#include "schedule.h"
#include "snapshot-interface.h"
#include "common.h"
+#include "clockvector.h"
#define INITIAL_THREAD_ID 0
diverge(NULL),
nextThread(THREAD_ID_T_NONE),
action_trace(new action_list_t()),
- thread_map(new std::map<int, class Thread *>),
+ thread_map(new std::map<int, Thread *>),
+ obj_map(new std::map<const void *, action_list_t>()),
obj_thrd_map(new std::map<void *, std::vector<action_list_t> >()),
thrd_last_action(new std::vector<ModelAction *>(1)),
node_stack(new NodeStack()),
/** @brief Destructor */
ModelChecker::~ModelChecker()
{
- std::map<int, class Thread *>::iterator it;
+ std::map<int, Thread *>::iterator it;
for (it = thread_map->begin(); it != thread_map->end(); it++)
delete (*it).second;
delete thread_map;
delete obj_thrd_map;
+ delete obj_map;
delete action_trace;
delete thrd_last_action;
delete node_stack;
}
/** @returns a sequence number for a new ModelAction */
-int ModelChecker::get_next_seq_num()
+modelclock_t ModelChecker::get_next_seq_num()
{
return ++used_sequence_numbers;
}
next = node_stack->get_next()->get_action();
if (next == diverge) {
- Node *node = next->get_node();
+ Node *node = next->get_node()->get_parent();
/* Reached divergence point */
DEBUG("*** Divergence point ***\n");
action_type type = act->get_type();
switch (type) {
- case THREAD_CREATE:
- case THREAD_YIELD:
- case THREAD_JOIN:
- return NULL;
case ATOMIC_READ:
case ATOMIC_WRITE:
- default:
+ case ATOMIC_RMW:
break;
+ default:
+ return NULL;
}
/* linear search: from most recent to oldest */
+ action_list_t *list = &(*obj_map)[act->get_location()];
action_list_t::reverse_iterator rit;
- for (rit = action_trace->rbegin(); rit != action_trace->rend(); rit++) {
+ for (rit = list->rbegin(); rit != list->rend(); rit++) {
ModelAction *prev = *rit;
if (act->is_synchronizing(prev))
return prev;
if (prev == NULL)
return;
- node = prev->get_node();
+ node = prev->get_node()->get_parent();
while (!node->is_enabled(t))
t = t->get_parent();
if (node->has_been_explored(t->get_id()))
return;
+ /* Cache the latest backtracking point */
if (!next_backtrack || *prev > *next_backtrack)
next_backtrack = prev;
Node *currnode;
ModelAction *curr = this->current_action;
+ ModelAction *tmp;
current_action = NULL;
if (!curr) {
DEBUG("trying to push NULL action...\n");
return;
}
- curr = node_stack->explore_action(curr);
- curr->create_cv(get_parent_action(curr->get_tid()));
+ tmp = node_stack->explore_action(curr);
+ if (tmp) {
+ /* Discard duplicate ModelAction; use action from NodeStack */
+ delete curr;
+ curr = tmp;
+ } else {
+ /*
+ * Perform one-time actions when pushing new ModelAction onto
+ * NodeStack
+ */
+ curr->create_cv(get_parent_action(curr->get_tid()));
+ /* Build may_read_from set */
+ if (curr->is_read())
+ build_reads_from_past(curr);
+ }
/* Assign 'creation' parent */
if (curr->get_type() == THREAD_CREATE) {
nextThread = get_next_replay_thread();
- currnode = curr->get_node();
+ currnode = curr->get_node()->get_parent();
if (!currnode->backtrack_empty())
if (!next_backtrack || *curr > *next_backtrack)
set_backtracking(curr);
add_action_to_lists(curr);
+
+ /* Assign reads_from values */
+ /* TODO: perform release/acquire synchronization here; include
+ * reads_from as ModelAction member? */
+ Thread *th = get_thread(curr->get_tid());
+ int value = VALUE_NONE;
+ if (curr->is_read()) {
+ const ModelAction *reads_from = curr->get_node()->get_next_read_from();
+ value = reads_from->get_value();
+ /* Assign reads_from, perform release/acquire synchronization */
+ curr->read_from(reads_from);
+ }
+ th->set_return_value(value);
}
+/**
+ * Performs various bookkeeping operations for the current ModelAction. For
+ * instance, adds action to the per-object, per-thread action vector and to the
+ * action trace list of all thread actions.
+ *
+ * @param act is the ModelAction to add.
