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),
53 int currtid = id_to_int(act->get_tid());
54 int prevtid = prevfairness ? id_to_int(prevfairness->action->get_tid()) : 0;
56 if (model->params.fairwindow != 0) {
57 for (int i = 0; i < num_threads; i++) {
58 ASSERT(i < ((int)fairness.size()));
59 struct fairness_info *fi = &fairness[i];
60 struct fairness_info *prevfi = (parent && i < parent->get_num_threads()) ? &parent->fairness[i] : NULL;
64 if (parent && parent->is_enabled(int_to_id(i))) {
71 /* Do window processing */
72 if (prevfairness != NULL) {
73 if (prevfairness->parent->is_enabled(int_to_id(i)))
78 /* Need full window to start evaluating
80 * If we meet the enabled count and have no
81 * turns, give us priority */
82 if ((fi->enabled_count >= model->params.enabledcount) &&
90 int Node::get_yield_data(int tid1, int tid2) const {
91 if (tid1<num_threads && tid2 < num_threads)
92 return yield_data[YIELD_INDEX(tid1,tid2,num_threads)];
94 return YIELD_S | YIELD_D;
97 void Node::update_yield(Scheduler * scheduler) {
98 yield_data=(int *) model_calloc(1, sizeof(int)*num_threads*num_threads);
100 if (parent == NULL) {
101 for(int i = 0; i < num_threads*num_threads; i++) {
102 yield_data[i] = YIELD_S | YIELD_D;
106 int curr_tid=id_to_int(action->get_tid());
108 for(int u = 0; u < num_threads; u++) {
109 for(int v = 0; v < num_threads; v++) {
110 int yield_state=parent->get_yield_data(u, v);
111 bool next_enabled=scheduler->is_enabled(int_to_id(v));
112 bool curr_enabled=parent->is_enabled(int_to_id(v));
114 //Compute intersection of ES and E
115 yield_state&=~YIELD_E;
116 //Check to see if we disabled the thread
117 if (u==curr_tid && curr_enabled)
118 yield_state|=YIELD_D;
120 yield_data[YIELD_INDEX(u, v, num_threads)]=yield_state;
122 yield_data[YIELD_INDEX(u, curr_tid, num_threads)]=(yield_data[YIELD_INDEX(u, curr_tid, num_threads)]&~YIELD_P)|YIELD_S;
124 //handle curr.yield(t) part of computation
125 if (action->is_yield()) {
126 for(int v = 0; v < num_threads; v++) {
127 int yield_state=yield_data[YIELD_INDEX(curr_tid, v, num_threads)];
128 if ((yield_state & (YIELD_E | YIELD_D)) && (!(yield_state & YIELD_S)))
129 yield_state |= YIELD_P;
130 yield_state &= YIELD_P;
131 if (scheduler->is_enabled(int_to_id(v))) {
132 yield_state|=YIELD_E;
134 yield_data[YIELD_INDEX(curr_tid, v, num_threads)]=yield_state;
139 /** @brief Node desctructor */
144 model_free(enabled_array);
146 model_free(yield_data);
149 /** Prints debugging info for the ModelAction associated with this Node */
150 void Node::print() const
153 model_print(" thread status: ");
155 for (int i = 0; i < num_threads; i++) {
157 enabled_type_to_string(enabled_array[i], str);
158 model_print("[%d: %s]", i, str);
162 model_print("(info not available)\n");
163 model_print(" backtrack: %s", backtrack_empty() ? "empty" : "non-empty ");
164 for (int i = 0; i < (int)backtrack.size(); i++)
165 if (backtrack[i] == true)
166 model_print("[%d]", i);
169 model_print(" read from past: %s", read_from_past_empty() ? "empty" : "non-empty ");
170 for (int i = read_from_past_idx + 1; i < (int)read_from_past.size(); i++)
171 model_print("[%d]", read_from_past[i]->get_seq_number());
174 model_print(" read-from promises: %s", read_from_promise_empty() ? "empty" : "non-empty ");
175 for (int i = read_from_promise_idx + 1; i < (int)read_from_promises.size(); i++)
176 model_print("[%d]", read_from_promises[i]->get_seq_number());
179 model_print(" future values: %s", future_value_empty() ? "empty" : "non-empty ");
180 for (int i = future_index + 1; i < (int)future_values.size(); i++)
181 model_print("[%#" PRIx64 "]", future_values[i].value);
184 model_print(" promises: %s\n", promise_empty() ? "empty" : "non-empty");
185 model_print(" misc: %s\n", misc_empty() ? "empty" : "non-empty");
186 model_print(" rel seq break: %s\n", relseq_break_empty() ? "empty" : "non-empty");
189 /*********************************** promise **********************************/
192 * Sets a promise to explore meeting with the given node.
