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),
32 num_threads(nthreads),
33 explored_children(num_threads),
34 backtrack(num_threads),
35 fairness(num_threads),
39 read_from_past_idx(0),
41 read_from_promise_idx(-1),
45 resolve_promise_idx(-1),
46 relseq_break_writes(),
47 relseq_break_index(0),
54 int currtid = id_to_int(act->get_tid());
55 int prevtid = prevfairness ? id_to_int(prevfairness->action->get_tid()) : 0;
57 if (model->params.fairwindow != 0) {
58 for (int i = 0; i < num_threads; i++) {
59 ASSERT(i < ((int)fairness.size()));
60 struct fairness_info *fi = &fairness[i];
61 struct fairness_info *prevfi = (parent && i < parent->get_num_threads()) ? &parent->fairness[i] : NULL;
65 if (parent && parent->is_enabled(int_to_id(i))) {
72 /* Do window processing */
73 if (prevfairness != NULL) {
74 if (prevfairness->parent->is_enabled(int_to_id(i)))
79 /* Need full window to start evaluating
81 * If we meet the enabled count and have no
82 * turns, give us priority */
83 if ((fi->enabled_count >= model->params.enabledcount) &&
91 int Node::get_yield_data(int tid1, int tid2) const {
92 if (tid1<num_threads && tid2 < num_threads)
93 return yield_data[YIELD_INDEX(tid1,tid2,num_threads)];
95 return YIELD_S | YIELD_D;
98 void Node::update_yield(Scheduler * scheduler) {
99 yield_data=(int *) model_calloc(1, sizeof(int)*num_threads*num_threads);
101 if (parent == NULL) {
102 for(int i = 0; i < num_threads*num_threads; i++) {
103 yield_data[i] = YIELD_S | YIELD_D;
107 int curr_tid=id_to_int(action->get_tid());
109 for(int u = 0; u < num_threads; u++) {
110 for(int v = 0; v < num_threads; v++) {
111 int yield_state=parent->get_yield_data(u, v);
112 bool next_enabled=scheduler->is_enabled(int_to_id(v));
113 bool curr_enabled=parent->is_enabled(int_to_id(v));
115 //Compute intersection of ES and E
116 yield_state&=~YIELD_E;
117 //Check to see if we disabled the thread
118 if (u==curr_tid && curr_enabled)
119 yield_state|=YIELD_D;
121 yield_data[YIELD_INDEX(u, v, num_threads)]=yield_state;
123 yield_data[YIELD_INDEX(u, curr_tid, num_threads)]=(yield_data[YIELD_INDEX(u, curr_tid, num_threads)]&~YIELD_P)|YIELD_S;
125 //handle curr.yield(t) part of computation
126 if (action->is_yield()) {
127 for(int v = 0; v < num_threads; v++) {
128 int yield_state=yield_data[YIELD_INDEX(curr_tid, v, num_threads)];
129 if ((yield_state & (YIELD_E | YIELD_D)) && (!(yield_state & YIELD_S)))
130 yield_state |= YIELD_P;
131 yield_state &= YIELD_P;
132 if (scheduler->is_enabled(int_to_id(v))) {
133 yield_state|=YIELD_E;
135 yield_data[YIELD_INDEX(curr_tid, v, num_threads)]=yield_state;
140 /** @brief Node desctructor */
145 delete uninit_action;
147 model_free(enabled_array);
149 model_free(yield_data);
152 /** Prints debugging info for the ModelAction associated with this Node */
153 void Node::print() const
156 model_print(" thread status: ");
158 for (int i = 0; i < num_threads; i++) {
160 enabled_type_to_string(enabled_array[i], str);
161 model_print("[%d: %s]", i, str);
165 model_print("(info not available)\n");
166 model_print(" backtrack: %s", backtrack_empty() ? "empty" : "non-empty ");
167 for (int i = 0; i < (int)backtrack.size(); i++)
168 if (backtrack[i] == true)
169 model_print("[%d]", i);
172 model_print(" read from past: %s", read_from_past_empty() ? "empty" : "non-empty ");
173 for (int i = read_from_past_idx + 1; i < (int)read_from_past.size(); i++)
174 model_print("[%d]", read_from_past[i]->get_seq_number());
177 model_print(" read-from promises: %s", read_from_promise_empty() ? "empty" : "non-empty ");
178 for (int i = read_from_promise_idx + 1; i < (int)read_from_promises.size(); i++)
179 model_print("[%d]", read_from_promises[i]->get_seq_number());
182 model_print(" future values: %s", future_value_empty() ? "empty" : "non-empty ");
183 for (int i = future_index + 1; i < (int)future_values.size(); i++)
184 model_print("[%#" PRIx64 "]", future_values[i].value);
187 model_print(" promises: %s\n", promise_empty() ? "empty" : "non-empty");
188 model_print(" misc: %s\n", misc_empty() ? "empty" : "non-empty");
189 model_print(" rel seq break: %s\n", relseq_break_empty() ? "empty" : "non-empty");
192 /*********************************** promise **********************************/
195 * Sets a promise to explore meeting with the given node.
