#ifndef __ACTION_H__
#define __ACTION_H__
-#include <list>
#include <cstddef>
#include <inttypes.h>
#include "memoryorder.h"
#include "modeltypes.h"
+/* Forward declarations */
class ClockVector;
class Thread;
+class Promise;
+
+namespace std {
+ class mutex;
+}
using std::memory_order;
using std::memory_order_relaxed;
using std::memory_order_acq_rel;
using std::memory_order_seq_cst;
-/** Note that this value can be legitimately used by a program, and
- hence by iteself does not indicate no value. */
-
+/**
+ * @brief A recognizable don't-care value for use in the ModelAction::value
+ * field
+ *
+ * Note that this value can be legitimately used by a program, and hence by
+ * iteself does not indicate no value.
+ */
#define VALUE_NONE 0xdeadbeef
-/** A special value to represent a successful trylock */
-
-#define VALUE_TRYSUCCESS 1
-
-/** A special value to represent a failed trylock */
-#define VALUE_TRYFAILED 0
+/**
+ * @brief The "location" at which a fence occurs
+ *
+ * We need a non-zero memory location to associate with fences, since our hash
+ * tables don't handle NULL-pointer keys. HACK: Hopefully this doesn't collide
+ * with any legitimate memory locations.
+ */
+#define FENCE_LOCATION ((void *)0x7)
/** @brief Represents an action type, identifying one of several types of
* ModelAction */
THREAD_YIELD, /**< A thread yield action */
THREAD_JOIN, /**< A thread join action */
THREAD_FINISH, /**< A thread completion action */
+ ATOMIC_UNINIT, /**< Represents an uninitialized atomic */
ATOMIC_READ, /**< An atomic read action */
ATOMIC_WRITE, /**< An atomic write action */
ATOMIC_RMWR, /**< The read part of an atomic RMW action */
class ClockVector;
/**
- * The ModelAction class encapsulates an atomic action.
+ * @brief Represents a single atomic action
+ *
+ * A ModelAction is always allocated as non-snapshotting, because it is used in
+ * multiple executions during backtracking. Except for fake uninitialized
+ * (ATOMIC_UNINIT) ModelActions, each action is assigned a unique sequence
+ * number.
*/
class ModelAction {
public:
void * get_location() const { return location; }
modelclock_t get_seq_number() const { return seq_number; }
uint64_t get_value() const { return value; }
+ uint64_t get_reads_from_value() const;
+ uint64_t get_write_value() const;
+ uint64_t get_return_value() const;
const ModelAction * get_reads_from() const { return reads_from; }
+ Promise * get_reads_from_promise() const { return reads_from_promise; }
+ std::mutex * get_mutex() const;
- Node * get_node() const { return node; }
+ Node * get_node() const;
void set_node(Node *n) { node = n; }
void set_read_from(const ModelAction *act);
+ void set_read_from_promise(Promise *promise);
/** Store the most recent fence-release from the same thread
* @param fence The fence-release that occured prior to this */
void set_seq_number(modelclock_t num);
void set_try_lock(bool obtainedlock);
bool is_thread_start() const;
+ bool is_thread_join() const;
bool is_relseq_fixup() const;
bool is_mutex_op() const;
bool is_lock() const;
bool is_notify_one() const;
bool is_success_lock() const;
bool is_failed_trylock() const;
+ bool is_atomic_var() const;
+ bool is_uninitialized() const;
bool is_read() const;
bool is_write() const;
+ bool is_yield() const;
bool could_be_write() const;
bool is_rmwr() const;
bool is_rmwc() const;
bool is_conflicting_lock(const ModelAction *act) const;
bool could_synchronize_with(const ModelAction *act) const;
+ Thread * get_thread_operand() const;
+
void create_cv(const ModelAction *parent = NULL);
ClockVector * get_cv() const { return cv; }
bool synchronize_with(const ModelAction *act);
bool get_sleep_flag() { return sleep_flag; }
unsigned int hash() const;
+ bool equals(const ModelAction *x) const { return this == x; }
+ bool equals(const Promise *x) const { return false; }
+
+ bool may_read_from(const ModelAction *write) const;
+ bool may_read_from(const Promise *promise) const;
MEMALLOC
private:
- /** Type of action (read, write, thread create, thread yield, thread join) */
+ /** @brief Type of action (read, write, RMW, fence, thread create, etc.) */
action_type type;
- /** The memory order for this operation. */
+ /** @brief The memory order for this operation. */
memory_order order;
- /** A pointer to the memory location for this action. */
+ /** @brief A pointer to the memory location for this action. */
void *location;
- /** The thread id that performed this action. */
+ /** @brief The thread id that performed this action. */
thread_id_t tid;
- /** The value written (for write or RMW; undefined for read) */
+ /** @brief The value written (for write or RMW; undefined for read) */
uint64_t value;
- /** The action that this action reads from. Only valid for reads */
+ /**
+ * @brief The store that this action reads from
+ *
+ * Only valid for reads
+ */
const ModelAction *reads_from;
- /** The last fence release from the same thread */
+ /**
+ * @brief The promise that this action reads from
+ *
+ * Only valid for reads
+ */
+ Promise *reads_from_promise;
+
+ /** @brief The last fence release from the same thread */
const ModelAction *last_fence_release;
- /** A back reference to a Node in NodeStack, if this ModelAction is
- * saved on the NodeStack. */
+ /**
+ * @brief A back reference to a Node in NodeStack
+ *
+ * Only set if this ModelAction is saved on the NodeStack. (A
+ * ModelAction can be thrown away before it ever enters the NodeStack.)
+ */
Node *node;
+ /**
+ * @brief The sequence number of this action
+ *
+ * Except for ATOMIC_UNINIT actions, this number should be unique and
+ * should represent the action's position in the execution order.
+ */
modelclock_t seq_number;
- /** The clock vector stored with this action; only needed if this
- * action is a store release? */
+ /**
+ * @brief The clock vector for this operation
+ *
+ * Technically, this is only needed for potentially synchronizing
+ * (e.g., non-relaxed) operations, but it is very handy to have these
+ * vectors for all operations.
+ */
ClockVector *cv;
bool sleep_flag;
};
-typedef std::list< ModelAction *, SnapshotAlloc<ModelAction *> > action_list_t;
-
#endif /* __ACTION_H__ */