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 /*********************************** promise **********************************/
196 * Sets a promise to explore meeting with the given node.
197 * @param i is the promise index.
199 void Node::set_promise(unsigned int i)
201 if (i >= resolve_promise.size())
202 resolve_promise.resize(i + 1, false);
203 resolve_promise[i] = true;
207 * Looks up whether a given promise should be satisfied by this node.
208 * @param i The promise index.
209 * @return true if the promise should be satisfied by the given ModelAction.
211 bool Node::get_promise(unsigned int i) const
213 return (i < resolve_promise.size()) && (int)i == resolve_promise_idx;
217 * Increments to the next promise to resolve.
218 * @return true if we have a valid combination.
220 bool Node::increment_promise()
223 if (resolve_promise.empty())
225 int prev_idx = resolve_promise_idx;
226 resolve_promise_idx++;
227 for ( ; resolve_promise_idx < (int)resolve_promise.size(); resolve_promise_idx++)
228 if (resolve_promise[resolve_promise_idx])
230 resolve_promise_idx = prev_idx;
235 * Returns whether the promise set is empty.
236 * @return true if we have explored all promise combinations.
238 bool Node::promise_empty() const
240 for (int i = resolve_promise_idx + 1; i < (int)resolve_promise.size(); i++)
241 if (i >= 0 && resolve_promise[i])
246 /** @brief Clear any promise-resolution information for this Node */
247 void Node::clear_promise_resolutions()
249 resolve_promise.clear();
250 resolve_promise_idx = -1;
253 /******************************* end promise **********************************/
255 void Node::set_misc_max(int i)
260 int Node::get_misc() const
265 bool Node::increment_misc()
267 return (misc_index < misc_max) && ((++misc_index) < misc_max);
270 bool Node::misc_empty() const
272 return (misc_index + 1) >= misc_max;
276 * Checks if the Thread associated with this thread ID has been explored from
278 * @param tid is the thread ID to check
279 * @return true if this thread choice has been explored already, false
282 bool Node::has_been_explored(thread_id_t tid) const
284 int id = id_to_int(tid);
285 return explored_children[id];
289 * Checks if the backtracking set is empty.
290 * @return true if the backtracking set is empty
292 bool Node::backtrack_empty() const
294 return (numBacktracks == 0);
298 * Mark the appropriate backtracking information for exploring a thread choice.
299 * @param act The ModelAction to explore
301 void Node::explore_child(ModelAction *act, enabled_type_t *is_enabled)
304 enabled_array = (enabled_type_t *)model_malloc(sizeof(enabled_type_t) * num_threads);
305 if (is_enabled != NULL)
306 memcpy(enabled_array, is_enabled, sizeof(enabled_type_t) * num_threads);
308 for (int i = 0; i < num_threads; i++)
309 enabled_array[i] = THREAD_DISABLED;
312 explore(act->get_tid());
316 * Records a backtracking reference for a thread choice within this Node.
317 * Provides feedback as to whether this thread choice is already set for
319 * @return false if the thread was already set to be backtracked, true
322 bool Node::set_backtrack(thread_id_t id)
324 int i = id_to_int(id);
325 ASSERT(i < ((int)backtrack.size()));
333 thread_id_t Node::get_next_backtrack()
335 /** @todo Find next backtrack */
337 for (i = 0; i < backtrack.size(); i++)
338 if (backtrack[i] == true)
340 /* Backtrack set was empty? */
341 ASSERT(i != backtrack.size());
343 backtrack[i] = false;
348 void Node::clear_backtracking()
350 for (unsigned int i = 0; i < backtrack.size(); i++)
351 backtrack[i] = false;
352 for (unsigned int i = 0; i < explored_children.size(); i++)
353 explored_children[i] = false;
357 bool Node::is_enabled(Thread *t) const
359 int thread_id = id_to_int(t->get_id());
360 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
363 enabled_type_t Node::enabled_status(thread_id_t tid) const
365 int thread_id = id_to_int(tid);
366 if (thread_id < num_threads)
367 return enabled_array[thread_id];
369 return THREAD_DISABLED;
372 bool Node::is_enabled(thread_id_t tid) const
374 int thread_id = id_to_int(tid);
375 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
378 bool Node::has_priority(thread_id_t tid) const
380 return fairness[id_to_int(tid)].priority;
383 bool Node::has_priority_over(thread_id_t tid1, thread_id_t tid2) const
385 return get_yield_data(id_to_int(tid1), id_to_int(tid2)) & YIELD_P;
388 /*********************************** read from ********************************/
391 * Get the current state of the may-read-from set iteration
392 * @return The read-from type we should currently be checking (past or future)
394 read_from_type_t Node::get_read_from_status()
396 if (read_from_status == READ_FROM_PAST && read_from_past.empty())
397 increment_read_from();
398 return read_from_status;
402 * Iterate one step in the may-read-from iteration. This includes a step in
403 * reading from the either the past or the future.
