+#include <string.h>
+
#include "nodestack.h"
#include "action.h"
#include "common.h"
#include "model.h"
+#include "threads-model.h"
/**
* @brief Node constructor
* @param nthreads The number of threads which exist at this point in the
* execution trace.
*/
-Node::Node(ModelAction *act, Node *par, int nthreads)
+Node::Node(ModelAction *act, Node *par, int nthreads, Node *prevfairness)
: action(act),
parent(par),
num_threads(nthreads),
explored_children(num_threads),
backtrack(num_threads),
+ fairness(num_threads),
numBacktracks(0),
- may_read_from()
+ enabled_array(NULL),
+ may_read_from(),
+ read_from_index(0),
+ future_values(),
+ future_index(-1),
+ relseq_break_writes(),
+ relseq_break_index(0),
+ misc_index(0),
+ misc_max(0)
{
- if (act)
- act->set_node(this);
+ ASSERT(act);
+ act->set_node(this);
+ int currtid = id_to_int(act->get_tid());
+ int prevtid = (prevfairness != NULL) ? id_to_int(prevfairness->action->get_tid()) : 0;
+
+ if (model->params.fairwindow != 0) {
+ for (int i = 0; i < nthreads; i++) {
+ ASSERT(i < ((int)fairness.size()));
+ struct fairness_info *fi = &fairness[i];
+ struct fairness_info *prevfi = (par != NULL) && (i < par->get_num_threads()) ? &par->fairness[i] : NULL;
+ if (prevfi) {
+ *fi = *prevfi;
+ }
+ if (parent && parent->is_enabled(int_to_id(i))) {
+ fi->enabled_count++;
+ }
+ if (i == currtid) {
+ fi->turns++;
+ fi->priority = false;
+ }
+ /* Do window processing */
+ if (prevfairness != NULL) {
+ if (prevfairness->parent->is_enabled(int_to_id(i)))
+ fi->enabled_count--;
+ if (i == prevtid) {
+ fi->turns--;
+ }
+ /* Need full window to start evaluating
+ * conditions
+ * If we meet the enabled count and have no
+ * turns, give us priority */
+ if ((fi->enabled_count >= model->params.enabledcount) &&
+ (fi->turns == 0))
+ fi->priority = true;
+ }
+ }
+ }
}
/** @brief Node desctructor */
Node::~Node()
{
- if (action)
- delete action;
+ delete action;
+ if (enabled_array)
+ model_free(enabled_array);
}
/** Prints debugging info for the ModelAction associated with this Node */
void Node::print()
{
- if (action)
- action->print();
- else
- printf("******** empty action ********\n");
+ action->print();
+ model_print(" backtrack: %s\n", backtrack_empty() ? "empty" : "non-empty");
+ model_print(" future values: %s\n", future_value_empty() ? "empty" : "non-empty");
+ model_print(" read-from: %s\n", read_from_empty() ? "empty" : "non-empty");
+ model_print(" promises: %s\n", promise_empty() ? "empty" : "non-empty");
+ model_print(" misc: %s\n", misc_empty() ? "empty" : "non-empty");
+ model_print(" rel seq break: %s\n", relseq_break_empty() ? "empty" : "non-empty");
+}
+
+/** @brief Prints info about may_read_from set */
+void Node::print_may_read_from()
+{
+ 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, bool is_rmw)
+{
+ if (i >= promises.size())
+ promises.resize(i + 1, PROMISE_IGNORE);
+ if (promises[i] == PROMISE_IGNORE) {
+ promises[i] = PROMISE_UNFULFILLED;
+ if (is_rmw)
+ promises[i] |= PROMISE_RMW;
+ }
+}
+
+/**
+ * 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) const
+{
+ return (i < promises.size()) && ((promises[i] & PROMISE_MASK) == PROMISE_FULFILLED);
+}
+
+/**
+ * Increments to the next combination of promises.
+ * @return true if we have a valid combination.
