1 #define __STDC_FORMAT_MACROS
10 #include "threads-model.h"
11 #include "modeltypes.h"
14 * @brief Node constructor
16 * Constructs a single Node for use in a NodeStack. Each Node is associated
17 * with exactly one ModelAction (exception: the first Node should be created
18 * as an empty stub, to represent the first thread "choice") and up to one
21 * @param act The ModelAction to associate with this Node. May be NULL.
22 * @param par The parent Node in the NodeStack. May be NULL if there is no
24 * @param nthreads The number of threads which exist at this point in the
27 Node::Node(ModelAction *act, Node *par, int nthreads, Node *prevfairness) :
28 read_from_status(READ_FROM_PAST),
31 num_threads(nthreads),
32 explored_children(num_threads),
33 backtrack(num_threads),
34 fairness(num_threads),
38 read_from_past_idx(0),
40 read_from_promise_idx(-1),
44 resolve_promise_idx(-1),
45 relseq_break_writes(),
46 relseq_break_index(0),
52 int currtid = id_to_int(act->get_tid());
53 int prevtid = prevfairness ? id_to_int(prevfairness->action->get_tid()) : 0;
55 if (model->params.fairwindow != 0) {
56 for (int i = 0; i < num_threads; i++) {
57 ASSERT(i < ((int)fairness.size()));
58 struct fairness_info *fi = &fairness[i];
59 struct fairness_info *prevfi = (parent && i < parent->get_num_threads()) ? &parent->fairness[i] : NULL;
63 if (parent && parent->is_enabled(int_to_id(i))) {
70 /* Do window processing */
71 if (prevfairness != NULL) {
72 if (prevfairness->parent->is_enabled(int_to_id(i)))
77 /* Need full window to start evaluating
79 * If we meet the enabled count and have no
80 * turns, give us priority */
81 if ((fi->enabled_count >= model->params.enabledcount) &&
89 /** @brief Node desctructor */
94 model_free(enabled_array);
97 /** Prints debugging info for the ModelAction associated with this Node */
98 void Node::print() const
101 model_print(" backtrack: %s", backtrack_empty() ? "empty" : "non-empty ");
102 for (int i = 0; i < (int)backtrack.size(); i++)
103 if (backtrack[i] == true)
104 model_print("[%d]", i);
107 model_print(" read from past: %s", read_from_past_empty() ? "empty" : "non-empty ");
108 for (int i = read_from_past_idx + 1; i < (int)read_from_past.size(); i++)
109 model_print("[%d]", read_from_past[i]->get_seq_number());
112 model_print(" read-from promises: %s", read_from_promise_empty() ? "empty" : "non-empty ");
113 for (int i = read_from_promise_idx + 1; i < (int)read_from_promises.size(); i++)
114 model_print("[%d]", read_from_promises[i]->get_seq_number());
117 model_print(" future values: %s", future_value_empty() ? "empty" : "non-empty ");
118 for (int i = future_index + 1; i < (int)future_values.size(); i++)
119 model_print("[%#" PRIx64 "]", future_values[i].value);
122 model_print(" promises: %s\n", promise_empty() ? "empty" : "non-empty");
123 model_print(" misc: %s\n", misc_empty() ? "empty" : "non-empty");
124 model_print(" rel seq break: %s\n", relseq_break_empty() ? "empty" : "non-empty");
127 /*********************************** promise **********************************/
130 * Sets a promise to explore meeting with the given node.
131 * @param i is the promise index.
133 void Node::set_promise(unsigned int i)
135 if (i >= resolve_promise.size())
136 resolve_promise.resize(i + 1, false);
137 resolve_promise[i] = true;
141 * Looks up whether a given promise should be satisfied by this node.
142 * @param i The promise index.
143 * @return true if the promise should be satisfied by the given ModelAction.
145 bool Node::get_promise(unsigned int i) const
147 return (i < resolve_promise.size()) && (int)i == resolve_promise_idx;
151 * Increments to the next promise to resolve.
152 * @return true if we have a valid combination.
154 bool Node::increment_promise()
157 if (resolve_promise.empty())
159 int prev_idx = resolve_promise_idx;
160 resolve_promise_idx++;
161 for ( ; resolve_promise_idx < (int)resolve_promise.size(); resolve_promise_idx++)
162 if (resolve_promise[resolve_promise_idx])
164 resolve_promise_idx = prev_idx;
169 * Returns whether the promise set is empty.
170 * @return true if we have explored all promise combinations.
