1 #define __STDC_FORMAT_MACROS
10 #include "threads-model.h"
11 #include "modeltypes.h"
12 #include "execution.h"
15 * @brief Node constructor
17 * Constructs a single Node for use in a NodeStack. Each Node is associated
18 * with exactly one ModelAction (exception: the first Node should be created
19 * as an empty stub, to represent the first thread "choice") and up to one
22 * @param act The ModelAction to associate with this Node. May be NULL.
23 * @param par The parent Node in the NodeStack. May be NULL if there is no
25 * @param nthreads The number of threads which exist at this point in the
28 Node::Node(ModelAction *act, Node *par, int nthreads, Node *prevfairness) :
29 read_from_status(READ_FROM_PAST),
33 num_threads(nthreads),
34 explored_children(num_threads),
35 backtrack(num_threads),
36 fairness(num_threads),
40 read_from_past_idx(0),
42 read_from_promise_idx(-1),
46 resolve_promise_idx(-1),
47 relseq_break_writes(),
48 relseq_break_index(0),
55 int currtid = id_to_int(act->get_tid());
56 int prevtid = prevfairness ? id_to_int(prevfairness->action->get_tid()) : 0;
58 if (model->params.fairwindow != 0) {
59 for (int i = 0; i < num_threads; i++) {
60 ASSERT(i < ((int)fairness.size()));
61 struct fairness_info *fi = &fairness[i];
62 struct fairness_info *prevfi = (parent && i < parent->get_num_threads()) ? &parent->fairness[i] : NULL;
66 if (parent && parent->is_enabled(int_to_id(i))) {
73 /* Do window processing */
74 if (prevfairness != NULL) {
75 if (prevfairness->parent->is_enabled(int_to_id(i)))
80 /* Need full window to start evaluating
82 * If we meet the enabled count and have no
83 * turns, give us priority */
84 if ((fi->enabled_count >= model->params.enabledcount) &&
92 int Node::get_yield_data(int tid1, int tid2) const {
93 if (tid1<num_threads && tid2 < num_threads)
94 return yield_data[YIELD_INDEX(tid1,tid2,num_threads)];
96 return YIELD_S | YIELD_D;
99 void Node::update_yield(Scheduler * scheduler) {
100 if (yield_data==NULL)
101 yield_data=(int *) model_calloc(1, sizeof(int)*num_threads*num_threads);
103 if (parent == NULL) {
104 for(int i = 0; i < num_threads*num_threads; i++) {
105 yield_data[i] = YIELD_S | YIELD_D;
109 int curr_tid=id_to_int(action->get_tid());
111 for(int u = 0; u < num_threads; u++) {
112 for(int v = 0; v < num_threads; v++) {
113 int yield_state=parent->get_yield_data(u, v);
114 bool next_enabled=scheduler->is_enabled(int_to_id(v));
115 bool curr_enabled=parent->is_enabled(int_to_id(v));
117 //Compute intersection of ES and E
118 yield_state&=~YIELD_E;
119 //Check to see if we disabled the thread
120 if (u==curr_tid && curr_enabled)
121 yield_state|=YIELD_D;
123 yield_data[YIELD_INDEX(u, v, num_threads)]=yield_state;
125 yield_data[YIELD_INDEX(u, curr_tid, num_threads)]=(yield_data[YIELD_INDEX(u, curr_tid, num_threads)]&~YIELD_P)|YIELD_S;
127 //handle curr.yield(t) part of computation
128 if (action->is_yield()) {
129 for(int v = 0; v < num_threads; v++) {
130 int yield_state=yield_data[YIELD_INDEX(curr_tid, v, num_threads)];
131 if ((yield_state & (YIELD_E | YIELD_D)) && (!(yield_state & YIELD_S)))
132 yield_state |= YIELD_P;
133 yield_state &= YIELD_P;
134 if (scheduler->is_enabled(int_to_id(v))) {
135 yield_state|=YIELD_E;
137 yield_data[YIELD_INDEX(curr_tid, v, num_threads)]=yield_state;
142 /** @brief Node desctructor */
147 delete uninit_action;
149 model_free(enabled_array);
151 model_free(yield_data);
154 /** Prints debugging info for the ModelAction associated with this Node */
155 void Node::print() const
158 model_print(" thread status: ");
160 for (int i = 0; i < num_threads; i++) {
162 enabled_type_to_string(enabled_array[i], str);
163 model_print("[%d: %s]", i, str);
167 model_print("(info not available)\n");
168 model_print(" backtrack: %s", backtrack_empty() ? "empty" : "non-empty ");