196 * @param i is the promise index.
198 void Node::set_promise(unsigned int i)
200 if (i >= resolve_promise.size())
201 resolve_promise.resize(i + 1, false);
202 resolve_promise[i] = true;
206 * Looks up whether a given promise should be satisfied by this node.
207 * @param i The promise index.
208 * @return true if the promise should be satisfied by the given ModelAction.
210 bool Node::get_promise(unsigned int i) const
212 return (i < resolve_promise.size()) && (int)i == resolve_promise_idx;
216 * Increments to the next promise to resolve.
217 * @return true if we have a valid combination.
219 bool Node::increment_promise()
222 if (resolve_promise.empty())
224 int prev_idx = resolve_promise_idx;
225 resolve_promise_idx++;
226 for ( ; resolve_promise_idx < (int)resolve_promise.size(); resolve_promise_idx++)
227 if (resolve_promise[resolve_promise_idx])
229 resolve_promise_idx = prev_idx;
234 * Returns whether the promise set is empty.
235 * @return true if we have explored all promise combinations.
237 bool Node::promise_empty() const
239 for (int i = resolve_promise_idx + 1; i < (int)resolve_promise.size(); i++)
240 if (i >= 0 && resolve_promise[i])
245 /** @brief Clear any promise-resolution information for this Node */
246 void Node::clear_promise_resolutions()
248 resolve_promise.clear();
249 resolve_promise_idx = -1;
252 /******************************* end promise **********************************/
254 void Node::set_misc_max(int i)
259 int Node::get_misc() const
264 bool Node::increment_misc()
266 return (misc_index < misc_max) && ((++misc_index) < misc_max);
269 bool Node::misc_empty() const
271 return (misc_index + 1) >= misc_max;
275 * Checks if the Thread associated with this thread ID has been explored from
277 * @param tid is the thread ID to check
278 * @return true if this thread choice has been explored already, false
281 bool Node::has_been_explored(thread_id_t tid) const
283 int id = id_to_int(tid);
284 return explored_children[id];
288 * Checks if the backtracking set is empty.
289 * @return true if the backtracking set is empty
291 bool Node::backtrack_empty() const
293 return (numBacktracks == 0);
297 * Mark the appropriate backtracking information for exploring a thread choice.
298 * @param act The ModelAction to explore
300 void Node::explore_child(ModelAction *act, enabled_type_t *is_enabled)
303 enabled_array = (enabled_type_t *)model_malloc(sizeof(enabled_type_t) * num_threads);
304 if (is_enabled != NULL)
305 memcpy(enabled_array, is_enabled, sizeof(enabled_type_t) * num_threads);
307 for (int i = 0; i < num_threads; i++)
308 enabled_array[i] = THREAD_DISABLED;
311 explore(act->get_tid());
315 * Records a backtracking reference for a thread choice within this Node.
