make scheduler choose fair schedules when threads with priority are sleeping...

[model-checker.git] / action.cc

diff --git a/action.cc b/action.cc
index 5e050810e7526408828b27c74cad76fcdef95a4b..ca1285612b00c75fd7294bee5af80d3aa52a3468 100644 (file)
--- a/action.cc
+++ b/action.cc
@@ -36,6 +36,9 @@ ModelAction::ModelAction(action_type_t type, memory_order order, void *loc,
        cv(NULL),
        sleep_flag(false)
 {
+       /* References to NULL atomic variables can end up here */
+       ASSERT(loc || type == MODEL_FIXUP_RELSEQ);
+
        Thread *t = thread ? thread : thread_current();
        this->tid = t->get_id();
 }
@@ -111,6 +114,11 @@ bool ModelAction::is_write() const
        return type == ATOMIC_WRITE || type == ATOMIC_RMW || type == ATOMIC_INIT;
 }
 
+bool ModelAction::could_be_write() const
+{
+       return is_write() || is_rmwr();
+}
+
 bool ModelAction::is_rmwr() const
 {
        return type == ATOMIC_RMWR;
@@ -217,11 +225,11 @@ bool ModelAction::could_synchronize_with(const ModelAction *act) const
 
        // Explore interleavings of seqcst writes to guarantee total order
        // of seq_cst operations that don't commute
-       if ((is_write() || act->is_write()) && is_seqcst() && act->is_seqcst())
+       if ((could_be_write() || act->could_be_write()) && is_seqcst() && act->is_seqcst())
                return true;
 
        // Explore synchronizing read/write pairs
-       if (is_read() && is_acquire() && act->is_write() && act->is_release())
+       if (is_read() && is_acquire() && act->could_be_write() && act->is_release())
                return true;
 
        // Otherwise handle by reads_from relation