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(" thread status: ");
103 for (int i = 0; i < num_threads; i++) {
105 enabled_type_to_string(enabled_array[i], str);
106 model_print("[%d: %s]", i, str);
110 model_print("(info not available)\n");
111 model_print(" backtrack: %s", backtrack_empty() ? "empty" : "non-empty ");
112 for (int i = 0; i < (int)backtrack.size(); i++)
113 if (backtrack[i] == true)
114 model_print("[%d]", i);
117 model_print(" read from past: %s", read_from_past_empty() ? "empty" : "non-empty ");
118 for (int i = read_from_past_idx + 1; i < (int)read_from_past.size(); i++)
119 model_print("[%d]", read_from_past[i]->get_seq_number());
122 model_print(" read-from promises: %s", read_from_promise_empty() ? "empty" : "non-empty ");
123 for (int i = read_from_promise_idx + 1; i < (int)read_from_promises.size(); i++)
124 model_print("[%d]", read_from_promises[i]->get_seq_number());
127 model_print(" future values: %s", future_value_empty() ? "empty" : "non-empty ");
128 for (int i = future_index + 1; i < (int)future_values.size(); i++)
129 model_print("[%#" PRIx64 "]", future_values[i].value);
132 model_print(" promises: %s\n", promise_empty() ? "empty" : "non-empty");
133 model_print(" misc: %s\n", misc_empty() ? "empty" : "non-empty");
134 model_print(" rel seq break: %s\n", relseq_break_empty() ? "empty" : "non-empty");
137 /*********************************** promise **********************************/
140 * Sets a promise to explore meeting with the given node.
141 * @param i is the promise index.
143 void Node::set_promise(unsigned int i)
145 if (i >= resolve_promise.size())
146 resolve_promise.resize(i + 1, false);
147 resolve_promise[i] = true;
151 * Looks up whether a given promise should be satisfied by this node.
152 * @param i The promise index.
153 * @return true if the promise should be satisfied by the given ModelAction.
155 bool Node::get_promise(unsigned int i) const
157 return (i < resolve_promise.size()) && (int)i == resolve_promise_idx;
161 * Increments to the next promise to resolve.
162 * @return true if we have a valid combination.
164 bool Node::increment_promise()
167 if (resolve_promise.empty())
169 int prev_idx = resolve_promise_idx;
170 resolve_promise_idx++;
171 for ( ; resolve_promise_idx < (int)resolve_promise.size(); resolve_promise_idx++)
172 if (resolve_promise[resolve_promise_idx])
174 resolve_promise_idx = prev_idx;
179 * Returns whether the promise set is empty.
180 * @return true if we have explored all promise combinations.
182 bool Node::promise_empty() const
184 for (int i = resolve_promise_idx + 1; i < (int)resolve_promise.size(); i++)
185 if (i >= 0 && resolve_promise[i])
190 /** @brief Clear any promise-resolution information for this Node */
191 void Node::clear_promise_resolutions()
193 resolve_promise.clear();
194 resolve_promise_idx = -1;
197 /******************************* end promise **********************************/
199 void Node::set_misc_max(int i)
204 int Node::get_misc() const
209 bool Node::increment_misc()
211 return (misc_index < misc_max) && ((++misc_index) < misc_max);
214 bool Node::misc_empty() const
216 return (misc_index + 1) >= misc_max;
220 * Checks if the Thread associated with this thread ID has been explored from
222 * @param tid is the thread ID to check
223 * @return true if this thread choice has been explored already, false
226 bool Node::has_been_explored(thread_id_t tid) const
228 int id = id_to_int(tid);
229 return explored_children[id];
233 * Checks if the backtracking set is empty.
234 * @return true if the backtracking set is empty
236 bool Node::backtrack_empty() const
238 return (numBacktracks == 0);
242 * Mark the appropriate backtracking information for exploring a thread choice.
