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)
30 num_threads(nthreads),
31 explored_children(num_threads),
32 backtrack(num_threads),
33 fairness(num_threads),
40 relseq_break_writes(),
41 relseq_break_index(0),
47 int currtid = id_to_int(act->get_tid());
48 int prevtid = prevfairness ? id_to_int(prevfairness->action->get_tid()) : 0;
50 if (model->params.fairwindow != 0) {
51 for (int i = 0; i < num_threads; i++) {
52 ASSERT(i < ((int)fairness.size()));
53 struct fairness_info *fi = &fairness[i];
54 struct fairness_info *prevfi = (parent && i < parent->get_num_threads()) ? &parent->fairness[i] : NULL;
58 if (parent && parent->is_enabled(int_to_id(i))) {
65 /* Do window processing */
66 if (prevfairness != NULL) {
67 if (prevfairness->parent->is_enabled(int_to_id(i)))
72 /* Need full window to start evaluating
74 * If we meet the enabled count and have no
75 * turns, give us priority */
76 if ((fi->enabled_count >= model->params.enabledcount) &&
84 /** @brief Node desctructor */
89 model_free(enabled_array);
92 /** Prints debugging info for the ModelAction associated with this Node */
93 void Node::print() const
96 model_print(" backtrack: %s", backtrack_empty() ? "empty" : "non-empty ");
97 for (int i = 0; i < (int)backtrack.size(); i++)
98 if (backtrack[i] == true)
99 model_print("[%d]", i);
101 model_print(" future values: %s", future_value_empty() ? "empty" : "non-empty ");
102 for (int i = future_index + 1; i < (int)future_values.size(); i++)
103 model_print("[%#" PRIx64 "]", future_values[i].value);
106 model_print(" read-from: %s", read_from_empty() ? "empty" : "non-empty ");
107 for (int i = read_from_index + 1; i < (int)may_read_from.size(); i++)
108 model_print("[%d]", may_read_from[i]->get_seq_number());
111 model_print(" promises: %s\n", promise_empty() ? "empty" : "non-empty");
112 model_print(" misc: %s\n", misc_empty() ? "empty" : "non-empty");
113 model_print(" rel seq break: %s\n", relseq_break_empty() ? "empty" : "non-empty");
116 /** @brief Prints info about may_read_from set */
117 void Node::print_may_read_from()
119 for (unsigned int i = 0; i < may_read_from.size(); i++)
120 may_read_from[i]->print();
124 * Sets a promise to explore meeting with the given node.
125 * @param i is the promise index.
127 void Node::set_promise(unsigned int i, bool is_rmw)
129 if (i >= promises.size())
130 promises.resize(i + 1, PROMISE_IGNORE);
131 if (promises[i] == PROMISE_IGNORE) {
132 promises[i] = PROMISE_UNFULFILLED;
134 promises[i] |= PROMISE_RMW;
139 * Looks up whether a given promise should be satisfied by this node.
140 * @param i The promise index.
141 * @return true if the promise should be satisfied by the given model action.
143 bool Node::get_promise(unsigned int i) const
145 return (i < promises.size()) && ((promises[i] & PROMISE_MASK) == PROMISE_FULFILLED);
149 * Increments to the next combination of promises.
150 * @return true if we have a valid combination.
152 bool Node::increment_promise()
155 unsigned int rmw_count = 0;
156 for (unsigned int i = 0; i < promises.size(); i++) {
157 if (promises[i] == (PROMISE_RMW|PROMISE_FULFILLED))
161 for (unsigned int i = 0; i < promises.size(); i++) {
162 if ((promises[i] & PROMISE_MASK) == PROMISE_UNFULFILLED) {
163 if ((rmw_count > 0) && (promises[i] & PROMISE_RMW)) {
164 //sending our value to two rmws... not going to work..try next combination
167 promises[i] = (promises[i] & PROMISE_RMW) |PROMISE_FULFILLED;
170 if ((promises[i] & PROMISE_MASK) == PROMISE_FULFILLED)
171 promises[i] = (promises[i] & PROMISE_RMW) | PROMISE_UNFULFILLED;
174 } else if (promises[i] == (PROMISE_RMW|PROMISE_FULFILLED)) {
182 * Returns whether the promise set is empty.
183 * @return true if we have explored all promise combinations.
