cyclegraph: add full promise resolution, node merging

[c11tester.git] / model.cc

diff --git a/model.cc b/model.cc
index ede2bcc840d8710ae00e3d021accadb6ef8e0698..e39266d41218feecb14d4fde94701c22cd2040d3 100644 (file)
--- a/model.cc
+++ b/model.cc
@@ -721,7 +721,6 @@ bool ModelChecker::process_read(ModelAction *curr, bool second_part_of_rmw)
                                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())) {
                                mo_graph->rollbackChanges();
                                priv->too_many_reads = false;
@@ -737,6 +736,7 @@ bool ModelChecker::process_read(ModelAction *curr, bool second_part_of_rmw)
                        /* Read from future value */
                        struct future_value fv = curr->get_node()->get_future_value();
                        value = fv.value;
+                       curr->set_value(fv.value);
                        curr->set_read_from(NULL);
                        promises->push_back(new Promise(curr, fv));
                }
@@ -855,10 +855,22 @@ bool ModelChecker::process_mutex(ModelAction *curr)
 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) &&
-                       reader->get_node()->add_future_value(writer,
-                               writer->get_seq_number() + params.maxfuturedelay))
-               set_latest_backtrack(reader);
+       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);
+       }
 }
 
 /**
@@ -955,6 +967,12 @@ bool ModelChecker::process_thread_action(ModelAction *curr)
        case THREAD_CREATE: {
                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: {
@@ -971,6 +989,13 @@ bool ModelChecker::process_thread_action(ModelAction *curr)
                        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;
        }
@@ -1347,8 +1372,6 @@ 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)
@@ -1382,21 +1405,10 @@ bool ModelChecker::is_feasible_prefix_ignore_relseq() const
  */
 bool ModelChecker::is_infeasible() const
 {
-       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
-{
-       return mo_graph->checkForCycles() || priv->failed_promise ||
-               priv->too_many_reads || priv->bad_synchronization ||
+       return mo_graph->checkForCycles() ||
+               priv->failed_promise ||
+               priv->too_many_reads ||
+               priv->bad_synchronization ||
                promises_expired();
 }
 
@@ -1785,10 +1797,10 @@ bool ModelChecker::w_modification_order(ModelAction *curr)
 
                                 */
                                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())) {
+                                       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);
                                }
                        }
                }
@@ -2327,7 +2339,7 @@ bool ModelChecker::resolve_promises(ModelAction *write)
                        post_r_modification_order(read, write);
                        //Make sure the promise's value matches the write's value
                        ASSERT(promise->get_value() == write->get_value());
-                       delete(promise);
+                       delete promise;
 
                        promises->erase(promises->begin() + promise_index);
                        actions_to_check.push_back(read);
@@ -2462,7 +2474,7 @@ void ModelChecker::mo_check_promises(thread_id_t tid, const ModelAction *write,
                }
 
                // Don't do any lookups twice for the same thread
-               if (promise->thread_is_eliminated(tid))
+               if (!promise->thread_is_available(tid))
                        continue;
 
                if (promise->get_write() && mo_graph->checkReachable(promise->get_write(), write)) {
@@ -2635,7 +2647,6 @@ void ModelChecker::dumpGraph(char *filename) const
 void ModelChecker::print_summary() const
 {
 #if SUPPORT_MOD_ORDER_DUMP
-       scheduler->print();
        char buffername[100];
        sprintf(buffername, "exec%04u", stats.num_total);
        mo_graph->dumpGraphToFile(buffername);