#include <stdio.h>
#include <algorithm>
#include <mutex>
+#include <new>
#include "model.h"
#include "action.h"
/* First thread created will have id INITIAL_THREAD_ID */
next_thread_id(INITIAL_THREAD_ID),
used_sequence_numbers(0),
- nextThread(NULL),
next_backtrack(NULL),
bugs(),
stats(),
ModelAction *current_action;
unsigned int next_thread_id;
modelclock_t used_sequence_numbers;
- Thread *nextThread;
ModelAction *next_backtrack;
std::vector< bug_message *, SnapshotAlloc<bug_message *> > bugs;
struct execution_stats stats;
delete priv;
}
-static action_list_t * get_safe_ptr_action(HashTable<const void *, action_list_t *, uintptr_t, 4> * hash, void * ptr) {
- action_list_t * tmp=hash->get(ptr);
- if (tmp==NULL) {
- tmp=new action_list_t();
+static action_list_t * get_safe_ptr_action(HashTable<const void *, action_list_t *, uintptr_t, 4> * hash, void * ptr)
+{
+ action_list_t *tmp = hash->get(ptr);
+ if (tmp == NULL) {
+ tmp = new action_list_t();
hash->put(ptr, tmp);
}
return tmp;
}
-static std::vector<action_list_t> * get_safe_ptr_vect_action(HashTable<void *, std::vector<action_list_t> *, uintptr_t, 4> * hash, void * ptr) {
- std::vector<action_list_t> * tmp=hash->get(ptr);
- if (tmp==NULL) {
- tmp=new std::vector<action_list_t>();
+static std::vector<action_list_t> * get_safe_ptr_vect_action(HashTable<void *, std::vector<action_list_t> *, uintptr_t, 4> * hash, void * ptr)
+{
+ std::vector<action_list_t> *tmp = hash->get(ptr);
+ if (tmp == NULL) {
+ tmp = new std::vector<action_list_t>();
hash->put(ptr, tmp);
}
return tmp;
/* Print all model-checker output before rollback */
fflush(model_out);
- snapshotObject->backTrackBeforeStep(0);
+ snapshot_backtrack_before(0);
}
/** @return a thread ID for a new Thread */
return priv->next_thread_id;
}
-/** @return The currently executing Thread. */
+/**
+ * Must be called from user-thread context (e.g., through the global
+ * thread_current() interface)
+ *
+ * @return The currently executing Thread.
+ */
Thread * ModelChecker::get_current_thread() const
{
return scheduler->get_current_thread();
{
thread_id_t tid;
- if (curr!=NULL) {
+ if (curr != NULL) {
/* Do not split atomic actions. */
if (curr->is_rmwr())
return thread_current();
- /* The THREAD_CREATE action points to the created Thread */
else if (curr->get_type() == THREAD_CREATE)
- return (Thread *)curr->get_location();
+ return curr->get_thread_operand();
}
/* Have we completed exploring the preselected path? */
if (next == diverge) {
if (earliest_diverge == NULL || *diverge < *earliest_diverge)
- earliest_diverge=diverge;
+ earliest_diverge = diverge;
Node *nextnode = next->get_node();
Node *prevnode = nextnode->get_parent();
tid = next->get_tid();
node_stack->pop_restofstack(2);
} else {
+ ASSERT(prevnode);
/* Make a different thread execute for next step */
- scheduler->add_sleep(thread_map->get(id_to_int(next->get_tid())));
+ scheduler->add_sleep(get_thread(next->get_tid()));
tid = prevnode->get_next_backtrack();
/* Make sure the backtracked thread isn't sleeping. */
node_stack->pop_restofstack(1);
- if (diverge==earliest_diverge) {
- earliest_diverge=prevnode->get_action();
+ if (diverge == earliest_diverge) {
+ earliest_diverge = prevnode->get_action();
}
}
/* The correct sleep set is in the parent node. */
* the corresponding thread object's pending action.
