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) {
100 yield_data=(int *) model_calloc(1, sizeof(int)*num_threads*num_threads);
102 if (parent == NULL) {
103 for(int i = 0; i < num_threads*num_threads; i++) {
104 yield_data[i] = YIELD_S | YIELD_D;
108 int curr_tid=id_to_int(action->get_tid());
110 for(int u = 0; u < num_threads; u++) {
111 for(int v = 0; v < num_threads; v++) {
112 int yield_state=parent->get_yield_data(u, v);
113 bool next_enabled=scheduler->is_enabled(int_to_id(v));
114 bool curr_enabled=parent->is_enabled(int_to_id(v));
116 //Compute intersection of ES and E
117 yield_state&=~YIELD_E;
118 //Check to see if we disabled the thread
119 if (u==curr_tid && curr_enabled)
120 yield_state|=YIELD_D;
122 yield_data[YIELD_INDEX(u, v, num_threads)]=yield_state;
124 yield_data[YIELD_INDEX(u, curr_tid, num_threads)]=(yield_data[YIELD_INDEX(u, curr_tid, num_threads)]&~YIELD_P)|YIELD_S;
126 //handle curr.yield(t) part of computation
127 if (action->is_yield()) {
128 for(int v = 0; v < num_threads; v++) {
129 int yield_state=yield_data[YIELD_INDEX(curr_tid, v, num_threads)];
130 if ((yield_state & (YIELD_E | YIELD_D)) && (!(yield_state & YIELD_S)))
131 yield_state |= YIELD_P;
132 yield_state &= YIELD_P;
133 if (scheduler->is_enabled(int_to_id(v))) {
134 yield_state|=YIELD_E;
136 yield_data[YIELD_INDEX(curr_tid, v, num_threads)]=yield_state;
141 /** @brief Node desctructor */
146 delete uninit_action;
148 model_free(enabled_array);
150 model_free(yield_data);
153 /** Prints debugging info for the ModelAction associated with this Node */
154 void Node::print() const
157 model_print(" thread status: ");
159 for (int i = 0; i < num_threads; i++) {
161 enabled_type_to_string(enabled_array[i], str);
162 model_print("[%d: %s]", i, str);
166 model_print("(info not available)\n");
167 model_print(" backtrack: %s", backtrack_empty() ? "empty" : "non-empty ");
168 for (int i = 0; i < (int)backtrack.size(); i++)
169 if (backtrack[i] == true)
170 model_print("[%d]", i);
173 model_print(" read from past: %s", read_from_past_empty() ? "empty" : "non-empty ");
174 for (int i = read_from_past_idx + 1; i < (int)read_from_past.size(); i++)
175 model_print("[%d]", read_from_past[i]->get_seq_number());
178 model_print(" read-from promises: %s", read_from_promise_empty() ? "empty" : "non-empty ");
179 for (int i = read_from_promise_idx + 1; i < (int)read_from_promises.size(); i++)
180 model_print("[%d]", read_from_promises[i]->get_seq_number());
183 model_print(" future values: %s", future_value_empty() ? "empty" : "non-empty ");
184 for (int i = future_index + 1; i < (int)future_values.size(); i++)
185 model_print("[%#" PRIx64 "]", future_values[i].value);
188 model_print(" promises: %s\n", promise_empty() ? "empty" : "non-empty");
189 model_print(" misc: %s\n", misc_empty() ? "empty" : "non-empty");
190 model_print(" rel seq break: %s\n", relseq_break_empty() ? "empty" : "non-empty");
193 /****************************** threads backtracking **************************/
196 * Checks if the Thread associated with this thread ID has been explored from
198 * @param tid is the thread ID to check
199 * @return true if this thread choice has been explored already, false
202 bool Node::has_been_explored(thread_id_t tid) const
204 int id = id_to_int(tid);
205 return explored_children[id];
209 * Checks if the backtracking set is empty.
210 * @return true if the backtracking set is empty
212 bool Node::backtrack_empty() const
214 return (numBacktracks == 0);
217 void Node::explore(thread_id_t tid)
219 int i = id_to_int(tid);
220 ASSERT(i < ((int)backtrack.size()));
222 backtrack[i] = false;
225 explored_children[i] = true;
229 * Mark the appropriate backtracking information for exploring a thread choice.
230 * @param act The ModelAction to explore
232 void Node::explore_child(ModelAction *act, enabled_type_t *is_enabled)
235 enabled_array = (enabled_type_t *)model_malloc(sizeof(enabled_type_t) * num_threads);
236 if (is_enabled != NULL)
237 memcpy(enabled_array, is_enabled, sizeof(enabled_type_t) * num_threads);
239 for (int i = 0; i < num_threads; i++)
240 enabled_array[i] = THREAD_DISABLED;
243 explore(act->get_tid());
247 * Records a backtracking reference for a thread choice within this Node.