185 bool Node::promise_empty() const
187 bool fulfilledrmw = false;
188 for (int i = promises.size() - 1; i >= 0; i--) {
189 if (promises[i] == PROMISE_UNFULFILLED)
191 if (!fulfilledrmw && ((promises[i]&PROMISE_MASK) == PROMISE_UNFULFILLED))
193 if (promises[i] == (PROMISE_FULFILLED|PROMISE_RMW))
199 void Node::set_misc_max(int i)
204 int Node::get_misc() const
209 bool Node::increment_misc()
211 return (misc_index < misc_max) && ((++misc_index) < misc_max);
214 bool Node::misc_empty() const
216 return (misc_index + 1) >= misc_max;
220 * Adds a value from a weakly ordered future write to backtrack to. This
221 * operation may "fail" if the future value has already been run (within some
222 * sloppiness window of this expiration), or if the futurevalues set has
223 * reached its maximum.
224 * @see model_params.maxfuturevalues
226 * @param value is the value to backtrack to.
227 * @return True if the future value was successully added; false otherwise
229 bool Node::add_future_value(const ModelAction *writer, modelclock_t expiration)
231 uint64_t value = writer->get_value();
232 int idx = -1; /* Highest index where value is found */
233 for (unsigned int i = 0; i < future_values.size(); i++) {
234 if (future_values[i].value == value) {
235 if (expiration <= future_values[i].expiration)
240 if (idx > future_index) {
241 /* Future value hasn't been explored; update expiration */
242 future_values[idx].expiration = expiration;
244 } else if (idx >= 0 && expiration <= future_values[idx].expiration + model->params.expireslop) {
245 /* Future value has been explored and is within the "sloppy" window */
249 /* Limit the size of the future-values set */
250 if (model->params.maxfuturevalues > 0 &&
251 (int)future_values.size() >= model->params.maxfuturevalues)
254 struct future_value newfv = {value, expiration};
255 future_values.push_back(newfv);
260 * Checks whether the future_values set for this node is empty.
261 * @return true if the future_values set is empty.
263 bool Node::future_value_empty() const
265 return ((future_index + 1) >= ((int)future_values.size()));
269 * Checks if the Thread associated with this thread ID has been explored from
271 * @param tid is the thread ID to check
272 * @return true if this thread choice has been explored already, false
275 bool Node::has_been_explored(thread_id_t tid) const
277 int id = id_to_int(tid);
278 return explored_children[id];
282 * Checks if the backtracking set is empty.
283 * @return true if the backtracking set is empty
285 bool Node::backtrack_empty() const
287 return (numBacktracks == 0);
291 * Checks whether the readsfrom set for this node is empty.
292 * @return true if the readsfrom set is empty.
294 bool Node::read_from_empty() const
296 return ((read_from_index + 1) >= may_read_from.size());
300 * Mark the appropriate backtracking information for exploring a thread choice.
301 * @param act The ModelAction to explore
303 void Node::explore_child(ModelAction *act, enabled_type_t *is_enabled)
306 enabled_array = (enabled_type_t *)model_malloc(sizeof(enabled_type_t) * num_threads);
307 if (is_enabled != NULL)
308 memcpy(enabled_array, is_enabled, sizeof(enabled_type_t) * num_threads);
310 for (int i = 0; i < num_threads; i++)
311 enabled_array[i] = THREAD_DISABLED;
314 explore(act->get_tid());
318 * Records a backtracking reference for a thread choice within this Node.
319 * Provides feedback as to whether this thread choice is already set for
321 * @return false if the thread was already set to be backtracked, true
324 bool Node::set_backtrack(thread_id_t id)
326 int i = id_to_int(id);
327 ASSERT(i < ((int)backtrack.size()));
335 thread_id_t Node::get_next_backtrack()
337 /** @todo Find next backtrack */
339 for (i = 0; i < backtrack.size(); i++)
340 if (backtrack[i] == true)
342 /* Backtrack set was empty? */
343 ASSERT(i != backtrack.size());
345 backtrack[i] = false;
350 bool Node::is_enabled(Thread *t) const
352 int thread_id = id_to_int(t->get_id());
353 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
356 enabled_type_t Node::enabled_status(thread_id_t tid) const
358 int thread_id = id_to_int(tid);
359 if (thread_id < num_threads)
360 return enabled_array[thread_id];
362 return THREAD_DISABLED;
365 bool Node::is_enabled(thread_id_t tid) const
367 int thread_id = id_to_int(tid);
368 return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
371 bool Node::has_priority(thread_id_t tid) const
373 return fairness[id_to_int(tid)].priority;
377 * Add an action to the may_read_from set.
378 * @param act is the action to add
380 void Node::add_read_from(const ModelAction *act)
382 may_read_from.push_back(act);
386 * Gets the next 'future_value' from this Node. Only valid for a node where
387 * this->action is a 'read'.
