obj_thrd_map(new HashTable<void *, std::vector<action_list_t>, uintptr_t, 4 >()),
promises(new std::vector<Promise *>()),
futurevalues(new std::vector<struct PendingFutureValue>()),
- pending_acq_rel_seq(new std::vector<ModelAction *>()),
+ pending_rel_seqs(new std::vector<struct release_seq *>()),
thrd_last_action(new std::vector<ModelAction *>(1)),
node_stack(new NodeStack()),
mo_graph(new CycleGraph()),
delete (*promises)[i];
delete promises;
- delete pending_acq_rel_seq;
+ delete pending_rel_seqs;
delete thrd_last_action;
delete node_stack;
}
DEBUG("Number of acquires waiting on pending release sequences: %lu\n",
- pending_acq_rel_seq->size());
+ pending_rel_seqs->size());
if (isfinalfeasible() || DBG_ENABLED())
print_summary();
/** @return whether the current partial trace must be a prefix of a
* feasible trace. */
bool ModelChecker::isfeasibleprefix() {
- return promises->size() == 0 && pending_acq_rel_seq->size() == 0;
+ return promises->size() == 0 && pending_rel_seqs->size() == 0;
}
/** @return whether the current partial trace is feasible. */
* @todo Finish lazy updating, when promises are fulfilled in the future
* @param rf The action that might be part of a release sequence. Must be a
* write.
- * @param release_heads A pass-by-reference style return parameter. After
+ * @param release_heads A pass-by-reference style return parameter. After
* execution of this function, release_heads will contain the heads of all the
- * relevant release sequences, if any exists
+ * relevant release sequences, if any exists with certainty
+ * @param pending A pass-by-reference style return parameter which is only used
+ * when returning false (i.e., uncertain). Returns most information regarding
+ * an uncertain release sequence, including any write operations that might
+ * break the sequence.
* @return true, if the ModelChecker is certain that release_heads is complete;
* false otherwise
*/
- bool ModelChecker::release_seq_heads(const ModelAction *rf, rel_heads_list_t *release_heads) const
+ bool ModelChecker::release_seq_heads(const ModelAction *rf,
+ rel_heads_list_t *release_heads,
+ struct release_seq *pending) const
{
/* Only check for release sequences if there are no cycles */
if (mo_graph->checkForCycles())
};
if (!rf) {
/* read from future: need to settle this later */
+ pending->rf = NULL;
return false; /* incomplete */
}
ASSERT(rf->same_thread(release));
+ pending->writes.clear();
+
bool certain = true;
for (unsigned int i = 0; i < thrd_lists->size(); i++) {
if (id_to_int(rf->get_tid()) == (int)i)
/* release --mo-> act --mo--> rf */
return true; /* complete */
}
+ /* act may break release sequence */
+ pending->writes.push_back(act);
certain = false;
}
if (!future_ordered)
- return false; /* This thread is uncertain */
+ certain = false; /* This thread is uncertain */
}
- if (certain)
+ if (certain) {
release_heads->push_back(release);
+ pending->writes.clear();
+ } else {
+ pending->release = release;
+ pending->rf = rf;
+ }
return certain;
}
void ModelChecker::get_release_seq_heads(ModelAction *act, rel_heads_list_t *release_heads)
{
const ModelAction *rf = act->get_reads_from();
+ struct release_seq *sequence = (struct release_seq *)snapshot_calloc(1, sizeof(struct release_seq));
+ sequence->acquire = act;
- if (!release_seq_heads(rf, release_heads)) {
+ if (!release_seq_heads(rf, release_heads, sequence)) {
/* add act to 'lazy checking' list */
- pending_acq_rel_seq->push_back(act);
+ pending_rel_seqs->push_back(sequence);
+ } else {
+ snapshot_free(sequence);
}
}
bool ModelChecker::resolve_release_sequences(void *location, work_queue_t *work_queue)
{
bool updated = false;
- std::vector<ModelAction *>::iterator it = pending_acq_rel_seq->begin();
- while (it != pending_acq_rel_seq->end()) {
- ModelAction *act = *it;
+ std::vector<struct release_seq *>::iterator it = pending_rel_seqs->begin();
+ while (it != pending_rel_seqs->end()) {
+ struct release_seq *pending = *it;
+ ModelAction *act = pending->acquire;
/* Only resolve sequences on the given location, if provided */
if (location && act->get_location() != location) {
const ModelAction *rf = act->get_reads_from();
rel_heads_list_t release_heads;
bool complete;
- complete = release_seq_heads(rf, &release_heads);
+ complete = release_seq_heads(rf, &release_heads, pending);
for (unsigned int i = 0; i < release_heads.size(); i++) {
if (!act->has_synchronized_with(release_heads[i])) {
if (act->synchronize_with(release_heads[i]))
}
}
}
- if (complete)
- it = pending_acq_rel_seq->erase(it);
- else
+ if (complete) {
+ it = pending_rel_seqs->erase(it);
+ snapshot_free(pending);
+ } else {
it++;
+ }
}
// If we resolved promises or data races, see if we have realized a data race.
} else
promise_index++;
}
+
+ //Check whether reading these writes has made threads unable to
+ //resolve promises
+
for(unsigned int i=0;i<threads_to_check.size();i++)
mo_check_promises(threads_to_check[i], write);
}
}
-/** Checks promises in response to change in ClockVector Threads. */
+/** Checks promises in response to addition to modification order for threads.
+ * Definitions:
+ * pthread is the thread that performed the read that created the promise
+ *
+ * pread is the read that created the promise
+ *
+ * pwrite is either the first write to same location as pread by
+ * pthread that is sequenced after pread or the value read by the
+ * first read to the same lcoation as pread by pthread that is
+ * sequenced after pread..
+ *
+ * 1. If tid=pthread, then we check what other threads are reachable
+ * through the mode order starting with pwrite. Those threads cannot
+ * perform a write that will resolve the promise due to modification
+ * order constraints.
+ *
+ * 2. If the tid is not pthread, we check whether pwrite can reach the
+ * action write through the modification order. If so, that thread
+ * cannot perform a future write that will resolve the promise due to
+ * modificatin order constraints.
+ *
+ * @parem tid The thread that either read from the model action
+ * write, or actually did the model action write.
+ *
+ * @parem write The ModelAction representing the relevant write.
+ */
+
void ModelChecker::mo_check_promises(thread_id_t tid, const ModelAction *write) {
void * location = write->get_location();
for (unsigned int i = 0; i < promises->size(); i++) {
if ( act->get_location() != location )
continue;
- if ( act->get_tid()==tid) {
+ //same thread as the promise
+ if ( act->get_tid()==tid ) {
+
+ //do we have a pwrite for the promise, if not, set it
if (promise->get_write() == NULL ) {
promise->set_write(write);
}
projects / model-checker.git / commitdiff