/* Initialize default scheduler */
scheduler(new Scheduler()),
num_executions(0),
+ num_feasible_executions(0),
params(params),
diverge(NULL),
action_trace(new action_list_t()),
DBG();
num_executions++;
+ if (isfinalfeasible())
+ num_feasible_executions++;
if (isfinalfeasible() || DBG_ENABLED())
print_summary();
break;
}
- bool updated = false;
+ work_queue_t work_queue(1, CheckCurrWorkEntry(curr));
+
+ while (!work_queue.empty()) {
+ WorkQueueEntry work = work_queue.front();
+ work_queue.pop_front();
- if (curr->is_read() && process_read(curr, second_part_of_rmw))
- updated = true;
+ switch (work.type) {
+ case WORK_CHECK_CURR_ACTION: {
+ ModelAction *act = work.action;
+ bool updated = false;
+ if (act->is_read() && process_read(act, second_part_of_rmw))
+ updated = true;
- if (curr->is_write() && process_write(curr))
- updated = true;
+ if (act->is_write() && process_write(act))
+ updated = true;
- if (updated)
- resolve_release_sequences(curr->get_location());
+ if (updated)
+ work_queue.push_back(CheckRelSeqWorkEntry(act->get_location()));
+ break;
+ }
+ case WORK_CHECK_RELEASE_SEQ:
+ resolve_release_sequences(work.location, &work_queue);
+ break;
+ case WORK_CHECK_MO_EDGES:
+ /** @todo Perform follow-up mo_graph checks */
+ default:
+ ASSERT(false);
+ break;
+ }
+ }
/* Add action to list. */
if (!second_part_of_rmw)
/** @returns whether the current partial trace is feasible other than
* multiple RMW reading from the same store. */
bool ModelChecker::isfeasibleotherthanRMW() {
+ if (DBG_ENABLED()) {
+ if (mo_graph->checkForCycles())
+ DEBUG("Infeasible: modification order cycles\n");
+ if (failed_promise)
+ DEBUG("Infeasible: failed promise\n");
+ if (too_many_reads)
+ DEBUG("Infeasible: too many reads\n");
+ if (promises_expired())
+ DEBUG("Infeasible: promises expired\n");
+ }
return !mo_graph->checkForCycles() && !failed_promise && !too_many_reads && !promises_expired();
}
/** Returns whether the current completed trace is feasible. */
bool ModelChecker::isfinalfeasible() {
+ if (DBG_ENABLED() && promises->size() != 0)
+ DEBUG("Infeasible: unrevolved promises\n");
+
return isfeasible() && promises->size() == 0;
}
}
/**
- * Updates the mo_graph with the constraints imposed from the current read.
+ * Updates the mo_graph with the constraints imposed from the current
+ * read.
+ *
+ * Basic idea is the following: Go through each other thread and find
+ * the lastest action that happened before our read. Two cases:
+ *
+ * (1) The action is a write => that write must either occur before
+ * the write we read from or be the write we read from.
+ *
+ * (2) The action is a read => the write that that action read from
+ * must occur before the write we read from or be the same write.
+ *
* @param curr The current action. Must be a read.
* @param rf The action that curr reads from. Must be a write.
* @return True if modification order edges were added; false otherwise
return added;
}
-/** Updates the mo_graph with the constraints imposed from the current read. */
+/** This method fixes up the modification order when we resolve a
+ * promises. The basic problem is that actions that occur after the
+ * read curr could not property add items to the modification order
+ * for our read.
+ *
+ * So for each thread, we find the earliest item that happens after
+ * the read curr. This is the item we have to fix up with additional
+ * constraints. If that action is write, we add a MO edge between
+ * the Action rf and that action. If the action is a read, we add a
+ * MO edge between the Action rf, and whatever the read accessed.
+ *
+ * @param curr is the read ModelAction that we are fixing up MO edges for.
+ * @param rf is the write ModelAction that curr reads from.
+ *
+ */
+
void ModelChecker::post_r_modification_order(ModelAction *curr, const ModelAction *rf)
{
std::vector<action_list_t> *thrd_lists = obj_thrd_map->get_safe_ptr(curr->get_location());
/**
* Updates the mo_graph with the constraints imposed from the current write.
+ *
+ * Basic idea is the following: Go through each other thread and find
+ * the lastest action that happened before our write. Two cases:
+ *
+ * (1) The action is a write => that write must occur before
+ * the current write
+ *
+ * (2) The action is a read => the write that that action read from
+ * must occur before the current write.
+ *
+ * This method also handles two other issues:
+ *
+ * (I) Sequential Consistency: Making sure that if the current write is
+ * seq_cst, that it occurs after the previous seq_cst write.
+ *
+ * (II) Sending the write back to non-synchronizing reads.
+ *
* @param curr The current action. Must be a write.
* @return True if modification order edges were added; false otherwise
*/
*
* @param location The location/object that should be checked for release
* sequence resolutions
- * @return True if any updates occurred (new synchronization, new mo_graph edges)
+ * @param work_queue The work queue to which to add work items as they are
+ * generated
+ * @return True if any updates occurred (new synchronization, new mo_graph
+ * edges)
*/
-bool ModelChecker::resolve_release_sequences(void *location)
+bool ModelChecker::resolve_release_sequences(void *location, work_queue_t *work_queue)
{
std::list<ModelAction *> *list;
list = lazy_sync_with_release->getptr(location);
}
if (updated) {
+ /* Re-check act for mo_graph edges */
+ work_queue->push_back(MOEdgeWorkEntry(act));
+
/* propagate synchronization to later actions */
action_list_t::reverse_iterator it = action_trace->rbegin();
while ((*it) != act) {
ModelAction *propagate = *it;
- if (act->happens_before(propagate))
- /** @todo new mo_graph edges along with
- * this synchronization? */
+ if (act->happens_before(propagate)) {
propagate->synchronize_with(act);
+ /* Re-check 'propagate' for mo_graph edges */
+ work_queue->push_back(MOEdgeWorkEntry(propagate));
+ }
}
}
if (complete) {
if (read->is_rmw()) {
mo_graph->addRMWEdge(write, read);
}
+ //First fix up the modification order for actions that happened
+ //before the read
r_modification_order(read, write);
+ //Next fix up the modification order for actions that happened
+ //after the read.
post_r_modification_order(read, write);
promises->erase(promises->begin() + promise_index);
resolved = true;
{
printf("\n");
printf("Number of executions: %d\n", num_executions);
+ printf("Number of feasible executions: %d\n", num_feasible_executions);
printf("Total nodes created: %d\n", node_stack->get_total_nodes());
+#if SUPPORT_MOD_ORDER_DUMP
scheduler->print();
+ char buffername[100];
+ sprintf(buffername, "exec%u",num_executions);
+ mo_graph->dumpGraphToFile(buffername);
+#endif
if (!isfinalfeasible())
printf("INFEASIBLE EXECUTION!\n");
projects / model-checker.git / blobdiff