404 * @return True if there is a new read-from to explore; false otherwise
406 bool Node::increment_read_from()
408 clear_promise_resolutions();
409 if (increment_read_from_past()) {
410 read_from_status = READ_FROM_PAST;
412 } else if (increment_read_from_promise()) {
413 read_from_status = READ_FROM_PROMISE;
415 } else if (increment_future_value()) {
416 read_from_status = READ_FROM_FUTURE;
419 read_from_status = READ_FROM_NONE;
424 * @return True if there are any new read-froms to explore
426 bool Node::read_from_empty() const
428 return read_from_past_empty() &&
429 read_from_promise_empty() &&
430 future_value_empty();
434 * Get the total size of the may-read-from set, including both past and future
436 * @return The size of may-read-from
438 unsigned int Node::read_from_size() const
440 return read_from_past.size() +
441 read_from_promises.size() +
442 future_values.size();
445 /******************************* end read from ********************************/
447 /****************************** read from past ********************************/
449 /** @brief Prints info about read_from_past set */
450 void Node::print_read_from_past()
452 for (unsigned int i = 0; i < read_from_past.size(); i++)
453 read_from_past[i]->print();
457 * Add an action to the read_from_past set.
458 * @param act is the action to add
460 void Node::add_read_from_past(const ModelAction *act)
462 read_from_past.push_back(act);
466 * Gets the next 'read_from_past' action from this Node. Only valid for a node
467 * where this->action is a 'read'.
468 * @return The first element in read_from_past
470 const ModelAction * Node::get_read_from_past() const
472 if (read_from_past_idx < read_from_past.size())
473 return read_from_past[read_from_past_idx];
478 const ModelAction * Node::get_read_from_past(int i) const
480 return read_from_past[i];
483 int Node::get_read_from_past_size() const
485 return read_from_past.size();
489 * Checks whether the readsfrom set for this node is empty.
490 * @return true if the readsfrom set is empty.
492 bool Node::read_from_past_empty() const
494 return ((read_from_past_idx + 1) >= read_from_past.size());
498 * Increments the index into the readsfrom set to explore the next item.
499 * @return Returns false if we have explored all items.
501 bool Node::increment_read_from_past()
504 if (read_from_past_idx < read_from_past.size()) {
505 read_from_past_idx++;
506 return read_from_past_idx < read_from_past.size();
511 /************************** end read from past ********************************/
513 /***************************** read_from_promises *****************************/
516 * Add an action to the read_from_promises set.
517 * @param reader The read which generated the Promise; we use the ModelAction
518 * instead of the Promise because the Promise does not last across executions
520 void Node::add_read_from_promise(const ModelAction *reader)
522 read_from_promises.push_back(reader);
526 * Gets the next 'read-from-promise' from this Node. Only valid for a node
527 * where this->action is a 'read'.
528 * @return The current element in read_from_promises
530 Promise * Node::get_read_from_promise() const
532 ASSERT(read_from_promise_idx >= 0 && read_from_promise_idx < ((int)read_from_promises.size()));
533 return read_from_promises[read_from_promise_idx]->get_reads_from_promise();
537 * Gets a particular 'read-from-promise' form this Node. Only vlaid for a node
538 * where this->action is a 'read'.
539 * @param i The index of the Promise to get
540 * @return The Promise at index i, if the Promise is still available; NULL
543 Promise * Node::get_read_from_promise(int i) const
545 return read_from_promises[i]->get_reads_from_promise();
548 /** @return The size of the read-from-promise set */
549 int Node::get_read_from_promise_size() const
551 return read_from_promises.size();
555 * Checks whether the read_from_promises set for this node is empty.
556 * @return true if the read_from_promises set is empty.
558 bool Node::read_from_promise_empty() const
560 return ((read_from_promise_idx + 1) >= ((int)read_from_promises.size()));
564 * Increments the index into the read_from_promises set to explore the next item.
565 * @return Returns false if we have explored all promises.
567 bool Node::increment_read_from_promise()
570 if (read_from_promise_idx < ((int)read_from_promises.size())) {
571 read_from_promise_idx++;
572 return (read_from_promise_idx < ((int)read_from_promises.size()));
577 /************************* end read_from_promises *****************************/
579 /****************************** future values *********************************/
582 * Adds a value from a weakly ordered future write to backtrack to. This
583 * operation may "fail" if the future value has already been run (within some
584 * sloppiness window of this expiration), or if the futurevalues set has
585 * reached its maximum.
586 * @see model_params.maxfuturevalues
588 * @param value is the value to backtrack to.
