#include "cyclegraph.h"
#include "promise.h"
#include "datarace.h"
+#include "mutex.h"
#define INITIAL_THREAD_ID 0
action_trace(new action_list_t()),
thread_map(new HashTable<int, Thread *, int>()),
obj_map(new HashTable<const void *, action_list_t, uintptr_t, 4>()),
+ lock_waiters_map(new HashTable<const void *, action_list_t, uintptr_t, 4>()),
obj_thrd_map(new HashTable<void *, std::vector<action_list_t>, uintptr_t, 4 >()),
promises(new std::vector<Promise *>()),
futurevalues(new std::vector<struct PendingFutureValue>()),
- lazy_sync_with_release(new HashTable<void *, std::list<ModelAction *>, uintptr_t, 4>()),
+ lazy_sync_with_release(new HashTable<void *, action_list_t, uintptr_t, 4>()),
thrd_last_action(new std::vector<ModelAction *>(1)),
node_stack(new NodeStack()),
mo_graph(new CycleGraph()),
delete obj_thrd_map;
delete obj_map;
+ delete lock_waiters_map;
delete action_trace;
for (unsigned int i = 0; i < promises->size(); i++)
snapshotObject->backTrackBeforeStep(0);
}
-/** @returns a thread ID for a new Thread */
+/** @return a thread ID for a new Thread */
thread_id_t ModelChecker::get_next_id()
{
return priv->next_thread_id++;
}
-/** @returns the number of user threads created during this execution */
+/** @return the number of user threads created during this execution */
int ModelChecker::get_num_threads()
{
return priv->next_thread_id;
}
-/** @returns a sequence number for a new ModelAction */
+/** @return a sequence number for a new ModelAction */
modelclock_t ModelChecker::get_next_seq_num()
{
return ++priv->used_sequence_numbers;
{
thread_id_t tid;
- /* 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();
+ 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();
+ }
/* Have we completed exploring the preselected path? */
if (diverge == NULL)
ModelAction * ModelChecker::get_last_conflict(ModelAction *act)
{
- action_type type = act->get_type();
-
- switch (type) {
- case ATOMIC_READ:
- case ATOMIC_WRITE:
- case ATOMIC_RMW:
- break;
- default:
- return NULL;
+ switch (act->get_type()) {
+ case ATOMIC_READ:
+ case ATOMIC_WRITE:
+ case ATOMIC_RMW: {
+ /* linear search: from most recent to oldest */
+ action_list_t *list = obj_map->get_safe_ptr(act->get_location());
+ action_list_t::reverse_iterator rit;
+ for (rit = list->rbegin(); rit != list->rend(); rit++) {
+ ModelAction *prev = *rit;
+ if (act->is_synchronizing(prev))
+ return prev;
+ }
+ break;
}
- /* linear search: from most recent to oldest */
- action_list_t *list = obj_map->get_safe_ptr(act->get_location());
- action_list_t::reverse_iterator rit;
- for (rit = list->rbegin(); rit != list->rend(); rit++) {
- ModelAction *prev = *rit;
- if (act->is_synchronizing(prev))
- return prev;
+ case ATOMIC_LOCK:
+ case ATOMIC_TRYLOCK: {
+ /* linear search: from most recent to oldest */
+ action_list_t *list = obj_map->get_safe_ptr(act->get_location());
+ action_list_t::reverse_iterator rit;
+ for (rit = list->rbegin(); rit != list->rend(); rit++) {
+ ModelAction *prev = *rit;
+ if (act->is_conflicting_lock(prev))
+ return prev;
+ }
+ break;
+ }
+ case ATOMIC_UNLOCK: {
+ /* linear search: from most recent to oldest */
+ action_list_t *list = obj_map->get_safe_ptr(act->get_location());
+ 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())
+ return prev;
+ }
+ break;
+ }
+ default:
+ break;
}
return NULL;
}
void ModelChecker::set_backtracking(ModelAction *act)
{
- ModelAction *prev;
- Node *node;
Thread *t = get_thread(act);
-
- prev = get_last_conflict(act);
+ ModelAction * prev = get_last_conflict(act);
if (prev == NULL)
return;
- node = prev->get_node()->get_parent();
-
- while (!node->is_enabled(t))
- t = t->get_parent();
+ Node * node = prev->get_node()->get_parent();
- /* Check if this has been explored already */
- if (node->has_been_explored(t->get_id()))
- return;
-
- /* Cache the latest backtracking point */
- if (!priv->next_backtrack || *prev > *priv->next_backtrack)
- priv->next_backtrack = prev;
+ int low_tid, high_tid;
+ if (node->is_enabled(t)) {
+ low_tid=id_to_int(act->get_tid());
+ high_tid=low_tid+1;
+ } else {
+ low_tid=0;
+ high_tid=get_num_threads();
+ }
+
+ for(int i=low_tid;i<high_tid;i++) {
+ thread_id_t tid=int_to_id(i);
+ if (!node->is_enabled(tid))
+ continue;
- /* If this is a new backtracking point, mark the tree */
- if (!node->set_backtrack(t->get_id()))
- return;
- DEBUG("Setting backtrack: conflict = %d, instead tid = %d\n",
- prev->get_tid(), t->get_id());
- if (DBG_ENABLED()) {
- prev->print();
- act->print();
+ /* Check if this has been explored already */
+ if (node->has_been_explored(tid))
+ continue;
+
+ /* Cache the latest backtracking point */
+ if (!priv->next_backtrack || *prev > *priv->next_backtrack)
+ priv->next_backtrack = prev;
+
+ /* If this is a new backtracking point, mark the tree */
+ if (!node->set_backtrack(tid))
+ continue;
+ DEBUG("Setting backtrack: conflict = %d, instead tid = %d\n",
+ prev->get_tid(), t->get_id());
+ if (DBG_ENABLED()) {
+ prev->print();
+ act->print();
+ }
}
}
}
}
+/**
+ * Processes a lock, trylock, or unlock model action. @param curr is
+ * the read model action to process.