316 * Provides feedback as to whether this thread choice is already set for
318 * @return false if the thread was already set to be backtracked, true
321 bool Node::set_backtrack(thread_id_t id)
323 int i = id_to_int(id);
324 ASSERT(i < ((int)backtrack.size()));
332 thread_id_t Node::get_next_backtrack()
334 /** @todo Find next backtrack */
336 for (i = 0; i < backtrack.size(); i++)
337 if (backtrack[i] == true)
339 /* Backtrack set was empty? */
340 ASSERT(i != backtrack.size());
342 backtrack[i] = false;
347 void Node::clear_backtracking()
349 for (unsigned int i = 0; i < backtrack.size(); i++)
350 backtrack[i] = false;
351 for (unsigned int i = 0; i < explored_children.size(); i++)
352 explored_children[i] = false;
356 bool Node::is_enabled(Thread *t) const
358 int thread_id = id_to_int(t->get_id());
359 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
362 enabled_type_t Node::enabled_status(thread_id_t tid) const
364 int thread_id = id_to_int(tid);
365 if (thread_id < num_threads)
366 return enabled_array[thread_id];
368 return THREAD_DISABLED;
371 bool Node::is_enabled(thread_id_t tid) const
373 int thread_id = id_to_int(tid);
374 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
377 bool Node::has_priority(thread_id_t tid) const
379 return fairness[id_to_int(tid)].priority;
382 bool Node::has_priority_over(thread_id_t tid1, thread_id_t tid2) const
384 return get_yield_data(id_to_int(tid1), id_to_int(tid2)) & YIELD_P;
387 /*********************************** read from ********************************/
390 * Get the current state of the may-read-from set iteration
391 * @return The read-from type we should currently be checking (past or future)
393 read_from_type_t Node::get_read_from_status()
395 if (read_from_status == READ_FROM_PAST && read_from_past.empty())
396 increment_read_from();
397 return read_from_status;
401 * Iterate one step in the may-read-from iteration. This includes a step in
402 * reading from the either the past or the future.
403 * @return True if there is a new read-from to explore; false otherwise
405 bool Node::increment_read_from()
407 clear_promise_resolutions();
408 if (increment_read_from_past()) {
409 read_from_status = READ_FROM_PAST;
411 } else if (increment_read_from_promise()) {
412 read_from_status = READ_FROM_PROMISE;
414 } else if (increment_future_value()) {
415 read_from_status = READ_FROM_FUTURE;
418 read_from_status = READ_FROM_NONE;
423 * @return True if there are any new read-froms to explore
425 bool Node::read_from_empty() const
427 return read_from_past_empty() &&
428 read_from_promise_empty() &&
429 future_value_empty();
433 * Get the total size of the may-read-from set, including both past and future
435 * @return The size of may-read-from
437 unsigned int Node::read_from_size() const
439 return read_from_past.size() +
440 read_from_promises.size() +
441 future_values.size();
444 /******************************* end read from ********************************/
446 /****************************** read from past ********************************/
448 /** @brief Prints info about read_from_past set */
449 void Node::print_read_from_past()
451 for (unsigned int i = 0; i < read_from_past.size(); i++)
452 read_from_past[i]->print();
456 * Add an action to the read_from_past set.
457 * @param act is the action to add
459 void Node::add_read_from_past(const ModelAction *act)
461 read_from_past.push_back(act);
465 * Gets the next 'read_from_past' action from this Node. Only valid for a node
466 * where this->action is a 'read'.
467 * @return The first element in read_from_past
469 const ModelAction * Node::get_read_from_past() const
471 if (read_from_past_idx < read_from_past.size())
472 return read_from_past[read_from_past_idx];
477 const ModelAction * Node::get_read_from_past(int i) const
479 return read_from_past[i];
482 int Node::get_read_from_past_size() const
484 return read_from_past.size();
488 * Checks whether the readsfrom set for this node is empty.
489 * @return true if the readsfrom set is empty.