193 * @param i is the promise index.
195 void Node::set_promise(unsigned int i)
197 if (i >= resolve_promise.size())
198 resolve_promise.resize(i + 1, false);
199 resolve_promise[i] = true;
203 * Looks up whether a given promise should be satisfied by this node.
204 * @param i The promise index.
205 * @return true if the promise should be satisfied by the given ModelAction.
207 bool Node::get_promise(unsigned int i) const
209 return (i < resolve_promise.size()) && (int)i == resolve_promise_idx;
213 * Increments to the next promise to resolve.
214 * @return true if we have a valid combination.
216 bool Node::increment_promise()
219 if (resolve_promise.empty())
221 int prev_idx = resolve_promise_idx;
222 resolve_promise_idx++;
223 for ( ; resolve_promise_idx < (int)resolve_promise.size(); resolve_promise_idx++)
224 if (resolve_promise[resolve_promise_idx])
226 resolve_promise_idx = prev_idx;
231 * Returns whether the promise set is empty.
232 * @return true if we have explored all promise combinations.
234 bool Node::promise_empty() const
236 for (int i = resolve_promise_idx + 1; i < (int)resolve_promise.size(); i++)
237 if (i >= 0 && resolve_promise[i])
242 /** @brief Clear any promise-resolution information for this Node */
243 void Node::clear_promise_resolutions()
245 resolve_promise.clear();
246 resolve_promise_idx = -1;
249 /******************************* end promise **********************************/
251 void Node::set_misc_max(int i)
256 int Node::get_misc() const
261 bool Node::increment_misc()
263 return (misc_index < misc_max) && ((++misc_index) < misc_max);
266 bool Node::misc_empty() const
268 return (misc_index + 1) >= misc_max;
272 * Checks if the Thread associated with this thread ID has been explored from
274 * @param tid is the thread ID to check
275 * @return true if this thread choice has been explored already, false
278 bool Node::has_been_explored(thread_id_t tid) const
280 int id = id_to_int(tid);
281 return explored_children[id];
285 * Checks if the backtracking set is empty.
286 * @return true if the backtracking set is empty
288 bool Node::backtrack_empty() const
290 return (numBacktracks == 0);
294 * Mark the appropriate backtracking information for exploring a thread choice.
295 * @param act The ModelAction to explore
297 void Node::explore_child(ModelAction *act, enabled_type_t *is_enabled)
300 enabled_array = (enabled_type_t *)model_malloc(sizeof(enabled_type_t) * num_threads);
301 if (is_enabled != NULL)
302 memcpy(enabled_array, is_enabled, sizeof(enabled_type_t) * num_threads);
304 for (int i = 0; i < num_threads; i++)
305 enabled_array[i] = THREAD_DISABLED;
308 explore(act->get_tid());
312 * Records a backtracking reference for a thread choice within this Node.
