read_from(curr, reads_from);
mo_graph->commitChanges();
- mo_check_promises(curr->get_tid(), reads_from);
+ mo_check_promises(curr->get_tid(), reads_from, NULL);
updated |= r_status;
} else if (!second_part_of_rmw) {
/* Read from future value */
- value = curr->get_node()->get_future_value();
- modelclock_t expiration = curr->get_node()->get_future_value_expiration();
+ struct future_value fv = curr->get_node()->get_future_value();
+ value = fv.value;
+ curr->set_value(fv.value);
curr->set_read_from(NULL);
- Promise *valuepromise = new Promise(curr, value, expiration);
- promises->push_back(valuepromise);
+ promises->push_back(new Promise(curr, fv));
}
get_thread(curr)->set_return_value(value);
return updated;
void ModelChecker::add_future_value(const ModelAction *writer, ModelAction *reader)
{
/* Do more ambitious checks now that mo is more complete */
- if (mo_may_allow(writer, reader) &&
- reader->get_node()->add_future_value(writer->get_value(),
- writer->get_seq_number() + params.maxfuturedelay))
- set_latest_backtrack(reader);
+ if (mo_may_allow(writer, reader)) {
+ Node *node = reader->get_node();
+
+ /* Find an ancestor thread which exists at the time of the reader */
+ Thread *write_thread = get_thread(writer);
+ while (id_to_int(write_thread->get_id()) >= node->get_num_threads())
+ write_thread = write_thread->get_parent();
+
+ struct future_value fv = {
+ writer->get_value(),
+ writer->get_seq_number() + params.maxfuturedelay,
+ write_thread->get_id(),
+ };
+ if (node->add_future_value(fv))
+ set_latest_backtrack(reader);
+ }
}
/**
}
mo_graph->commitChanges();
- mo_check_promises(curr->get_tid(), curr);
+ mo_check_promises(curr->get_tid(), curr, NULL);
get_thread(curr)->set_return_value(VALUE_NONE);
return updated_mod_order || updated_promises;
bool ModelChecker::resolve_promises(ModelAction *write)
{
bool resolved = false;
- std::vector< thread_id_t, ModelAlloc<thread_id_t> > threads_to_check;
+ std::vector< ModelAction *, ModelAlloc<ModelAction *> > actions_to_check;
for (unsigned int i = 0, promise_index = 0; promise_index < promises->size(); i++) {
Promise *promise = (*promises)[promise_index];
delete(promise);
promises->erase(promises->begin() + promise_index);
- threads_to_check.push_back(read->get_tid());
+ actions_to_check.push_back(read);
resolved = true;
} else
//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);
+ for (unsigned int i = 0; i < actions_to_check.size(); i++) {
+ ModelAction *read=actions_to_check[i];
+ mo_check_promises(read->get_tid(), write, read);
+ }
return resolved;
}
const ModelAction *act = promise->get_action();
if ((old_cv == NULL || !old_cv->synchronized_since(act)) &&
merge_cv->synchronized_since(act)) {
- if (promise->increment_threads(tid)) {
+ if (promise->eliminate_thread(tid)) {
//Promise has failed
priv->failed_promise = true;
return;
}
}
-void ModelChecker::check_promises_thread_disabled() {
+void ModelChecker::check_promises_thread_disabled()
+{
for (unsigned int i = 0; i < promises->size(); i++) {
Promise *promise = (*promises)[i];
- if (promise->check_promise()) {
+ if (promise->has_failed()) {
priv->failed_promise = true;
return;
}
}
}
-/** Checks promises in response to addition to modification order for threads.
+/**
+ * @brief 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..
+ * pthread that is sequenced after pread or the write read by the
+ * first read to the same location 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
+ * 1. If tid=pthread, then we check what other threads are reachable
+ * through the mod order starting with pwrite. Those threads cannot
* perform a write that will resolve the promise due to modification
* order constraints.
*
* cannot perform a future write that will resolve the promise due to
* modificatin order constraints.
*
- * @param tid The thread that either read from the model action
- * write, or actually did the model action write.
+ * @param tid The thread that either read from the model action write, or
+ * actually did the model action write.
*
- * @param write The ModelAction representing the relevant write.
+ * @param write The ModelAction representing the relevant write.
+ * @param read The ModelAction that reads a promised write, or NULL otherwise.
*/
-void ModelChecker::mo_check_promises(thread_id_t tid, const ModelAction *write)
+void ModelChecker::mo_check_promises(thread_id_t tid, const ModelAction *write, const ModelAction *read)
{
void *location = write->get_location();
for (unsigned int i = 0; i < promises->size(); i++) {
Promise *promise = (*promises)[i];
const ModelAction *act = promise->get_action();
- //Is this promise on the same location?
+ // Is this promise on the same location?
if (act->get_location() != location)
continue;
- //same thread as the promise
+ // same thread as the promise
if (act->get_tid() == tid) {
+ // make sure that the reader of this write happens after the promise
+ if ((read == NULL) || (promise->get_action()->happens_before(read))) {
+ // do we have a pwrite for the promise, if not, set it
+ if (promise->get_write() == NULL) {
+ promise->set_write(write);
+ // The pwrite cannot happen before the promise
+ if (write->happens_before(act) && (write != act)) {
+ priv->failed_promise = true;
+ return;
+ }
+ }
- //do we have a pwrite for the promise, if not, set it
- if (promise->get_write() == NULL) {
- promise->set_write(write);
- //The pwrite cannot happen before the promise
- if (write->happens_before(act) && (write != act)) {
+ if (mo_graph->checkPromise(write, promise)) {
priv->failed_promise = true;
return;
}
}
- if (mo_graph->checkPromise(write, promise)) {
- priv->failed_promise = true;
- return;
- }
}
- //Don't do any lookups twice for the same thread
- if (promise->has_sync_thread(tid))
+ // Don't do any lookups twice for the same thread
+ if (promise->thread_is_eliminated(tid))
continue;
if (promise->get_write() && mo_graph->checkReachable(promise->get_write(), write)) {
- if (promise->increment_threads(tid)) {
+ if (promise->eliminate_thread(tid)) {
priv->failed_promise = true;
return;
}
* @param act The ModelAction
* @return A Thread reference
*/
-Thread * ModelChecker::get_thread(ModelAction *act) const
+Thread * ModelChecker::get_thread(const ModelAction *act) const
{
return get_thread(act->get_tid());
}
projects / model-checker.git / blobdiff