388 * @return The first element in future_values
390 struct future_value Node::get_future_value() const
392 ASSERT(future_index >= 0 && future_index < ((int)future_values.size()));
393 return future_values[future_index];
396 int Node::get_read_from_size() const
398 return may_read_from.size();
401 const ModelAction * Node::get_read_from_at(int i) const
403 return may_read_from[i];
407 * Gets the next 'may_read_from' action from this Node. Only valid for a node
408 * where this->action is a 'read'.
409 * @return The first element in may_read_from
411 const ModelAction * Node::get_read_from() const
413 if (read_from_index < may_read_from.size())
414 return may_read_from[read_from_index];
420 * Increments the index into the readsfrom set to explore the next item.
421 * @return Returns false if we have explored all items.
423 bool Node::increment_read_from()
427 if (read_from_index < may_read_from.size()) {
429 return read_from_index < may_read_from.size();
435 * Increments the index into the future_values set to explore the next item.
436 * @return Returns false if we have explored all values.
438 bool Node::increment_future_value()
442 if (future_index < ((int)future_values.size())) {
444 return (future_index < ((int)future_values.size()));
450 * Add a write ModelAction to the set of writes that may break the release
451 * sequence. This is used during replay exploration of pending release
452 * sequences. This Node must correspond to a release sequence fixup action.
454 * @param write The write that may break the release sequence. NULL means we
455 * allow the release sequence to synchronize.
457 void Node::add_relseq_break(const ModelAction *write)
459 relseq_break_writes.push_back(write);
463 * Get the write that may break the current pending release sequence,
464 * according to the replay / divergence pattern.
466 * @return A write that may break the release sequence. If NULL, that means
467 * the release sequence should not be broken.
469 const ModelAction * Node::get_relseq_break() const
471 if (relseq_break_index < (int)relseq_break_writes.size())
472 return relseq_break_writes[relseq_break_index];
478 * Increments the index into the relseq_break_writes set to explore the next
480 * @return Returns false if we have explored all values.
482 bool Node::increment_relseq_break()
486 if (relseq_break_index < ((int)relseq_break_writes.size())) {
487 relseq_break_index++;
488 return (relseq_break_index < ((int)relseq_break_writes.size()));
494 * @return True if all writes that may break the release sequence have been
497 bool Node::relseq_break_empty() const
499 return ((relseq_break_index + 1) >= ((int)relseq_break_writes.size()));
502 void Node::explore(thread_id_t tid)
504 int i = id_to_int(tid);
505 ASSERT(i < ((int)backtrack.size()));
507 backtrack[i] = false;
510 explored_children[i] = true;
513 NodeStack::NodeStack() :
521 NodeStack::~NodeStack()
523 for (unsigned int i = 0; i < node_list.size(); i++)
527 void NodeStack::print() const
529 model_print("............................................\n");
530 model_print("NodeStack printing node_list:\n");
531 for (unsigned int it = 0; it < node_list.size(); it++) {
532 if ((int)it == this->head_idx)
533 model_print("vvv following action is the current iterator vvv\n");
534 node_list[it]->print();
536 model_print("............................................\n");
539 /** Note: The is_enabled set contains what actions were enabled when
541 ModelAction * NodeStack::explore_action(ModelAction *act, enabled_type_t *is_enabled)
545 if ((head_idx + 1) < (int)node_list.size()) {
547 return node_list[head_idx]->get_action();
551 Node *head = get_head();
552 Node *prevfairness = NULL;
554 head->explore_child(act, is_enabled);
555 if (model->params.fairwindow != 0 && head_idx > (int)model->params.fairwindow)
556 prevfairness = node_list[head_idx - model->params.fairwindow];
558 node_list.push_back(new Node(act, head, model->get_num_threads(), prevfairness));
565 * Empties the stack of all trailing nodes after a given position and calls the
566 * destructor for each. This function is provided an offset which determines
567 * how many nodes (relative to the current replay state) to save before popping
569 * @param numAhead gives the number of Nodes (including this Node) to skip over
570 * before removing nodes.
572 void NodeStack::pop_restofstack(int numAhead)
574 /* Diverging from previous execution; clear out remainder of list */
575 unsigned int it = head_idx + numAhead;
576 for (unsigned int i = it; i < node_list.size(); i++)
578 node_list.resize(it);
581 Node * NodeStack::get_head() const
583 if (node_list.empty() || head_idx < 0)
585 return node_list[head_idx];
588 Node * NodeStack::get_next() const
590 if (node_list.empty()) {
594 unsigned int it = head_idx + 1;
595 if (it == node_list.size()) {
599 return node_list[it];
602 void NodeStack::reset_execution()