2 #define __STDC_FORMAT_MACROS
8 #include "clockvector.h"
10 #include "threads-model.h"
13 #define ACTION_INITIAL_CLOCK 0
15 /** @brief A special value to represent a successful trylock */
16 #define VALUE_TRYSUCCESS 1
18 /** @brief A special value to represent a failed trylock */
19 #define VALUE_TRYFAILED 0
22 * @brief Construct a new ModelAction
24 * @param type The type of action
25 * @param order The memory order of this action. A "don't care" for non-ATOMIC
26 * actions (e.g., THREAD_* or MODEL_* actions).
27 * @param loc The location that this action acts upon
28 * @param value (optional) A value associated with the action (e.g., the value
29 * read or written). Defaults to a given macro constant, for debugging purposes.
30 * @param thread (optional) The Thread in which this action occurred. If NULL
31 * (default), then a Thread is assigned according to the scheduler.
33 ModelAction::ModelAction(action_type_t type, memory_order order, void *loc,
34 uint64_t value, Thread *thread) :
38 last_fence_release(NULL),
47 original_type(ATOMIC_NOP),
49 original_order(order),
50 seq_number(ACTION_INITIAL_CLOCK)
52 /* References to NULL atomic variables can end up here */
53 ASSERT(loc || type == ATOMIC_FENCE || type == ATOMIC_NOP);
55 Thread *t = thread ? thread : thread_current();
56 this->tid = t!= NULL ? t->get_id() : -1;
61 * @brief Construct a new ModelAction for sleep actions
63 * @param type The type of action: THREAD_SLEEP
64 * @param order The memory order of this action. A "don't care" for non-ATOMIC
65 * actions (e.g., THREAD_* or MODEL_* actions).
66 * @param loc The location that this action acts upon
67 * @param value The time duration a thread is scheduled to sleep.
68 * @param _time The this sleep action is constructed
70 ModelAction::ModelAction(action_type_t type, memory_order order, uint64_t value, uint64_t _time) :
74 last_fence_release(NULL),
82 original_type(ATOMIC_NOP),
84 original_order(order),
85 seq_number(ACTION_INITIAL_CLOCK)
87 Thread *t = thread_current();
88 this->tid = t!= NULL ? t->get_id() : -1;
92 * @brief Construct a new ModelAction
94 * @param type The type of action
95 * @param order The memory order of this action. A "don't care" for non-ATOMIC
96 * actions (e.g., THREAD_* or MODEL_* actions).
97 * @param loc The location that this action acts upon
98 * @param value (optional) A value associated with the action (e.g., the value
99 * read or written). Defaults to a given macro constant, for debugging purposes.
100 * @param size (optional) The Thread in which this action occurred. If NULL
101 * (default), then a Thread is assigned according to the scheduler.
103 ModelAction::ModelAction(action_type_t type, memory_order order, void *loc,
104 uint64_t value, int size) :
108 last_fence_release(NULL),
116 original_type(ATOMIC_NOP),
118 original_order(order),
119 seq_number(ACTION_INITIAL_CLOCK)
121 /* References to NULL atomic variables can end up here */
124 Thread *t = thread_current();
125 this->tid = t->get_id();
130 * @brief Construct a new ModelAction with source line number (requires llvm support)
132 * @param type The type of action
133 * @param order The memory order of this action. A "don't care" for non-ATOMIC
134 * actions (e.g., THREAD_* or MODEL_* actions).
135 * @param loc The location that this action acts upon
136 * @param value (optional) A value associated with the action (e.g., the value
137 * read or written). Defaults to a given macro constant, for debugging purposes.
138 * @param size (optional) The Thread in which this action occurred. If NULL
139 * (default), then a Thread is assigned according to the scheduler.