491 bool Node::read_from_past_empty() const
493 return ((read_from_past_idx + 1) >= read_from_past.size());
497 * Increments the index into the readsfrom set to explore the next item.
498 * @return Returns false if we have explored all items.
500 bool Node::increment_read_from_past()
503 if (read_from_past_idx < read_from_past.size()) {
504 read_from_past_idx++;
505 return read_from_past_idx < read_from_past.size();
510 /************************** end read from past ********************************/
512 /***************************** read_from_promises *****************************/
515 * Add an action to the read_from_promises set.
516 * @param reader The read which generated the Promise; we use the ModelAction
517 * instead of the Promise because the Promise does not last across executions
519 void Node::add_read_from_promise(const ModelAction *reader)
521 read_from_promises.push_back(reader);
525 * Gets the next 'read-from-promise' from this Node. Only valid for a node
526 * where this->action is a 'read'.
527 * @return The current element in read_from_promises
529 Promise * Node::get_read_from_promise() const
531 ASSERT(read_from_promise_idx >= 0 && read_from_promise_idx < ((int)read_from_promises.size()));
532 return read_from_promises[read_from_promise_idx]->get_reads_from_promise();
536 * Gets a particular 'read-from-promise' form this Node. Only vlaid for a node
537 * where this->action is a 'read'.
538 * @param i The index of the Promise to get
539 * @return The Promise at index i, if the Promise is still available; NULL
542 Promise * Node::get_read_from_promise(int i) const
544 return read_from_promises[i]->get_reads_from_promise();
547 /** @return The size of the read-from-promise set */
548 int Node::get_read_from_promise_size() const
550 return read_from_promises.size();
554 * Checks whether the read_from_promises set for this node is empty.
555 * @return true if the read_from_promises set is empty.
557 bool Node::read_from_promise_empty() const
559 return ((read_from_promise_idx + 1) >= ((int)read_from_promises.size()));
563 * Increments the index into the read_from_promises set to explore the next item.
564 * @return Returns false if we have explored all promises.
566 bool Node::increment_read_from_promise()
569 if (read_from_promise_idx < ((int)read_from_promises.size())) {
570 read_from_promise_idx++;
571 return (read_from_promise_idx < ((int)read_from_promises.size()));
576 /************************* end read_from_promises *****************************/
578 /****************************** future values *********************************/
581 * Adds a value from a weakly ordered future write to backtrack to. This
582 * operation may "fail" if the future value has already been run (within some
583 * sloppiness window of this expiration), or if the futurevalues set has
584 * reached its maximum.
585 * @see model_params.maxfuturevalues
587 * @param value is the value to backtrack to.
588 * @return True if the future value was successully added; false otherwise
590 bool Node::add_future_value(struct future_value fv)
592 uint64_t value = fv.value;
593 modelclock_t expiration = fv.expiration;
594 thread_id_t tid = fv.tid;
595 int idx = -1; /* Highest index where value is found */
596 for (unsigned int i = 0; i < future_values.size(); i++) {
597 if (future_values[i].value == value && future_values[i].tid == tid) {
598 if (expiration <= future_values[i].expiration)
603 if (idx > future_index) {
604 /* Future value hasn't been explored; update expiration */
605 future_values[idx].expiration = expiration;
607 } else if (idx >= 0 && expiration <= future_values[idx].expiration + model->params.expireslop) {
608 /* Future value has been explored and is within the "sloppy" window */
612 /* Limit the size of the future-values set */
613 if (model->params.maxfuturevalues > 0 &&
614 (int)future_values.size() >= model->params.maxfuturevalues)
617 future_values.push_back(fv);
622 * Gets the next 'future_value' from this Node. Only valid for a node where
623 * this->action is a 'read'.
624 * @return The first element in future_values
626 struct future_value Node::get_future_value() const
628 ASSERT(future_index >= 0 && future_index < ((int)future_values.size()));
629 return future_values[future_index];
633 * Checks whether the future_values set for this node is empty.
634 * @return true if the future_values set is empty.