243 * @param act The ModelAction to explore
245 void Node::explore_child(ModelAction *act, enabled_type_t *is_enabled)
248 enabled_array = (enabled_type_t *)model_malloc(sizeof(enabled_type_t) * num_threads);
249 if (is_enabled != NULL)
250 memcpy(enabled_array, is_enabled, sizeof(enabled_type_t) * num_threads);
252 for (int i = 0; i < num_threads; i++)
253 enabled_array[i] = THREAD_DISABLED;
256 explore(act->get_tid());
260 * Records a backtracking reference for a thread choice within this Node.
261 * Provides feedback as to whether this thread choice is already set for
263 * @return false if the thread was already set to be backtracked, true
266 bool Node::set_backtrack(thread_id_t id)
268 int i = id_to_int(id);
269 ASSERT(i < ((int)backtrack.size()));
277 thread_id_t Node::get_next_backtrack()
279 /** @todo Find next backtrack */
281 for (i = 0; i < backtrack.size(); i++)
282 if (backtrack[i] == true)
284 /* Backtrack set was empty? */
285 ASSERT(i != backtrack.size());
287 backtrack[i] = false;
292 void Node::clear_backtracking()
294 for (unsigned int i = 0; i < backtrack.size(); i++)
295 backtrack[i] = false;
296 for (unsigned int i = 0; i < explored_children.size(); i++)
297 explored_children[i] = false;
301 bool Node::is_enabled(Thread *t) const
303 int thread_id = id_to_int(t->get_id());
304 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
307 enabled_type_t Node::enabled_status(thread_id_t tid) const
309 int thread_id = id_to_int(tid);
310 if (thread_id < num_threads)
311 return enabled_array[thread_id];
313 return THREAD_DISABLED;
316 bool Node::is_enabled(thread_id_t tid) const
318 int thread_id = id_to_int(tid);
319 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
322 bool Node::has_priority(thread_id_t tid) const
324 return fairness[id_to_int(tid)].priority;
327 /*********************************** read from ********************************/
330 * Get the current state of the may-read-from set iteration
331 * @return The read-from type we should currently be checking (past or future)
333 read_from_type_t Node::get_read_from_status()
335 if (read_from_status == READ_FROM_PAST && read_from_past.empty())
336 increment_read_from();
337 return read_from_status;
341 * Iterate one step in the may-read-from iteration. This includes a step in
342 * reading from the either the past or the future.
343 * @return True if there is a new read-from to explore; false otherwise
345 bool Node::increment_read_from()
347 clear_promise_resolutions();
348 if (increment_read_from_past()) {
349 read_from_status = READ_FROM_PAST;
351 } else if (increment_read_from_promise()) {
352 read_from_status = READ_FROM_PROMISE;
354 } else if (increment_future_value()) {
355 read_from_status = READ_FROM_FUTURE;
358 read_from_status = READ_FROM_NONE;
363 * @return True if there are any new read-froms to explore
365 bool Node::read_from_empty() const
367 return read_from_past_empty() &&
368 read_from_promise_empty() &&
369 future_value_empty();
373 * Get the total size of the may-read-from set, including both past and future
375 * @return The size of may-read-from
377 unsigned int Node::read_from_size() const
379 return read_from_past.size() +
380 read_from_promises.size() +
381 future_values.size();
384 /******************************* end read from ********************************/
386 /****************************** read from past ********************************/
388 /** @brief Prints info about read_from_past set */
389 void Node::print_read_from_past()
391 for (unsigned int i = 0; i < read_from_past.size(); i++)
392 read_from_past[i]->print();
396 * Add an action to the read_from_past set.
397 * @param act is the action to add
399 void Node::add_read_from_past(const ModelAction *act)
401 read_from_past.push_back(act);
405 * Gets the next 'read_from_past' action from this Node. Only valid for a node
406 * where this->action is a 'read'.
407 * @return The first element in read_from_past
409 const ModelAction * Node::get_read_from_past() const
411 if (read_from_past_idx < read_from_past.size())
412 return read_from_past[read_from_past_idx];
417 const ModelAction * Node::get_read_from_past(int i) const
419 return read_from_past[i];
422 int Node::get_read_from_past_size() const
424 return read_from_past.size();
428 * Checks whether the readsfrom set for this node is empty.