169 for (int i = 0; i < (int)backtrack.size(); i++)
170 if (backtrack[i] == true)
171 model_print("[%d]", i);
174 model_print(" read from past: %s", read_from_past_empty() ? "empty" : "non-empty ");
175 for (int i = read_from_past_idx + 1; i < (int)read_from_past.size(); i++)
176 model_print("[%d]", read_from_past[i]->get_seq_number());
179 model_print(" read-from promises: %s", read_from_promise_empty() ? "empty" : "non-empty ");
180 for (int i = read_from_promise_idx + 1; i < (int)read_from_promises.size(); i++)
181 model_print("[%d]", read_from_promises[i]->get_seq_number());
184 model_print(" future values: %s", future_value_empty() ? "empty" : "non-empty ");
185 for (int i = future_index + 1; i < (int)future_values.size(); i++)
186 model_print("[%#" PRIx64 "]", future_values[i].value);
189 model_print(" promises: %s\n", promise_empty() ? "empty" : "non-empty");
190 model_print(" misc: %s\n", misc_empty() ? "empty" : "non-empty");
191 model_print(" rel seq break: %s\n", relseq_break_empty() ? "empty" : "non-empty");
194 /****************************** threads backtracking **************************/
197 * Checks if the Thread associated with this thread ID has been explored from
199 * @param tid is the thread ID to check
200 * @return true if this thread choice has been explored already, false
203 bool Node::has_been_explored(thread_id_t tid) const
205 int id = id_to_int(tid);
206 return explored_children[id];
210 * Checks if the backtracking set is empty.
211 * @return true if the backtracking set is empty
213 bool Node::backtrack_empty() const
215 return (numBacktracks == 0);
218 void Node::explore(thread_id_t tid)
220 int i = id_to_int(tid);
221 ASSERT(i < ((int)backtrack.size()));
223 backtrack[i] = false;
226 explored_children[i] = true;
230 * Mark the appropriate backtracking information for exploring a thread choice.
231 * @param act The ModelAction to explore
233 void Node::explore_child(ModelAction *act, enabled_type_t *is_enabled)
236 enabled_array = (enabled_type_t *)model_malloc(sizeof(enabled_type_t) * num_threads);
237 if (is_enabled != NULL)
238 memcpy(enabled_array, is_enabled, sizeof(enabled_type_t) * num_threads);
240 for (int i = 0; i < num_threads; i++)
241 enabled_array[i] = THREAD_DISABLED;
244 explore(act->get_tid());
248 * Records a backtracking reference for a thread choice within this Node.
249 * Provides feedback as to whether this thread choice is already set for
251 * @return false if the thread was already set to be backtracked, true
254 bool Node::set_backtrack(thread_id_t id)
256 int i = id_to_int(id);
257 ASSERT(i < ((int)backtrack.size()));
265 thread_id_t Node::get_next_backtrack()
267 /** @todo Find next backtrack */
269 for (i = 0; i < backtrack.size(); i++)
270 if (backtrack[i] == true)
272 /* Backtrack set was empty? */
273 ASSERT(i != backtrack.size());
275 backtrack[i] = false;
280 void Node::clear_backtracking()
282 for (unsigned int i = 0; i < backtrack.size(); i++)
283 backtrack[i] = false;
284 for (unsigned int i = 0; i < explored_children.size(); i++)
285 explored_children[i] = false;
289 /************************** end threads backtracking **************************/
291 /*********************************** promise **********************************/
294 * Sets a promise to explore meeting with the given node.
295 * @param i is the promise index.
297 void Node::set_promise(unsigned int i)
299 if (i >= resolve_promise.size())
300 resolve_promise.resize(i + 1, false);
301 resolve_promise[i] = true;
305 * Looks up whether a given promise should be satisfied by this node.
306 * @param i The promise index.
307 * @return true if the promise should be satisfied by the given ModelAction.
309 bool Node::get_promise(unsigned int i) const
311 return (i < resolve_promise.size()) && (int)i == resolve_promise_idx;
315 * Increments to the next promise to resolve.