313 * Provides feedback as to whether this thread choice is already set for
315 * @return false if the thread was already set to be backtracked, true
318 bool Node::set_backtrack(thread_id_t id)
320 int i = id_to_int(id);
321 ASSERT(i < ((int)backtrack.size()));
329 thread_id_t Node::get_next_backtrack()
331 /** @todo Find next backtrack */
333 for (i = 0; i < backtrack.size(); i++)
334 if (backtrack[i] == true)
336 /* Backtrack set was empty? */
337 ASSERT(i != backtrack.size());
339 backtrack[i] = false;
344 void Node::clear_backtracking()
346 for (unsigned int i = 0; i < backtrack.size(); i++)
347 backtrack[i] = false;
348 for (unsigned int i = 0; i < explored_children.size(); i++)
349 explored_children[i] = false;
353 bool Node::is_enabled(Thread *t) const
355 int thread_id = id_to_int(t->get_id());
356 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
359 enabled_type_t Node::enabled_status(thread_id_t tid) const
361 int thread_id = id_to_int(tid);
362 if (thread_id < num_threads)
363 return enabled_array[thread_id];
365 return THREAD_DISABLED;
368 bool Node::is_enabled(thread_id_t tid) const
370 int thread_id = id_to_int(tid);
371 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
374 bool Node::has_priority(thread_id_t tid) const
376 return fairness[id_to_int(tid)].priority;
379 bool Node::has_priority_over(thread_id_t tid1, thread_id_t tid2) const
381 return get_yield_data(id_to_int(tid1), id_to_int(tid2)) & YIELD_P;
384 /*********************************** read from ********************************/
387 * Get the current state of the may-read-from set iteration
388 * @return The read-from type we should currently be checking (past or future)
390 read_from_type_t Node::get_read_from_status()
392 if (read_from_status == READ_FROM_PAST && read_from_past.empty())
393 increment_read_from();
394 return read_from_status;
398 * Iterate one step in the may-read-from iteration. This includes a step in
399 * reading from the either the past or the future.
400 * @return True if there is a new read-from to explore; false otherwise
402 bool Node::increment_read_from()
404 clear_promise_resolutions();
405 if (increment_read_from_past()) {
406 read_from_status = READ_FROM_PAST;
408 } else if (increment_read_from_promise()) {
409 read_from_status = READ_FROM_PROMISE;
411 } else if (increment_future_value()) {
412 read_from_status = READ_FROM_FUTURE;
415 read_from_status = READ_FROM_NONE;
420 * @return True if there are any new read-froms to explore
422 bool Node::read_from_empty() const
424 return read_from_past_empty() &&
425 read_from_promise_empty() &&
426 future_value_empty();
430 * Get the total size of the may-read-from set, including both past and future
432 * @return The size of may-read-from
434 unsigned int Node::read_from_size() const
436 return read_from_past.size() +
437 read_from_promises.size() +
438 future_values.size();
441 /******************************* end read from ********************************/
443 /****************************** read from past ********************************/
445 /** @brief Prints info about read_from_past set */
446 void Node::print_read_from_past()
448 for (unsigned int i = 0; i < read_from_past.size(); i++)
449 read_from_past[i]->print();
453 * Add an action to the read_from_past set.
454 * @param act is the action to add
456 void Node::add_read_from_past(const ModelAction *act)
458 read_from_past.push_back(act);
462 * Gets the next 'read_from_past' action from this Node. Only valid for a node
463 * where this->action is a 'read'.
464 * @return The first element in read_from_past
466 const ModelAction * Node::get_read_from_past() const
468 if (read_from_past_idx < read_from_past.size())
469 return read_from_past[read_from_past_idx];
474 const ModelAction * Node::get_read_from_past(int i) const
476 return read_from_past[i];
479 int Node::get_read_from_past_size() const
481 return read_from_past.size();
485 * Checks whether the readsfrom set for this node is empty.
486 * @return true if the readsfrom set is empty.
488 bool Node::read_from_past_empty() const
490 return ((read_from_past_idx + 1) >= read_from_past.size());
494 * Increments the index into the readsfrom set to explore the next item.
495 * @return Returns false if we have explored all items.
