#include "action.h"
#include "clockvector.h"
#include "common.h"
+#include "threads.h"
+
+#define ACTION_INITIAL_CLOCK 0
ModelAction::ModelAction(action_type_t type, memory_order order, void *loc, uint64_t value) :
type(type),
location(loc),
value(value),
reads_from(NULL),
+ seq_number(ACTION_INITIAL_CLOCK),
cv(NULL)
{
Thread *t = thread_current();
this->tid = t->get_id();
- this->seq_number = model->get_next_seq_num();
}
+/** @brief ModelAction destructor */
ModelAction::~ModelAction()
{
- if (cv)
- delete cv;
+ /**
+ * We can't free the clock vector:
+ * Clock vectors are snapshotting state. When we delete model actions,
+ * they are at the end of the node list and have invalid old clock
+ * vectors which have already been rolled back to an unallocated state.
+ */
+
+ /*
+ if (cv)
+ delete cv; */
+}
+
+void ModelAction::copy_from_new(ModelAction *newaction)
+{
+ seq_number = newaction->seq_number;
+}
+
+void ModelAction::set_seq_number(modelclock_t num)
+{
+ ASSERT(seq_number == ACTION_INITIAL_CLOCK);
+ seq_number = num;
+}
+
+bool ModelAction::is_relseq_fixup() const
+{
+ return type == MODEL_FIXUP_RELSEQ;
}
-bool ModelAction::is_mutex_op() const {
+bool ModelAction::is_mutex_op() const
+{
return type == ATOMIC_LOCK || type == ATOMIC_TRYLOCK || type == ATOMIC_UNLOCK;
}
-bool ModelAction::is_lock() const {
+bool ModelAction::is_lock() const
+{
return type == ATOMIC_LOCK;
}
-bool ModelAction::is_unlock() const {
+bool ModelAction::is_unlock() const
+{
return type == ATOMIC_UNLOCK;
}
-bool ModelAction::is_trylock() const {
+bool ModelAction::is_trylock() const
+{
return type == ATOMIC_TRYLOCK;
}
-bool ModelAction::is_success_lock() const {
+bool ModelAction::is_success_lock() const
+{
return type == ATOMIC_LOCK || (type == ATOMIC_TRYLOCK && value == VALUE_TRYSUCCESS);
}
-bool ModelAction::is_failed_trylock() const {
+bool ModelAction::is_failed_trylock() const
+{
return (type == ATOMIC_TRYLOCK && value == VALUE_TRYFAILED);
}
}
void ModelAction::copy_typeandorder(ModelAction * act) {
- this->type=act->type;
- this->order=act->order;
+ this->type = act->type;
+ this->order = act->order;
}
/** This method changes an existing read part of an RMW action into either:
* @param act is the action to consider exploring a reordering.
* @return tells whether we have to explore a reordering.
*/
-bool ModelAction::is_synchronizing(const ModelAction *act) const
+bool ModelAction::could_synchronize_with(const ModelAction *act) const
{
//Same thread can't be reordered
if (same_thread(act))
// Explore interleavings of seqcst writes to guarantee total order
// of seq_cst operations that don't commute
- if (is_write() && is_seqcst() && act->is_write() && act->is_seqcst())
+ if ((is_write() || act->is_write()) && is_seqcst() && act->is_seqcst())
return true;
// Explore synchronizing read/write pairs
if (is_read() && is_acquire() && act->is_write() && act->is_release())
return true;
- if (is_write() && is_release() && act->is_read() && act->is_acquire())
- return true;
// Otherwise handle by reads_from relation
return false;
}
-void ModelAction::create_cv(const ModelAction *parent)
+bool ModelAction::is_conflicting_lock(const ModelAction *act) const
{
- if (cv)
- delete cv;
+ //Must be different threads to reorder
+ if (same_thread(act))
+ return false;
+
+ //Try to reorder a lock past a successful lock
+ if (act->is_success_lock())
+ return true;
+
+ //Try to push a successful trylock past an unlock
+ if (act->is_unlock() && is_trylock() && value == VALUE_TRYSUCCESS)
+ return true;
+
+ return false;
+}
+/**
+ * Create a new clock vector for this action. Note that this function allows a
+ * user to clobber (and leak) a ModelAction's existing clock vector. A user
+ * should ensure that the vector has already either been rolled back
+ * (effectively "freed") or freed.
+ *
+ * @param parent A ModelAction from which to inherit a ClockVector
+ */
+void ModelAction::create_cv(const ModelAction *parent)
+{
if (parent)
cv = new ClockVector(parent->cv, this);
else
value=VALUE_TRYFAILED;
}
-/** Update the model action's read_from action */
-void ModelAction::read_from(const ModelAction *act)
+/**
+ * Update the model action's read_from action
+ * @param act The action to read from; should be a write
+ * @return True if this read established synchronization
+ */
+bool ModelAction::read_from(const ModelAction *act)
{
ASSERT(cv);
reads_from = act;
if (act != NULL && this->is_acquire()) {
rel_heads_list_t release_heads;
model->get_release_seq_heads(this, &release_heads);
+ int num_heads = release_heads.size();
for (unsigned int i = 0; i < release_heads.size(); i++)
- synchronize_with(release_heads[i]);
+ if (!synchronize_with(release_heads[i])) {
+ model->set_bad_synchronization();
+ num_heads--;
+ }
+ return num_heads > 0;
}
+ return false;
}
/**
* Synchronize the current thread with the thread corresponding to the
* ModelAction parameter.
* @param act The ModelAction to synchronize with
+ * @return True if this is a valid synchronization; false otherwise
*/
-void ModelAction::synchronize_with(const ModelAction *act) {
- ASSERT(*act < *this || type == THREAD_JOIN);
- model->check_promises(cv, act->cv);
+bool ModelAction::synchronize_with(const ModelAction *act) {
+ if (*this < *act && type != THREAD_JOIN && type != ATOMIC_LOCK)
+ return false;
+ model->check_promises(act->get_tid(), cv, act->cv);
cv->merge(act->cv);
+ return true;
}
bool ModelAction::has_synchronized_with(const ModelAction *act) const
return act->cv->synchronized_since(this);
}
-void ModelAction::print(void) const
+/** @brief Print nicely-formatted info about this ModelAction */
+void ModelAction::print() const
{
const char *type_str, *mo_str;
switch (this->type) {
+ case MODEL_FIXUP_RELSEQ:
+ type_str = "relseq fixup";
+ break;
case THREAD_CREATE:
type_str = "thread create";
break;
case ATOMIC_INIT:
type_str = "init atomic";
break;
+ case ATOMIC_LOCK:
+ type_str = "lock";
+ break;
+ case ATOMIC_UNLOCK:
+ type_str = "unlock";
+ break;
+ case ATOMIC_TRYLOCK:
+ type_str = "trylock";
+ break;
default:
type_str = "unknown type";
}
projects / model-checker.git / blobdiff