+ */
void ModelChecker::add_action_to_lists(ModelAction *act)
{
+ int tid = id_to_int(act->get_tid());
action_trace->push_back(act);
+ (*obj_map)[act->get_location()].push_back(act);
+
std::vector<action_list_t> *vec = &(*obj_thrd_map)[act->get_location()];
- if (id_to_int(act->get_tid()) >= (int)vec->size())
+ if (tid >= (int)vec->size())
vec->resize(next_thread_id);
- (*vec)[id_to_int(act->get_tid())].push_back(act);
+ (*vec)[tid].push_back(act);
- (*thrd_last_action)[id_to_int(act->get_tid())] = act;
+ if ((int)thrd_last_action->size() <= tid)
+ thrd_last_action->resize(get_num_threads());
+ (*thrd_last_action)[tid] = act;
}
ModelAction * ModelChecker::get_last_action(thread_id_t tid)
return (*thrd_last_action)[id_to_int(tid)];
}
+/**
+ * Gets the last memory_order_seq_cst action (in the total global sequence)
+ * performed on a particular object (i.e., memory location).
+ * @param location The object location to check
+ * @return The last seq_cst action performed
+ */
+ModelAction * ModelChecker::get_last_seq_cst(const void *location)
+{
+ action_list_t *list = &(*obj_map)[location];
+ /* Find: max({i in dom(S) | seq_cst(t_i) && isWrite(t_i) && samevar(t_i, t)}) */
+ action_list_t::reverse_iterator rit;
+ for (rit = list->rbegin(); rit != list->rend(); rit++)
+ if ((*rit)->is_write() && (*rit)->is_seqcst())
+ return *rit;
+ return NULL;
+}
+
ModelAction * ModelChecker::get_parent_action(thread_id_t tid)
{
ModelAction *parent = get_last_action(tid);
return parent;
}
-void ModelChecker::print_summary(void)
+ClockVector * ModelChecker::get_cv(thread_id_t tid) {
+ return get_parent_action(tid)->get_cv();
+}
+
+/**
+ * Build up an initial set of all past writes that this 'read' action may read
+ * from. This set is determined by the clock vector's "happens before"
+ * relationship.
+ * @param curr is the current ModelAction that we are exploring; it must be a
+ * 'read' operation.
+ */
+void ModelChecker::build_reads_from_past(ModelAction *curr)
{
- printf("\n");
- printf("Number of executions: %d\n", num_executions);
- printf("Total nodes created: %d\n", node_stack->get_total_nodes());
+ std::vector<action_list_t> *thrd_lists = &(*obj_thrd_map)[curr->get_location()];
+ unsigned int i;
+
+ ASSERT(curr->is_read());
+
+ ModelAction *last_seq_cst = NULL;
+
+ if (curr->is_seqcst())
+ last_seq_cst = get_last_seq_cst(curr->get_location());
+
+ /* Track whether this object has been initialized */
+ bool initialized = false;
+
+ for (i = 0; i < thrd_lists->size(); i++) {
+ action_list_t *list = &(*thrd_lists)[i];
+ action_list_t::reverse_iterator rit;
+ for (rit = list->rbegin(); rit != list->rend(); rit++) {
+ ModelAction *act = *rit;
+
+ /* Only consider 'write' actions */
+ if (!act->is_write())
+ continue;
+
+ /* Don't consider more than one seq_cst write */
+ if (!act->is_seqcst() || act == last_seq_cst) {
+ DEBUG("Adding action to may_read_from:\n");
+ if (DBG_ENABLED()) {
+ act->print();
+ curr->print();
+ }
+ curr->get_node()->add_read_from(act);
+ }
+
+ /* Include at most one act per-thread that "happens before" curr */
+ if (act->happens_before(curr)) {
+ initialized = true;
+ break;
+ }
+ }
+ }
- scheduler->print();
+ if (!initialized) {
+ /* TODO: need a more informative way of reporting errors */
+ printf("ERROR: may read from uninitialized atomic\n");
+ }
- print_list(action_trace);
- printf("\n");
+ if (DBG_ENABLED() || !initialized) {
+ printf("Reached read action:\n");
+ curr->print();
+ printf("Printing may_read_from\n");
+ curr->get_node()->print_may_read_from();
+ printf("End printing may_read_from\n");
+ }
+
+ ASSERT(initialized);
}
-void ModelChecker::print_list(action_list_t *list)
+static void print_list(action_list_t *list)
{
action_list_t::iterator it;
printf("---------------------------------------------------------------------\n");
}
+void ModelChecker::print_summary(void)
+{
+ printf("\n");
+ printf("Number of executions: %d\n", num_executions);
+ printf("Total nodes created: %d\n", node_stack->get_total_nodes());
+
+ scheduler->print();
+
+ print_list(action_trace);
+ printf("\n");
+}
+
int ModelChecker::add_thread(Thread *t)
{
(*thread_map)[id_to_int(t->get_id())] = t;
projects / c11tester.git / blobdiff