497 bool Node::increment_read_from_past()
500 if (read_from_past_idx < read_from_past.size()) {
501 read_from_past_idx++;
502 return read_from_past_idx < read_from_past.size();
507 /************************** end read from past ********************************/
509 /***************************** read_from_promises *****************************/
512 * Add an action to the read_from_promises set.
513 * @param reader The read which generated the Promise; we use the ModelAction
514 * instead of the Promise because the Promise does not last across executions
516 void Node::add_read_from_promise(const ModelAction *reader)
518 read_from_promises.push_back(reader);
522 * Gets the next 'read-from-promise' from this Node. Only valid for a node
523 * where this->action is a 'read'.
524 * @return The current element in read_from_promises
526 Promise * Node::get_read_from_promise() const
528 ASSERT(read_from_promise_idx >= 0 && read_from_promise_idx < ((int)read_from_promises.size()));
529 return read_from_promises[read_from_promise_idx]->get_reads_from_promise();
533 * Gets a particular 'read-from-promise' form this Node. Only vlaid for a node
534 * where this->action is a 'read'.
535 * @param i The index of the Promise to get
536 * @return The Promise at index i, if the Promise is still available; NULL
539 Promise * Node::get_read_from_promise(int i) const
541 return read_from_promises[i]->get_reads_from_promise();
544 /** @return The size of the read-from-promise set */
545 int Node::get_read_from_promise_size() const
547 return read_from_promises.size();
551 * Checks whether the read_from_promises set for this node is empty.
552 * @return true if the read_from_promises set is empty.
554 bool Node::read_from_promise_empty() const
556 return ((read_from_promise_idx + 1) >= ((int)read_from_promises.size()));
560 * Increments the index into the read_from_promises set to explore the next item.
561 * @return Returns false if we have explored all promises.
563 bool Node::increment_read_from_promise()
566 if (read_from_promise_idx < ((int)read_from_promises.size())) {
567 read_from_promise_idx++;
568 return (read_from_promise_idx < ((int)read_from_promises.size()));
573 /************************* end read_from_promises *****************************/
575 /****************************** future values *********************************/
578 * Adds a value from a weakly ordered future write to backtrack to. This
579 * operation may "fail" if the future value has already been run (within some
580 * sloppiness window of this expiration), or if the futurevalues set has
581 * reached its maximum.
582 * @see model_params.maxfuturevalues
584 * @param value is the value to backtrack to.
585 * @return True if the future value was successully added; false otherwise
587 bool Node::add_future_value(struct future_value fv)
589 uint64_t value = fv.value;
590 modelclock_t expiration = fv.expiration;
591 thread_id_t tid = fv.tid;
592 int idx = -1; /* Highest index where value is found */
593 for (unsigned int i = 0; i < future_values.size(); i++) {
594 if (future_values[i].value == value && future_values[i].tid == tid) {
595 if (expiration <= future_values[i].expiration)
600 if (idx > future_index) {
601 /* Future value hasn't been explored; update expiration */
602 future_values[idx].expiration = expiration;
604 } else if (idx >= 0 && expiration <= future_values[idx].expiration + model->params.expireslop) {
605 /* Future value has been explored and is within the "sloppy" window */
609 /* Limit the size of the future-values set */
610 if (model->params.maxfuturevalues > 0 &&
611 (int)future_values.size() >= model->params.maxfuturevalues)
614 future_values.push_back(fv);
619 * Gets the next 'future_value' from this Node. Only valid for a node where
620 * this->action is a 'read'.
621 * @return The first element in future_values
623 struct future_value Node::get_future_value() const
625 ASSERT(future_index >= 0 && future_index < ((int)future_values.size()));
626 return future_values[future_index];
630 * Checks whether the future_values set for this node is empty.
631 * @return true if the future_values set is empty.
633 bool Node::future_value_empty() const
635 return ((future_index + 1) >= ((int)future_values.size()));
639 * Increments the index into the future_values set to explore the next item.