429 * @return true if the readsfrom set is empty.
431 bool Node::read_from_past_empty() const
433 return ((read_from_past_idx + 1) >= read_from_past.size());
437 * Increments the index into the readsfrom set to explore the next item.
438 * @return Returns false if we have explored all items.
440 bool Node::increment_read_from_past()
443 if (read_from_past_idx < read_from_past.size()) {
444 read_from_past_idx++;
445 return read_from_past_idx < read_from_past.size();
450 /************************** end read from past ********************************/
452 /***************************** read_from_promises *****************************/
455 * Add an action to the read_from_promises set.
456 * @param reader The read which generated the Promise; we use the ModelAction
457 * instead of the Promise because the Promise does not last across executions
459 void Node::add_read_from_promise(const ModelAction *reader)
461 read_from_promises.push_back(reader);
465 * Gets the next 'read-from-promise' from this Node. Only valid for a node
466 * where this->action is a 'read'.
467 * @return The current element in read_from_promises
469 Promise * Node::get_read_from_promise() const
471 ASSERT(read_from_promise_idx >= 0 && read_from_promise_idx < ((int)read_from_promises.size()));
472 return read_from_promises[read_from_promise_idx]->get_reads_from_promise();
476 * Gets a particular 'read-from-promise' form this Node. Only vlaid for a node
477 * where this->action is a 'read'.
478 * @param i The index of the Promise to get
479 * @return The Promise at index i, if the Promise is still available; NULL
482 Promise * Node::get_read_from_promise(int i) const
484 return read_from_promises[i]->get_reads_from_promise();
487 /** @return The size of the read-from-promise set */
488 int Node::get_read_from_promise_size() const
490 return read_from_promises.size();
494 * Checks whether the read_from_promises set for this node is empty.
495 * @return true if the read_from_promises set is empty.
497 bool Node::read_from_promise_empty() const
499 return ((read_from_promise_idx + 1) >= ((int)read_from_promises.size()));
503 * Increments the index into the read_from_promises set to explore the next item.
504 * @return Returns false if we have explored all promises.
506 bool Node::increment_read_from_promise()
509 if (read_from_promise_idx < ((int)read_from_promises.size())) {
510 read_from_promise_idx++;
511 return (read_from_promise_idx < ((int)read_from_promises.size()));
516 /************************* end read_from_promises *****************************/
518 /****************************** future values *********************************/
521 * Adds a value from a weakly ordered future write to backtrack to. This
522 * operation may "fail" if the future value has already been run (within some
523 * sloppiness window of this expiration), or if the futurevalues set has
524 * reached its maximum.
525 * @see model_params.maxfuturevalues
527 * @param value is the value to backtrack to.
528 * @return True if the future value was successully added; false otherwise
530 bool Node::add_future_value(struct future_value fv)
532 uint64_t value = fv.value;
533 modelclock_t expiration = fv.expiration;
534 thread_id_t tid = fv.tid;
535 int idx = -1; /* Highest index where value is found */
536 for (unsigned int i = 0; i < future_values.size(); i++) {
537 if (future_values[i].value == value && future_values[i].tid == tid) {
538 if (expiration <= future_values[i].expiration)
543 if (idx > future_index) {
544 /* Future value hasn't been explored; update expiration */
545 future_values[idx].expiration = expiration;
547 } else if (idx >= 0 && expiration <= future_values[idx].expiration + model->params.expireslop) {
548 /* Future value has been explored and is within the "sloppy" window */
552 /* Limit the size of the future-values set */
553 if (model->params.maxfuturevalues > 0 &&
554 (int)future_values.size() >= model->params.maxfuturevalues)
557 future_values.push_back(fv);
562 * Gets the next 'future_value' from this Node. Only valid for a node where
563 * this->action is a 'read'.
564 * @return The first element in future_values
566 struct future_value Node::get_future_value() const
568 ASSERT(future_index >= 0 && future_index < ((int)future_values.size()));
569 return future_values[future_index];
573 * Checks whether the future_values set for this node is empty.
574 * @return true if the future_values set is empty.