172 bool Node::promise_empty() const
174 for (int i = resolve_promise_idx + 1; i < (int)resolve_promise.size(); i++)
175 if (i >= 0 && resolve_promise[i])
180 /** @brief Clear any promise-resolution information for this Node */
181 void Node::clear_promise_resolutions()
183 resolve_promise.clear();
184 resolve_promise_idx = -1;
187 /******************************* end promise **********************************/
189 void Node::set_misc_max(int i)
194 int Node::get_misc() const
199 bool Node::increment_misc()
201 return (misc_index < misc_max) && ((++misc_index) < misc_max);
204 bool Node::misc_empty() const
206 return (misc_index + 1) >= misc_max;
210 * Checks if the Thread associated with this thread ID has been explored from
212 * @param tid is the thread ID to check
213 * @return true if this thread choice has been explored already, false
216 bool Node::has_been_explored(thread_id_t tid) const
218 int id = id_to_int(tid);
219 return explored_children[id];
223 * Checks if the backtracking set is empty.
224 * @return true if the backtracking set is empty
226 bool Node::backtrack_empty() const
228 return (numBacktracks == 0);
232 * Mark the appropriate backtracking information for exploring a thread choice.
233 * @param act The ModelAction to explore
235 void Node::explore_child(ModelAction *act, enabled_type_t *is_enabled)
238 enabled_array = (enabled_type_t *)model_malloc(sizeof(enabled_type_t) * num_threads);
239 if (is_enabled != NULL)
240 memcpy(enabled_array, is_enabled, sizeof(enabled_type_t) * num_threads);
242 for (int i = 0; i < num_threads; i++)
243 enabled_array[i] = THREAD_DISABLED;
246 explore(act->get_tid());
250 * Records a backtracking reference for a thread choice within this Node.
251 * Provides feedback as to whether this thread choice is already set for
253 * @return false if the thread was already set to be backtracked, true
256 bool Node::set_backtrack(thread_id_t id)
258 int i = id_to_int(id);
259 ASSERT(i < ((int)backtrack.size()));
267 thread_id_t Node::get_next_backtrack()
269 /** @todo Find next backtrack */
271 for (i = 0; i < backtrack.size(); i++)
272 if (backtrack[i] == true)
274 /* Backtrack set was empty? */
275 ASSERT(i != backtrack.size());
277 backtrack[i] = false;
282 void Node::clear_backtracking()
284 for (unsigned int i = 0; i < backtrack.size(); i++)
285 backtrack[i] = false;
286 for (unsigned int i = 0; i < explored_children.size(); i++)
287 explored_children[i] = false;
291 bool Node::is_enabled(Thread *t) const
293 int thread_id = id_to_int(t->get_id());
294 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
297 enabled_type_t Node::enabled_status(thread_id_t tid) const
299 int thread_id = id_to_int(tid);
300 if (thread_id < num_threads)
301 return enabled_array[thread_id];
303 return THREAD_DISABLED;
306 bool Node::is_enabled(thread_id_t tid) const
308 int thread_id = id_to_int(tid);
309 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
312 bool Node::has_priority(thread_id_t tid) const
314 return fairness[id_to_int(tid)].priority;
317 /*********************************** read from ********************************/
320 * Get the current state of the may-read-from set iteration
321 * @return The read-from type we should currently be checking (past or future)
323 read_from_type_t Node::get_read_from_status()
325 if (read_from_status == READ_FROM_PAST && read_from_past.empty())
326 increment_read_from();
327 return read_from_status;
331 * Iterate one step in the may-read-from iteration. This includes a step in
332 * reading from the either the past or the future.
333 * @return True if there is a new read-from to explore; false otherwise
335 bool Node::increment_read_from()
337 clear_promise_resolutions();
338 if (increment_read_from_past()) {
339 read_from_status = READ_FROM_PAST;
341 } else if (increment_read_from_promise()) {
342 read_from_status = READ_FROM_PROMISE;
344 } else if (increment_future_value()) {
345 read_from_status = READ_FROM_FUTURE;
348 read_from_status = READ_FROM_NONE;
353 * @return True if there are any new read-froms to explore
355 bool Node::read_from_empty() const
357 return read_from_past_empty() &&
358 read_from_promise_empty() &&
359 future_value_empty();
363 * Get the total size of the may-read-from set, including both past and future
365 * @return The size of may-read-from
367 unsigned int Node::read_from_size() const
369 return read_from_past.size() +
370 read_from_promises.size() +
371 future_values.size();
374 /******************************* end read from ********************************/
376 /****************************** read from past ********************************/
378 /** @brief Prints info about read_from_past set */
379 void Node::print_read_from_past()
381 for (unsigned int i = 0; i < read_from_past.size(); i++)
382 read_from_past[i]->print();
386 * Add an action to the read_from_past set.