640 * @return Returns false if we have explored all values.
642 bool Node::increment_future_value()
645 if (future_index < ((int)future_values.size())) {
647 return (future_index < ((int)future_values.size()));
652 /************************** end future values *********************************/
655 * Add a write ModelAction to the set of writes that may break the release
656 * sequence. This is used during replay exploration of pending release
657 * sequences. This Node must correspond to a release sequence fixup action.
659 * @param write The write that may break the release sequence. NULL means we
660 * allow the release sequence to synchronize.
662 void Node::add_relseq_break(const ModelAction *write)
664 relseq_break_writes.push_back(write);
668 * Get the write that may break the current pending release sequence,
669 * according to the replay / divergence pattern.
671 * @return A write that may break the release sequence. If NULL, that means
672 * the release sequence should not be broken.
674 const ModelAction * Node::get_relseq_break() const
676 if (relseq_break_index < (int)relseq_break_writes.size())
677 return relseq_break_writes[relseq_break_index];
683 * Increments the index into the relseq_break_writes set to explore the next
685 * @return Returns false if we have explored all values.
687 bool Node::increment_relseq_break()
690 if (relseq_break_index < ((int)relseq_break_writes.size())) {
691 relseq_break_index++;
692 return (relseq_break_index < ((int)relseq_break_writes.size()));
698 * @return True if all writes that may break the release sequence have been
701 bool Node::relseq_break_empty() const
703 return ((relseq_break_index + 1) >= ((int)relseq_break_writes.size()));
706 void Node::explore(thread_id_t tid)
708 int i = id_to_int(tid);
709 ASSERT(i < ((int)backtrack.size()));
711 backtrack[i] = false;
714 explored_children[i] = true;
717 NodeStack::NodeStack() :
725 NodeStack::~NodeStack()
727 for (unsigned int i = 0; i < node_list.size(); i++)
731 void NodeStack::print() const
733 model_print("............................................\n");
734 model_print("NodeStack printing node_list:\n");
735 for (unsigned int it = 0; it < node_list.size(); it++) {
736 if ((int)it == this->head_idx)
737 model_print("vvv following action is the current iterator vvv\n");
738 node_list[it]->print();
740 model_print("............................................\n");
743 /** Note: The is_enabled set contains what actions were enabled when
745 ModelAction * NodeStack::explore_action(ModelAction *act, enabled_type_t *is_enabled)
749 if ((head_idx + 1) < (int)node_list.size()) {
751 return node_list[head_idx]->get_action();
755 Node *head = get_head();
756 Node *prevfairness = NULL;
758 head->explore_child(act, is_enabled);
759 if (model->params.fairwindow != 0 && head_idx > (int)model->params.fairwindow)
760 prevfairness = node_list[head_idx - model->params.fairwindow];
763 int next_threads = model->get_num_threads();
764 if (act->get_type() == THREAD_CREATE)
766 node_list.push_back(new Node(act, head, next_threads, prevfairness));
773 * Empties the stack of all trailing nodes after a given position and calls the
774 * destructor for each. This function is provided an offset which determines
775 * how many nodes (relative to the current replay state) to save before popping
777 * @param numAhead gives the number of Nodes (including this Node) to skip over
778 * before removing nodes.
780 void NodeStack::pop_restofstack(int numAhead)
782 /* Diverging from previous execution; clear out remainder of list */
783 unsigned int it = head_idx + numAhead;
784 for (unsigned int i = it; i < node_list.size(); i++)
786 node_list.resize(it);
787 node_list.back()->clear_backtracking();
790 Node * NodeStack::get_head() const
792 if (node_list.empty() || head_idx < 0)
794 return node_list[head_idx];
797 Node * NodeStack::get_next() const
799 if (node_list.empty()) {
803 unsigned int it = head_idx + 1;
804 if (it == node_list.size()) {
808 return node_list[it];
811 void NodeStack::reset_execution()