*/
-void ModelChecker::execute_sleep_set() {
- for(unsigned int i=0;i<get_num_threads();i++) {
- thread_id_t tid=int_to_id(i);
- Thread *thr=get_thread(tid);
+void ModelChecker::execute_sleep_set()
+{
+ for (unsigned int i = 0; i < get_num_threads(); i++) {
+ thread_id_t tid = int_to_id(i);
+ Thread *thr = get_thread(tid);
if (scheduler->is_sleep_set(thr) && thr->get_pending() == NULL) {
thr->set_state(THREAD_RUNNING);
scheduler->next_thread(thr);
thr->set_pending(priv->current_action);
}
}
- priv->current_action = NULL;
}
void ModelChecker::wake_up_sleeping_actions(ModelAction *curr)
record_stats();
/* Output */
- if (DBG_ENABLED() || params.verbose || have_bug_reports())
+ if (DBG_ENABLED() || params.verbose || (complete && have_bug_reports()))
print_execution(complete);
else
clear_program_output();
action_list_t::reverse_iterator rit;
for (rit = list->rbegin(); rit != list->rend(); rit++) {
ModelAction *prev = *rit;
- if (!act->same_thread(prev)&&prev->is_failed_trylock())
+ if (!act->same_thread(prev) && prev->is_failed_trylock())
return prev;
}
break;
action_list_t::reverse_iterator rit;
for (rit = list->rbegin(); rit != list->rend(); rit++) {
ModelAction *prev = *rit;
- if (!act->same_thread(prev)&&prev->is_failed_trylock())
+ if (!act->same_thread(prev) && prev->is_failed_trylock())
return prev;
- if (!act->same_thread(prev)&&prev->is_notify())
+ if (!act->same_thread(prev) && prev->is_notify())
return prev;
}
break;
action_list_t::reverse_iterator rit;
for (rit = list->rbegin(); rit != list->rend(); rit++) {
ModelAction *prev = *rit;
- if (!act->same_thread(prev)&&prev->is_wait())
+ if (!act->same_thread(prev) && prev->is_wait())
return prev;
}
break;
void ModelChecker::set_backtracking(ModelAction *act)
{
Thread *t = get_thread(act);
- ModelAction * prev = get_last_conflict(act);
+ ModelAction *prev = get_last_conflict(act);
if (prev == NULL)
return;
- Node * node = prev->get_node()->get_parent();
+ Node *node = prev->get_node()->get_parent();
int low_tid, high_tid;
- if (node->is_enabled(t)) {
+ if (node->enabled_status(t->get_id()) == THREAD_ENABLED) {
low_tid = id_to_int(act->get_tid());
- high_tid = low_tid+1;
+ high_tid = low_tid + 1;
} else {
low_tid = 0;
high_tid = get_num_threads();
}
- for(int i = low_tid; i < high_tid; i++) {
+ for (int i = low_tid; i < high_tid; i++) {
thread_id_t tid = int_to_id(i);
/* Make sure this thread can be enabled here. */
break;
/* Don't backtrack into a point where the thread is disabled or sleeping. */
- if (node->enabled_status(tid)!=THREAD_ENABLED)
+ if (node->enabled_status(tid) != THREAD_ENABLED)
continue;
/* Check if this has been explored already */
/* See if fairness allows */
if (model->params.fairwindow != 0 && !node->has_priority(tid)) {
- bool unfair=false;
- for(int t=0;t<node->get_num_threads();t++) {
- thread_id_t tother=int_to_id(t);
+ bool unfair = false;
+ for (int t = 0; t < node->get_num_threads(); t++) {
+ thread_id_t tother = int_to_id(t);
if (node->is_enabled(tother) && node->has_priority(tother)) {
- unfair=true;
+ unfair = true;
break;
}
}
continue;
}
/* Cache the latest backtracking point */
- if (!priv->next_backtrack || *prev > *priv->next_backtrack)
- priv->next_backtrack = prev;
+ set_latest_backtrack(prev);
/* If this is a new backtracking point, mark the tree */
if (!node->set_backtrack(tid))
}
}
+/**
+ * @brief Cache the a backtracking point as the "most recent", if eligible
+ *
+ * Note that this does not prepare the NodeStack for this backtracking
+ * operation, it only caches the action on a per-execution basis
+ *
+ * @param act The operation at which we should explore a different next action
+ * (i.e., backtracking point)
+ * @return True, if this action is now the most recent backtracking point;
+ * false otherwise
+ */
+bool ModelChecker::set_latest_backtrack(ModelAction *act)
+{
+ if (!priv->next_backtrack || *act > *priv->next_backtrack) {
+ priv->next_backtrack = act;
+ return true;
+ }
+ return false;
+}
+
/**
* Returns last backtracking point. The model checker will explore a different
* path for this point in the next execution.
r_status = r_modification_order(curr, reads_from);
}
-
- if (!second_part_of_rmw&&is_infeasible()&&(curr->get_node()->increment_read_from()||curr->get_node()->increment_future_value())) {
+ if (!second_part_of_rmw && is_infeasible() && (curr->get_node()->increment_read_from() || curr->get_node()->increment_future_value())) {
mo_graph->rollbackChanges();
priv->too_many_reads = false;
continue;
read_from(curr, reads_from);
mo_graph->commitChanges();
- mo_check_promises(curr->get_tid(), reads_from);
+ mo_check_promises(curr->get_tid(), reads_from, NULL);
updated |= r_status;
} else if (!second_part_of_rmw) {
/* Read from future value */
- value = curr->get_node()->get_future_value();
- modelclock_t expiration = curr->get_node()->get_future_value_expiration();
+ struct future_value fv = curr->get_node()->get_future_value();