141 ModelAction::ModelAction(action_type_t type, const char * position, memory_order order, void *loc,
142 uint64_t value, int size) :
146 last_fence_release(NULL),
154 original_type(ATOMIC_NOP),
156 original_order(order),
157 seq_number(ACTION_INITIAL_CLOCK)
159 /* References to NULL atomic variables can end up here */
162 Thread *t = thread_current();
163 this->tid = t->get_id();
168 * @brief Construct a new ModelAction with source line number (requires llvm support)
170 * @param type The type of action
171 * @param position The source line number of this atomic operation
172 * @param order The memory order of this action. A "don't care" for non-ATOMIC
173 * actions (e.g., THREAD_* or MODEL_* actions).
174 * @param loc The location that this action acts upon
175 * @param value (optional) A value associated with the action (e.g., the value
176 * read or written). Defaults to a given macro constant, for debugging purposes.
177 * @param thread (optional) The Thread in which this action occurred. If NULL
178 * (default), then a Thread is assigned according to the scheduler.
180 ModelAction::ModelAction(action_type_t type, const char * position, memory_order order,
181 void *loc, uint64_t value, Thread *thread) :
185 last_fence_release(NULL),
193 original_type(ATOMIC_NOP),
195 original_order(order),
196 seq_number(ACTION_INITIAL_CLOCK)
198 /* References to NULL atomic variables can end up here */
199 ASSERT(loc || type == ATOMIC_FENCE);
201 Thread *t = thread ? thread : thread_current();
202 this->tid = t->get_id();
206 /** @brief ModelAction destructor */
207 ModelAction::~ModelAction()
210 * We can't free the clock vector:
211 * Clock vectors are snapshotting state. When we delete model actions,
212 * they are at the end of the node list and have invalid old clock
213 * vectors which have already been rolled back to an unallocated state.
221 int ModelAction::getSize() const {
225 void ModelAction::copy_from_new(ModelAction *newaction)
227 seq_number = newaction->seq_number;
230 void ModelAction::set_seq_number(modelclock_t num)
232 ASSERT(seq_number == ACTION_INITIAL_CLOCK);
236 void ModelAction::reset_seq_number()
241 bool ModelAction::is_thread_start() const
243 return type == THREAD_START;
246 bool ModelAction::is_thread_join() const
248 return type == THREAD_JOIN || type == PTHREAD_JOIN;
251 bool ModelAction::is_mutex_op() const
253 return type == ATOMIC_LOCK || type == ATOMIC_TRYLOCK || type == ATOMIC_UNLOCK || type == ATOMIC_WAIT || type == ATOMIC_TIMEDWAIT || type == ATOMIC_NOTIFY_ONE || type == ATOMIC_NOTIFY_ALL;
256 bool ModelAction::is_lock() const
258 return type == ATOMIC_LOCK;
261 bool ModelAction::is_sleep() const
263 return type == THREAD_SLEEP;
266 bool ModelAction::is_wait() const {
267 return type == ATOMIC_WAIT || type == ATOMIC_TIMEDWAIT;
270 bool ModelAction::is_notify() const {
271 return type == ATOMIC_NOTIFY_ONE || type == ATOMIC_NOTIFY_ALL;
274 bool ModelAction::is_notify_one() const {
275 return type == ATOMIC_NOTIFY_ONE;
278 bool ModelAction::is_unlock() const
280 return type == ATOMIC_UNLOCK;
283 bool ModelAction::is_trylock() const
285 return type == ATOMIC_TRYLOCK;
288 bool ModelAction::is_success_lock() const
290 return type == ATOMIC_LOCK || (type == ATOMIC_TRYLOCK && value == VALUE_TRYSUCCESS);
293 bool ModelAction::is_failed_trylock() const
295 return (type == ATOMIC_TRYLOCK && value == VALUE_TRYFAILED);
298 /** @return True if this operation is performed on a C/C++ atomic variable */
299 bool ModelAction::is_atomic_var() const
301 return is_read() || could_be_write();
304 bool ModelAction::is_read() const
306 return type == ATOMIC_READ || type == ATOMIC_RMWR || type == ATOMIC_RMWRCAS || type == ATOMIC_RMW;
309 bool ModelAction::is_write() const
311 return type == ATOMIC_WRITE || type == ATOMIC_RMW || type == ATOMIC_INIT || type == NONATOMIC_WRITE;