+ */
+bool Node::increment_promise()
+{
+ DBG();
+ unsigned int rmw_count = 0;
+ for (unsigned int i = 0; i < promises.size(); i++) {
+ if (promises[i] == (PROMISE_RMW|PROMISE_FULFILLED))
+ rmw_count++;
+ }
+
+ for (unsigned int i = 0; i < promises.size(); i++) {
+ if ((promises[i] & PROMISE_MASK) == PROMISE_UNFULFILLED) {
+ if ((rmw_count > 0) && (promises[i] & PROMISE_RMW)) {
+ //sending our value to two rmws... not going to work..try next combination
+ continue;
+ }
+ promises[i] = (promises[i] & PROMISE_RMW) |PROMISE_FULFILLED;
+ while (i > 0) {
+ i--;
+ if ((promises[i] & PROMISE_MASK) == PROMISE_FULFILLED)
+ promises[i] = (promises[i] & PROMISE_RMW) | PROMISE_UNFULFILLED;
+ }
+ return true;
+ } else if (promises[i] == (PROMISE_RMW|PROMISE_FULFILLED)) {
+ rmw_count--;
+ }
+ }
+ return false;
+}
+
+/**
+ * Returns whether the promise set is empty.
+ * @return true if we have explored all promise combinations.
+ */
+bool Node::promise_empty() const
+{
+ bool fulfilledrmw = false;
+ for (int i = promises.size() - 1; i >= 0; i--) {
+ if (promises[i] == PROMISE_UNFULFILLED)
+ return false;
+ if (!fulfilledrmw && ((promises[i]&PROMISE_MASK) == PROMISE_UNFULFILLED))
+ return false;
+ if (promises[i] == (PROMISE_FULFILLED|PROMISE_RMW))
+ fulfilledrmw = true;
+ }
+ return true;
+}
+
+
+void Node::set_misc_max(int i)
+{
+ misc_max = i;
+}
+
+int Node::get_misc() const
+{
+ return misc_index;
+}
+
+bool Node::increment_misc()
+{
+ return (misc_index < misc_max) && ((++misc_index) < misc_max);
+}
+
+bool Node::misc_empty() const
+{
+ return (misc_index + 1) >= misc_max;
+}
+
+
+/**
+ * Adds a value from a weakly ordered future write to backtrack to. This
+ * operation may "fail" if the future value has already been run (within some
+ * sloppiness window of this expiration), or if the futurevalues set has
+ * reached its maximum.
+ * @see model_params.maxfuturevalues
+ *
+ * @param value is the value to backtrack to.
+ * @return True if the future value was successully added; false otherwise
+ */
+bool Node::add_future_value(uint64_t value, modelclock_t expiration)
+{
+ int idx = -1; /* Highest index where value is found */
+ for (unsigned int i = 0; i < future_values.size(); i++) {
+ if (future_values[i].value == value) {
+ if (expiration <= future_values[i].expiration)
+ return false;
+ idx = i;
+ }
+ }
+ if (idx > future_index) {
+ /* Future value hasn't been explored; update expiration */
+ future_values[idx].expiration = expiration;
+ return true;
+ } else if (idx >= 0 && expiration <= future_values[idx].expiration + model->params.expireslop) {
+ /* Future value has been explored and is within the "sloppy" window */
+ return false;
+ }
+
+ /* Limit the size of the future-values set */
+ if (model->params.maxfuturevalues > 0 &&
+ (int)future_values.size() >= model->params.maxfuturevalues)
+ return false;
+
+ struct future_value newfv = {value, expiration};
+ future_values.push_back(newfv);
+ 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() const
+{
+ return ((future_index + 1) >= ((int)future_values.size()));
}
/**
* @return true if this thread choice has been explored already, false
* otherwise
*/
-bool Node::has_been_explored(thread_id_t tid)
+bool Node::has_been_explored(thread_id_t tid) const
{
int id = id_to_int(tid);
return explored_children[id];
* Checks if the backtracking set is empty.
* @return true if the backtracking set is empty
*/
-bool Node::backtrack_empty()
+bool Node::backtrack_empty() const
+{
+ return (numBacktracks == 0);
+}
+
+/**
+ * Checks whether the readsfrom set for this node is empty.
+ * @return true if the readsfrom set is empty.
+ */
+bool Node::read_from_empty() const
{
- return numBacktracks == 0;
+ return ((read_from_index + 1) >= may_read_from.size());
}
/**
- * Mark the appropriate backtracking infromation for exploring a thread choice.