+ *
+ * The try lock operation checks whether the lock is taken. If not,
+ * it falls to the normal lock operation case. If so, it returns
+ * fail.
+ *
+ * The lock operation has already been checked that it is enabled, so
+ * it just grabs the lock and synchronizes with the previous unlock.
+ *
+ * The unlock operation has to re-enable all of the threads that are
+ * waiting on the lock.
+ */
+
+void ModelChecker::process_mutex(ModelAction *curr) {
+ std::mutex * mutex=(std::mutex *) curr->get_location();
+ struct std::mutex_state * state=mutex->get_state();
+ switch(curr->get_type()) {
+ case ATOMIC_TRYLOCK: {
+ bool success=!state->islocked;
+ curr->set_try_lock(success);
+ if (!success) {
+ get_thread(curr)->set_return_value(0);
+ break;
+ }
+ get_thread(curr)->set_return_value(1);
+ }
+ //otherwise fall into the lock case
+ case ATOMIC_LOCK: {
+ if (curr->get_cv()->getClock(state->alloc_tid)<=state->alloc_clock) {
+ printf("Lock access before initialization\n");
+ set_assert();
+ }
+ state->islocked=true;
+ ModelAction *unlock=get_last_unlock(curr);
+ //synchronize with the previous unlock statement
+ if ( unlock != NULL )
+ curr->synchronize_with(unlock);
+ break;
+ }
+ case ATOMIC_UNLOCK: {
+ //unlock the lock
+ state->islocked=false;
+ //wake up the other threads
+ action_list_t * waiters = lock_waiters_map->get_safe_ptr(curr->get_location());
+ //activate all the waiting threads
+ for(action_list_t::iterator rit = waiters->begin(); rit!=waiters->end(); rit++) {
+ scheduler->add_thread(get_thread((*rit)->get_tid()));
+ }
+ waiters->clear();
+ break;
+ }
+ default:
+ ASSERT(0);
+ }
+}
+
+
/**
* Process a write ModelAction
* @param curr The ModelAction to process
return updated_mod_order || updated_promises;
}
+/**
+ * Initialize the current action by performing one or more of the following
+ * actions, as appropriate: merging RMWR and RMWC/RMW actions, stepping forward
+ * in the NodeStack, manipulating backtracking sets, allocating and
+ * initializing clock vectors, and computing the promises to fulfill.
+ *
+ * @param curr The current action, as passed from the user context; may be
+ * freed/invalidated after the execution of this function
+ * @return The current action, as processed by the ModelChecker. Is only the
+ * same as the parameter @a curr if this is a newly-explored action.
+ */
ModelAction * ModelChecker::initialize_curr_action(ModelAction *curr)
{
ModelAction *newcurr;
return newcurr;
}
- newcurr = node_stack->explore_action(curr);
+ newcurr = node_stack->explore_action(curr, scheduler->get_enabled());
if (newcurr) {
/* First restore type and order in case of RMW operation */
if (curr->is_rmwr())
newcurr->copy_typeandorder(curr);
+ ASSERT(curr->get_location()==newcurr->get_location());
+ newcurr->copy_from_new(curr);
+
/* Discard duplicate ModelAction; use action from NodeStack */
delete curr;
return newcurr;
}
+/**
+ * This method checks whether a model action is enabled at the given point.
+ * At this point, it checks whether a lock operation would be successful at this point.
+ * If not, it puts the thread in a waiter list.
+ * @param curr is the ModelAction to check whether it is enabled.
+ * @return a bool that indicates whether the action is enabled.
