location(loc),
value(value),
reads_from(NULL),
+ reads_from_promise(NULL),
last_fence_release(NULL),
node(NULL),
seq_number(ACTION_INITIAL_CLOCK),
}
bool ModelAction::is_notify() const {
- return type==ATOMIC_NOTIFY_ONE || type==ATOMIC_NOTIFY_ALL;
+ return type == ATOMIC_NOTIFY_ONE || type == ATOMIC_NOTIFY_ALL;
}
bool ModelAction::is_notify_one() const {
- return type==ATOMIC_NOTIFY_ONE;
+ return type == ATOMIC_NOTIFY_ONE;
}
bool ModelAction::is_unlock() const
return type == ATOMIC_RMWC;
}
-bool ModelAction::is_fence() const
+bool ModelAction::is_fence() const
{
return type == ATOMIC_FENCE;
}
bool ModelAction::is_seqcst() const
{
- return order==std::memory_order_seq_cst;
+ return order == std::memory_order_seq_cst;
}
bool ModelAction::same_var(const ModelAction *act) const
{
- if ( act->is_wait() || is_wait() ) {
- if ( act->is_wait() && is_wait() ) {
- if ( ((void *)value) == ((void *)act->value) )
+ if (act->is_wait() || is_wait()) {
+ if (act->is_wait() && is_wait()) {
+ if (((void *)value) == ((void *)act->value))
return true;
- } else if ( is_wait() ) {
- if ( ((void *)value) == act->location )
+ } else if (is_wait()) {
+ if (((void *)value) == act->location)
return true;
- } else if ( act->is_wait() ) {
- if ( location == ((void *)act->value) )
+ } else if (act->is_wait()) {
+ if (location == ((void *)act->value))
return true;
}
}
return tid == act->tid;
}
-void ModelAction::copy_typeandorder(ModelAction * act) {
+void ModelAction::copy_typeandorder(ModelAction * act)
+{
this->type = act->type;
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.
* @todo If the memory_order changes, we may potentially need to update our
* clock vector.
*/
-void ModelAction::process_rmw(ModelAction * act) {
- this->order=act->order;
+void ModelAction::process_rmw(ModelAction *act)
+{
+ this->order = act->order;
if (act->is_rmwc())
- this->type=ATOMIC_READ;
+ this->type = ATOMIC_READ;
else if (act->is_rmw()) {
- this->type=ATOMIC_RMW;
- this->value=act->value;
+ this->type = ATOMIC_RMW;
+ this->value = act->value;
}
}
// 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
- if ((is_lock() ||is_trylock()) && (act->is_unlock()||act->is_wait()))
+ if ((is_lock() || is_trylock()) && (act->is_unlock() || act->is_wait()))
return true;
// lock just acquired...we can fail to grab lock
return true;
// other thread stalling on lock...we can release lock
- if (is_unlock() && (act->is_trylock()||act->is_lock()))
+ if (is_unlock() && (act->is_trylock() || act->is_lock()))
return true;
- if (is_trylock() && (act->is_unlock()||act->is_wait()))
+ if (is_trylock() && (act->is_unlock() || act->is_wait()))
return true;
- if ( is_notify() && act->is_wait() )
+ if (is_notify() && act->is_wait())
return true;
- if ( is_wait() && act->is_notify() )
+ if (is_wait() && act->is_notify())
return true;
// Otherwise handle by reads_from relation
// 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;
void ModelAction::set_try_lock(bool obtainedlock) {
if (obtainedlock)
- value=VALUE_TRYSUCCESS;
+ value = VALUE_TRYSUCCESS;
else
- value=VALUE_TRYFAILED;
+ 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;
}
/** @return The Node associated with this ModelAction */
*/
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.
* @param act The ModelAction to synchronize with
* @return True if this is a valid synchronization; false otherwise
*/
-bool ModelAction::synchronize_with(const ModelAction *act) {
+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);
type_str = "unknown type";
}
- uint64_t valuetoprint=type==ATOMIC_READ?(reads_from!=NULL?reads_from->value:VALUE_NONE):value;
+ uint64_t valuetoprint;
+ if (is_read())
+ valuetoprint = get_reads_from_value();
+ else if (is_write())
+ valuetoprint = get_write_value();
+ else
+ valuetoprint = value;
switch (this->order) {
case std::memory_order_relaxed:
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) {
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;
- hash^=((unsigned int)this->order)<<3;
- hash^=seq_number<<5;
+ unsigned int hash = (unsigned int)this->type;
+ hash ^= ((unsigned int)this->order) << 3;
+ hash ^= seq_number << 5;
hash ^= id_to_int(tid) << 6;
- if (is_read()) {
- if (reads_from)
- hash^=reads_from->get_seq_number();
- }
+ if (is_read() && reads_from)
+ 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;
+}