314 bool ModelAction::is_create() const
316 return type == THREAD_CREATE || type == PTHREAD_CREATE;
319 bool ModelAction::is_free() const
321 return type == READY_FREE;
324 bool ModelAction::could_be_write() const
326 return is_write() || is_rmwr();
329 bool ModelAction::is_yield() const
331 return type == THREAD_YIELD;
334 bool ModelAction::is_rmwr() const
336 return type == ATOMIC_RMWR || type == ATOMIC_RMWRCAS;
339 bool ModelAction::is_rmwrcas() const
341 return type == ATOMIC_RMWRCAS;
344 bool ModelAction::is_rmw() const
346 return type == ATOMIC_RMW;
349 bool ModelAction::is_rmwc() const
351 return type == ATOMIC_RMWC;
354 bool ModelAction::is_fence() const
356 return type == ATOMIC_FENCE;
359 bool ModelAction::is_initialization() const
361 return type == ATOMIC_INIT;
364 bool ModelAction::is_annotation() const
366 return type == ATOMIC_ANNOTATION;
369 bool ModelAction::is_relaxed() const
371 return order == std::memory_order_relaxed;
374 bool ModelAction::is_acquire() const
377 case std::memory_order_acquire:
378 case std::memory_order_acq_rel:
379 case std::memory_order_seq_cst:
386 bool ModelAction::is_release() const
389 case std::memory_order_release:
390 case std::memory_order_acq_rel:
391 case std::memory_order_seq_cst:
398 bool ModelAction::is_seqcst() const
400 return order == std::memory_order_seq_cst;
403 bool ModelAction::same_var(const ModelAction *act) const
405 if (act->is_wait() || is_wait()) {
406 if (act->is_wait() && is_wait()) {
407 if (((void *)value) == ((void *)act->value))
409 } else if (is_wait()) {
410 if (((void *)value) == act->location)
412 } else if (act->is_wait()) {
413 if (location == ((void *)act->value))
418 return location == act->location;
421 bool ModelAction::same_thread(const ModelAction *act) const
423 return tid == act->tid;
426 void ModelAction::copy_typeandorder(ModelAction * act)
428 this->type = act->type;
429 this->order = act->order;
433 * Get the Thread which is the operand of this action. This is only valid for
434 * THREAD_* operations (currently only for THREAD_CREATE and THREAD_JOIN). Note
435 * that this provides a central place for determining the conventions of Thread
436 * storage in ModelAction, where we generally aren't very type-safe (e.g., we
437 * store object references in a (void *) address.
439 * For THREAD_CREATE, this yields the Thread which is created.
440 * For THREAD_JOIN, this yields the Thread we are joining with.
442 * @return The Thread which this action acts on, if exists; otherwise NULL
444 Thread * ModelAction::get_thread_operand() const
446 if (type == THREAD_CREATE) {
447 /* thread_operand is set in execution.cc */
448 return thread_operand;
449 } else if (type == PTHREAD_CREATE) {
450 return thread_operand;
451 } else if (type == THREAD_JOIN) {
452 /* THREAD_JOIN uses (Thread *) for location */
453 return (Thread *)get_location();
454 } else if (type == PTHREAD_JOIN) {
456 // thread_operand is stored in execution::pthread_map;
457 return (Thread *)get_location();
463 * @brief Convert the read portion of an RMW
465 * Changes an existing read part of an RMW action into either:
466 * -# a full RMW action in case of the completed write or
467 * -# a READ action in case a failed action.
469 * @todo If the memory_order changes, we may potentially need to update our
472 * @param act The second half of the RMW (either RMWC or RMW)
474 void ModelAction::process_rmw(ModelAction *act)
476 this->order = act->order;
478 this->type = ATOMIC_READ;
479 else if (act->is_rmw()) {
480 this->type = ATOMIC_RMW;
481 this->value = act->value;
486 * @brief Check if this action should be backtracked with another, due to
487 * potential synchronization
489 * The is_synchronizing method should only explore interleavings if:
490 * -# the operations are seq_cst and don't commute or
491 * -# the reordering may establish or break a synchronization relation.