+ value = fv.value;
+ curr->set_value(fv.value);
curr->set_read_from(NULL);
- Promise *valuepromise = new Promise(curr, value, expiration);
- promises->push_back(valuepromise);
+ promises->push_back(new Promise(curr, fv));
}
get_thread(curr)->set_return_value(value);
return updated;
*
* @return True if synchronization was updated; false otherwise
*/
-bool ModelChecker::process_mutex(ModelAction *curr) {
- std::mutex *mutex=NULL;
- struct std::mutex_state *state=NULL;
+bool ModelChecker::process_mutex(ModelAction *curr)
+{
+ std::mutex *mutex = NULL;
+ struct std::mutex_state *state = NULL;
if (curr->is_trylock() || curr->is_lock() || curr->is_unlock()) {
mutex = (std::mutex *)curr->get_location();
state = mutex->get_state();
- } else if(curr->is_wait()) {
+ } else if (curr->is_wait()) {
mutex = (std::mutex *)curr->get_value();
state = mutex->get_state();
}
}
waiters->clear();
//check whether we should go to sleep or not...simulate spurious failures
- if (curr->get_node()->get_misc()==0) {
+ if (curr->get_node()->get_misc() == 0) {
get_safe_ptr_action(condvar_waiters_map, curr->get_location())->push_back(curr);
//disable us
- scheduler->sleep(get_current_thread());
+ scheduler->sleep(get_thread(curr));
}
break;
}
}
case ATOMIC_NOTIFY_ONE: {
action_list_t *waiters = get_safe_ptr_action(condvar_waiters_map, curr->get_location());
- int wakeupthread=curr->get_node()->get_misc();
+ int wakeupthread = curr->get_node()->get_misc();
action_list_t::iterator it = waiters->begin();
advance(it, wakeupthread);
scheduler->wake(get_thread(*it));
return false;
}
+void ModelChecker::add_future_value(const ModelAction *writer, ModelAction *reader)
+{
+ /* Do more ambitious checks now that mo is more complete */
+ if (mo_may_allow(writer, reader)) {
+ Node *node = reader->get_node();
+
+ /* Find an ancestor thread which exists at the time of the reader */
+ Thread *write_thread = get_thread(writer);
+ while (id_to_int(write_thread->get_id()) >= node->get_num_threads())
+ write_thread = write_thread->get_parent();
+
+ struct future_value fv = {
+ writer->get_value(),
+ writer->get_seq_number() + params.maxfuturedelay,
+ write_thread->get_id(),
+ };
+ if (node->add_future_value(fv))
+ set_latest_backtrack(reader);
+ }
+}
+
/**
* Process a write ModelAction
* @param curr The ModelAction to process
if (promises->size() == 0) {
for (unsigned int i = 0; i < futurevalues->size(); i++) {
struct PendingFutureValue pfv = (*futurevalues)[i];
- //Do more ambitious checks now that mo is more complete
- if (mo_may_allow(pfv.writer, pfv.act)&&
- pfv.act->get_node()->add_future_value(pfv.writer->get_value(), pfv.writer->get_seq_number()+params.maxfuturedelay) &&
- (!priv->next_backtrack || *pfv.act > *priv->next_backtrack))
- priv->next_backtrack = pfv.act;
+ add_future_value(pfv.writer, pfv.act);
}
- futurevalues->resize(0);
+ futurevalues->clear();
}
mo_graph->commitChanges();
- mo_check_promises(curr->get_tid(), curr);
+ mo_check_promises(curr->get_tid(), curr, NULL);
get_thread(curr)->set_return_value(VALUE_NONE);
return updated_mod_order || updated_promises;
switch (curr->get_type()) {
case THREAD_CREATE: {
- Thread *th = (Thread *)curr->get_location();
+ Thread *th = curr->get_thread_operand();
th->set_creation(curr);
+ /* Promises can be satisfied by children */
+ for (unsigned int i = 0; i < promises->size(); i++) {
+ Promise *promise = (*promises)[i];
+ if (promise->thread_is_available(curr->get_tid()))
+ promise->add_thread(th->get_id());
+ }
break;
}
case THREAD_JOIN: {
- Thread *blocking = (Thread *)curr->get_location();
+ Thread *blocking = curr->get_thread_operand();
ModelAction *act = get_last_action(blocking->get_id());
curr->synchronize_with(act);
updated = true; /* trigger rel-seq checks */
scheduler->wake(get_thread(act));
}
th->complete();
+ /* Completed thread can't satisfy promises */
+ for (unsigned int i = 0; i < promises->size(); i++) {
+ Promise *promise = (*promises)[i];
+ if (promise->thread_is_available(th->get_id()))
+ if (promise->eliminate_thread(th->get_id()))
+ priv->failed_promise = true;
+ }
updated = true; /* trigger rel-seq checks */
break;
}
*/
bool ModelChecker::check_action_enabled(ModelAction *curr) {
if (curr->is_lock()) {
- std::mutex * lock = (std::mutex *)curr->get_location();
- struct std::mutex_state * state = lock->get_state();
+ std::mutex *lock = (std::mutex *)curr->get_location();
+ struct std::mutex_state *state = lock->get_state();
if (state->islocked) {
//Stick the action in the appropriate waiting queue
get_safe_ptr_action(lock_waiters_map, curr->get_location())->push_back(curr);
* execution when running permutations of previously-observed executions.
*
* @param curr The current action to process
- * @return The next Thread that must be executed. May be NULL if ModelChecker
- * makes no choice (e.g., according to replay execution, combining RMW actions,
- * etc.)