387 * @param act is the action to add
389 void Node::add_read_from_past(const ModelAction *act)
391 read_from_past.push_back(act);
395 * Gets the next 'read_from_past' action from this Node. Only valid for a node
396 * where this->action is a 'read'.
397 * @return The first element in read_from_past
399 const ModelAction * Node::get_read_from_past() const
401 if (read_from_past_idx < read_from_past.size())
402 return read_from_past[read_from_past_idx];
407 const ModelAction * Node::get_read_from_past(int i) const
409 return read_from_past[i];
412 int Node::get_read_from_past_size() const
414 return read_from_past.size();
418 * Checks whether the readsfrom set for this node is empty.
419 * @return true if the readsfrom set is empty.
421 bool Node::read_from_past_empty() const
423 return ((read_from_past_idx + 1) >= read_from_past.size());
427 * Increments the index into the readsfrom set to explore the next item.
428 * @return Returns false if we have explored all items.
430 bool Node::increment_read_from_past()
433 if (read_from_past_idx < read_from_past.size()) {
434 read_from_past_idx++;
435 return read_from_past_idx < read_from_past.size();
440 /************************** end read from past ********************************/
442 /***************************** read_from_promises *****************************/
445 * Add an action to the read_from_promises set.
446 * @param reader The read which generated the Promise; we use the ModelAction
447 * instead of the Promise because the Promise does not last across executions
449 void Node::add_read_from_promise(const ModelAction *reader)
451 read_from_promises.push_back(reader);
455 * Gets the next 'read-from-promise' from this Node. Only valid for a node
456 * where this->action is a 'read'.
457 * @return The current element in read_from_promises
459 Promise * Node::get_read_from_promise() const
461 ASSERT(read_from_promise_idx >= 0 && read_from_promise_idx < ((int)read_from_promises.size()));
462 return read_from_promises[read_from_promise_idx]->get_reads_from_promise();
466 * Gets a particular 'read-from-promise' form this Node. Only vlaid for a node
467 * where this->action is a 'read'.
468 * @param i The index of the Promise to get
469 * @return The Promise at index i, if the Promise is still available; NULL
472 Promise * Node::get_read_from_promise(int i) const
474 return read_from_promises[i]->get_reads_from_promise();
477 /** @return The size of the read-from-promise set */
478 int Node::get_read_from_promise_size() const
480 return read_from_promises.size();
484 * Checks whether the read_from_promises set for this node is empty.
485 * @return true if the read_from_promises set is empty.
487 bool Node::read_from_promise_empty() const
489 return ((read_from_promise_idx + 1) >= ((int)read_from_promises.size()));
493 * Increments the index into the read_from_promises set to explore the next item.
494 * @return Returns false if we have explored all promises.
496 bool Node::increment_read_from_promise()
499 if (read_from_promise_idx < ((int)read_from_promises.size())) {
500 read_from_promise_idx++;
501 return (read_from_promise_idx < ((int)read_from_promises.size()));
506 /************************* end read_from_promises *****************************/
508 /****************************** future values *********************************/
511 * Adds a value from a weakly ordered future write to backtrack to. This
512 * operation may "fail" if the future value has already been run (within some
513 * sloppiness window of this expiration), or if the futurevalues set has
514 * reached its maximum.
515 * @see model_params.maxfuturevalues
517 * @param value is the value to backtrack to.
518 * @return True if the future value was successully added; false otherwise
520 bool Node::add_future_value(struct future_value fv)
522 uint64_t value = fv.value;
523 modelclock_t expiration = fv.expiration;
524 thread_id_t tid = fv.tid;
525 int idx = -1; /* Highest index where value is found */
526 for (unsigned int i = 0; i < future_values.size(); i++) {
527 if (future_values[i].value == value && future_values[i].tid == tid) {
528 if (expiration <= future_values[i].expiration)
533 if (idx > future_index) {
534 /* Future value hasn't been explored; update expiration */
535 future_values[idx].expiration = expiration;
537 } else if (idx >= 0 && expiration <= future_values[idx].expiration + model->params.expireslop) {
538 /* Future value has been explored and is within the "sloppy" window */
542 /* Limit the size of the future-values set */
543 if (model->params.maxfuturevalues > 0 &&
544 (int)future_values.size() >= model->params.maxfuturevalues)
547 future_values.push_back(fv);
552 * Gets the next 'future_value' from this Node. Only valid for a node where
553 * this->action is a 'read'.
