7 * @brief Node constructor
9 * Constructs a single Node for use in a NodeStack. Each Node is associated
10 * with exactly one ModelAction (exception: the first Node should be created
11 * as an empty stub, to represent the first thread "choice") and up to one
14 * @param act The ModelAction to associate with this Node. May be NULL.
15 * @param par The parent Node in the NodeStack. May be NULL if there is no
17 * @param nthreads The number of threads which exist at this point in the
20 Node::Node(ModelAction *act, Node *par, int nthreads)
23 num_threads(nthreads),
24 explored_children(num_threads),
25 backtrack(num_threads),
36 /** @brief Node desctructor */
43 /** Prints debugging info for the ModelAction associated with this Node */
49 printf("******** empty action ********\n");
52 /** @brief Prints info about may_read_from set */
53 void Node::print_may_read_from()
55 readfrom_set_t::iterator it;
56 for (it = may_read_from.begin(); it != may_read_from.end(); it++)
61 * Sets a promise to explore meeting with the given node.
62 * @param i is the promise index.
64 void Node::set_promise(uint32_t i) {
65 if (i>=promises.size())
66 promises.resize(i+1,0);
71 * Looks up whether a given promise should be satisfied by this node.
72 * @param i The promise index.
73 * @return true if the promise should be satisfied by the given model action.
75 bool Node::get_promise(uint32_t i) {
76 return (i<promises.size())&&(promises[i]==2);
80 * Increments to the next combination of promises.
81 * @return true if we have a valid combination.
83 bool Node::increment_promise() {
84 for (unsigned int i=0;i<promises.size();i++) {
99 * Returns whether the promise set is empty.
100 * @return true if we have explored all promise combinations.
102 bool Node::promise_empty() {
103 for (unsigned int i=0;i<promises.size();i++)
110 * Adds a value from a weakly ordered future write to backtrack to.
111 * @param value is the value to backtrack to.
113 bool Node::add_future_value(uint64_t value) {
114 for(unsigned int i=0;i<future_values.size();i++)
115 if (future_values[i]==value)
118 future_values.push_back(value);
123 * Checks whether the future_values set for this node is empty.
124 * @return true if the future_values set is empty.
126 bool Node::future_value_empty() {
127 return ((future_index+1)>=future_values.size());
131 * Checks if the Thread associated with this thread ID has been explored from
133 * @param tid is the thread ID to check
134 * @return true if this thread choice has been explored already, false
137 bool Node::has_been_explored(thread_id_t tid)
139 int id = id_to_int(tid);
140 return explored_children[id];
144 * Checks if the backtracking set is empty.
145 * @return true if the backtracking set is empty
147 bool Node::backtrack_empty()
149 return (numBacktracks == 0);
153 * Checks whether the readsfrom set for this node is empty.
154 * @return true if the readsfrom set is empty.
156 bool Node::read_from_empty() {
157 return ((read_from_index+1)>=may_read_from.size());
161 * Mark the appropriate backtracking information for exploring a thread choice.
162 * @param act The ModelAction to explore
164 void Node::explore_child(ModelAction *act)
166 explore(act->get_tid());
170 * Records a backtracking reference for a thread choice within this Node.
171 * Provides feedback as to whether this thread choice is already set for
173 * @return false if the thread was already set to be backtracked, true
176 bool Node::set_backtrack(thread_id_t id)
178 int i = id_to_int(id);
186 thread_id_t Node::get_next_backtrack()
188 /** @todo Find next backtrack */
190 for (i = 0; i < backtrack.size(); i++)
191 if (backtrack[i] == true)
193 /* Backtrack set was empty? */
194 ASSERT(i != backtrack.size());
196 backtrack[i] = false;
201 bool Node::is_enabled(Thread *t)
203 return id_to_int(t->get_id()) < num_threads;
207 * Add an action to the may_read_from set.
208 * @param act is the action to add
210 void Node::add_read_from(const ModelAction *act)
212 may_read_from.push_back(act);
216 * Gets the next 'future_value' value from this Node. Only valid for a node
217 * where this->action is a 'read'.
218 * @return The first element in future_values
220 uint64_t Node::get_future_value() {
221 ASSERT(future_index<future_values.size());
222 return future_values[future_index];
226 * Gets the next 'may_read_from' action from this Node. Only valid for a node
227 * where this->action is a 'read'.
228 * @return The first element in may_read_from
230 const ModelAction * Node::get_read_from() {
231 if (read_from_index<may_read_from.size())
232 return may_read_from[read_from_index];
238 * Increments the index into the readsfrom set to explore the next item.
239 * @return Returns false if we have explored all items.
241 bool Node::increment_read_from() {
243 return (read_from_index<may_read_from.size());
247 * Increments the index into the future_values set to explore the next item.
248 * @return Returns false if we have explored all values.
250 bool Node::increment_future_value() {
252 return (future_index<future_values.size());
255 void Node::explore(thread_id_t tid)
257 int i = id_to_int(tid);
259 backtrack[i] = false;
262 explored_children[i] = true;
265 static void clear_node_list(node_list_t *list, node_list_t::iterator start,
266 node_list_t::iterator end)
268 node_list_t::iterator it;
270 for (it = start; it != end; it++)
272 list->erase(start, end);
275 NodeStack::NodeStack()
278 node_list.push_back(new Node());
280 iter = node_list.begin();
283 NodeStack::~NodeStack()
285 clear_node_list(&node_list, node_list.begin(), node_list.end());
288 void NodeStack::print()
290 node_list_t::iterator it;
291 printf("............................................\n");
292 printf("NodeStack printing node_list:\n");
293 for (it = node_list.begin(); it != node_list.end(); it++) {
294 if (it == this->iter)
295 printf("vvv following action is the current iterator vvv\n");
298 printf("............................................\n");
301 ModelAction * NodeStack::explore_action(ModelAction *act)
305 ASSERT(!node_list.empty());
306 node_list_t::iterator it=iter;
309 if (it != node_list.end()) {
311 return (*iter)->get_action();
315 get_head()->explore_child(act);
316 node_list.push_back(new Node(act, get_head(), model->get_num_threads()));
323 * Empties the stack of all trailing nodes after a given position and calls the
324 * destructor for each. This function is provided an offset which determines
325 * how many nodes (relative to the current replay state) to save before popping
327 * @param numAhead gives the number of Nodes (including this Node) to skip over
328 * before removing nodes.
330 void NodeStack::pop_restofstack(int numAhead)
332 /* Diverging from previous execution; clear out remainder of list */
333 node_list_t::iterator it = iter;
336 clear_node_list(&node_list, it, node_list.end());
339 Node * NodeStack::get_head()
341 if (node_list.empty())
346 Node * NodeStack::get_next()
348 node_list_t::iterator it = iter;
349 if (node_list.empty()) {
354 if (it == node_list.end()) {
361 void NodeStack::reset_execution()
363 iter = node_list.begin();