+ * @return The ModelAction that is actually executed; may be different than
+ * curr; may be NULL, if the current action is not enabled to run
*/
-Thread * ModelChecker::check_current_action(ModelAction *curr)
+ModelAction * ModelChecker::check_current_action(ModelAction *curr)
{
ASSERT(curr);
bool second_part_of_rmw = curr->is_rmwc() || curr->is_rmw();
if (!check_action_enabled(curr)) {
/* Make the execution look like we chose to run this action
* much later, when a lock/join can succeed */
- get_current_thread()->set_pending(curr);
- scheduler->sleep(get_current_thread());
- return get_next_thread(NULL);
+ get_thread(curr)->set_pending(curr);
+ scheduler->sleep(get_thread(curr));
+ return NULL;
}
bool newly_explored = initialize_curr_action(&curr);
+ DBG();
+ if (DBG_ENABLED())
+ curr->print();
+
wake_up_sleeping_actions(curr);
/* Add the action to lists before any other model-checking tasks */
check_curr_backtracking(curr);
set_backtracking(curr);
- return get_next_thread(curr);
+ return curr;
}
-void ModelChecker::check_curr_backtracking(ModelAction * curr) {
+void ModelChecker::check_curr_backtracking(ModelAction *curr)
+{
Node *currnode = curr->get_node();
Node *parnode = currnode->get_parent();
- if ((!parnode->backtrack_empty() ||
+ if ((parnode && !parnode->backtrack_empty()) ||
!currnode->misc_empty() ||
!currnode->read_from_empty() ||
!currnode->future_value_empty() ||
!currnode->promise_empty() ||
- !currnode->relseq_break_empty())
- && (!priv->next_backtrack ||
- *curr > *priv->next_backtrack)) {
- priv->next_backtrack = curr;
+ !currnode->relseq_break_empty()) {
+ set_latest_backtrack(curr);
}
}
bool ModelChecker::promises_expired() const
{
- for (unsigned int promise_index = 0; promise_index < promises->size(); promise_index++) {
- Promise *promise = (*promises)[promise_index];
- if (promise->get_expiration()<priv->used_sequence_numbers) {
+ for (unsigned int i = 0; i < promises->size(); i++) {
+ Promise *promise = (*promises)[i];
+ if (promise->get_expiration() < priv->used_sequence_numbers)
return true;
- }
}
return false;
}
return pending_rel_seqs->size() == 0 && is_feasible_prefix_ignore_relseq();
}
+/**
+ * Print disagnostic information about an infeasible execution
+ * @param prefix A string to prefix the output with; if NULL, then a default
+ * message prefix will be provided
+ */
+void ModelChecker::print_infeasibility(const char *prefix) const
+{
+ char buf[100];
+ char *ptr = buf;
+ if (mo_graph->checkForRMWViolation())
+ ptr += sprintf(ptr, "[RMW atomicity]");
+ if (mo_graph->checkForCycles())
+ ptr += sprintf(ptr, "[mo cycle]");
+ if (priv->failed_promise)
+ ptr += sprintf(ptr, "[failed promise]");
+ if (priv->too_many_reads)
+ ptr += sprintf(ptr, "[too many reads]");
+ if (priv->bad_synchronization)
+ ptr += sprintf(ptr, "[bad sw ordering]");
+ if (promises_expired())
+ ptr += sprintf(ptr, "[promise expired]");
+ if (promises->size() != 0)
+ ptr += sprintf(ptr, "[unresolved promise]");
+ if (ptr != buf)
+ model_print("%s: %s\n", prefix ? prefix : "Infeasible", buf);
+}
+
/**
* Returns whether the current completed trace is feasible, except for pending
* release sequences.
*/
bool ModelChecker::is_feasible_prefix_ignore_relseq() const
{
- if (DBG_ENABLED() && promises->size() != 0)
- DEBUG("Infeasible: unrevolved promises\n");
-
return !is_infeasible() && promises->size() == 0;
}
*/
bool ModelChecker::is_infeasible() const
{
- if (DBG_ENABLED() && mo_graph->checkForRMWViolation())
- DEBUG("Infeasible: RMW violation\n");
-
- return mo_graph->checkForRMWViolation() || is_infeasible_ignoreRMW();
-}
-
-/**
- * Check If the current partial trace is infeasible, while ignoring
- * infeasibility related to 2 RMW's reading from the same store. It does not
- * check end-of-execution feasibility.
- * @see ModelChecker::is_infeasible
- * @return whether the current partial trace is infeasible, ignoring multiple
- * RMWs reading from the same store.
- * */
-bool ModelChecker::is_infeasible_ignoreRMW() const
-{
- if (DBG_ENABLED()) {
- if (mo_graph->checkForCycles())
- DEBUG("Infeasible: modification order cycles\n");
- if (priv->failed_promise)
- DEBUG("Infeasible: failed promise\n");
- if (priv->too_many_reads)
- DEBUG("Infeasible: too many reads\n");
- if (priv->bad_synchronization)
- DEBUG("Infeasible: bad synchronization ordering\n");
- if (promises_expired())
- DEBUG("Infeasible: promises expired\n");
- }
- return mo_graph->checkForCycles() || priv->failed_promise ||
- priv->too_many_reads || priv->bad_synchronization ||
+ return mo_graph->checkForRMWViolation() ||
+ mo_graph->checkForCycles() ||
+ priv->failed_promise ||
+ priv->too_many_reads ||
+ priv->bad_synchronization ||
promises_expired();
}
ModelAction * ModelChecker::process_rmw(ModelAction *act) {
ModelAction *lastread = get_last_action(act->get_tid());
lastread->process_rmw(act);
- if (act->is_rmw() && lastread->get_reads_from()!=NULL) {
+ if (act->is_rmw() && lastread->get_reads_from() != NULL) {
mo_graph->addRMWEdge(lastread->get_reads_from(), lastread);
mo_graph->commitChanges();
}
*
* If so, we decide that the execution is no longer feasible.
