model: schedule appropriate fence backtracking points

[c11tester.git] / action.cc

diff --git a/action.cc b/action.cc
index 84c20eb5c42f0ff9b1fa4f3ef668aa6432b793d5..317c6a7cd87d9a94fbb695ecb95615ed5bae5613 100644 (file)
--- a/action.cc
+++ b/action.cc
@@ -31,6 +31,7 @@ ModelAction::ModelAction(action_type_t type, memory_order order, void *loc,
        location(loc),
        value(value),
        reads_from(NULL),
+       reads_from_promise(NULL),
        last_fence_release(NULL),
        node(NULL),
        seq_number(ACTION_INITIAL_CLOCK),
@@ -238,6 +239,31 @@ void ModelAction::copy_typeandorder(ModelAction * act)
        this->order = act->order;
 }
 
+/**
+ * Get the Thread which is the operand of this action. This is only valid for
+ * THREAD_* operations (currently only for THREAD_CREATE and THREAD_JOIN). Note
+ * that this provides a central place for determining the conventions of Thread
+ * storage in ModelAction, where we generally aren't very type-safe (e.g., we
+ * store object references in a (void *) address.
+ *
+ * For THREAD_CREATE, this yields the Thread which is created.
+ * For THREAD_JOIN, this yields the Thread we are joining with.
+ *
+ * @return The Thread which this action acts on, if exists; otherwise NULL
+ */
+Thread * ModelAction::get_thread_operand() const
+{
+       if (type == THREAD_CREATE) {
+               /* THREAD_CREATE stores its (Thread *) in a thrd_t::priv */
+               thrd_t *thrd = (thrd_t *)get_location();
+               return thrd->priv;
+       } else if (type == THREAD_JOIN)
+               /* THREAD_JOIN uses (Thread *) for location */
+               return (Thread *)get_location();
+       else
+               return NULL;
+}
+
 /** This method changes an existing read part of an RMW action into either:
  *  (1) a full RMW action in case of the completed write or
  *  (2) a READ action in case a failed action.
@@ -274,15 +300,13 @@ bool ModelAction::could_synchronize_with(const ModelAction *act) const
        if (!same_var(act))
                return false;
 
-       // Explore interleavings of seqcst writes/fences to guarantee total
+       // Explore interleavings of seqcst writes to guarantee total
        // order of seq_cst operations that don't commute
-       if ((could_be_write() || act->could_be_write() || is_fence() || act->is_fence())
-                       && is_seqcst() && act->is_seqcst())
+       if ((could_be_write() || act->could_be_write()) && is_seqcst() && act->is_seqcst())
                return true;
 
-       // Explore synchronizing read/write/fence pairs
-       if (is_acquire() && act->is_release() && (is_read() || is_fence()) &&
-                       (act->could_be_write() || act->is_fence()))
+       // Explore synchronizing read/write pairs
+       if (is_acquire() && act->is_release() && is_read() && act->could_be_write())
                return true;
 
        // lock just released...we can grab lock
@@ -369,10 +393,22 @@ Node * ModelAction::get_node() const
 void ModelAction::set_read_from(const ModelAction *act)
 {
        reads_from = act;
+       reads_from_promise = NULL;
        if (act && act->is_uninitialized())
                model->assert_bug("May read from uninitialized atomic\n");
 }
 
+/**
+ * Set this action's read-from promise
+ * @param promise The promise to read from
+ */
+void ModelAction::set_read_from_promise(const Promise *promise)
+{
+       ASSERT(is_read());
+       reads_from_promise = promise;
+       reads_from = NULL;
+}
+
 /**
  * Synchronize the current thread with the thread corresponding to the
  * ModelAction parameter.
@@ -474,8 +510,10 @@ void ModelAction::print() const
        }
 
        uint64_t valuetoprint;
-       if (type == ATOMIC_READ && reads_from != NULL)
+       if (is_read() && reads_from)
                valuetoprint = reads_from->value;
+       else if (is_read() && reads_from_promise)
+               valuetoprint = reads_from_promise->get_value();
        else
                valuetoprint = value;
 
@@ -518,7 +556,7 @@ void ModelAction::print() const
                model_print("\n");
 }
 
-/** @brief Print nicely-formatted info about this ModelAction */
+/** @brief Get a (likely) unique hash for this ModelAction */
 unsigned int ModelAction::hash() const
 {
        unsigned int hash = (unsigned int)this->type;