636 bool Node::future_value_empty() const
638 return ((future_index + 1) >= ((int)future_values.size()));
642 * Increments the index into the future_values set to explore the next item.
643 * @return Returns false if we have explored all values.
645 bool Node::increment_future_value()
648 if (future_index < ((int)future_values.size())) {
650 return (future_index < ((int)future_values.size()));
655 /************************** end future values *********************************/
658 * Add a write ModelAction to the set of writes that may break the release
659 * sequence. This is used during replay exploration of pending release
660 * sequences. This Node must correspond to a release sequence fixup action.
662 * @param write The write that may break the release sequence. NULL means we
663 * allow the release sequence to synchronize.
665 void Node::add_relseq_break(const ModelAction *write)
667 relseq_break_writes.push_back(write);
671 * Get the write that may break the current pending release sequence,
672 * according to the replay / divergence pattern.
674 * @return A write that may break the release sequence. If NULL, that means
675 * the release sequence should not be broken.
677 const ModelAction * Node::get_relseq_break() const
679 if (relseq_break_index < (int)relseq_break_writes.size())
680 return relseq_break_writes[relseq_break_index];
686 * Increments the index into the relseq_break_writes set to explore the next
688 * @return Returns false if we have explored all values.
690 bool Node::increment_relseq_break()
693 if (relseq_break_index < ((int)relseq_break_writes.size())) {
694 relseq_break_index++;
695 return (relseq_break_index < ((int)relseq_break_writes.size()));
701 * @return True if all writes that may break the release sequence have been
704 bool Node::relseq_break_empty() const
706 return ((relseq_break_index + 1) >= ((int)relseq_break_writes.size()));
709 void Node::explore(thread_id_t tid)
711 int i = id_to_int(tid);
712 ASSERT(i < ((int)backtrack.size()));
714 backtrack[i] = false;
717 explored_children[i] = true;
720 NodeStack::NodeStack() :
728 NodeStack::~NodeStack()
730 for (unsigned int i = 0; i < node_list.size(); i++)
734 void NodeStack::print() const
736 model_print("............................................\n");
737 model_print("NodeStack printing node_list:\n");
738 for (unsigned int it = 0; it < node_list.size(); it++) {
739 if ((int)it == this->head_idx)
740 model_print("vvv following action is the current iterator vvv\n");
741 node_list[it]->print();
743 model_print("............................................\n");
746 /** Note: The is_enabled set contains what actions were enabled when
748 ModelAction * NodeStack::explore_action(ModelAction *act, enabled_type_t *is_enabled)
752 if ((head_idx + 1) < (int)node_list.size()) {
754 return node_list[head_idx]->get_action();
758 Node *head = get_head();
759 Node *prevfairness = NULL;
761 head->explore_child(act, is_enabled);
762 if (model->params.fairwindow != 0 && head_idx > (int)model->params.fairwindow)
763 prevfairness = node_list[head_idx - model->params.fairwindow];
766 int next_threads = model->get_num_threads();
767 if (act->get_type() == THREAD_CREATE)
769 node_list.push_back(new Node(act, head, next_threads, prevfairness));
776 * Empties the stack of all trailing nodes after a given position and calls the
777 * destructor for each. This function is provided an offset which determines
778 * how many nodes (relative to the current replay state) to save before popping
780 * @param numAhead gives the number of Nodes (including this Node) to skip over
781 * before removing nodes.
783 void NodeStack::pop_restofstack(int numAhead)
785 /* Diverging from previous execution; clear out remainder of list */
786 unsigned int it = head_idx + numAhead;
787 for (unsigned int i = it; i < node_list.size(); i++)
789 node_list.resize(it);
790 node_list.back()->clear_backtracking();
793 Node * NodeStack::get_head() const
795 if (node_list.empty() || head_idx < 0)
797 return node_list[head_idx];
800 Node * NodeStack::get_next() const
802 if (node_list.empty()) {
806 unsigned int it = head_idx + 1;
807 if (it == node_list.size()) {
811 return node_list[it];
814 void NodeStack::reset_execution()