*/
-void ModelChecker::check_recency(ModelAction *curr, const ModelAction *rf) {
+void ModelChecker::check_recency(ModelAction *curr, const ModelAction *rf)
+{
if (params.maxreads != 0) {
-
if (curr->get_node()->get_read_from_size() <= 1)
return;
//Must make sure that execution is currently feasible... We could
action_list_t::reverse_iterator ritcopy = rit;
//See if we have enough reads from the same value
int count = 0;
- for (; count < params.maxreads; rit++,count++) {
- if (rit==list->rend())
+ for (; count < params.maxreads; rit++, count++) {
+ if (rit == list->rend())
return;
ModelAction *act = *rit;
if (!act->is_read())
if (act->get_node()->get_read_from_size() <= 1)
return;
}
- for (int i = 0; i<curr->get_node()->get_read_from_size(); i++) {
- //Get write
- const ModelAction * write = curr->get_node()->get_read_from_at(i);
+ for (int i = 0; i < curr->get_node()->get_read_from_size(); i++) {
+ /* Get write */
+ const ModelAction *write = curr->get_node()->get_read_from_at(i);
- //Need a different write
- if (write==rf)
+ /* Need a different write */
+ if (write == rf)
continue;
- /* Test to see whether this is a feasible write to read from*/
+ /* Test to see whether this is a feasible write to read from */
mo_graph->startChanges();
r_modification_order(curr, write);
bool feasiblereadfrom = !is_infeasible();
bool feasiblewrite = true;
//new we need to see if this write works for everyone
- for (int loop = count; loop>0; loop--,rit++) {
- ModelAction *act=*rit;
+ for (int loop = count; loop > 0; loop--, rit++) {
+ ModelAction *act = *rit;
bool foundvalue = false;
- for (int j = 0; j<act->get_node()->get_read_from_size(); j++) {
- if (act->get_node()->get_read_from_at(j)==write) {
+ for (int j = 0; j < act->get_node()->get_read_from_size(); j++) {
+ if (act->get_node()->get_read_from_at(j) == write) {
foundvalue = true;
break;
}
/* Include at most one act per-thread that "happens before" curr */
if (lastact != NULL) {
- if (lastact==curr) {
+ if (lastact == curr) {
//Case 1: The resolved read is a RMW, and we need to make sure
//that the write portion of the RMW mod order after rf
//is mod ordered after rf
const ModelAction *postreadfrom = lastact->get_reads_from();
- if (postreadfrom != NULL&&rf != postreadfrom)
+ if (postreadfrom != NULL && rf != postreadfrom)
mo_graph->addEdge(rf, postreadfrom);
} else {
//Case 3: The resolved read is a normal read and the next
//operation is a write, and we need to make sure that the
//write is mod ordered after rf
- if (lastact!=rf)
+ if (lastact != rf)
mo_graph->addEdge(rf, lastact);
}
break;
* continue processing list.
*/
if (curr->is_rmw()) {
- if (curr->get_reads_from()!=NULL)
+ if (curr->get_reads_from() != NULL)
break;
else
continue;
*/
if (thin_air_constraint_may_allow(curr, act)) {
- if (!is_infeasible() ||
- (curr->is_rmw() && act->is_rmw() && curr->get_reads_from() == act->get_reads_from() && !is_infeasible_ignoreRMW())) {
- struct PendingFutureValue pfv = {curr,act};
- futurevalues->push_back(pfv);
- }
+ if (!is_infeasible())
+ futurevalues->push_back(PendingFutureValue(curr, act));
+ else if (curr->is_rmw() && act->is_rmw() && curr->get_reads_from() && curr->get_reads_from() == act->get_reads_from())
+ add_future_value(curr, act);
}
}
}
/** Arbitrary reads from the future are not allowed. Section 29.3
* part 9 places some constraints. This method checks one result of constraint
* constraint. Others require compiler support. */
-bool ModelChecker::thin_air_constraint_may_allow(const ModelAction * writer, const ModelAction *reader) {
+bool ModelChecker::thin_air_constraint_may_allow(const ModelAction *writer, const ModelAction *reader)
+{
if (!writer->is_rmw())
return true;
for (rit = list->rbegin(); rit != list->rend(); rit++) {
ModelAction *act = *rit;
- if (!reader->happens_before(act))
+ /* Don't disallow due to act == reader */
+ if (!reader->happens_before(act) || reader == act)
break;
else if (act->is_write())
write_after_read = act;
- else if (act->is_read() && act->get_reads_from() != NULL && act != reader) {
+ else if (act->is_read() && act->get_reads_from() != NULL)
write_after_read = act->get_reads_from();
- }
}
- if (write_after_read && write_after_read!=writer && mo_graph->checkReachable(write_after_read, writer))
+ if (write_after_read && write_after_read != writer && mo_graph->checkReachable(write_after_read, writer))
return false;
}
return true;
void ModelChecker::add_action_to_lists(ModelAction *act)
{
int tid = id_to_int(act->get_tid());
- action_trace->push_back(act);
+ ModelAction *uninit = NULL;
+ int uninit_id = -1;
+ action_list_t *list = get_safe_ptr_action(obj_map, act->get_location());
+ if (list->empty() && act->is_atomic_var()) {