248 * Provides feedback as to whether this thread choice is already set for
250 * @return false if the thread was already set to be backtracked, true
253 bool Node::set_backtrack(thread_id_t id)
255 int i = id_to_int(id);
256 ASSERT(i < ((int)backtrack.size()));
264 thread_id_t Node::get_next_backtrack()
266 /** @todo Find next backtrack */
268 for (i = 0; i < backtrack.size(); i++)
269 if (backtrack[i] == true)
271 /* Backtrack set was empty? */
272 ASSERT(i != backtrack.size());
274 backtrack[i] = false;
279 void Node::clear_backtracking()
281 for (unsigned int i = 0; i < backtrack.size(); i++)
282 backtrack[i] = false;
283 for (unsigned int i = 0; i < explored_children.size(); i++)
284 explored_children[i] = false;
288 /************************** end threads backtracking **************************/
290 /*********************************** promise **********************************/
293 * Sets a promise to explore meeting with the given node.
294 * @param i is the promise index.
296 void Node::set_promise(unsigned int i)
298 if (i >= resolve_promise.size())
299 resolve_promise.resize(i + 1, false);
300 resolve_promise[i] = true;
304 * Looks up whether a given promise should be satisfied by this node.
305 * @param i The promise index.
306 * @return true if the promise should be satisfied by the given ModelAction.
308 bool Node::get_promise(unsigned int i) const
310 return (i < resolve_promise.size()) && (int)i == resolve_promise_idx;
314 * Increments to the next promise to resolve.
315 * @return true if we have a valid combination.
317 bool Node::increment_promise()
320 if (resolve_promise.empty())
322 int prev_idx = resolve_promise_idx;
323 resolve_promise_idx++;
324 for ( ; resolve_promise_idx < (int)resolve_promise.size(); resolve_promise_idx++)
325 if (resolve_promise[resolve_promise_idx])
327 resolve_promise_idx = prev_idx;
332 * Returns whether the promise set is empty.
333 * @return true if we have explored all promise combinations.
335 bool Node::promise_empty() const
337 for (int i = resolve_promise_idx + 1; i < (int)resolve_promise.size(); i++)
338 if (i >= 0 && resolve_promise[i])
343 /** @brief Clear any promise-resolution information for this Node */
344 void Node::clear_promise_resolutions()
346 resolve_promise.clear();
347 resolve_promise_idx = -1;
350 /******************************* end promise **********************************/
352 void Node::set_misc_max(int i)
357 int Node::get_misc() const
362 bool Node::increment_misc()
364 return (misc_index < misc_max) && ((++misc_index) < misc_max);
367 bool Node::misc_empty() const
369 return (misc_index + 1) >= misc_max;
372 bool Node::is_enabled(Thread *t) const
374 int thread_id = id_to_int(t->get_id());
375 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
378 enabled_type_t Node::enabled_status(thread_id_t tid) const
380 int thread_id = id_to_int(tid);
381 if (thread_id < num_threads)
382 return enabled_array[thread_id];
384 return THREAD_DISABLED;
387 bool Node::is_enabled(thread_id_t tid) const
389 int thread_id = id_to_int(tid);
390 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
393 bool Node::has_priority(thread_id_t tid) const
395 return fairness[id_to_int(tid)].priority;
398 bool Node::has_priority_over(thread_id_t tid1, thread_id_t tid2) const
400 return get_yield_data(id_to_int(tid1), id_to_int(tid2)) & YIELD_P;
403 /*********************************** read from ********************************/
406 * Get the current state of the may-read-from set iteration
407 * @return The read-from type we should currently be checking (past or future)
409 read_from_type_t Node::get_read_from_status()
411 if (read_from_status == READ_FROM_PAST && read_from_past.empty())
412 increment_read_from();
413 return read_from_status;
417 * Iterate one step in the may-read-from iteration. This includes a step in
418 * reading from the either the past or the future.
419 * @return True if there is a new read-from to explore; false otherwise
421 bool Node::increment_read_from()
423 clear_promise_resolutions();
424 if (increment_read_from_past()) {
425 read_from_status = READ_FROM_PAST;
427 } else if (increment_read_from_promise()) {
428 read_from_status = READ_FROM_PROMISE;
430 } else if (increment_future_value()) {
431 read_from_status = READ_FROM_FUTURE;
434 read_from_status = READ_FROM_NONE;
439 * @return True if there are any new read-froms to explore
441 bool Node::read_from_empty() const
443 return read_from_past_empty() &&
444 read_from_promise_empty() &&
445 future_value_empty();
449 * Get the total size of the may-read-from set, including both past and future
451 * @return The size of may-read-from
453 unsigned int Node::read_from_size() const
455 return read_from_past.size() +
456 read_from_promises.size() +
457 future_values.size();
460 /******************************* end read from ********************************/
462 /****************************** read from past ********************************/
464 /** @brief Prints info about read_from_past set */
465 void Node::print_read_from_past()
467 for (unsigned int i = 0; i < read_from_past.size(); i++)
468 read_from_past[i]->print();
472 * Add an action to the read_from_past set.