316 * @return true if we have a valid combination.
318 bool Node::increment_promise()
321 if (resolve_promise.empty())
323 int prev_idx = resolve_promise_idx;
324 resolve_promise_idx++;
325 for ( ; resolve_promise_idx < (int)resolve_promise.size(); resolve_promise_idx++)
326 if (resolve_promise[resolve_promise_idx])
328 resolve_promise_idx = prev_idx;
333 * Returns whether the promise set is empty.
334 * @return true if we have explored all promise combinations.
336 bool Node::promise_empty() const
338 for (int i = resolve_promise_idx + 1; i < (int)resolve_promise.size(); i++)
339 if (i >= 0 && resolve_promise[i])
344 /** @brief Clear any promise-resolution information for this Node */
345 void Node::clear_promise_resolutions()
347 resolve_promise.clear();
348 resolve_promise_idx = -1;
351 /******************************* end promise **********************************/
353 void Node::set_misc_max(int i)
358 int Node::get_misc() const
363 bool Node::increment_misc()
365 return (misc_index < misc_max) && ((++misc_index) < misc_max);
368 bool Node::misc_empty() const
370 return (misc_index + 1) >= misc_max;
373 bool Node::is_enabled(Thread *t) const
375 int thread_id = id_to_int(t->get_id());
376 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
379 enabled_type_t Node::enabled_status(thread_id_t tid) const
381 int thread_id = id_to_int(tid);
382 if (thread_id < num_threads)
383 return enabled_array[thread_id];
385 return THREAD_DISABLED;
388 bool Node::is_enabled(thread_id_t tid) const
390 int thread_id = id_to_int(tid);
391 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
394 bool Node::has_priority(thread_id_t tid) const
396 return fairness[id_to_int(tid)].priority;
399 bool Node::has_priority_over(thread_id_t tid1, thread_id_t tid2) const
401 return get_yield_data(id_to_int(tid1), id_to_int(tid2)) & YIELD_P;
404 /*********************************** read from ********************************/
407 * Get the current state of the may-read-from set iteration
408 * @return The read-from type we should currently be checking (past or future)
410 read_from_type_t Node::get_read_from_status()
412 if (read_from_status == READ_FROM_PAST && read_from_past.empty())
413 increment_read_from();
414 return read_from_status;
418 * Iterate one step in the may-read-from iteration. This includes a step in
419 * reading from the either the past or the future.
420 * @return True if there is a new read-from to explore; false otherwise
422 bool Node::increment_read_from()
424 clear_promise_resolutions();
425 if (increment_read_from_past()) {
426 read_from_status = READ_FROM_PAST;
428 } else if (increment_read_from_promise()) {
429 read_from_status = READ_FROM_PROMISE;
431 } else if (increment_future_value()) {
432 read_from_status = READ_FROM_FUTURE;
435 read_from_status = READ_FROM_NONE;
440 * @return True if there are any new read-froms to explore
442 bool Node::read_from_empty() const
444 return read_from_past_empty() &&
445 read_from_promise_empty() &&
446 future_value_empty();
450 * Get the total size of the may-read-from set, including both past and future
452 * @return The size of may-read-from
454 unsigned int Node::read_from_size() const
456 return read_from_past.size() +
457 read_from_promises.size() +
458 future_values.size();
461 /******************************* end read from ********************************/
463 /****************************** read from past ********************************/
465 /** @brief Prints info about read_from_past set */
466 void Node::print_read_from_past()
468 for (unsigned int i = 0; i < read_from_past.size(); i++)
469 read_from_past[i]->print();
473 * Add an action to the read_from_past set.
474 * @param act is the action to add
476 void Node::add_read_from_past(const ModelAction *act)
478 read_from_past.push_back(act);
482 * Gets the next 'read_from_past' action from this Node. Only valid for a node
483 * where this->action is a 'read'.
484 * @return The first element in read_from_past
486 const ModelAction * Node::get_read_from_past() const
488 if (read_from_past_idx < read_from_past.size())
489 return read_from_past[read_from_past_idx];
494 const ModelAction * Node::get_read_from_past(int i) const
496 return read_from_past[i];
499 int Node::get_read_from_past_size() const
501 return read_from_past.size();
505 * Checks whether the readsfrom set for this node is empty.
506 * @return true if the readsfrom set is empty.