493 * Other memory operations will be dealt with by using the reads_from relation.
495 * @param act The action to consider exploring a reordering
496 * @return True, if we have to explore a reordering; otherwise false
498 bool ModelAction::could_synchronize_with(const ModelAction *act) const
500 // Same thread can't be reordered
501 if (same_thread(act))
504 // Different locations commute
505 if (!same_var(act) && !is_fence() && !act->is_fence())
508 // Explore interleavings of seqcst writes/fences to guarantee total
509 // order of seq_cst operations that don't commute
510 if ((could_be_write() || act->could_be_write() || is_fence() || act->is_fence()) && is_seqcst() && act->is_seqcst())
513 // Explore synchronizing read/write pairs
514 if (is_acquire() && act->is_release() && is_read() && act->could_be_write())
517 // lock just released...we can grab lock
518 if ((is_lock() || is_trylock()) && (act->is_unlock() || act->is_wait()))
521 // lock just acquired...we can fail to grab lock
522 if (is_trylock() && act->is_success_lock())
525 // other thread stalling on lock...we can release lock
526 if (is_unlock() && (act->is_trylock() || act->is_lock()))
529 if (is_trylock() && (act->is_unlock() || act->is_wait()))
532 if (is_notify() && act->is_wait())
535 if (is_wait() && act->is_notify())
538 // Otherwise handle by reads_from relation
542 bool ModelAction::is_conflicting_lock(const ModelAction *act) const
544 // Must be different threads to reorder
545 if (same_thread(act))
548 // Try to reorder a lock past a successful lock
549 if (act->is_success_lock())
552 // Try to push a successful trylock past an unlock
553 if (act->is_unlock() && is_trylock() && value == VALUE_TRYSUCCESS)
556 // Try to push a successful trylock past a wait
557 if (act->is_wait() && is_trylock() && value == VALUE_TRYSUCCESS)
564 * Create a new clock vector for this action. Note that this function allows a
565 * user to clobber (and leak) a ModelAction's existing clock vector. A user
566 * should ensure that the vector has already either been rolled back
567 * (effectively "freed") or freed.
569 * @param parent A ModelAction from which to inherit a ClockVector
571 void ModelAction::create_cv(const ModelAction *parent)
574 cv = new ClockVector(parent->cv, this);
576 cv = new ClockVector(NULL, this);
579 void ModelAction::set_try_lock(bool obtainedlock)
581 value = obtainedlock ? VALUE_TRYSUCCESS : VALUE_TRYFAILED;
585 * @brief Get the value read by this load
587 * We differentiate this function from ModelAction::get_write_value and
588 * ModelAction::get_value for the purpose of RMW's, which may have both a
589 * 'read' and a 'write' value.
591 * Note: 'this' must be a load.
593 * @return The value read by this load
595 uint64_t ModelAction::get_reads_from_value() const
599 return reads_from->get_write_value();
601 return VALUE_NONE; // Only for new actions with no reads-from
605 * @brief Get the value written by this store
607 * We differentiate this function from ModelAction::get_reads_from_value and
608 * ModelAction::get_value for the purpose of RMW's, which may have both a
609 * 'read' and a 'write' value.
611 * Note: 'this' must be a store.
613 * @return The value written by this store
615 uint64_t ModelAction::get_write_value() const
622 * @brief Get the value returned by this action
624 * For atomic reads (including RMW), an operation returns the value it read.
625 * For atomic writes, an operation returns the value it wrote. For other
626 * operations, the return value varies (sometimes is a "don't care"), but the
627 * value is simply stored in the "value" field.
629 * @return This action's return value
631 uint64_t ModelAction::get_return_value() const
634 return get_reads_from_value();
636 return get_write_value();
642 * Update the model action's read_from action
643 * @param act The action to read from; should be a write
645 void ModelAction::set_read_from(ModelAction *act)
653 * Synchronize the current thread with the thread corresponding to the
654 * ModelAction parameter.