473 * @param act is the action to add
475 void Node::add_read_from_past(const ModelAction *act)
477 read_from_past.push_back(act);
481 * Gets the next 'read_from_past' action from this Node. Only valid for a node
482 * where this->action is a 'read'.
483 * @return The first element in read_from_past
485 const ModelAction * Node::get_read_from_past() const
487 if (read_from_past_idx < read_from_past.size())
488 return read_from_past[read_from_past_idx];
493 const ModelAction * Node::get_read_from_past(int i) const
495 return read_from_past[i];
498 int Node::get_read_from_past_size() const
500 return read_from_past.size();
504 * Checks whether the readsfrom set for this node is empty.
505 * @return true if the readsfrom set is empty.
507 bool Node::read_from_past_empty() const
509 return ((read_from_past_idx + 1) >= read_from_past.size());
513 * Increments the index into the readsfrom set to explore the next item.
514 * @return Returns false if we have explored all items.
516 bool Node::increment_read_from_past()
519 if (read_from_past_idx < read_from_past.size()) {
520 read_from_past_idx++;
521 return read_from_past_idx < read_from_past.size();
526 /************************** end read from past ********************************/
528 /***************************** read_from_promises *****************************/
531 * Add an action to the read_from_promises set.
532 * @param reader The read which generated the Promise; we use the ModelAction
533 * instead of the Promise because the Promise does not last across executions
535 void Node::add_read_from_promise(const ModelAction *reader)
537 read_from_promises.push_back(reader);
541 * Gets the next 'read-from-promise' from this Node. Only valid for a node
542 * where this->action is a 'read'.
543 * @return The current element in read_from_promises
545 Promise * Node::get_read_from_promise() const
547 ASSERT(read_from_promise_idx >= 0 && read_from_promise_idx < ((int)read_from_promises.size()));
548 return read_from_promises[read_from_promise_idx]->get_reads_from_promise();
552 * Gets a particular 'read-from-promise' form this Node. Only vlaid for a node
553 * where this->action is a 'read'.
554 * @param i The index of the Promise to get
555 * @return The Promise at index i, if the Promise is still available; NULL
558 Promise * Node::get_read_from_promise(int i) const
560 return read_from_promises[i]->get_reads_from_promise();
563 /** @return The size of the read-from-promise set */
564 int Node::get_read_from_promise_size() const
566 return read_from_promises.size();
570 * Checks whether the read_from_promises set for this node is empty.
571 * @return true if the read_from_promises set is empty.
573 bool Node::read_from_promise_empty() const
575 return ((read_from_promise_idx + 1) >= ((int)read_from_promises.size()));
579 * Increments the index into the read_from_promises set to explore the next item.
580 * @return Returns false if we have explored all promises.
582 bool Node::increment_read_from_promise()
585 if (read_from_promise_idx < ((int)read_from_promises.size())) {
586 read_from_promise_idx++;
587 return (read_from_promise_idx < ((int)read_from_promises.size()));
592 /************************* end read_from_promises *****************************/
594 /****************************** future values *********************************/
597 * Adds a value from a weakly ordered future write to backtrack to. This
598 * operation may "fail" if the future value has already been run (within some
599 * sloppiness window of this expiration), or if the futurevalues set has
600 * reached its maximum.
601 * @see model_params.maxfuturevalues
603 * @param value is the value to backtrack to.
604 * @return True if the future value was successully added; false otherwise
606 bool Node::add_future_value(struct future_value fv)
608 uint64_t value = fv.value;
609 modelclock_t expiration = fv.expiration;
610 thread_id_t tid = fv.tid;
611 int idx = -1; /* Highest index where value is found */
612 for (unsigned int i = 0; i < future_values.size(); i++) {
613 if (future_values[i].value == value && future_values[i].tid == tid) {
614 if (expiration <= future_values[i].expiration)
619 if (idx > future_index) {
620 /* Future value hasn't been explored; update expiration */
621 future_values[idx].expiration = expiration;
623 } else if (idx >= 0 && expiration <= future_values[idx].expiration + model->params.expireslop) {
624 /* Future value has been explored and is within the "sloppy" window */
628 /* Limit the size of the future-values set */
629 if (model->params.maxfuturevalues > 0 &&
630 (int)future_values.size() >= model->params.maxfuturevalues)
633 future_values.push_back(fv);
638 * Gets the next 'future_value' from this Node. Only valid for a node where
639 * this->action is a 'read'.
