#include "promise.h"
#include "datarace.h"
#include "mutex.h"
+#include "threads.h"
#define INITIAL_THREAD_ID 0
return priv->next_thread_id;
}
+/** @return The currently executing Thread. */
+Thread * ModelChecker::get_current_thread()
+{
+ return scheduler->get_current_thread();
+}
+
/** @return a sequence number for a new ModelAction */
modelclock_t ModelChecker::get_next_seq_num()
{
DBG();
num_executions++;
+
if (isfinalfeasible()) {
printf("Earliest divergence point since last feasible execution:\n");
if (earliest_diverge)
num_feasible_executions++;
}
+ DEBUG("Number of acquires waiting on pending release sequences: %lu\n",
+ pending_acq_rel_seq->size());
+
if (isfinalfeasible() || DBG_ENABLED())
print_summary();
* (e.g., ATOMIC_{READ,WRITE,RMW,LOCK}, etc.)
*
* @param curr The current action
- * @return True if synchronization was updated
+ * @return True if synchronization was updated or a thread completed
*/
bool ModelChecker::process_thread_action(ModelAction *curr)
{
- bool synchronized = false;
+ bool updated = false;
switch (curr->get_type()) {
case THREAD_CREATE: {
break;
}
case THREAD_JOIN: {
- Thread *blocking = (Thread *)curr->get_location();
- ModelAction *act = get_last_action(blocking->get_id());
- curr->synchronize_with(act);
- synchronized = true;
+ Thread *waiting, *blocking;
+ waiting = get_thread(curr);
+ blocking = (Thread *)curr->get_location();
+ if (!blocking->is_complete()) {
+ blocking->push_wait_list(curr);
+ scheduler->sleep(waiting);
+ } else {
+ do_complete_join(curr);
+ updated = true; /* trigger rel-seq checks */
+ }
break;
}
case THREAD_FINISH: {
Thread *th = get_thread(curr);
while (!th->wait_list_empty()) {
ModelAction *act = th->pop_wait_list();
- scheduler->wake(get_thread(act));
+ Thread *wake = get_thread(act);
+ scheduler->wake(wake);
+ do_complete_join(act);
+ updated = true; /* trigger rel-seq checks */
}
th->complete();
+ updated = true; /* trigger rel-seq checks */
break;
}
case THREAD_START: {
break;
}
- return synchronized;
+ return updated;
}
/**
}
/**
- * @brief Check whether a model action is enabled.
- *
- * Checks whether a lock or join operation would be successful (i.e., is the
- * lock already locked, or is the joined thread already complete). If not, put
- * the action in a waiter list.
- *
+ * 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.
*/
lock_waiters_map->get_safe_ptr(curr->get_location())->push_back(curr);
return false;
}
- } else if (curr->get_type() == THREAD_JOIN) {
- Thread *blocking = (Thread *)curr->get_location();
- if (!blocking->is_complete()) {
- blocking->push_wait_list(curr);
- return false;
- }
}
return true;
if (!check_action_enabled(curr)) {
/* Make the execution look like we chose to run this action
- * much later, when a lock/join can succeed */
+ * much later, when a lock is actually available to release */
get_current_thread()->set_pending(curr);
scheduler->sleep(get_current_thread());
return get_next_thread(NULL);
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();
}
} else {
const ModelAction *prevreadfrom = act->get_reads_from();
- if (prevreadfrom != NULL && rf != prevreadfrom) {
+ //if the previous read is unresolved, keep going...
+ if (prevreadfrom == NULL)
+ continue;
+
+ if (rf != prevreadfrom) {
mo_graph->addEdge(prevreadfrom, rf);
added = true;
}
ModelAction *act = *rit;
if (act == curr) {
/*
- * If RMW, we already have all relevant edges,
- * so just skip to next thread.
- * If normal write, we need to look at earlier
- * actions, so continue processing list.
+ * 1) If RMW and it actually read from something, then we
+ * already have all relevant edges, so just skip to next
+ * thread.
+ *
+ * 2) If RMW and it didn't read from anything, we should
+ * whatever edge we can get to speed up convergence.
+ *
+ * 3) If normal write, we need to look at earlier actions, so
+ * continue processing list.
*/
- if (curr->is_rmw())
- break;
- else
+ if (curr->is_rmw()) {
+ if (curr->get_reads_from()!=NULL)
+ break;
+ else
+ continue;
+ } else
continue;
}
*/
if (act->is_write())
mo_graph->addEdge(act, curr);
- else if (act->is_read() && act->get_reads_from() != NULL)
+ else if (act->is_read()) {
+ //if previous read accessed a null, just keep going
+ if (act->get_reads_from() == NULL)
+ continue;
mo_graph->addEdge(act->get_reads_from(), curr);
+ }
added = true;
break;
} else if (act->is_read() && !act->is_synchronizing(curr) &&
}
if (updated) {
+ /* Re-check all pending release sequences */
+ work_queue->push_back(CheckRelSeqWorkEntry(NULL));
/* Re-check act for mo_graph edges */
work_queue->push_back(MOEdgeWorkEntry(act));
//Make sure the promise's value matches the write's value
ASSERT(promise->get_value() == write->get_value());
+ delete(promise);
promises->erase(promises->begin() + promise_index);
resolved = true;
} else
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());
- fprintf(file, "N%u -> N%u[label=\"rf\", color=red];\n", action->get_seq_number(), action->get_reads_from()->get_seq_number());
+ 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());
scheduler->remove_thread(t);
}
+/**
+ * @brief Get a Thread reference by its ID
+ * @param tid The Thread's ID
+ * @return A Thread reference
+ */
+Thread * ModelChecker::get_thread(thread_id_t tid)
+{
+ return thread_map->get(id_to_int(tid));
+}
+
+/**
+ * @brief Get a reference to the Thread in which a ModelAction was executed
+ * @param act The ModelAction
+ * @return A Thread reference
+ */
+Thread * ModelChecker::get_thread(ModelAction *act)
+{
+ return get_thread(act->get_tid());
+}
+
/**
* Switch from a user-context to the "master thread" context (a.k.a. system
* context). This switch is made with the intention of exploring a particular
* model-checking action (described by a ModelAction object). Must be called
* from a user-thread context.
- * @param act The current action that will be explored. Must not be NULL.
+ *
+ * @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)
*/
int ModelChecker::switch_to_master(ModelAction *act)
projects / model-checker.git / blobdiff