+ * Mark the appropriate backtracking information for exploring a thread choice.
* @param act The ModelAction to explore
*/
-void Node::explore_child(ModelAction *act)
+void Node::explore_child(ModelAction *act, enabled_type_t *is_enabled)
{
+ if (!enabled_array)
+ enabled_array = (enabled_type_t *)model_malloc(sizeof(enabled_type_t) * num_threads);
+ if (is_enabled != NULL)
+ memcpy(enabled_array, is_enabled, sizeof(enabled_type_t) * num_threads);
+ else {
+ for (int i = 0; i < num_threads; i++)
+ enabled_array[i] = THREAD_DISABLED;
+ }
+
explore(act->get_tid());
}
bool Node::set_backtrack(thread_id_t id)
{
int i = id_to_int(id);
+ ASSERT(i < ((int)backtrack.size()));
if (backtrack[i])
return false;
backtrack[i] = true;
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);
}
-bool Node::is_enabled(Thread *t)
+bool Node::is_enabled(Thread *t) const
+{
+ int thread_id = id_to_int(t->get_id());
+ return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
+}
+
+enabled_type_t Node::enabled_status(thread_id_t tid) const
+{
+ int thread_id = id_to_int(tid);
+ if (thread_id < num_threads)
+ return enabled_array[thread_id];
+ else
+ return THREAD_DISABLED;
+}
+
+bool Node::is_enabled(thread_id_t tid) const
{
- return id_to_int(t->get_id()) < num_threads;
+ int thread_id = id_to_int(tid);
+ return thread_id < num_threads && (enabled_array[thread_id] != THREAD_DISABLED);
+}
+
+bool Node::has_priority(thread_id_t tid) const
+{
+ return fairness[id_to_int(tid)].priority;
}
/**
* Add an action to the may_read_from set.
* @param act is the action to add
*/
-void Node::add_read_from(ModelAction *act)
+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() const
+{
+ ASSERT(future_index >= 0 && future_index < ((int)future_values.size()));
+ return future_values[future_index].value;
+}
+
+modelclock_t Node::get_future_value_expiration() const
+{
+ ASSERT(future_index >= 0 && future_index < ((int)future_values.size()));
+ return future_values[future_index].expiration;
+}
+
+
+int Node::get_read_from_size() const
+{
+ return may_read_from.size();
+}
+
+const ModelAction * Node::get_read_from_at(int i) const
+{
+ return may_read_from[i];
+}
+
+/**
+ * Gets the next 'may_read_from' action from this Node. Only valid for a node
+ * where this->action is a 'read'.
+ * @return The first element in may_read_from
+ */
+const ModelAction * Node::get_read_from() const
+{
+ 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()
+{
+ DBG();
+ promises.clear();
+ if (read_from_index < may_read_from.size()) {
+ read_from_index++;
+ return read_from_index < may_read_from.size();
+ }
+ return false;
+}
+
+/**
+ * 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()
+{
+ DBG();
+ promises.clear();
+ if (future_index < ((int)future_values.size())) {
+ future_index++;
+ return (future_index < ((int)future_values.size()));
+ }
+ return false;
+}
+
+/**
+ * Add a write ModelAction to the set of writes that may break the release
+ * sequence. This is used during replay exploration of pending release
+ * sequences. This Node must correspond to a release sequence fixup action.
+ *
+ * @param write The write that may break the release sequence. NULL means we
+ * allow the release sequence to synchronize.
+ */
+void Node::add_relseq_break(const ModelAction *write)
+{
+ relseq_break_writes.push_back(write);
+}
+
+/**
+ * Get the write that may break the current pending release sequence,
+ * according to the replay / divergence pattern.
+ *
+ * @return A write that may break the release sequence. If NULL, that means
+ * the release sequence should not be broken.
+ */
+const ModelAction * Node::get_relseq_break() const
+{
+ if (relseq_break_index < (int)relseq_break_writes.size())
+ return relseq_break_writes[relseq_break_index];
+ else
+ return NULL;
+}
+
+/**
+ * Increments the index into the relseq_break_writes set to explore the next
+ * item.
+ * @return Returns false if we have explored all values.
