1 #define __STDC_FORMAT_MACROS
10 #include "threads-model.h"
13 * @brief Node constructor
15 * Constructs a single Node for use in a NodeStack. Each Node is associated
16 * with exactly one ModelAction (exception: the first Node should be created
17 * as an empty stub, to represent the first thread "choice") and up to one
20 * @param act The ModelAction to associate with this Node. May be NULL.
21 * @param par The parent Node in the NodeStack. May be NULL if there is no
23 * @param nthreads The number of threads which exist at this point in the
26 Node::Node(ModelAction *act, Node *par, int nthreads, Node *prevfairness)
29 num_threads(nthreads),
30 explored_children(num_threads),
31 backtrack(num_threads),
32 fairness(num_threads),
39 relseq_break_writes(),
40 relseq_break_index(0),
46 int currtid = id_to_int(act->get_tid());
47 int prevtid = prevfairness ? id_to_int(prevfairness->action->get_tid()) : 0;
49 if (model->params.fairwindow != 0) {
50 for (int i = 0; i < num_threads; i++) {
51 ASSERT(i < ((int)fairness.size()));
52 struct fairness_info *fi = &fairness[i];
53 struct fairness_info *prevfi = (parent && i < parent->get_num_threads()) ? &parent->fairness[i] : NULL;
57 if (parent && parent->is_enabled(int_to_id(i))) {
64 /* Do window processing */
65 if (prevfairness != NULL) {
66 if (prevfairness->parent->is_enabled(int_to_id(i)))
71 /* Need full window to start evaluating
73 * If we meet the enabled count and have no
74 * turns, give us priority */
75 if ((fi->enabled_count >= model->params.enabledcount) &&
83 /** @brief Node desctructor */
88 model_free(enabled_array);
91 /** Prints debugging info for the ModelAction associated with this Node */
95 model_print(" backtrack: %s", backtrack_empty() ? "empty" : "non-empty ");
96 for (int i = 0; i < (int)backtrack.size(); i++)
97 if (backtrack[i] == true)
98 model_print("[%d]", i);
100 model_print(" future values: %s", future_value_empty() ? "empty" : "non-empty ");
101 for (int i = future_index + 1; i < (int)future_values.size(); i++)
102 model_print("[%#" PRIx64 "]", future_values[i].value);
105 model_print(" read-from: %s", read_from_empty() ? "empty" : "non-empty ");
106 for (int i = read_from_index + 1; i < (int)may_read_from.size(); i++)
107 model_print("[%d]", may_read_from[i]->get_seq_number());
110 model_print(" promises: %s\n", promise_empty() ? "empty" : "non-empty");
111 model_print(" misc: %s\n", misc_empty() ? "empty" : "non-empty");
112 model_print(" rel seq break: %s\n", relseq_break_empty() ? "empty" : "non-empty");
115 /** @brief Prints info about may_read_from set */
116 void Node::print_may_read_from()
118 for (unsigned int i = 0; i < may_read_from.size(); i++)
119 may_read_from[i]->print();
123 * Sets a promise to explore meeting with the given node.
124 * @param i is the promise index.
126 void Node::set_promise(unsigned int i, bool is_rmw)
128 if (i >= promises.size())
129 promises.resize(i + 1, PROMISE_IGNORE);
130 if (promises[i] == PROMISE_IGNORE) {
131 promises[i] = PROMISE_UNFULFILLED;
133 promises[i] |= PROMISE_RMW;
138 * Looks up whether a given promise should be satisfied by this node.
139 * @param i The promise index.
140 * @return true if the promise should be satisfied by the given model action.
142 bool Node::get_promise(unsigned int i) const
144 return (i < promises.size()) && ((promises[i] & PROMISE_MASK) == PROMISE_FULFILLED);
148 * Increments to the next combination of promises.
149 * @return true if we have a valid combination.
151 bool Node::increment_promise()
154 unsigned int rmw_count = 0;
155 for (unsigned int i = 0; i < promises.size(); i++) {
156 if (promises[i] == (PROMISE_RMW|PROMISE_FULFILLED))
160 for (unsigned int i = 0; i < promises.size(); i++) {
161 if ((promises[i] & PROMISE_MASK) == PROMISE_UNFULFILLED) {
162 if ((rmw_count > 0) && (promises[i] & PROMISE_RMW)) {
163 //sending our value to two rmws... not going to work..try next combination
166 promises[i] = (promises[i] & PROMISE_RMW) |PROMISE_FULFILLED;
169 if ((promises[i] & PROMISE_MASK) == PROMISE_FULFILLED)
170 promises[i] = (promises[i] & PROMISE_RMW) | PROMISE_UNFULFILLED;
173 } else if (promises[i] == (PROMISE_RMW|PROMISE_FULFILLED)) {
181 * Returns whether the promise set is empty.
182 * @return true if we have explored all promise combinations.
