X-Git-Url: http://plrg.eecs.uci.edu/git/?p=model-checker.git;a=blobdiff_plain;f=action.cc;h=be8c4a6c0cdc69bde75fd08436a33705fa9157af;hp=84c20eb5c42f0ff9b1fa4f3ef668aa6432b793d5;hb=ff3ab0abac18649da161a495781c3925cbcd62a4;hpb=0e8659aba12909cfc5785163022378519837710e

diff --git a/action.cc b/action.cc
index 84c20eb..be8c4a6 100644
--- 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.
@@ -276,13 +302,11 @@ bool ModelAction::could_synchronize_with(const ModelAction *act) const
 
 	// Explore interleavings of seqcst writes/fences 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_fence() || act->is_fence()) && 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
@@ -354,6 +378,64 @@ void ModelAction::set_try_lock(bool obtainedlock) {
 		value = VALUE_TRYFAILED;
 }
 
+/**
+ * @brief Get the value read by this load
+ *
+ * We differentiate this function from ModelAction::get_write_value and
+ * ModelAction::get_value for the purpose of RMW's, which may have both a
+ * 'read' and a 'write' value.
+ *
+ * Note: 'this' must be a load.
+ *
+ * @return The value read by this load
+ */
+uint64_t ModelAction::get_reads_from_value() const
+{
+	ASSERT(is_read());
+	if (reads_from)
+		return reads_from->get_write_value();
+	else if (reads_from_promise)
+		return reads_from_promise->get_value();
+	return VALUE_NONE; /* Only for new actions with no reads-from */
+}
+
+/**
+ * @brief Get the value written by this store
+ *
+ * We differentiate this function from ModelAction::get_reads_from_value and
+ * ModelAction::get_value for the purpose of RMW's, which may have both a
+ * 'read' and a 'write' value.
+ *
+ * Note: 'this' must be a store.
+ *
+ * @return The value written by this store
+ */
+uint64_t ModelAction::get_write_value() const
+{
+	ASSERT(is_write());
+	return value;
+}
+
+/**
+ * @brief Get the value returned by this action
+ *
+ * For atomic reads (including RMW), an operation returns the value it read.
+ * For atomic writes, an operation returns the value it wrote. For other
+ * operations, the return value varies (sometimes is a "don't care"), but the
+ * value is simply stored in the "value" field.
+ *
+ * @return This action's return value
+ */
+uint64_t ModelAction::get_return_value() const
+{
+	if (is_read())
+		return get_reads_from_value();
+	else if (is_write())
+		return get_write_value();
+	else
+		return value;
+}
+
 /** @return The Node associated with this ModelAction */
 Node * ModelAction::get_node() const
 {
@@ -368,11 +450,24 @@ Node * ModelAction::get_node() const
  */
 void ModelAction::set_read_from(const ModelAction *act)
 {
+	ASSERT(act);
 	reads_from = act;
-	if (act && act->is_uninitialized())
+	reads_from_promise = NULL;
+	if (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(Promise *promise)
+{
+	ASSERT(is_read());
+	reads_from_promise = promise;
+	reads_from = NULL;
+}
+
 /**
  * Synchronize the current thread with the thread corresponding to the
  * ModelAction parameter.
@@ -473,12 +568,6 @@ void ModelAction::print() const
 		type_str = "unknown type";
 	}
 
-	uint64_t valuetoprint;
-	if (type == ATOMIC_READ && reads_from != NULL)
-		valuetoprint = reads_from->value;
-	else
-		valuetoprint = value;
-
 	switch (this->order) {
 	case std::memory_order_relaxed:
 		mo_str = "relaxed";
@@ -501,11 +590,17 @@ void ModelAction::print() const
 	}
 
 	model_print("(%4d) Thread: %-2d   Action: %-13s   MO: %7s  Loc: %14p   Value: %-#18" PRIx64,
-			seq_number, id_to_int(tid), type_str, mo_str, location, valuetoprint);
+			seq_number, id_to_int(tid), type_str, mo_str, location, get_return_value());
 	if (is_read()) {
 		if (reads_from)
 			model_print("  Rf: %-3d", reads_from->get_seq_number());
-		else
+		else if (reads_from_promise) {
+			int idx = model->get_promise_number(reads_from_promise);
+			if (idx >= 0)
+				model_print("  Rf: P%-2d", idx);
+			else
+				model_print("  RF: P? ");
+		} else
 			model_print("  Rf: ?  ");
 	}
 	if (cv) {
@@ -518,7 +613,7 @@ 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;
@@ -530,3 +625,43 @@ unsigned int ModelAction::hash() const
 		hash ^= reads_from->get_seq_number();
 	return hash;
 }
+
+/**
+ * @brief Checks the NodeStack to see if a ModelAction is in our may-read-from set
+ * @param write The ModelAction to check for
+ * @return True if the ModelAction is found; false otherwise
+ */
+bool ModelAction::may_read_from(const ModelAction *write) const
+{
+	for (int i = 0; i < node->get_read_from_past_size(); i++)
+		if (node->get_read_from_past(i) == write)
+			return true;
+	return false;
+}
+
+/**
+ * @brief Checks the NodeStack to see if a Promise is in our may-read-from set
+ * @param promise The Promise to check for
+ * @return True if the Promise is found; false otherwise
+ */
+bool ModelAction::may_read_from(const Promise *promise) const
+{
+	for (int i = 0; i < node->get_read_from_promise_size(); i++)
+		if (node->get_read_from_promise(i) == promise)
+			return true;
+	return false;
+}
+
+/**
+ * Only valid for LOCK, TRY_LOCK, UNLOCK, and WAIT operations.
+ * @return The mutex operated on by this action, if any; otherwise NULL
+ */
+std::mutex * ModelAction::get_mutex() const
+{
+	if (is_trylock() || is_lock() || is_unlock())
+		return (std::mutex *)get_location();
+	else if (is_wait())
+		return (std::mutex *)get_value();
+	else
+		return NULL;
+}