#include <stdio.h>
#define __STDC_FORMAT_MACROS
#include <inttypes.h>
-#include <vector>
#include "model.h"
#include "action.h"
#define ACTION_INITIAL_CLOCK 0
+/** @brief A special value to represent a successful trylock */
+#define VALUE_TRYSUCCESS 1
+
+/** @brief A special value to represent a failed trylock */
+#define VALUE_TRYFAILED 0
+
/**
* @brief Construct a new ModelAction
*
location(loc),
value(value),
reads_from(NULL),
+ reads_from_promise(NULL),
last_fence_release(NULL),
node(NULL),
seq_number(ACTION_INITIAL_CLOCK),
return type == THREAD_START;
}
+bool ModelAction::is_thread_join() const
+{
+ return type == THREAD_JOIN;
+}
+
bool ModelAction::is_relseq_fixup() const
{
return type == MODEL_FIXUP_RELSEQ;
return is_write() || is_rmwr();
}
+bool ModelAction::is_yield() const
+{
+ return type == THREAD_YIELD;
+}
+
bool ModelAction::is_rmwr() const
{
return type == ATOMIC_RMWR;
*/
Thread * ModelAction::get_thread_operand() const
{
- if (type == THREAD_CREATE)
- /* THREAD_CREATE uses (Thread *) for location */
- return (Thread *)get_location();
- else if (type == THREAD_JOIN)
+ 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.
+/**
+ * @brief Convert the read portion of an RMW
+ *
+ * Changes an existing read part of an RMW action into either:
+ * -# a full RMW action in case of the completed write or
+ * -# a READ action in case a failed action.
+ *
* @todo If the memory_order changes, we may potentially need to update our
* clock vector.
+ *
+ * @param act The second half of the RMW (either RMWC or RMW)
*/
void ModelAction::process_rmw(ModelAction *act)
{
}
}
-/** The is_synchronizing method should only explore interleavings if:
- * (1) the operations are seq_cst and don't commute or
- * (2) the reordering may establish or break a synchronization relation.
- * Other memory operations will be dealt with by using the reads_from
- * relation.
+/**
+ * @brief Check if this action should be backtracked with another, due to
+ * potential synchronization
*
- * @param act is the action to consider exploring a reordering.
- * @return tells whether we have to explore a reordering.
+ * The is_synchronizing method should only explore interleavings if:
+ * -# the operations are seq_cst and don't commute or
+ * -# the reordering may establish or break a synchronization relation.
+ *
+ * Other memory operations will be dealt with by using the reads_from relation.
+ *
+ * @param act The action to consider exploring a reordering
+ * @return True, if we have to explore a reordering; otherwise false
*/
bool ModelAction::could_synchronize_with(const ModelAction *act) const
{
if (!same_var(act))
return false;
- // Explore interleavings of seqcst writes to guarantee total
+ // 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_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 pairs
cv = new ClockVector(NULL, this);
}
-void ModelAction::set_try_lock(bool obtainedlock) {
- if (obtainedlock)
- value = VALUE_TRYSUCCESS;
+void ModelAction::set_try_lock(bool obtainedlock)
+{
+ value = obtainedlock ? VALUE_TRYSUCCESS : 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
- value = VALUE_TRYFAILED;
+ 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.
*/
bool ModelAction::synchronize_with(const ModelAction *act)
{
- if (*this < *act && type != THREAD_JOIN && type != ATOMIC_LOCK)
+ if (*this < *act)
return false;
- model->check_promises(act->get_tid(), cv, act->cv);
cv->merge(act->cv);
return true;
}
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";
}
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 = reads_from_promise->get_index();
+ 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 ^= seq_number << 5;
hash ^= id_to_int(tid) << 6;
- if (is_read() && reads_from)
- hash ^= reads_from->get_seq_number();
+ if (is_read()) {
+ if (reads_from)
+ hash ^= reads_from->get_seq_number();
+ else if (reads_from_promise)
+ hash ^= reads_from_promise->get_index();
+ hash ^= get_reads_from_value();
+ }
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;
+}
projects / model-checker.git / blobdiff