589 * @return True if the future value was successully added; false otherwise
591 bool Node::add_future_value(struct future_value fv)
593 uint64_t value = fv.value;
594 modelclock_t expiration = fv.expiration;
595 thread_id_t tid = fv.tid;
596 int idx = -1; /* Highest index where value is found */
597 for (unsigned int i = 0; i < future_values.size(); i++) {
598 if (future_values[i].value == value && future_values[i].tid == tid) {
599 if (expiration <= future_values[i].expiration)
604 if (idx > future_index) {
605 /* Future value hasn't been explored; update expiration */
606 future_values[idx].expiration = expiration;
608 } else if (idx >= 0 && expiration <= future_values[idx].expiration + model->params.expireslop) {
609 /* Future value has been explored and is within the "sloppy" window */
613 /* Limit the size of the future-values set */
614 if (model->params.maxfuturevalues > 0 &&
615 (int)future_values.size() >= model->params.maxfuturevalues)
618 future_values.push_back(fv);
623 * Gets the next 'future_value' from this Node. Only valid for a node where
624 * this->action is a 'read'.
625 * @return The first element in future_values
627 struct future_value Node::get_future_value() const
629 ASSERT(future_index >= 0 && future_index < ((int)future_values.size()));
630 return future_values[future_index];
634 * Checks whether the future_values set for this node is empty.
635 * @return true if the future_values set is empty.
637 bool Node::future_value_empty() const
639 return ((future_index + 1) >= ((int)future_values.size()));
643 * Increments the index into the future_values set to explore the next item.
644 * @return Returns false if we have explored all values.
646 bool Node::increment_future_value()
649 if (future_index < ((int)future_values.size())) {
651 return (future_index < ((int)future_values.size()));
656 /************************** end future values *********************************/
659 * Add a write ModelAction to the set of writes that may break the release
660 * sequence. This is used during replay exploration of pending release
661 * sequences. This Node must correspond to a release sequence fixup action.
663 * @param write The write that may break the release sequence. NULL means we
664 * allow the release sequence to synchronize.
666 void Node::add_relseq_break(const ModelAction *write)
668 relseq_break_writes.push_back(write);
672 * Get the write that may break the current pending release sequence,
673 * according to the replay / divergence pattern.
675 * @return A write that may break the release sequence. If NULL, that means
676 * the release sequence should not be broken.
678 const ModelAction * Node::get_relseq_break() const
680 if (relseq_break_index < (int)relseq_break_writes.size())
681 return relseq_break_writes[relseq_break_index];
687 * Increments the index into the relseq_break_writes set to explore the next
689 * @return Returns false if we have explored all values.
691 bool Node::increment_relseq_break()
694 if (relseq_break_index < ((int)relseq_break_writes.size())) {
695 relseq_break_index++;
696 return (relseq_break_index < ((int)relseq_break_writes.size()));
702 * @return True if all writes that may break the release sequence have been
705 bool Node::relseq_break_empty() const
707 return ((relseq_break_index + 1) >= ((int)relseq_break_writes.size()));
710 void Node::explore(thread_id_t tid)
712 int i = id_to_int(tid);
713 ASSERT(i < ((int)backtrack.size()));
715 backtrack[i] = false;
718 explored_children[i] = true;
721 NodeStack::NodeStack() :
729 NodeStack::~NodeStack()
731 for (unsigned int i = 0; i < node_list.size(); i++)
735 void NodeStack::print() const
737 model_print("............................................\n");
738 model_print("NodeStack printing node_list:\n");
739 for (unsigned int it = 0; it < node_list.size(); it++) {
740 if ((int)it == this->head_idx)
741 model_print("vvv following action is the current iterator vvv\n");
742 node_list[it]->print();
744 model_print("............................................\n");
747 /** Note: The is_enabled set contains what actions were enabled when
749 ModelAction * NodeStack::explore_action(ModelAction *act, enabled_type_t *is_enabled)
753 if ((head_idx + 1) < (int)node_list.size()) {
755 return node_list[head_idx]->get_action();
759 Node *head = get_head();
760 Node *prevfairness = NULL;
762 head->explore_child(act, is_enabled);
763 if (model->params.fairwindow != 0 && head_idx > (int)model->params.fairwindow)
764 prevfairness = node_list[head_idx - model->params.fairwindow];
767 int next_threads = model->get_num_threads();
768 if (act->get_type() == THREAD_CREATE)
770 node_list.push_back(new Node(act, head, next_threads, prevfairness));
777 * Empties the stack of all trailing nodes after a given position and calls the
778 * destructor for each. This function is provided an offset which determines
779 * how many nodes (relative to the current replay state) to save before popping
781 * @param numAhead gives the number of Nodes (including this Node) to skip over
782 * before removing nodes.
784 void NodeStack::pop_restofstack(int numAhead)
786 /* Diverging from previous execution; clear out remainder of list */
787 unsigned int it = head_idx + numAhead;
788 for (unsigned int i = it; i < node_list.size(); i++)
790 node_list.resize(it);
791 node_list.back()->clear_backtracking();
794 Node * NodeStack::get_head() const
796 if (node_list.empty() || head_idx < 0)
798 return node_list[head_idx];
801 Node * NodeStack::get_next() const
803 if (node_list.empty()) {
807 unsigned int it = head_idx + 1;
808 if (it == node_list.size()) {
812 return node_list[it];
815 void NodeStack::reset_execution()