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());
132 * Checks if the Thread associated with this thread ID has been explored from
134 * @param tid is the thread ID to check
135 * @return true if this thread choice has been explored already, false
138 bool Node::has_been_explored(thread_id_t tid)
140 int id = id_to_int(tid);
141 return explored_children[id];
145 * Checks if the backtracking set is empty.
146 * @return true if the backtracking set is empty
148 bool Node::backtrack_empty()
150 return (numBacktracks == 0);
155 * Checks whether the readsfrom set for this node is empty.
156 * @return true if the readsfrom set is empty.
158 bool Node::read_from_empty() {
159 return ((read_from_index+1)>=may_read_from.size());
165 * Mark the appropriate backtracking information for exploring a thread choice.
166 * @param act The ModelAction to explore
168 void Node::explore_child(ModelAction *act)
170 explore(act->get_tid());
174 * Records a backtracking reference for a thread choice within this Node.
175 * Provides feedback as to whether this thread choice is already set for
177 * @return false if the thread was already set to be backtracked, true
180 bool Node::set_backtrack(thread_id_t id)
182 int i = id_to_int(id);
190 thread_id_t Node::get_next_backtrack()
192 /** @todo Find next backtrack */
194 for (i = 0; i < backtrack.size(); i++)
195 if (backtrack[i] == true)
197 /* Backtrack set was empty? */
198 ASSERT(i != backtrack.size());
200 backtrack[i] = false;
205 bool Node::is_enabled(Thread *t)
207 return id_to_int(t->get_id()) < num_threads;
211 * Add an action to the may_read_from set.
212 * @param act is the action to add
214 void Node::add_read_from(const ModelAction *act)
216 may_read_from.push_back(act);
220 * Gets the next 'future_value' value from this Node. Only valid for a node
221 * where this->action is a 'read'.
222 * @return The first element in future_values
225 uint64_t Node::get_future_value() {
226 ASSERT(future_index<future_values.size());
227 return future_values[future_index];
231 * Gets the next 'may_read_from' action from this Node. Only valid for a node
232 * where this->action is a 'read'.
233 * @return The first element in may_read_from
235 const ModelAction * Node::get_read_from() {
236 if (read_from_index<may_read_from.size())
237 return may_read_from[read_from_index];
243 * Increments the index into the readsfrom set to explore the next item.
244 * @return Returns false if we have explored all items.
246 bool Node::increment_read_from() {
248 return (read_from_index<may_read_from.size());
252 * Increments the index into the future_values set to explore the next item.
253 * @return Returns false if we have explored all values.
255 bool Node::increment_future_value() {
257 return (future_index<future_values.size());
260 void Node::explore(thread_id_t tid)
262 int i = id_to_int(tid);
264 backtrack[i] = false;
267 explored_children[i] = true;
270 static void clear_node_list(node_list_t *list, node_list_t::iterator start,
271 node_list_t::iterator end)
273 node_list_t::iterator it;
275 for (it = start; it != end; it++)
277 list->erase(start, end);
280 NodeStack::NodeStack()
283 node_list.push_back(new Node());
285 iter = node_list.begin();
288 NodeStack::~NodeStack()
290 clear_node_list(&node_list, node_list.begin(), node_list.end());
293 void NodeStack::print()
295 node_list_t::iterator it;
296 printf("............................................\n");
297 printf("NodeStack printing node_list:\n");
298 for (it = node_list.begin(); it != node_list.end(); it++) {
299 if (it == this->iter)
300 printf("vvv following action is the current iterator vvv\n");
303 printf("............................................\n");
306 ModelAction * NodeStack::explore_action(ModelAction *act)
310 ASSERT(!node_list.empty());
311 node_list_t::iterator it=iter;
314 if (it != node_list.end()) {
316 return (*iter)->get_action();
320 get_head()->explore_child(act);
321 node_list.push_back(new Node(act, get_head(), model->get_num_threads()));
328 * Empties the stack of all trailing nodes after a given position and calls the
329 * destructor for each. This function is provided an offset which determines
330 * how many nodes (relative to the current replay state) to save before popping
332 * @param numAhead gives the number of Nodes (including this Node) to skip over
333 * before removing nodes.
335 void NodeStack::pop_restofstack(int numAhead)
337 /* Diverging from previous execution; clear out remainder of list */
338 node_list_t::iterator it = iter;
341 clear_node_list(&node_list, it, node_list.end());
344 Node * NodeStack::get_head()
346 if (node_list.empty())
351 Node * NodeStack::get_next()
353 node_list_t::iterator it = iter;
354 if (node_list.empty()) {
359 if (it == node_list.end()) {
366 void NodeStack::reset_execution()
368 iter = node_list.begin();