return next;
}
-
/**
* Processes a read or rmw model action.
* @param curr is the read model action to process.
* @param second_part_of_rmw is boolean that is true is this is the second action of a rmw.
* @return True if processing this read updates the mo_graph.
*/
-
bool ModelChecker::process_read(ModelAction *curr, Thread * th, bool second_part_of_rmw) {
uint64_t value;
- bool updated=false;
- while(true) {
+ bool updated = false;
+ while (true) {
const ModelAction *reads_from = curr->get_node()->get_read_from();
if (reads_from != NULL) {
mo_graph->startChanges();
value = reads_from->get_value();
- bool r_status=false;
+ bool r_status = false;
if (!second_part_of_rmw) {
check_recency(curr,false);
- r_status=r_modification_order(curr, reads_from);
+ r_status = r_modification_order(curr, reads_from);
}
if (!second_part_of_rmw&&!isfeasible()&&(curr->get_node()->increment_read_from()||curr->get_node()->increment_future_value())) {
mo_graph->rollbackChanges();
- too_many_reads=false;
+ too_many_reads = false;
continue;
}
}
/* Thread specific actions */
- switch(curr->get_type()) {
+ switch (curr->get_type()) {
case THREAD_CREATE: {
Thread *th = (Thread *)curr->get_location();
th->set_creation(curr);
break;
}
- Thread *th = get_thread(curr);
-
bool updated = false;
+
if (curr->is_read()) {
- updated=process_read(curr, th, second_part_of_rmw);
+ updated = process_read(curr, get_thread(curr), second_part_of_rmw);
}
if (curr->is_write()) {
- bool updated_mod_order=w_modification_order(curr);
- bool updated_promises=resolve_promises(curr);
- updated=updated_mod_order|updated_promises;
+ bool updated_mod_order = w_modification_order(curr);
+ bool updated_promises = resolve_promises(curr);
+ updated = updated || updated_mod_order || updated_promises;
if (promises->size()==0) {
- for(unsigned int i=0;i<futurevalues->size();i++) {
+ for (unsigned int i = 0; i<futurevalues->size(); i++) {
struct PendingFutureValue pfv=(*futurevalues)[i];
if (pfv.act->get_node()->add_future_value(pfv.value, pfv.expiration) &&
(!priv->next_backtrack || *pfv.act > *priv->next_backtrack))
}
mo_graph->commitChanges();
- th->set_return_value(VALUE_NONE);
+ get_thread(curr)->set_return_value(VALUE_NONE);
}
if (updated)
add_action_to_lists(curr);
check_curr_backtracking(curr);
-
+
set_backtracking(curr);
return get_next_thread(curr);
void ModelChecker::check_curr_backtracking(ModelAction * curr) {
Node *currnode = curr->get_node();
Node *parnode = currnode->get_parent();
-
+
if ((!parnode->backtrack_empty() ||
!currnode->read_from_empty() ||
!currnode->future_value_empty() ||
}
}
-
bool ModelChecker::promises_expired() {
for (unsigned int promise_index = 0; promise_index < promises->size(); promise_index++) {
Promise *promise = (*promises)[promise_index];
rit++;
}
- action_list_t::reverse_iterator ritcopy=rit;
+ action_list_t::reverse_iterator ritcopy = rit;
//See if we have enough reads from the same value
- int count=0;
+ int count = 0;
for (; count < params.maxreads; rit++,count++) {
if (rit==list->rend())
return;
return;
}
- for (int i=0;i<curr->get_node()->get_read_from_size();i++) {
+ for (int i = 0; i<curr->get_node()->get_read_from_size(); i++) {
//Get write
- const ModelAction * write=curr->get_node()->get_read_from_at(i);
+ const ModelAction * write = curr->get_node()->get_read_from_at(i);
//Need a different write
if (write==curr->get_reads_from())
continue;
/* 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 = isfeasible();
mo_graph->rollbackChanges();
if (!feasiblereadfrom)
continue;
- rit=ritcopy;
+ rit = ritcopy;
- bool feasiblewrite=true;
+ bool feasiblewrite = true;
//new we need to see if this write works for everyone
- for (int loop=count;loop>0;loop--,rit++) {
+ for (int loop = count; loop>0; loop--,rit++) {
ModelAction *act=*rit;
- bool foundvalue=false;
- for(int j=0;j<act->get_node()->get_read_from_size();j++) {
+ bool foundvalue = false;
+ for (int j = 0; j<act->get_node()->get_read_from_size(); j++) {
if (act->get_node()->get_read_from_at(i)==write) {
- foundvalue=true;
+ foundvalue = true;
break;
}
}
if (!foundvalue) {
- feasiblewrite=false;
+ feasiblewrite = false;
break;
}
}
}
/**
- * 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
mo_graph->addEdge(prevreadfrom, rf);
added = true;
}
- }
+ }
break;
}
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
*/
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())) {
- struct PendingFutureValue pfv={curr->get_value(),curr->get_seq_number()+params.maxfuturedelay,act};
+ struct PendingFutureValue pfv = {curr->get_value(),curr->get_seq_number()+params.maxfuturedelay,act};
futurevalues->push_back(pfv);
}
}
if (!reader->is_rmw())
return true;
- for(const ModelAction *search=writer->get_reads_from();search!=NULL;search=search->get_reads_from()) {
+ for (const ModelAction *search = writer->get_reads_from(); search != NULL; search = search->get_reads_from()) {
if (search==reader)
return false;
- if (search->get_tid()==reader->get_tid()&&
+ if (search->get_tid() == reader->get_tid() &&
search->happens_before(reader))
break;
}
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
* false otherwise
*/
bool ModelChecker::release_seq_head(const ModelAction *rf,
- std::vector<const ModelAction *> *release_heads) const
+ std::vector< const ModelAction *, MyAlloc<const ModelAction *> > *release_heads) const
{
- ASSERT(rf->is_write());
if (!rf) {
/* read from future: need to settle this later */
return false; /* incomplete */
}
+
+ ASSERT(rf->is_write());
+
if (rf->is_release())
release_heads->push_back(rf);
if (rf->is_rmw()) {
* @see ModelChecker::release_seq_head
*/
void ModelChecker::get_release_seq_heads(ModelAction *act,
- std::vector<const ModelAction *> *release_heads)
+ std::vector< const ModelAction *, MyAlloc<const ModelAction *> > *release_heads)
{
const ModelAction *rf = act->get_reads_from();
bool complete;
while (it != list->end()) {
ModelAction *act = *it;
const ModelAction *rf = act->get_reads_from();
- std::vector<const ModelAction *> release_heads;
+ std::vector< const ModelAction *, MyAlloc<const ModelAction *> > release_heads;
bool complete;
complete = release_seq_head(rf, &release_heads);
for (unsigned int i = 0; i < release_heads.size(); i++) {
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;
return resolved;
}
-
-
/**
* Compute the set of promises that could potentially be satisfied by this
* action. Note that the set computation actually appears in the Node, not in
printf("Number of executions: %d\n", num_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");