X-Git-Url: http://plrg.eecs.uci.edu/git/?p=model-checker.git;a=blobdiff_plain;f=nodestack.cc;h=2ebfc718a3c89403fb19fff42390d11d284ad789;hp=2416ed7c5b35d23deadd2f2681cd890a926e7f98;hb=daac20299ebe62b104ee7994ed1266ed482ca721;hpb=8548c711d71b6474802af83f5a4800eb4ac30718 diff --git a/nodestack.cc b/nodestack.cc index 2416ed7..2ebfc71 100644 --- a/nodestack.cc +++ b/nodestack.cc @@ -24,7 +24,10 @@ Node::Node(ModelAction *act, Node *par, int nthreads) explored_children(num_threads), backtrack(num_threads), numBacktracks(0), - may_read_from() + may_read_from(), + read_from_index(0), + future_values(), + future_index(-1) { if (act) act->set_node(this); @@ -49,9 +52,78 @@ void Node::print() /** @brief Prints info about may_read_from set */ void Node::print_may_read_from() { - readfrom_set_t::iterator it; - for (it = may_read_from.begin(); it != may_read_from.end(); it++) - (*it)->print(); + for (unsigned int i = 0; i < may_read_from.size(); i++) + may_read_from[i]->print(); +} + +/** + * Sets a promise to explore meeting with the given node. + * @param i is the promise index. + */ +void Node::set_promise(unsigned int i) { + if (i >= promises.size()) + promises.resize(i + 1, PROMISE_IGNORE); + promises[i] = PROMISE_UNFULFILLED; +} + +/** + * Looks up whether a given promise should be satisfied by this node. + * @param i The promise index. + * @return true if the promise should be satisfied by the given model action. + */ +bool Node::get_promise(unsigned int i) { + return (i < promises.size()) && (promises[i] == PROMISE_FULFILLED); +} + +/** + * Increments to the next combination of promises. + * @return true if we have a valid combination. + */ +bool Node::increment_promise() { + for (unsigned int i = 0; i < promises.size(); i++) { + if (promises[i] == PROMISE_UNFULFILLED) { + promises[i] = PROMISE_FULFILLED; + while (i > 0) { + i--; + if (promises[i] == PROMISE_FULFILLED) + promises[i] = PROMISE_UNFULFILLED; + } + return true; + } + } + return false; +} + +/** + * Returns whether the promise set is empty. + * @return true if we have explored all promise combinations. + */ +bool Node::promise_empty() { + for (unsigned int i = 0; i < promises.size();i++) + if (promises[i] == PROMISE_UNFULFILLED) + return false; + return true; +} + +/** + * Adds a value from a weakly ordered future write to backtrack to. + * @param value is the value to backtrack to. + */ +bool Node::add_future_value(uint64_t value) { + for (unsigned int i = 0; i < future_values.size(); i++) + if (future_values[i] == value) + return false; + + future_values.push_back(value); + return true; +} + +/** + * Checks whether the future_values set for this node is empty. + * @return true if the future_values set is empty. + */ +bool Node::future_value_empty() { + return ((future_index + 1) >= future_values.size()); } /** @@ -73,11 +145,19 @@ bool Node::has_been_explored(thread_id_t tid) */ bool Node::backtrack_empty() { - return numBacktracks == 0; + return (numBacktracks == 0); } /** - * Mark the appropriate backtracking infromation for exploring a thread choice. + * Checks whether the readsfrom set for this node is empty. + * @return true if the readsfrom set is empty. + */ +bool Node::read_from_empty() { + return ((read_from_index+1) >= may_read_from.size()); +} + +/** + * Mark the appropriate backtracking information for exploring a thread choice. * @param act The ModelAction to explore */ void Node::explore_child(ModelAction *act) @@ -104,13 +184,14 @@ bool Node::set_backtrack(thread_id_t id) thread_id_t Node::get_next_backtrack() { - /* TODO: find next backtrack */ + /** @todo Find next backtrack */ unsigned int i; for (i = 0; i < backtrack.size(); i++) if (backtrack[i] == true) break; - if (i >= backtrack.size()) - return THREAD_ID_T_NONE; + /* Backtrack set was empty? */ + ASSERT(i != backtrack.size()); + backtrack[i] = false; numBacktracks--; return int_to_id(i); @@ -130,20 +211,44 @@ void Node::add_read_from(const ModelAction *act) may_read_from.push_back(act); } +/** + * Gets the next 'future_value' value from this Node. Only valid for a node + * where this->action is a 'read'. + * @return The first element in future_values + */ +uint64_t Node::get_future_value() { + ASSERT(future_indexaction is a 'read'. - * @todo Perform reads_from backtracking/replay properly, so that this function - * may remove elements from may_read_from * @return The first element in may_read_from */ -const ModelAction * Node::get_next_read_from() { - const ModelAction *act; - ASSERT(!may_read_from.empty()); - act = may_read_from.front(); - /* TODO: perform reads_from replay properly */ - /* may_read_from.pop_front(); */ - return act; +const ModelAction * Node::get_read_from() { + if (read_from_index < may_read_from.size()) + return may_read_from[read_from_index]; + else + return NULL; +} + +/** + * Increments the index into the readsfrom set to explore the next item. + * @return Returns false if we have explored all items. + */ +bool Node::increment_read_from() { + read_from_index++; + return (read_from_index < may_read_from.size()); +} + +/** + * Increments the index into the future_values set to explore the next item. + * @return Returns false if we have explored all values. + */ +bool Node::increment_future_value() { + future_index++; + return (future_index < future_values.size()); } void Node::explore(thread_id_t tid) @@ -157,7 +262,7 @@ void Node::explore(thread_id_t tid) } static void clear_node_list(node_list_t *list, node_list_t::iterator start, - node_list_t::iterator end) + node_list_t::iterator end) { node_list_t::iterator it; @@ -197,17 +302,14 @@ ModelAction * NodeStack::explore_action(ModelAction *act) DBG(); ASSERT(!node_list.empty()); + node_list_t::iterator it=iter; + it++; - if (get_head()->has_been_explored(act->get_tid())) { + if (it != node_list.end()) { iter++; return (*iter)->get_action(); } - /* Diverging from previous execution; clear out remainder of list */ - node_list_t::iterator it = iter; - it++; - clear_node_list(&node_list, it, node_list.end()); - /* Record action */ get_head()->explore_child(act); node_list.push_back(new Node(act, get_head(), model->get_num_threads())); @@ -216,6 +318,23 @@ ModelAction * NodeStack::explore_action(ModelAction *act) return NULL; } +/** + * Empties the stack of all trailing nodes after a given position and calls the + * destructor for each. This function is provided an offset which determines + * how many nodes (relative to the current replay state) to save before popping + * the stack. + * @param numAhead gives the number of Nodes (including this Node) to skip over + * before removing nodes. + */ +void NodeStack::pop_restofstack(int numAhead) +{ + /* Diverging from previous execution; clear out remainder of list */ + node_list_t::iterator it = iter; + while (numAhead--) + it++; + clear_node_list(&node_list, it, node_list.end()); +} + Node * NodeStack::get_head() { if (node_list.empty())