508 bool Node::read_from_past_empty() const
510 return ((read_from_past_idx + 1) >= read_from_past.size());
514 * Increments the index into the readsfrom set to explore the next item.
515 * @return Returns false if we have explored all items.
517 bool Node::increment_read_from_past()
520 if (read_from_past_idx < read_from_past.size()) {
521 read_from_past_idx++;
522 return read_from_past_idx < read_from_past.size();
527 /************************** end read from past ********************************/
529 /***************************** read_from_promises *****************************/
532 * Add an action to the read_from_promises set.
533 * @param reader The read which generated the Promise; we use the ModelAction
534 * instead of the Promise because the Promise does not last across executions
536 void Node::add_read_from_promise(const ModelAction *reader)
538 read_from_promises.push_back(reader);
542 * Gets the next 'read-from-promise' from this Node. Only valid for a node
543 * where this->action is a 'read'.
544 * @return The current element in read_from_promises
546 Promise * Node::get_read_from_promise() const
548 ASSERT(read_from_promise_idx >= 0 && read_from_promise_idx < ((int)read_from_promises.size()));
549 return read_from_promises[read_from_promise_idx]->get_reads_from_promise();
553 * Gets a particular 'read-from-promise' form this Node. Only vlaid for a node
554 * where this->action is a 'read'.
555 * @param i The index of the Promise to get
556 * @return The Promise at index i, if the Promise is still available; NULL
559 Promise * Node::get_read_from_promise(int i) const
561 return read_from_promises[i]->get_reads_from_promise();
564 /** @return The size of the read-from-promise set */
565 int Node::get_read_from_promise_size() const
567 return read_from_promises.size();
571 * Checks whether the read_from_promises set for this node is empty.
572 * @return true if the read_from_promises set is empty.
574 bool Node::read_from_promise_empty() const
576 return ((read_from_promise_idx + 1) >= ((int)read_from_promises.size()));
580 * Increments the index into the read_from_promises set to explore the next item.
581 * @return Returns false if we have explored all promises.
583 bool Node::increment_read_from_promise()
586 if (read_from_promise_idx < ((int)read_from_promises.size())) {
587 read_from_promise_idx++;
588 return (read_from_promise_idx < ((int)read_from_promises.size()));
593 /************************* end read_from_promises *****************************/
595 /****************************** future values *********************************/
598 * Adds a value from a weakly ordered future write to backtrack to. This
599 * operation may "fail" if the future value has already been run (within some
600 * sloppiness window of this expiration), or if the futurevalues set has
601 * reached its maximum.
602 * @see model_params.maxfuturevalues
604 * @param value is the value to backtrack to.
605 * @return True if the future value was successully added; false otherwise
607 bool Node::add_future_value(struct future_value fv)
609 uint64_t value = fv.value;
610 modelclock_t expiration = fv.expiration;
611 thread_id_t tid = fv.tid;
612 int idx = -1; /* Highest index where value is found */
613 for (unsigned int i = 0; i < future_values.size(); i++) {
614 if (future_values[i].value == value && future_values[i].tid == tid) {
615 if (expiration <= future_values[i].expiration)
620 if (idx > future_index) {
621 /* Future value hasn't been explored; update expiration */
622 future_values[idx].expiration = expiration;
624 } else if (idx >= 0 && expiration <= future_values[idx].expiration + model->params.expireslop) {
625 /* Future value has been explored and is within the "sloppy" window */
629 /* Limit the size of the future-values set */
630 if (model->params.maxfuturevalues > 0 &&
631 (int)future_values.size() >= model->params.maxfuturevalues)
634 future_values.push_back(fv);
639 * Gets the next 'future_value' from this Node. Only valid for a node where
640 * this->action is a 'read'.
641 * @return The first element in future_values
643 struct future_value Node::get_future_value() const
645 ASSERT(future_index >= 0 && future_index < ((int)future_values.size()));
646 return future_values[future_index];
650 * Checks whether the future_values set for this node is empty.
651 * @return true if the future_values set is empty.
653 bool Node::future_value_empty() const
655 return ((future_index + 1) >= ((int)future_values.size()));
659 * Increments the index into the future_values set to explore the next item.
660 * @return Returns false if we have explored all values.