640 * @return The first element in future_values
642 struct future_value Node::get_future_value() const
644 ASSERT(future_index >= 0 && future_index < ((int)future_values.size()));
645 return future_values[future_index];
649 * Checks whether the future_values set for this node is empty.
650 * @return true if the future_values set is empty.
652 bool Node::future_value_empty() const
654 return ((future_index + 1) >= ((int)future_values.size()));
658 * Increments the index into the future_values set to explore the next item.
659 * @return Returns false if we have explored all values.
661 bool Node::increment_future_value()
664 if (future_index < ((int)future_values.size())) {
666 return (future_index < ((int)future_values.size()));
671 /************************** end future values *********************************/
673 /*********************** breaking release sequences ***************************/
676 * Add a write ModelAction to the set of writes that may break the release
677 * sequence. This is used during replay exploration of pending release
678 * sequences. This Node must correspond to a release sequence fixup action.
680 * @param write The write that may break the release sequence. NULL means we
681 * allow the release sequence to synchronize.
683 void Node::add_relseq_break(const ModelAction *write)
685 relseq_break_writes.push_back(write);
689 * Get the write that may break the current pending release sequence,
690 * according to the replay / divergence pattern.
692 * @return A write that may break the release sequence. If NULL, that means
693 * the release sequence should not be broken.
695 const ModelAction * Node::get_relseq_break() const
697 if (relseq_break_index < (int)relseq_break_writes.size())
698 return relseq_break_writes[relseq_break_index];
704 * Increments the index into the relseq_break_writes set to explore the next
706 * @return Returns false if we have explored all values.
708 bool Node::increment_relseq_break()
711 if (relseq_break_index < ((int)relseq_break_writes.size())) {
712 relseq_break_index++;
713 return (relseq_break_index < ((int)relseq_break_writes.size()));
719 * @return True if all writes that may break the release sequence have been
722 bool Node::relseq_break_empty() const
724 return ((relseq_break_index + 1) >= ((int)relseq_break_writes.size()));
727 /******************* end breaking release sequences ***************************/
730 * Increments some behavior's index, if a new behavior is available
731 * @return True if there is a new behavior available; otherwise false
733 bool Node::increment_behaviors()
735 /* satisfy a different misc_index values */
736 if (increment_misc())
738 /* satisfy a different set of promises */
739 if (increment_promise())
741 /* read from a different value */
742 if (increment_read_from())
744 /* resolve a release sequence differently */
745 if (increment_relseq_break())
750 NodeStack::NodeStack() :
758 NodeStack::~NodeStack()
760 for (unsigned int i = 0; i < node_list.size(); i++)
764 void NodeStack::print() const
766 model_print("............................................\n");
767 model_print("NodeStack printing node_list:\n");
768 for (unsigned int it = 0; it < node_list.size(); it++) {
769 if ((int)it == this->head_idx)
770 model_print("vvv following action is the current iterator vvv\n");
771 node_list[it]->print();
773 model_print("............................................\n");
776 /** Note: The is_enabled set contains what actions were enabled when
778 ModelAction * NodeStack::explore_action(ModelAction *act, enabled_type_t *is_enabled)
782 if ((head_idx + 1) < (int)node_list.size()) {
784 return node_list[head_idx]->get_action();
788 Node *head = get_head();
789 Node *prevfairness = NULL;
791 head->explore_child(act, is_enabled);
792 if (model->params.fairwindow != 0 && head_idx > (int)model->params.fairwindow)
793 prevfairness = node_list[head_idx - model->params.fairwindow];
796 int next_threads = model->get_num_threads();
797 if (act->get_type() == THREAD_CREATE)
799 node_list.push_back(new Node(act, head, next_threads, prevfairness));
806 * Empties the stack of all trailing nodes after a given position and calls the
807 * destructor for each. This function is provided an offset which determines
808 * how many nodes (relative to the current replay state) to save before popping
810 * @param numAhead gives the number of Nodes (including this Node) to skip over
811 * before removing nodes.
813 void NodeStack::pop_restofstack(int numAhead)
815 /* Diverging from previous execution; clear out remainder of list */
816 unsigned int it = head_idx + numAhead;
817 for (unsigned int i = it; i < node_list.size(); i++)
819 node_list.resize(it);
820 node_list.back()->clear_backtracking();
823 Node * NodeStack::get_head() const
825 if (node_list.empty() || head_idx < 0)
827 return node_list[head_idx];
830 Node * NodeStack::get_next() const
832 if (node_list.empty()) {
836 unsigned int it = head_idx + 1;
837 if (it == node_list.size()) {
841 return node_list[it];
844 void NodeStack::reset_execution()