModelAction *curr) */ if (thin_air_constraint_may_allow(curr, act)) { - if (isfeasible() || - (curr->is_rmw() && act->is_rmw() && curr->get_reads_from() == act->get_reads_from() && isfeasibleotherthanRMW())) { + if (!is_infeasible() || + (curr->is_rmw() && act->is_rmw() && curr->get_reads_from() == act->get_reads_from() && !is_infeasible_ignoreRMW())) { struct PendingFutureValue pfv = {curr,act}; futurevalues->push_back(pfv); } @@ -1965,7 +1985,7 @@ ModelAction * ModelChecker::get_last_action(thread_id_t tid) const * check * @return The last seq_cst write */ -ModelAction * ModelChecker::get_last_seq_cst(ModelAction *curr) const +ModelAction * ModelChecker::get_last_seq_cst_write(ModelAction *curr) const { void *location = curr->get_location(); action_list_t *list = get_safe_ptr_action(obj_map, location); @@ -1977,6 +1997,35 @@ ModelAction * ModelChecker::get_last_seq_cst(ModelAction *curr) const return NULL; } +/** + * Gets the last memory_order_seq_cst fence (in the total global sequence) + * performed in a particular thread, prior to a particular fence. + * @param tid The ID of the thread to check + * @param before_fence The fence from which to begin the search; if NULL, then + * search for the most recent fence in the thread. + * @return The last prior seq_cst fence in the thread, if exists; otherwise, NULL + */ +ModelAction * ModelChecker::get_last_seq_cst_fence(thread_id_t tid, const ModelAction *before_fence) const +{ + /* All fences should have NULL location */ + action_list_t *list = get_safe_ptr_action(obj_map, NULL); + action_list_t::reverse_iterator rit = list->rbegin(); + + if (before_fence) { + for (; rit != list->rend(); rit++) + if (*rit == before_fence) + break; + + ASSERT(*rit == before_fence); + rit++; + } + + for (; rit != list->rend(); rit++) + if ((*rit)->is_fence() && (tid == (*rit)->get_tid()) && (*rit)->is_seqcst()) + return *rit; + return NULL; +} + /** * Gets the last unlock operation performed on a particular mutex (i.e., memory * location). This function identifies the mutex according to the current @@ -1997,7 +2046,7 @@ ModelAction * ModelChecker::get_last_unlock(ModelAction *curr) const return NULL; } -ModelAction * ModelChecker::get_parent_action(thread_id_t tid) +ModelAction * ModelChecker::get_parent_action(thread_id_t tid) const { ModelAction *parent = get_last_action(tid); if (!parent) @@ -2010,7 +2059,7 @@ ModelAction * ModelChecker::get_parent_action(thread_id_t tid) * @param tid The thread whose clock vector we want * @return Desired clock vector */ -ClockVector * ModelChecker::get_cv(thread_id_t tid) +ClockVector * ModelChecker::get_cv(thread_id_t tid) const { return get_parent_action(tid)->get_cv(); } @@ -2214,16 +2263,16 @@ void ModelChecker::build_reads_from_past(ModelAction *curr) unsigned int i; ASSERT(curr->is_read()); - ModelAction *last_seq_cst = NULL; + ModelAction *last_sc_write = NULL; /* Track whether this object has been initialized */ bool initialized = false; if (curr->is_seqcst()) { - last_seq_cst = get_last_seq_cst(curr); + last_sc_write = get_last_seq_cst_write(curr); /* We have to at least see the last sequentially consistent write, so we are initialized. */ - if (last_seq_cst != NULL) + if (last_sc_write != NULL) initialized = true; } @@ -2240,15 +2289,20 @@ void ModelChecker::build_reads_from_past(ModelAction *curr) continue; /* Don't consider more than one seq_cst write if we are a seq_cst read. */ - if (!curr->is_seqcst() || (!act->is_seqcst() && (last_seq_cst == NULL || !act->happens_before(last_seq_cst))) || act == last_seq_cst) { - if (!curr->get_sleep_flag() || curr->is_seqcst() || sleep_can_read_from(curr, act)) { - DEBUG("Adding action to may_read_from:\n"); - if (DBG_ENABLED()) { - act->print(); - curr->print(); - } - curr->get_node()->add_read_from(act); + bool allow_read = true; + + if (curr->is_seqcst() && (act->is_seqcst() || (last_sc_write != NULL && act->happens_before(last_sc_write))) && act != last_sc_write) + allow_read = false; + else if (curr->get_sleep_flag() && !curr->is_seqcst() && !sleep_can_read_from(curr, act)) + allow_read = false; + + if (allow_read) { + DEBUG("Adding action to may_read_from:\n"); + if (DBG_ENABLED()) { + act->print(); + curr->print(); } + curr->get_node()->add_read_from(act); } /* Include at most one act per-thread that "happens before" curr */ @@ -2345,7 +2399,7 @@ void ModelChecker::print_summary() const dumpGraph(buffername); #endif - if (!isfinalfeasible()) + if (!isfeasibleprefix()) model_print("INFEASIBLE EXECUTION!\n"); print_list(action_trace, stats.num_total); model_print("\n"); @@ -2456,7 +2510,7 @@ bool ModelChecker::take_step() { Thread *next = scheduler->next_thread(priv->nextThread); /* Infeasible -> don't take any more steps */ - if (!isfeasible()) + if (is_infeasible()) return false; else if (isfeasibleprefix() && have_bug_reports()) { set_assert(); @@ -2482,7 +2536,7 @@ bool ModelChecker::take_step() { * (4) no pending promises */ if (!pending_rel_seqs->empty() && (!next || next->is_model_thread()) && - isfinalfeasible() && !unrealizedraces.empty()) { + is_feasible_prefix_ignore_relseq() && !unrealizedraces.empty()) { model_print("*** WARNING: release sequence fixup action (%zu pending release seuqences) ***\n", pending_rel_seqs->size()); ModelAction *fixup = new ModelAction(MODEL_FIXUP_RELSEQ,