model: bugfix - correct the "equality" check for RR coherence

[model-checker.git] / model.cc

diff --git a/model.cc b/model.cc
index 9e064ea2c76bbebbe02fb03fcdf0bbf47a57dfb3..152e36ec2f296fc9f467b890e2e89d6ada3504ee 100644 (file)
--- a/model.cc
+++ b/model.cc
@@ -1327,6 +1327,30 @@ bool ModelChecker::read_from(ModelAction *act, const ModelAction *rf)
        return false;
 }
 
+/**
+ * Check promises and eliminate potentially-satisfying threads when a thread is
+ * blocked (e.g., join, lock). A thread which is waiting on another thread can
+ * no longer satisfy a promise generated from that thread.
+ *
+ * @param blocker The thread on which a thread is waiting
+ * @param waiting The waiting thread
+ */
+void ModelChecker::thread_blocking_check_promises(Thread *blocker, Thread *waiting)
+{
+       for (unsigned int i = 0; i < promises->size(); i++) {
+               Promise *promise = (*promises)[i];
+               ModelAction *reader = promise->get_action();
+               if (reader->get_tid() != blocker->get_id())
+                       continue;
+               if (!promise->thread_is_available(waiting->get_id()))
+                       continue;
+               if (promise->eliminate_thread(waiting->get_id())) {
+                       /* Promise has failed */
+                       priv->failed_promise = true;
+               }
+       }
+}
+
 /**
  * @brief Check whether a model action is enabled.
  *
@@ -1350,6 +1374,7 @@ bool ModelChecker::check_action_enabled(ModelAction *curr) {
                Thread *blocking = (Thread *)curr->get_location();
                if (!blocking->is_complete()) {
                        blocking->push_wait_list(curr);
+                       thread_blocking_check_promises(blocking, get_thread(curr));
                        return false;
                }
        }
@@ -1740,13 +1765,13 @@ bool ModelChecker::r_modification_order(ModelAction *curr, const rf_type *rf)
                                                added = mo_graph->addEdge(act, rf) || added;
                                        }
                                } else {
-                                       const ModelAction *prevreadfrom = act->get_reads_from();
-                                       //if the previous read is unresolved, keep going...
-                                       if (prevreadfrom == NULL)
-                                               continue;
-
-                                       if (!prevreadfrom->equals(rf)) {
-                                               added = mo_graph->addEdge(prevreadfrom, rf) || added;
+                                       const ModelAction *prevrf = act->get_reads_from();
+                                       const Promise *prevrf_promise = act->get_reads_from_promise();
+                                       if (prevrf) {
+                                               if (!prevrf->equals(rf))
+                                                       added = mo_graph->addEdge(prevrf, rf) || added;
+                                       } else if (!prevrf_promise->equals(rf)) {
+                                               added = mo_graph->addEdge(prevrf_promise, rf) || added;
                                        }
                                }
                                break;
@@ -2422,7 +2447,7 @@ bool ModelChecker::resolve_promises(ModelAction *write)
                        read_from(read, write);
                        //Make sure the promise's value matches the write's value
                        ASSERT(promise->is_compatible(write));
-                       mo_graph->resolvePromise(read, write, &mustResolve);
+                       mo_graph->resolvePromise(promise, write, &mustResolve);
 
                        resolved.push_back(promise);
                        promises->erase(promises->begin() + promise_index);