655 * @param act The ModelAction to synchronize with
656 * @return True if this is a valid synchronization; false otherwise
658 bool ModelAction::synchronize_with(const ModelAction *act)
666 bool ModelAction::has_synchronized_with(const ModelAction *act) const
668 return cv->synchronized_since(act);
672 * Check whether 'this' happens before act, according to the memory-model's
673 * happens before relation. This is checked via the ClockVector constructs.
674 * @return true if this action's thread has synchronized with act's thread
675 * since the execution of act, false otherwise.
677 bool ModelAction::happens_before(const ModelAction *act) const
679 return act->cv->synchronized_since(this);
682 const char * ModelAction::get_type_str() const
684 switch (this->type) {
685 case THREAD_CREATE: return "thread create";
686 case THREAD_START: return "thread start";
687 case THREAD_YIELD: return "thread yield";
688 case THREAD_JOIN: return "thread join";
689 case THREAD_FINISH: return "thread finish";
690 case THREAD_SLEEP: return "thread sleep";
691 case THREADONLY_FINISH: return "pthread_exit finish";
693 case PTHREAD_CREATE: return "pthread create";
694 case PTHREAD_JOIN: return "pthread join";
696 case NONATOMIC_WRITE: return "nonatomic write";
697 case ATOMIC_READ: return "atomic read";
698 case ATOMIC_WRITE: return "atomic write";
699 case ATOMIC_RMW: return "atomic rmw";
700 case ATOMIC_FENCE: return "fence";
701 case ATOMIC_RMWR: return "atomic rmwr";
702 case ATOMIC_RMWRCAS: return "atomic rmwrcas";
703 case ATOMIC_RMWC: return "atomic rmwc";
704 case ATOMIC_INIT: return "init atomic";
705 case ATOMIC_LOCK: return "lock";
706 case ATOMIC_UNLOCK: return "unlock";
707 case ATOMIC_TRYLOCK: return "trylock";
708 case ATOMIC_WAIT: return "wait";
709 case ATOMIC_TIMEDWAIT: return "timed wait";
710 case ATOMIC_NOTIFY_ONE: return "notify one";
711 case ATOMIC_NOTIFY_ALL: return "notify all";
712 case ATOMIC_ANNOTATION: return "annotation";
713 default: return "unknown type";
717 const char * ModelAction::get_mo_str() const
719 switch (this->order) {
720 case std::memory_order_relaxed: return "relaxed";
721 case std::memory_order_acquire: return "acquire";
722 case std::memory_order_release: return "release";
723 case std::memory_order_acq_rel: return "acq_rel";
724 case std::memory_order_seq_cst: return "seq_cst";
725 default: return "unknown";
729 /** @brief Print nicely-formatted info about this ModelAction */
730 void ModelAction::print() const
732 const char *type_str = get_type_str(), *mo_str = get_mo_str();
734 model_print("%-4d %-2d %-14s %7s %14p %-#18" PRIx64,
735 seq_number, id_to_int(tid), type_str, mo_str, location, get_return_value());
738 model_print(" %-3d", reads_from->get_seq_number());
752 /** @brief Get a (likely) unique hash for this ModelAction */
753 unsigned int ModelAction::hash() const
755 unsigned int hash = (unsigned int)this->type;
756 hash ^= ((unsigned int)this->order) << 3;
757 hash ^= seq_number << 5;
758 hash ^= id_to_int(tid) << 6;
762 hash ^= reads_from->get_seq_number();
763 hash ^= get_reads_from_value();
769 * Only valid for LOCK, TRY_LOCK, UNLOCK, and WAIT operations.
770 * @return The mutex operated on by this action, if any; otherwise NULL
772 cdsc::mutex * ModelAction::get_mutex() const
774 if (is_trylock() || is_lock() || is_unlock())
775 return (cdsc::mutex *)get_location();
777 return (cdsc::mutex *)get_value();
782 /** @brief Swap type with original type */
783 void ModelAction::use_original_type()
785 action_type_t tmp = type;
786 type = original_type;