662 bool Node::increment_future_value()
665 if (future_index < ((int)future_values.size())) {
667 return (future_index < ((int)future_values.size()));
672 /************************** end future values *********************************/
674 /*********************** breaking release sequences ***************************/
677 * Add a write ModelAction to the set of writes that may break the release
678 * sequence. This is used during replay exploration of pending release
679 * sequences. This Node must correspond to a release sequence fixup action.
681 * @param write The write that may break the release sequence. NULL means we
682 * allow the release sequence to synchronize.
684 void Node::add_relseq_break(const ModelAction *write)
686 relseq_break_writes.push_back(write);
690 * Get the write that may break the current pending release sequence,
691 * according to the replay / divergence pattern.
693 * @return A write that may break the release sequence. If NULL, that means
694 * the release sequence should not be broken.
696 const ModelAction * Node::get_relseq_break() const
698 if (relseq_break_index < (int)relseq_break_writes.size())
699 return relseq_break_writes[relseq_break_index];
705 * Increments the index into the relseq_break_writes set to explore the next
707 * @return Returns false if we have explored all values.
709 bool Node::increment_relseq_break()
712 if (relseq_break_index < ((int)relseq_break_writes.size())) {
713 relseq_break_index++;
714 return (relseq_break_index < ((int)relseq_break_writes.size()));
720 * @return True if all writes that may break the release sequence have been
723 bool Node::relseq_break_empty() const
725 return ((relseq_break_index + 1) >= ((int)relseq_break_writes.size()));
728 /******************* end breaking release sequences ***************************/
731 * Increments some behavior's index, if a new behavior is available
732 * @return True if there is a new behavior available; otherwise false
734 bool Node::increment_behaviors()
736 /* satisfy a different misc_index values */
737 if (increment_misc())
739 /* satisfy a different set of promises */
740 if (increment_promise())
742 /* read from a different value */
743 if (increment_read_from())
745 /* resolve a release sequence differently */
746 if (increment_relseq_break())
751 NodeStack::NodeStack() :
759 NodeStack::~NodeStack()
761 for (unsigned int i = 0; i < node_list.size(); i++)
766 * @brief Register the model-checker object with this NodeStack
767 * @param exec The execution structure for the ModelChecker
769 void NodeStack::register_engine(const ModelExecution *exec)
771 this->execution = exec;
774 void NodeStack::print() const
776 model_print("............................................\n");
777 model_print("NodeStack printing node_list:\n");
778 for (unsigned int it = 0; it < node_list.size(); it++) {
779 if ((int)it == this->head_idx)
780 model_print("vvv following action is the current iterator vvv\n");
781 node_list[it]->print();
783 model_print("............................................\n");
786 /** Note: The is_enabled set contains what actions were enabled when
788 ModelAction * NodeStack::explore_action(ModelAction *act, enabled_type_t *is_enabled)
792 if ((head_idx + 1) < (int)node_list.size()) {
794 return node_list[head_idx]->get_action();
798 Node *head = get_head();
799 Node *prevfairness = NULL;
801 head->explore_child(act, is_enabled);
802 if (model->params.fairwindow != 0 && head_idx > (int)model->params.fairwindow)
803 prevfairness = node_list[head_idx - model->params.fairwindow];
806 int next_threads = model->get_num_threads();
807 if (act->get_type() == THREAD_CREATE)
809 node_list.push_back(new Node(act, head, next_threads, prevfairness));
816 * Empties the stack of all trailing nodes after a given position and calls the
817 * destructor for each. This function is provided an offset which determines
818 * how many nodes (relative to the current replay state) to save before popping
820 * @param numAhead gives the number of Nodes (including this Node) to skip over
821 * before removing nodes.
823 void NodeStack::pop_restofstack(int numAhead)
825 /* Diverging from previous execution; clear out remainder of list */
826 unsigned int it = head_idx + numAhead;
827 for (unsigned int i = it; i < node_list.size(); i++)
829 node_list.resize(it);
830 node_list.back()->clear_backtracking();
833 Node * NodeStack::get_head() const
835 if (node_list.empty() || head_idx < 0)
837 return node_list[head_idx];
840 Node * NodeStack::get_next() const
842 if (node_list.empty()) {
846 unsigned int it = head_idx + 1;
847 if (it == node_list.size()) {
851 return node_list[it];
854 void NodeStack::reset_execution()