/* First thread created will have id INITIAL_THREAD_ID */
next_thread_id(INITIAL_THREAD_ID),
used_sequence_numbers(0),
-
num_executions(0),
current_action(NULL),
diverge(NULL),
if (next == diverge) {
Node *nextnode = next->get_node();
/* Reached divergence point */
- if (nextnode->increment_read_from()) {
+ 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);
+ } else if (nextnode->increment_read_from()) {
/* The next node will read from a different value. */
tid = next->get_tid();
node_stack->pop_restofstack(2);
- } else if (nextnode->increment_future_values()) {
+ } else if (nextnode->increment_future_value()) {
/* The next node will try to read from a different future value. */
tid = next->get_tid();
node_stack->pop_restofstack(2);
num_executions++;
- if (isfeasible() || DBG_ENABLED())
+ if (isfinalfeasible() || DBG_ENABLED())
print_summary();
if ((diverge = model->get_next_backtrack()) == NULL)
/* First restore type and order in case of RMW operation */
if (curr->is_rmwr())
tmp->copy_typeandorder(curr);
+
+ /* If we have diverged, we need to reset the clock vector. */
+ if (diverge==NULL) {
+ tmp->create_cv(get_parent_action(tmp->get_tid()));
+ }
+
delete curr;
curr = tmp;
} else {
/* Build may_read_from set */
if (curr->is_read())
build_reads_from_past(curr);
+ if (curr->is_write())
+ compute_promises(curr);
}
}
}
} else if (curr->is_write()) {
w_modification_order(curr);
+ resolve_promises(curr);
}
th->set_return_value(value);
Node *currnode = curr->get_node();
Node *parnode = currnode->get_parent();
- if (!parnode->backtrack_empty()||!currnode->readsfrom_empty()||!currnode->futurevalues_empty())
+ if (!parnode->backtrack_empty()||!currnode->read_from_empty()||!currnode->future_value_empty()||!currnode->promise_empty())
if (!next_backtrack || *curr > *next_backtrack)
next_backtrack = curr;
-
+
set_backtracking(curr);
}
-/** @returns whether the current trace is feasible. */
+/** @returns whether the current partial trace is feasible. */
bool ModelChecker::isfeasible() {
return !cyclegraph->checkForCycles() && !failed_promise;
}
+/** Returns whether the current completed trace is feasible. */
+bool ModelChecker::isfinalfeasible() {
+ return isfeasible() && promises->size()==0;
+}
+
/** Close out a RMWR by converting previous RMWR into a RMW or READ. */
ModelAction * ModelChecker::process_rmw(ModelAction * act) {
int tid = id_to_int(act->get_tid());
if (act->happens_before(curr)) {
if (act->is_read()) {
const ModelAction * prevreadfrom=act->get_reads_from();
- if (rf!=prevreadfrom)
+ if (prevreadfrom!=NULL&&rf!=prevreadfrom)
cyclegraph->addEdge(rf, prevreadfrom);
} else if (rf!=act) {
cyclegraph->addEdge(rf, act);
}
}
+/** Updates the cyclegraph with the constraints imposed from the
+ * current read. */
+void ModelChecker::post_r_modification_order(ModelAction * curr, const ModelAction *rf) {
+ std::vector<action_list_t> *thrd_lists = obj_thrd_map->ensureptr(curr->get_location());
+ unsigned int i;
+ ASSERT(curr->is_read());
+
+ /* Iterate over all threads */
+ for (i = 0; i < thrd_lists->size(); i++) {
+ /* Iterate over actions in thread, starting from most recent */
+ action_list_t *list = &(*thrd_lists)[i];
+ action_list_t::reverse_iterator rit;
+ ModelAction *lastact=NULL;
+
+ /* Find last action that happens after curr */
+ for (rit = list->rbegin(); rit != list->rend(); rit++) {
+ ModelAction *act = *rit;
+ if (curr->happens_before(act)) {
+ lastact=act;
+ } else
+ break;
+ }
+
+ /* Include at most one act per-thread that "happens before" curr */
+ if (lastact!=NULL) {
+ if (lastact->is_read()) {
+ const ModelAction * postreadfrom=lastact->get_reads_from();
+ if (postreadfrom!=NULL&&rf!=postreadfrom)
+ cyclegraph->addEdge(postreadfrom, rf);
+ } else if (rf!=lastact) {
+ cyclegraph->addEdge(lastact, rf);
+ }
+ break;
+ }
+ }
+}
+
/**
* Updates the cyclegraph with the constraints imposed from the current write.
* @param curr The current action. Must be a write.
(1) did not happen before us
(2) is a read and we are a write
(3) cannot synchronize with us
- (4) is in a different thread
+ (4) is in a different thread
=>
that read could potentially read from our write.
*/
-
if (act->get_node()->add_future_value(curr->get_value())&&
(!next_backtrack || *act > * next_backtrack))
next_backtrack = act;
return get_parent_action(tid)->get_cv();
}
+
+/** Resolve the given promises. */
+
+void ModelChecker::resolve_promises(ModelAction *write) {
+ for(unsigned int i=0, promise_index=0;promise_index<promises->size(); i++) {
+ Promise * promise=(*promises)[promise_index];
+ if (write->get_node()->get_promise(i)) {
+ ModelAction * read=promise->get_action();
+ read->read_from(write);
+ r_modification_order(read, write);
+ post_r_modification_order(read, write);
+ promises->erase(promises->begin()+promise_index);
+ } else
+ promise_index++;
+ }
+}
+
+/** Compute the set of promises that could potentially be satisfied by
+ * this action. */
+
+void ModelChecker::compute_promises(ModelAction *curr) {
+ for(unsigned int i=0;i<promises->size();i++) {
+ Promise * promise=(*promises)[i];
+ const ModelAction * act=promise->get_action();
+ if (!act->happens_before(curr)&&
+ act->is_read()&&
+ !act->is_synchronizing(curr)&&
+ !act->same_thread(curr)&&
+ promise->get_value()==curr->get_value()) {
+ curr->get_node()->set_promise(i);
+ }
+ }
+}
+
/** Checks promises in response to change in ClockVector Threads. */
void ModelChecker::check_promises(ClockVector *old_cv, ClockVector * merge_cv) {
scheduler->print();
- if (!isfeasible())
+ if (!isfinalfeasible())
printf("INFEASIBLE EXECUTION!\n");
print_list(action_trace);
printf("\n");
projects / model-checker.git / blobdiff