+ uninit = new_uninitialized_action(act->get_location());
+ uninit_id = id_to_int(uninit->get_tid());
+ list->push_back(uninit);
+ }
+ list->push_back(act);
- get_safe_ptr_action(obj_map, act->get_location())->push_back(act);
+ action_trace->push_back(act);
+ if (uninit)
+ action_trace->push_front(uninit);
std::vector<action_list_t> *vec = get_safe_ptr_vect_action(obj_thrd_map, act->get_location());
if (tid >= (int)vec->size())
vec->resize(priv->next_thread_id);
(*vec)[tid].push_back(act);
+ if (uninit)
+ (*vec)[uninit_id].push_front(uninit);
if ((int)thrd_last_action->size() <= tid)
thrd_last_action->resize(get_num_threads());
(*thrd_last_action)[tid] = act;
+ if (uninit)
+ (*thrd_last_action)[uninit_id] = uninit;
if (act->is_fence() && act->is_release()) {
if ((int)thrd_last_fence_release->size() <= tid)
}
if (act->is_wait()) {
- void *mutex_loc=(void *) act->get_value();
+ void *mutex_loc = (void *) act->get_value();
get_safe_ptr_action(obj_map, mutex_loc)->push_back(act);
std::vector<action_list_t> *vec = get_safe_ptr_vect_action(obj_thrd_map, mutex_loc);
bool ModelChecker::resolve_promises(ModelAction *write)
{
bool resolved = false;
- std::vector< thread_id_t, ModelAlloc<thread_id_t> > threads_to_check;
+ std::vector< ModelAction *, ModelAlloc<ModelAction *> > actions_to_check;
for (unsigned int i = 0, promise_index = 0; promise_index < promises->size(); i++) {
Promise *promise = (*promises)[promise_index];
delete(promise);
promises->erase(promises->begin() + promise_index);
- threads_to_check.push_back(read->get_tid());
+ actions_to_check.push_back(read);
resolved = true;
} else
//Check whether reading these writes has made threads unable to
//resolve promises
- for(unsigned int i=0;i<threads_to_check.size();i++)
- mo_check_promises(threads_to_check[i], write);
+ for (unsigned int i = 0; i < actions_to_check.size(); i++) {
+ ModelAction *read=actions_to_check[i];
+ mo_check_promises(read->get_tid(), write, read);
+ }
return resolved;
}
const ModelAction *act = promise->get_action();
if ((old_cv == NULL || !old_cv->synchronized_since(act)) &&
merge_cv->synchronized_since(act)) {
- if (promise->increment_threads(tid)) {
+ if (promise->eliminate_thread(tid)) {
//Promise has failed
priv->failed_promise = true;
return;
}
}
-void ModelChecker::check_promises_thread_disabled() {
+void ModelChecker::check_promises_thread_disabled()
+{
for (unsigned int i = 0; i < promises->size(); i++) {
Promise *promise = (*promises)[i];
- if (promise->check_promise()) {
+ if (promise->has_failed()) {
priv->failed_promise = true;
return;
}
}
}
-/** Checks promises in response to addition to modification order for threads.
+/**
+ * @brief Checks promises in response to addition to modification order for
+ * threads.
+ *
* Definitions:
+ *
* pthread is the thread that performed the read that created the promise
*
* pread is the read that created the promise
*
* pwrite is either the first write to same location as pread by
- * pthread that is sequenced after pread or the value read by the
- * first read to the same lcoation as pread by pthread that is
- * sequenced after pread..
+ * pthread that is sequenced after pread or the write read by the
+ * first read to the same location as pread by pthread that is
+ * sequenced after pread.
*
- * 1. If tid=pthread, then we check what other threads are reachable
- * through the mode order starting with pwrite. Those threads cannot
+ * 1. If tid=pthread, then we check what other threads are reachable
+ * through the mod order starting with pwrite. Those threads cannot
* perform a write that will resolve the promise due to modification
* order constraints.
*
* cannot perform a future write that will resolve the promise due to
* modificatin order constraints.
*
- * @parem tid The thread that either read from the model action
- * write, or actually did the model action write.
+ * @param tid The thread that either read from the model action write, or
+ * actually did the model action write.
*
- * @parem write The ModelAction representing the relevant write.
+ * @param write The ModelAction representing the relevant write.
+ * @param read The ModelAction that reads a promised write, or NULL otherwise.
*/
-
-void ModelChecker::mo_check_promises(thread_id_t tid, const ModelAction *write) {
- void * location = write->get_location();
+void ModelChecker::mo_check_promises(thread_id_t tid, const ModelAction *write, const ModelAction *read)
+{
+ void *location = write->get_location();
for (unsigned int i = 0; i < promises->size(); i++) {
Promise *promise = (*promises)[i];
const ModelAction *act = promise->get_action();
- //Is this promise on the same location?
- if ( act->get_location() != location )
+ // Is this promise on the same location?