554 * @return The first element in future_values
556 struct future_value Node::get_future_value() const
558 ASSERT(future_index >= 0 && future_index < ((int)future_values.size()));
559 return future_values[future_index];
563 * Checks whether the future_values set for this node is empty.
564 * @return true if the future_values set is empty.
566 bool Node::future_value_empty() const
568 return ((future_index + 1) >= ((int)future_values.size()));
572 * Increments the index into the future_values set to explore the next item.
573 * @return Returns false if we have explored all values.
575 bool Node::increment_future_value()
578 if (future_index < ((int)future_values.size())) {
580 return (future_index < ((int)future_values.size()));
585 /************************** end future values *********************************/
588 * Add a write ModelAction to the set of writes that may break the release
589 * sequence. This is used during replay exploration of pending release
590 * sequences. This Node must correspond to a release sequence fixup action.
592 * @param write The write that may break the release sequence. NULL means we
593 * allow the release sequence to synchronize.
595 void Node::add_relseq_break(const ModelAction *write)
597 relseq_break_writes.push_back(write);
601 * Get the write that may break the current pending release sequence,
602 * according to the replay / divergence pattern.
604 * @return A write that may break the release sequence. If NULL, that means
605 * the release sequence should not be broken.
607 const ModelAction * Node::get_relseq_break() const
609 if (relseq_break_index < (int)relseq_break_writes.size())
610 return relseq_break_writes[relseq_break_index];
616 * Increments the index into the relseq_break_writes set to explore the next
618 * @return Returns false if we have explored all values.
620 bool Node::increment_relseq_break()
623 if (relseq_break_index < ((int)relseq_break_writes.size())) {
624 relseq_break_index++;
625 return (relseq_break_index < ((int)relseq_break_writes.size()));
631 * @return True if all writes that may break the release sequence have been
634 bool Node::relseq_break_empty() const
636 return ((relseq_break_index + 1) >= ((int)relseq_break_writes.size()));
639 void Node::explore(thread_id_t tid)
641 int i = id_to_int(tid);
642 ASSERT(i < ((int)backtrack.size()));
644 backtrack[i] = false;
647 explored_children[i] = true;
650 NodeStack::NodeStack() :
658 NodeStack::~NodeStack()
660 for (unsigned int i = 0; i < node_list.size(); i++)
664 void NodeStack::print() const
666 model_print("............................................\n");
667 model_print("NodeStack printing node_list:\n");
668 for (unsigned int it = 0; it < node_list.size(); it++) {
669 if ((int)it == this->head_idx)
670 model_print("vvv following action is the current iterator vvv\n");
671 node_list[it]->print();
673 model_print("............................................\n");
676 /** Note: The is_enabled set contains what actions were enabled when
678 ModelAction * NodeStack::explore_action(ModelAction *act, enabled_type_t *is_enabled)
682 if ((head_idx + 1) < (int)node_list.size()) {
684 return node_list[head_idx]->get_action();
688 Node *head = get_head();
689 Node *prevfairness = NULL;
691 head->explore_child(act, is_enabled);
692 if (model->params.fairwindow != 0 && head_idx > (int)model->params.fairwindow)
693 prevfairness = node_list[head_idx - model->params.fairwindow];
696 int next_threads = model->get_num_threads();
697 if (act->get_type() == THREAD_CREATE)
699 node_list.push_back(new Node(act, head, next_threads, prevfairness));
706 * Empties the stack of all trailing nodes after a given position and calls the
707 * destructor for each. This function is provided an offset which determines
708 * how many nodes (relative to the current replay state) to save before popping
710 * @param numAhead gives the number of Nodes (including this Node) to skip over
711 * before removing nodes.
713 void NodeStack::pop_restofstack(int numAhead)
715 /* Diverging from previous execution; clear out remainder of list */
716 unsigned int it = head_idx + numAhead;
717 for (unsigned int i = it; i < node_list.size(); i++)
719 node_list.resize(it);
720 node_list.back()->clear_backtracking();
723 Node * NodeStack::get_head() const
725 if (node_list.empty() || head_idx < 0)
727 return node_list[head_idx];
730 Node * NodeStack::get_next() const
732 if (node_list.empty()) {
736 unsigned int it = head_idx + 1;
737 if (it == node_list.size()) {
741 return node_list[it];
744 void NodeStack::reset_execution()