576 bool Node::future_value_empty() const
578 return ((future_index + 1) >= ((int)future_values.size()));
582 * Increments the index into the future_values set to explore the next item.
583 * @return Returns false if we have explored all values.
585 bool Node::increment_future_value()
588 if (future_index < ((int)future_values.size())) {
590 return (future_index < ((int)future_values.size()));
595 /************************** end future values *********************************/
598 * Add a write ModelAction to the set of writes that may break the release
599 * sequence. This is used during replay exploration of pending release
600 * sequences. This Node must correspond to a release sequence fixup action.
602 * @param write The write that may break the release sequence. NULL means we
603 * allow the release sequence to synchronize.
605 void Node::add_relseq_break(const ModelAction *write)
607 relseq_break_writes.push_back(write);
611 * Get the write that may break the current pending release sequence,
612 * according to the replay / divergence pattern.
614 * @return A write that may break the release sequence. If NULL, that means
615 * the release sequence should not be broken.
617 const ModelAction * Node::get_relseq_break() const
619 if (relseq_break_index < (int)relseq_break_writes.size())
620 return relseq_break_writes[relseq_break_index];
626 * Increments the index into the relseq_break_writes set to explore the next
628 * @return Returns false if we have explored all values.
630 bool Node::increment_relseq_break()
633 if (relseq_break_index < ((int)relseq_break_writes.size())) {
634 relseq_break_index++;
635 return (relseq_break_index < ((int)relseq_break_writes.size()));
641 * @return True if all writes that may break the release sequence have been
644 bool Node::relseq_break_empty() const
646 return ((relseq_break_index + 1) >= ((int)relseq_break_writes.size()));
649 void Node::explore(thread_id_t tid)
651 int i = id_to_int(tid);
652 ASSERT(i < ((int)backtrack.size()));
654 backtrack[i] = false;
657 explored_children[i] = true;
660 NodeStack::NodeStack() :
668 NodeStack::~NodeStack()
670 for (unsigned int i = 0; i < node_list.size(); i++)
674 void NodeStack::print() const
676 model_print("............................................\n");
677 model_print("NodeStack printing node_list:\n");
678 for (unsigned int it = 0; it < node_list.size(); it++) {
679 if ((int)it == this->head_idx)
680 model_print("vvv following action is the current iterator vvv\n");
681 node_list[it]->print();
683 model_print("............................................\n");
686 /** Note: The is_enabled set contains what actions were enabled when
688 ModelAction * NodeStack::explore_action(ModelAction *act, enabled_type_t *is_enabled)
692 if ((head_idx + 1) < (int)node_list.size()) {
694 return node_list[head_idx]->get_action();
698 Node *head = get_head();
699 Node *prevfairness = NULL;
701 head->explore_child(act, is_enabled);
702 if (model->params.fairwindow != 0 && head_idx > (int)model->params.fairwindow)
703 prevfairness = node_list[head_idx - model->params.fairwindow];
706 int next_threads = model->get_num_threads();
707 if (act->get_type() == THREAD_CREATE)
709 node_list.push_back(new Node(act, head, next_threads, prevfairness));
716 * Empties the stack of all trailing nodes after a given position and calls the
717 * destructor for each. This function is provided an offset which determines
718 * how many nodes (relative to the current replay state) to save before popping
720 * @param numAhead gives the number of Nodes (including this Node) to skip over
721 * before removing nodes.
723 void NodeStack::pop_restofstack(int numAhead)
725 /* Diverging from previous execution; clear out remainder of list */
726 unsigned int it = head_idx + numAhead;
727 for (unsigned int i = it; i < node_list.size(); i++)
729 node_list.resize(it);
730 node_list.back()->clear_backtracking();
733 Node * NodeStack::get_head() const
735 if (node_list.empty() || head_idx < 0)
737 return node_list[head_idx];
740 Node * NodeStack::get_next() const
742 if (node_list.empty()) {
746 unsigned int it = head_idx + 1;
747 if (it == node_list.size()) {
751 return node_list[it];
754 void NodeStack::reset_execution()