+ if (act->get_location() != location)
continue;
- //same thread as the promise
- if ( act->get_tid()==tid ) {
+ // same thread as the promise
+ if (act->get_tid() == tid) {
+ // make sure that the reader of this write happens after the promise
+ if ((read == NULL) || (promise->get_action()->happens_before(read))) {
+ // do we have a pwrite for the promise, if not, set it
+ if (promise->get_write() == NULL) {
+ promise->set_write(write);
+ // The pwrite cannot happen before the promise
+ if (write->happens_before(act) && (write != act)) {
+ priv->failed_promise = true;
+ return;
+ }
+ }
- //do we have a pwrite for the promise, if not, set it
- if (promise->get_write() == NULL ) {
- promise->set_write(write);
- //The pwrite cannot happen before the promise
- if (write->happens_before(act) && (write != act)) {
+ if (mo_graph->checkPromise(write, promise)) {
priv->failed_promise = true;
return;
}
}
- if (mo_graph->checkPromise(write, promise)) {
- priv->failed_promise = true;
- return;
- }
}
- //Don't do any lookups twice for the same thread
- if (promise->has_sync_thread(tid))
+ // Don't do any lookups twice for the same thread
+ if (!promise->thread_is_available(tid))
continue;
- if (promise->get_write()&&mo_graph->checkReachable(promise->get_write(), write)) {
- if (promise->increment_threads(tid)) {
+ if (promise->get_write() && mo_graph->checkReachable(promise->get_write(), write)) {
+ if (promise->eliminate_thread(tid)) {
priv->failed_promise = true;
return;
}
ModelAction *last_sc_write = NULL;
- /* Track whether this object has been initialized */
- bool initialized = false;
-
- if (curr->is_seqcst()) {
+ if (curr->is_seqcst())
last_sc_write = get_last_seq_cst_write(curr);
- /* We have to at least see the last sequentially consistent write,
- so we are initialized. */
- if (last_sc_write != NULL)
- initialized = true;
- }
/* Iterate over all threads */
for (i = 0; i < thrd_lists->size(); i++) {
else if (curr->get_sleep_flag() && !curr->is_seqcst() && !sleep_can_read_from(curr, act))
allow_read = false;
- if (allow_read) {
- DEBUG("Adding action to may_read_from:\n");
- if (DBG_ENABLED()) {
- act->print();
- curr->print();
- }
+ if (allow_read)
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;
+ if (act->happens_before(curr))
break;
- }
}
}
- if (!initialized)
- assert_bug("May read from uninitialized atomic");
-
- if (DBG_ENABLED() || !initialized) {
+ if (DBG_ENABLED()) {
model_print("Reached read action:\n");
curr->print();
model_print("Printing may_read_from\n");
}
}
-bool ModelChecker::sleep_can_read_from(ModelAction * curr, const ModelAction *write) {
- while(true) {
- Node *prevnode=write->get_node()->get_parent();
+bool ModelChecker::sleep_can_read_from(ModelAction *curr, const ModelAction *write)
+{
+ while (true) {
+ /* UNINIT actions don't have a Node, and they never sleep */
+ if (write->is_uninitialized())
+ return true;
+ Node *prevnode = write->get_node()->get_parent();
- bool thread_sleep=prevnode->enabled_status(curr->get_tid())==THREAD_SLEEP_SET;
- if (write->is_release()&&thread_sleep)
+ bool thread_sleep = prevnode->enabled_status(curr->get_tid()) == THREAD_SLEEP_SET;
+ if (write->is_release() && thread_sleep)
return true;
if (!write->is_rmw()) {
return false;
}
- if (write->get_reads_from()==NULL)
+ if (write->get_reads_from() == NULL)
return true;
- write=write->get_reads_from();
+ write = write->get_reads_from();
}
}
-static void print_list(action_list_t *list, int exec_num = -1)
+/**
+ * @brief Create a new action representing an uninitialized atomic
+ * @param location The memory location of the atomic object
+ * @return A pointer to a new ModelAction
+ */
+ModelAction * ModelChecker::new_uninitialized_action(void *location) const
+{
+ ModelAction *act = (ModelAction *)snapshot_malloc(sizeof(class ModelAction));
+ act = new (act) ModelAction(ATOMIC_UNINIT, std::memory_order_relaxed, location, 0, model_thread);
+ act->create_cv(NULL);
+ return act;
+}
+
+static void print_list(action_list_t *list)
{
action_list_t::iterator it;
model_print("---------------------------------------------------------------------\n");
- if (exec_num >= 0)
- model_print("Execution %d:\n", exec_num);
- unsigned int hash=0;
+ unsigned int hash = 0;
for (it = list->begin(); it != list->end(); it++) {
(*it)->print();
- hash=hash^(hash<<3)^((*it)->hash());
+ hash = hash^(hash<<3)^((*it)->hash());
}
model_print("HASH %u\n", hash);
model_print("---------------------------------------------------------------------\n");
}
#if SUPPORT_MOD_ORDER_DUMP
-void ModelChecker::dumpGraph(char *filename) {
+void ModelChecker::dumpGraph(char *filename) const
+{
char buffer[200];
- sprintf(buffer, "%s.dot",filename);
- FILE *file=fopen(buffer, "w");
- fprintf(file, "digraph %s {\n",filename);
+ sprintf(buffer, "%s.dot", filename);
+ FILE *file = fopen(buffer, "w");
+ fprintf(file, "digraph %s {\n", filename);
mo_graph->dumpNodes(file);
- ModelAction ** thread_array=(ModelAction **)model_calloc(1, sizeof(ModelAction *)*get_num_threads());
+ ModelAction **thread_array = (ModelAction **)model_calloc(1, sizeof(ModelAction *) * get_num_threads());
for (action_list_t::iterator it = action_trace->begin(); it != action_trace->end(); it++) {
- ModelAction *action=*it;
+ ModelAction *action = *it;
if (action->is_read()) {
- fprintf(file, "N%u [label=\"%u, T%u\"];\n", action->get_seq_number(),action->get_seq_number(), action->get_tid());
- if (action->get_reads_from()!=NULL)
+ fprintf(file, "N%u [label=\"%u, T%u\"];\n", action->get_seq_number(), action->get_seq_number(), action->get_tid());
+ if (action->get_reads_from() != NULL)
fprintf(file, "N%u -> N%u[label=\"rf\", color=red];\n", action->get_seq_number(), action->get_reads_from()->get_seq_number());
}
if (thread_array[action->get_tid()] != NULL) {
fprintf(file, "N%u -> N%u[label=\"sb\", color=blue];\n", thread_array[action->get_tid()]->get_seq_number(), action->get_seq_number());
}
- thread_array[action->get_tid()]=action;
+ thread_array[action->get_tid()] = action;
}
- fprintf(file,"}\n");
+ fprintf(file, "}\n");
model_free(thread_array);
fclose(file);
}
dumpGraph(buffername);
#endif
- if (!isfeasibleprefix())
- model_print("INFEASIBLE EXECUTION!\n");
- print_list(action_trace, stats.num_total);
+ model_print("Execution %d:", stats.num_total);
+ if (isfeasibleprefix())
+ model_print("\n");
+ else
+ print_infeasibility(" INFEASIBLE");
+ print_list(action_trace);
model_print("\n");
}
* @param act The ModelAction
* @return A Thread reference
*/
-Thread * ModelChecker::get_thread(ModelAction *act) const
+Thread * ModelChecker::get_thread(const ModelAction *act) const
{
return get_thread(act->get_tid());
}
* @param act The current action that will be explored. May be NULL only if
* trace is exiting via an assertion (see ModelChecker::set_assert and
* ModelChecker::has_asserted).
