return priv->next_thread_id;
}
+/** @return The currently executing Thread. */
+Thread * ModelChecker::get_current_thread()
+{
+ return scheduler->get_current_thread();
+}
+
/** @return a sequence number for a new ModelAction */
modelclock_t ModelChecker::get_next_seq_num()
{
ModelAction *next = node_stack->get_next()->get_action();
if (next == diverge) {
+ if (earliest_diverge == NULL || *diverge < *earliest_diverge)
+ earliest_diverge=diverge;
+
Node *nextnode = next->get_node();
/* Reached divergence point */
if (nextnode->increment_promise()) {
Node *node = nextnode->get_parent();
tid = node->get_next_backtrack();
node_stack->pop_restofstack(1);
+ if (diverge==earliest_diverge) {
+ earliest_diverge=node->get_action();
+ }
}
DEBUG("*** Divergence point ***\n");
+
diverge = NULL;
} else {
tid = next->get_tid();
DBG();
num_executions++;
+
if (isfinalfeasible()) {
printf("Earliest divergence point since last feasible execution:\n");
if (earliest_diverge)
num_feasible_executions++;
}
+ DEBUG("Number of acquires waiting on pending release sequences: %lu\n",
+ pending_acq_rel_seq->size());
+
if (isfinalfeasible() || DBG_ENABLED())
print_summary();
if ((diverge = get_next_backtrack()) == NULL)
return false;
- if (earliest_diverge == NULL || *diverge < *earliest_diverge)
- earliest_diverge=diverge;
-
if (DBG_ENABLED()) {
printf("Next execution will diverge at:\n");
diverge->print();
* (e.g., ATOMIC_{READ,WRITE,RMW,LOCK}, etc.)
*
* @param curr The current action
- * @return True if synchronization was updated
+ * @return True if synchronization was updated or a thread completed
*/
bool ModelChecker::process_thread_action(ModelAction *curr)
{
- bool synchronized = false;
+ bool updated = false;
switch (curr->get_type()) {
case THREAD_CREATE: {
break;
}
case THREAD_JOIN: {
- Thread *blocking = (Thread *)curr->get_location();
- ModelAction *act = get_last_action(blocking->get_id());
- curr->synchronize_with(act);
- synchronized = true;
+ Thread *waiting, *blocking;
+ waiting = get_thread(curr);
+ blocking = (Thread *)curr->get_location();
+ if (!blocking->is_complete()) {
+ blocking->push_wait_list(curr);
+ scheduler->sleep(waiting);
+ } else {
+ do_complete_join(curr);
+ updated = true; /* trigger rel-seq checks */
+ }
break;
}
case THREAD_FINISH: {
Thread *th = get_thread(curr);
while (!th->wait_list_empty()) {
ModelAction *act = th->pop_wait_list();
- scheduler->wake(get_thread(act));
+ Thread *wake = get_thread(act);
+ scheduler->wake(wake);
+ do_complete_join(act);
+ updated = true; /* trigger rel-seq checks */
}
th->complete();
+ updated = true; /* trigger rel-seq checks */
break;
}
case THREAD_START: {
break;
}
- return synchronized;
+ return updated;
}
/**
return newcurr;
}
+ curr->set_seq_number(get_next_seq_num());
+
newcurr = node_stack->explore_action(curr, scheduler->get_enabled());
if (newcurr) {
/* First restore type and order in case of RMW operation */
}
/**
- * @brief Check whether a model action is enabled.
- *
- * Checks whether a lock or join operation would be successful (i.e., is the
- * lock already locked, or is the joined thread already complete). If not, put
- * the action in a waiter list.
- *
+ * This method checks whether a model action is enabled at the given point.
+ * At this point, it checks whether a lock operation would be successful at this point.
+ * If not, it puts the thread in a waiter list.
* @param curr is the ModelAction to check whether it is enabled.
* @return a bool that indicates whether the action is enabled.
*/
lock_waiters_map->get_safe_ptr(curr->get_location())->push_back(curr);
return false;
}
- } else if (curr->get_type() == THREAD_JOIN) {
- Thread *blocking = (Thread *)curr->get_location();
- if (!blocking->is_complete()) {
- blocking->push_wait_list(curr);
- return false;
- }
}
return true;
if (!check_action_enabled(curr)) {
/* Make the execution look like we chose to run this action
- * much later, when a lock/join can succeed */
+ * much later, when a lock is actually available to release */
get_current_thread()->set_pending(curr);
scheduler->sleep(get_current_thread());
return get_next_thread(NULL);
return get_next_thread(curr);
}
+/**
+ * Complete a THREAD_JOIN operation, by synchronizing with the THREAD_FINISH
+ * operation from the Thread it is joining with. Must be called after the
+ * completion of the Thread in question.
+ * @param join The THREAD_JOIN action
+ */
+void ModelChecker::do_complete_join(ModelAction *join)
+{
+ Thread *blocking = (Thread *)join->get_location();
+ ModelAction *act = get_last_action(blocking->get_id());
+ join->synchronize_with(act);
+}
+
void ModelChecker::check_curr_backtracking(ModelAction * curr) {
Node *currnode = curr->get_node();
Node *parnode = currnode->get_parent();
}
if (updated) {
+ /* Re-check all pending release sequences */
+ work_queue->push_back(CheckRelSeqWorkEntry(NULL));
/* Re-check act for mo_graph edges */
work_queue->push_back(MOEdgeWorkEntry(act));
//Make sure the promise's value matches the write's value
ASSERT(promise->get_value() == write->get_value());
+ delete(promise);
promises->erase(promises->begin() + promise_index);
resolved = true;
} else
scheduler->remove_thread(t);
}
+/**
+ * @brief Get a Thread reference by its ID
+ * @param tid The Thread's ID
+ * @return A Thread reference
+ */
+Thread * ModelChecker::get_thread(thread_id_t tid)
+{
+ return thread_map->get(id_to_int(tid));
+}
+
+/**
+ * @brief Get a reference to the Thread in which a ModelAction was executed
+ * @param act The ModelAction
+ * @return A Thread reference
+ */
+Thread * ModelChecker::get_thread(ModelAction *act)
+{
+ return get_thread(act->get_tid());
+}
+
/**
* Switch from a user-context to the "master thread" context (a.k.a. system
* context). This switch is made with the intention of exploring a particular
* model-checking action (described by a ModelAction object). Must be called
* from a user-thread context.
- * @param act The current action that will be explored. Must not be NULL.
+ *
+ * @param act The current action that will be explored. May be NULL only if
+ * trace is exiting via an assertion (see ModelChecker::set_assert and
+ * ModelChecker::has_asserted).
* @return Return status from the 'swap' call (i.e., success/fail, 0/-1)
*/
int ModelChecker::switch_to_master(ModelAction *act)
projects / model-checker.git / blobdiff