184 bool Node::promise_empty() const
186 bool fulfilledrmw = false;
187 for (int i = promises.size() - 1; i >= 0; i--) {
188 if (promises[i] == PROMISE_UNFULFILLED)
190 if (!fulfilledrmw && ((promises[i]&PROMISE_MASK) == PROMISE_UNFULFILLED))
192 if (promises[i] == (PROMISE_FULFILLED|PROMISE_RMW))
198 void Node::set_misc_max(int i)
203 int Node::get_misc() const
208 bool Node::increment_misc()
210 return (misc_index < misc_max) && ((++misc_index) < misc_max);
213 bool Node::misc_empty() const
215 return (misc_index + 1) >= misc_max;
219 * Adds a value from a weakly ordered future write to backtrack to. This
220 * operation may "fail" if the future value has already been run (within some
221 * sloppiness window of this expiration), or if the futurevalues set has
222 * reached its maximum.
223 * @see model_params.maxfuturevalues
225 * @param value is the value to backtrack to.
226 * @return True if the future value was successully added; false otherwise
228 bool Node::add_future_value(uint64_t value, modelclock_t expiration)
230 int idx = -1; /* Highest index where value is found */
231 for (unsigned int i = 0; i < future_values.size(); i++) {
232 if (future_values[i].value == value) {
233 if (expiration <= future_values[i].expiration)
238 if (idx > future_index) {
239 /* Future value hasn't been explored; update expiration */
240 future_values[idx].expiration = expiration;
242 } else if (idx >= 0 && expiration <= future_values[idx].expiration + model->params.expireslop) {
243 /* Future value has been explored and is within the "sloppy" window */
247 /* Limit the size of the future-values set */
248 if (model->params.maxfuturevalues > 0 &&
249 (int)future_values.size() >= model->params.maxfuturevalues)
252 struct future_value newfv = {value, expiration};
253 future_values.push_back(newfv);
258 * Checks whether the future_values set for this node is empty.
259 * @return true if the future_values set is empty.
261 bool Node::future_value_empty() const
263 return ((future_index + 1) >= ((int)future_values.size()));
267 * Checks if the Thread associated with this thread ID has been explored from
269 * @param tid is the thread ID to check
270 * @return true if this thread choice has been explored already, false
273 bool Node::has_been_explored(thread_id_t tid) const
275 int id = id_to_int(tid);
276 return explored_children[id];
280 * Checks if the backtracking set is empty.
281 * @return true if the backtracking set is empty
283 bool Node::backtrack_empty() const
285 return (numBacktracks == 0);
289 * Checks whether the readsfrom set for this node is empty.
290 * @return true if the readsfrom set is empty.
292 bool Node::read_from_empty() const
294 return ((read_from_index + 1) >= may_read_from.size());
298 * Mark the appropriate backtracking information for exploring a thread choice.
299 * @param act The ModelAction to explore
301 void Node::explore_child(ModelAction *act, enabled_type_t *is_enabled)
304 enabled_array = (enabled_type_t *)model_malloc(sizeof(enabled_type_t) * num_threads);
305 if (is_enabled != NULL)
306 memcpy(enabled_array, is_enabled, sizeof(enabled_type_t) * num_threads);
308 for (int i = 0; i < num_threads; i++)
309 enabled_array[i] = THREAD_DISABLED;
312 explore(act->get_tid());
316 * Records a backtracking reference for a thread choice within this Node.
317 * Provides feedback as to whether this thread choice is already set for
319 * @return false if the thread was already set to be backtracked, true
322 bool Node::set_backtrack(thread_id_t id)
324 int i = id_to_int(id);
325 ASSERT(i < ((int)backtrack.size()));
333 thread_id_t Node::get_next_backtrack()
335 /** @todo Find next backtrack */
337 for (i = 0; i < backtrack.size(); i++)
338 if (backtrack[i] == true)
340 /* Backtrack set was empty? */
341 ASSERT(i != backtrack.size());
343 backtrack[i] = false;
348 bool Node::is_enabled(Thread *t) const
350 int thread_id = id_to_int(t->get_id());
351 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
354 enabled_type_t Node::enabled_status(thread_id_t tid) const
356 int thread_id = id_to_int(tid);
357 if (thread_id < num_threads)
358 return enabled_array[thread_id];
360 return THREAD_DISABLED;
363 bool Node::is_enabled(thread_id_t tid) const
365 int thread_id = id_to_int(tid);
366 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
369 bool Node::has_priority(thread_id_t tid) const
371 return fairness[id_to_int(tid)].priority;
375 * Add an action to the may_read_from set.
376 * @param act is the action to add
378 void Node::add_read_from(const ModelAction *act)
380 may_read_from.push_back(act);
384 * Gets the next 'future_value' value from this Node. Only valid for a node
385 * where this->action is a 'read'.