- * @return Return status from the 'swap' call (i.e., success/fail, 0/-1)
+ * @return Return the value returned by the current action
*/
-int ModelChecker::switch_to_master(ModelAction *act)
+uint64_t ModelChecker::switch_to_master(ModelAction *act)
{
DBG();
Thread *old = thread_current();
set_current_action(act);
old->set_state(THREAD_READY);
- return Thread::swap(old, &system_context);
+ if (Thread::swap(old, &system_context) < 0) {
+ perror("swap threads");
+ exit(EXIT_FAILURE);
+ }
+ return old->get_return_value();
}
/**
* Takes the next step in the execution, if possible.
+ * @param curr The current step to take
* @return Returns true (success) if a step was taken and false otherwise.
*/
-bool ModelChecker::take_step() {
+bool ModelChecker::take_step(ModelAction *curr)
+{
if (has_asserted())
return false;
- Thread *curr = priv->current_action ? get_thread(priv->current_action) : NULL;
- if (curr) {
- if (curr->get_state() == THREAD_READY) {
- ASSERT(priv->current_action);
+ Thread *curr_thrd = get_thread(curr);
+ ASSERT(curr_thrd->get_state() == THREAD_READY);
- priv->nextThread = check_current_action(priv->current_action);
- priv->current_action = NULL;
-
- if (curr->is_blocked() || curr->is_complete())
- scheduler->remove_thread(curr);
- } else {
- ASSERT(false);
- }
- }
- Thread *next = scheduler->next_thread(priv->nextThread);
+ curr = check_current_action(curr);
/* Infeasible -> don't take any more steps */
if (is_infeasible())
return false;
}
- if (params.bound != 0) {
- if (priv->used_sequence_numbers > params.bound) {
+ if (params.bound != 0)
+ if (priv->used_sequence_numbers > params.bound)
return false;
- }
- }
- DEBUG("(%d, %d)\n", curr ? id_to_int(curr->get_id()) : -1,
- next ? id_to_int(next->get_id()) : -1);
+ if (curr_thrd->is_blocked() || curr_thrd->is_complete())
+ scheduler->remove_thread(curr_thrd);
+
+ Thread *next_thrd = get_next_thread(curr);
+ next_thrd = scheduler->next_thread(next_thrd);
+
+ DEBUG("(%d, %d)\n", curr_thrd ? id_to_int(curr_thrd->get_id()) : -1,
+ next_thrd ? id_to_int(next_thrd->get_id()) : -1);
/*
* Launch end-of-execution release sequence fixups only when there are:
* (3) pending assertions (i.e., data races)
* (4) no pending promises
*/
- if (!pending_rel_seqs->empty() && (!next || next->is_model_thread()) &&
+ if (!pending_rel_seqs->empty() && (!next_thrd || next_thrd->is_model_thread()) &&
is_feasible_prefix_ignore_relseq() && !unrealizedraces.empty()) {
model_print("*** WARNING: release sequence fixup action (%zu pending release seuqences) ***\n",
pending_rel_seqs->size());
return true;
}
- /* next == NULL -> don't take any more steps */
- if (!next)
+ /* next_thrd == NULL -> don't take any more steps */
+ if (!next_thrd)
return false;
- next->set_state(THREAD_RUNNING);
+ next_thrd->set_state(THREAD_RUNNING);
- if (next->get_pending() != NULL) {
+ if (next_thrd->get_pending() != NULL) {
/* restart a pending action */
- set_current_action(next->get_pending());
- next->set_pending(NULL);
- next->set_state(THREAD_READY);
+ set_current_action(next_thrd->get_pending());
+ next_thrd->set_pending(NULL);
+ next_thrd->set_state(THREAD_READY);
return true;
}
/* Return false only if swap fails with an error */
- return (Thread::swap(&system_context, next) == 0);
+ return (Thread::swap(&system_context, next_thrd) == 0);
}
/** Wrapper to run the user's main function, with appropriate arguments */
{
do {
thrd_t user_thread;
+ Thread *t = new Thread(&user_thread, &user_main_wrapper, NULL);
+
+ add_thread(t);
- /* Start user program */
- add_thread(new Thread(&user_thread, &user_main_wrapper, NULL));
+ /* Run user thread up to its first action */
+ scheduler->next_thread(t);
+ Thread::swap(&system_context, t);
/* Wait for all threads to complete */
- while (take_step());
+ while (take_step(priv->current_action));
} while (next_execution());
print_stats();
projects / c11tester.git / blobdiff