+ */
+
+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();
+ if (state->islocked) {
+ //Stick the action in the appropriate waiting queue
+ lock_waiters_map->get_safe_ptr(curr->get_location())->push_back(curr);
+ return false;
+ }
+ }
+
+ return true;
+}
+
/**
* This is the heart of the model checker routine. It performs model-checking
* actions corresponding to a given "current action." Among other processes, it
bool second_part_of_rmw = curr->is_rmwc() || curr->is_rmw();
+ if (!check_action_enabled(curr)) {
+ //we'll make the execution look like we chose to run this action
+ //much later...when a lock is actually available to relese
+ get_current_thread()->set_pending(curr);
+ remove_thread(get_current_thread());
+ return get_next_thread(NULL);
+ }
+
ModelAction *newcurr = initialize_curr_action(curr);
+ /* Add the action to lists before any other model-checking tasks */
+ if (!second_part_of_rmw)
+ add_action_to_lists(newcurr);
+
/* Build may_read_from set for newly-created actions */
if (curr == newcurr && curr->is_read())
build_reads_from_past(curr);
if (!blocking->is_complete()) {
blocking->push_wait_list(curr);
scheduler->sleep(waiting);
+ } else {
+ do_complete_join(curr);
}
break;
}
ModelAction *act = th->pop_wait_list();
Thread *wake = get_thread(act);
scheduler->wake(wake);
+ do_complete_join(act);
}
th->complete();
break;
break;
}
- /* Add current action to lists before work_queue loop */
- if (!second_part_of_rmw)
- add_action_to_lists(curr);
-
work_queue_t work_queue(1, CheckCurrWorkEntry(curr));
while (!work_queue.empty()) {
if (act->is_write() && process_write(act))
updated = true;
+ if (act->is_mutex_op())
+ process_mutex(act);
+
if (updated)
work_queue.push_back(CheckRelSeqWorkEntry(act->get_location()));
break;
return get_next_thread(curr);
}
+/**
+ * Complete a THREAD_JOIN operation, by synchronizing with the THREAD_FINISH
+ * operation from the Thread it is joining with. Must be called after the
+ * completion of the Thread in question.
+ * @param join The THREAD_JOIN action
+ */
+void ModelChecker::do_complete_join(ModelAction *join)
+{
+ Thread *blocking = (Thread *)join->get_location();
+ ModelAction *act = get_last_action(blocking->get_id());
+ join->synchronize_with(act);
+}
+
void ModelChecker::check_curr_backtracking(ModelAction * curr) {
Node *currnode = curr->get_node();
Node *parnode = currnode->get_parent();
return false;
}
-/** @returns whether the current partial trace must be a prefix of a
+/** @return whether the current partial trace must be a prefix of a
* feasible trace. */
bool ModelChecker::isfeasibleprefix() {
return promises->size() == 0 && *lazy_sync_size == 0;
}
-/** @returns whether the current partial trace is feasible. */
+/** @return whether the current partial trace is feasible. */
bool ModelChecker::isfeasible() {
return !mo_graph->checkForRMWViolation() && isfeasibleotherthanRMW();
}
-/** @returns whether the current partial trace is feasible other than
+/** @return whether the current partial trace is feasible other than
* multiple RMW reading from the same store. */
bool ModelChecker::isfeasibleotherthanRMW() {
if (DBG_ENABLED()) {
* @return true, if the ModelChecker is certain that release_heads is complete;
* false otherwise
*/
-bool ModelChecker::release_seq_head(const ModelAction *rf,
- std::vector< const ModelAction *, MyAlloc<const ModelAction *> > *release_heads) const
+bool ModelChecker::release_seq_head(const ModelAction *rf, rel_heads_list_t *release_heads) const
{
if (!rf) {
/* read from future: need to settle this later */
* the release seq? */
bool future_ordered = false;
+ ModelAction *last = get_last_action(int_to_id(i));
+ if (last && rf->happens_before(last))
+ future_ordered = true;
+
for (rit = list->rbegin(); rit != list->rend(); rit++) {
const ModelAction *act = *rit;
- if (!act->is_write())
- continue;
/* Reach synchronization -> this thread is complete */
if (act->happens_before(release))
break;
continue;
}
+ /* Only writes can break release sequences */
+ if (!act->is_write())
+ continue;
+
/* Check modification order */
if (mo_graph->checkReachable(rf, act)) {
/* rf --mo--> act */
* with the head(s) of the release sequence(s), if they exists with certainty.