386 * @return The first element in future_values
388 uint64_t Node::get_future_value() const
390 ASSERT(future_index >= 0 && future_index < ((int)future_values.size()));
391 return future_values[future_index].value;
394 modelclock_t Node::get_future_value_expiration() const
396 ASSERT(future_index >= 0 && future_index < ((int)future_values.size()));
397 return future_values[future_index].expiration;
400 int Node::get_read_from_size() const
402 return may_read_from.size();
405 const ModelAction * Node::get_read_from_at(int i) const
407 return may_read_from[i];
411 * Gets the next 'may_read_from' action from this Node. Only valid for a node
412 * where this->action is a 'read'.
413 * @return The first element in may_read_from
415 const ModelAction * Node::get_read_from() const
417 if (read_from_index < may_read_from.size())
418 return may_read_from[read_from_index];
424 * Increments the index into the readsfrom set to explore the next item.
425 * @return Returns false if we have explored all items.
427 bool Node::increment_read_from()
431 if (read_from_index < may_read_from.size()) {
433 return read_from_index < may_read_from.size();
439 * Increments the index into the future_values set to explore the next item.
440 * @return Returns false if we have explored all values.
442 bool Node::increment_future_value()
446 if (future_index < ((int)future_values.size())) {
448 return (future_index < ((int)future_values.size()));
454 * Add a write ModelAction to the set of writes that may break the release
455 * sequence. This is used during replay exploration of pending release
456 * sequences. This Node must correspond to a release sequence fixup action.
458 * @param write The write that may break the release sequence. NULL means we
459 * allow the release sequence to synchronize.
461 void Node::add_relseq_break(const ModelAction *write)
463 relseq_break_writes.push_back(write);
467 * Get the write that may break the current pending release sequence,
468 * according to the replay / divergence pattern.
470 * @return A write that may break the release sequence. If NULL, that means
471 * the release sequence should not be broken.
473 const ModelAction * Node::get_relseq_break() const
475 if (relseq_break_index < (int)relseq_break_writes.size())
476 return relseq_break_writes[relseq_break_index];
482 * Increments the index into the relseq_break_writes set to explore the next
484 * @return Returns false if we have explored all values.
486 bool Node::increment_relseq_break()
490 if (relseq_break_index < ((int)relseq_break_writes.size())) {
491 relseq_break_index++;
492 return (relseq_break_index < ((int)relseq_break_writes.size()));
498 * @return True if all writes that may break the release sequence have been
501 bool Node::relseq_break_empty() const
503 return ((relseq_break_index + 1) >= ((int)relseq_break_writes.size()));
506 void Node::explore(thread_id_t tid)
508 int i = id_to_int(tid);
509 ASSERT(i < ((int)backtrack.size()));
511 backtrack[i] = false;
514 explored_children[i] = true;
517 NodeStack::NodeStack() :
525 NodeStack::~NodeStack()
527 for (unsigned int i = 0; i < node_list.size(); i++)
531 void NodeStack::print() const
533 model_print("............................................\n");
534 model_print("NodeStack printing node_list:\n");
535 for (unsigned int it = 0; it < node_list.size(); it++) {
536 if ((int)it == this->head_idx)
537 model_print("vvv following action is the current iterator vvv\n");
538 node_list[it]->print();
540 model_print("............................................\n");
543 /** Note: The is_enabled set contains what actions were enabled when
545 ModelAction * NodeStack::explore_action(ModelAction *act, enabled_type_t *is_enabled)
549 if ((head_idx + 1) < (int)node_list.size()) {
551 return node_list[head_idx]->get_action();
555 Node *head = get_head();
556 Node *prevfairness = NULL;
558 head->explore_child(act, is_enabled);
559 if (model->params.fairwindow != 0 && head_idx > (int)model->params.fairwindow)
560 prevfairness = node_list[head_idx - model->params.fairwindow];
562 node_list.push_back(new Node(act, head, model->get_num_threads(), prevfairness));
569 * Empties the stack of all trailing nodes after a given position and calls the
570 * destructor for each. This function is provided an offset which determines
571 * how many nodes (relative to the current replay state) to save before popping
573 * @param numAhead gives the number of Nodes (including this Node) to skip over
574 * before removing nodes.
576 void NodeStack::pop_restofstack(int numAhead)
578 /* Diverging from previous execution; clear out remainder of list */
579 unsigned int it = head_idx + numAhead;
580 for (unsigned int i = it; i < node_list.size(); i++)
582 node_list.resize(it);
585 Node * NodeStack::get_head() const
587 if (node_list.empty() || head_idx < 0)
589 return node_list[head_idx];
592 Node * NodeStack::get_next() const
594 if (node_list.empty()) {
598 unsigned int it = head_idx + 1;
599 if (it == node_list.size()) {
603 return node_list[it];
606 void NodeStack::reset_execution()