+ */
+bool Node::increment_relseq_break()
+{
+ DBG();
+ promises.clear();
+ if (relseq_break_index < ((int)relseq_break_writes.size())) {
+ relseq_break_index++;
+ return (relseq_break_index < ((int)relseq_break_writes.size()));
+ }
+ return false;
+}
+
+/**
+ * @return True if all writes that may break the release sequence have been
+ * explored
+ */
+bool Node::relseq_break_empty() const
{
- may_read_from.insert(act);
+ return ((relseq_break_index + 1) >= ((int)relseq_break_writes.size()));
}
void Node::explore(thread_id_t tid)
{
int i = id_to_int(tid);
+ ASSERT(i < ((int)backtrack.size()));
if (backtrack[i]) {
backtrack[i] = false;
numBacktracks--;
explored_children[i] = true;
}
-static void clear_node_list(node_list_t *list, node_list_t::iterator start,
- node_list_t::iterator end)
-{
- node_list_t::iterator it;
-
- for (it = start; it != end; it++)
- delete (*it);
- list->erase(start, end);
-}
-
-NodeStack::NodeStack()
- : total_nodes(0)
+NodeStack::NodeStack() :
+ node_list(),
+ head_idx(-1),
+ total_nodes(0)
{
- node_list.push_back(new Node());
total_nodes++;
- iter = node_list.begin();
}
NodeStack::~NodeStack()
{
- clear_node_list(&node_list, node_list.begin(), node_list.end());
+ for (unsigned int i = 0; i < node_list.size(); i++)
+ delete node_list[i];
}
-void NodeStack::print()
+void NodeStack::print() const
{
- node_list_t::iterator it;
- printf("............................................\n");
- printf("NodeStack printing node_list:\n");
- for (it = node_list.begin(); it != node_list.end(); it++) {
- if (it == this->iter)
- printf("vvv following action is the current iterator vvv\n");
- (*it)->print();
+ model_print("............................................\n");
+ model_print("NodeStack printing node_list:\n");
+ for (unsigned int it = 0; it < node_list.size(); it++) {
+ if ((int)it == this->head_idx)
+ model_print("vvv following action is the current iterator vvv\n");
+ node_list[it]->print();
}
- printf("............................................\n");
+ model_print("............................................\n");
}
-ModelAction * NodeStack::explore_action(ModelAction *act)
+/** Note: The is_enabled set contains what actions were enabled when
+ * act was chosen. */
+ModelAction * NodeStack::explore_action(ModelAction *act, enabled_type_t *is_enabled)
{
DBG();
- ASSERT(!node_list.empty());
-
- if (get_head()->has_been_explored(act->get_tid())) {
- iter++;
- return (*iter)->get_action();
+ if ((head_idx + 1) < (int)node_list.size()) {
+ head_idx++;
+ return node_list[head_idx]->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()));
+ Node *head = get_head();
+ Node *prevfairness = NULL;
+ if (head) {
+ head->explore_child(act, is_enabled);
+ if (model->params.fairwindow != 0 && head_idx > (int)model->params.fairwindow)
+ prevfairness = node_list[head_idx - model->params.fairwindow];
+ }
+ node_list.push_back(new Node(act, head, model->get_num_threads(), prevfairness));
total_nodes++;
- iter++;
+ head_idx++;
return NULL;
}
-Node * NodeStack::get_head()
+/**
+ * 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 */
+ unsigned int it = head_idx + numAhead;
+ for (unsigned int i = it; i < node_list.size(); i++)
+ delete node_list[i];
+ node_list.resize(it);
+}
+
+Node * NodeStack::get_head() const
{
- if (node_list.empty())
+ if (node_list.empty() || head_idx < 0)
return NULL;
- return *iter;
+ return node_list[head_idx];
}
-Node * NodeStack::get_next()
+Node * NodeStack::get_next() const
{
- node_list_t::iterator it = iter;
if (node_list.empty()) {
DEBUG("Empty\n");
return NULL;
}
- it++;
- if (it == node_list.end()) {
+ unsigned int it = head_idx + 1;
+ if (it == node_list.size()) {
DEBUG("At end\n");
return NULL;
}
- return *it;
+ return node_list[it];
}
void NodeStack::reset_execution()
{
- iter = node_list.begin();
+ head_idx = -1;
}