* @see ModelChecker::release_seq_head
*/
-void ModelChecker::get_release_seq_heads(ModelAction *act,
- std::vector< const ModelAction *, MyAlloc<const ModelAction *> > *release_heads)
+void ModelChecker::get_release_seq_heads(ModelAction *act, rel_heads_list_t *release_heads)
{
const ModelAction *rf = act->get_reads_from();
bool complete;
complete = release_seq_head(rf, release_heads);
if (!complete) {
/* add act to 'lazy checking' list */
- std::list<ModelAction *> *list;
+ action_list_t *list;
list = lazy_sync_with_release->get_safe_ptr(act->get_location());
list->push_back(act);
(*lazy_sync_size)++;
*/
bool ModelChecker::resolve_release_sequences(void *location, work_queue_t *work_queue)
{
- std::list<ModelAction *> *list;
+ action_list_t *list;
list = lazy_sync_with_release->getptr(location);
if (!list)
return false;
bool updated = false;
- std::list<ModelAction *>::iterator it = list->begin();
+ action_list_t::iterator it = list->begin();
while (it != list->end()) {
ModelAction *act = *it;
const ModelAction *rf = act->get_reads_from();
- std::vector< const ModelAction *, MyAlloc<const ModelAction *> > release_heads;
+ rel_heads_list_t release_heads;
bool complete;
complete = release_seq_head(rf, &release_heads);
for (unsigned int i = 0; i < release_heads.size(); i++) {
(*thrd_last_action)[tid] = act;
}
-ModelAction * ModelChecker::get_last_action(thread_id_t tid)
+/**
+ * @brief Get the last action performed by a particular Thread
+ * @param tid The thread ID of the Thread in question
+ * @return The last action in the thread
+ */
+ModelAction * ModelChecker::get_last_action(thread_id_t tid) const
{
- int nthreads = get_num_threads();
- if ((int)thrd_last_action->size() < nthreads)
- thrd_last_action->resize(nthreads);
- return (*thrd_last_action)[id_to_int(tid)];
+ int threadid = id_to_int(tid);
+ if (threadid < (int)thrd_last_action->size())
+ return (*thrd_last_action)[id_to_int(tid)];
+ else
+ return NULL;
}
/**
* check
* @return The last seq_cst write
*/
-ModelAction * ModelChecker::get_last_seq_cst(ModelAction *curr)
+ModelAction * ModelChecker::get_last_seq_cst(ModelAction *curr) const
{
void *location = curr->get_location();
action_list_t *list = obj_map->get_safe_ptr(location);
return NULL;
}
+/**
+ * Gets the last unlock operation performed on a particular mutex (i.e., memory
+ * location). This function identifies the mutex according to the current
+ * action, which is presumed to perform on the same mutex.
+ * @param curr The current ModelAction; also denotes the object location to
+ * check
+ * @return The last unlock operation
+ */
+ModelAction * ModelChecker::get_last_unlock(ModelAction *curr) const
+{
+ void *location = curr->get_location();
+ action_list_t *list = obj_map->get_safe_ptr(location);
+ /* Find: max({i in dom(S) | isUnlock(t_i) && samevar(t_i, t)}) */
+ action_list_t::reverse_iterator rit;
+ for (rit = list->rbegin(); rit != list->rend(); rit++)
+ if ((*rit)->is_unlock())
+ return *rit;
+ return NULL;
+}
+
ModelAction * ModelChecker::get_parent_action(thread_id_t tid)
{
ModelAction *parent = get_last_action(tid);
#if SUPPORT_MOD_ORDER_DUMP
scheduler->print();
char buffername[100];
- sprintf(buffername, "exec%u",num_executions);
+ sprintf(buffername, "exec%04u", num_executions);
mo_graph->dumpGraphToFile(buffername);
#endif
* @return Returns true (success) if a step was taken and false otherwise.
*/
bool ModelChecker::take_step() {
- Thread *curr, *next;
-
if (has_asserted())
return false;
- curr = thread_current();
+ Thread * curr = thread_current();
if (curr) {
if (curr->get_state() == THREAD_READY) {
ASSERT(priv->current_action);
priv->nextThread = check_current_action(priv->current_action);
priv->current_action = NULL;
- if (!curr->is_blocked() && !curr->is_complete())
- scheduler->add_thread(curr);
+ if (curr->is_blocked() || curr->is_complete())
+ scheduler->remove_thread(curr);
} else {
ASSERT(false);
}
}
- next = scheduler->next_thread(priv->nextThread);
+ Thread * next = scheduler->next_thread(priv->nextThread);
/* Infeasible -> don't take any more steps */
if (!isfeasible())
/* next == NULL -> don't take any more steps */
if (!next)
return false;
+
+ if ( next->get_pending() != NULL ) {
+ //restart a pending action
+ set_current_action(next->get_pending());
+ next->set_pending(NULL);
+ next->set_state(THREAD_READY);
+ return true;
+ }
+
/* Return false only if swap fails with an error */
return (Thread::swap(&system_context, next) == 0);
}
projects / c11tester.git / blobdiff