2 #define __STDC_FORMAT_MACROS
8 #include "clockvector.h"
10 #include "threads-model.h"
11 #include "nodestack.h"
13 #define ACTION_INITIAL_CLOCK 0
16 * @brief Construct a new ModelAction
18 * @param type The type of action
19 * @param order The memory order of this action. A "don't care" for non-ATOMIC
20 * actions (e.g., THREAD_* or MODEL_* actions).
21 * @param loc The location that this action acts upon
22 * @param value (optional) A value associated with the action (e.g., the value
23 * read or written). Defaults to a given macro constant, for debugging purposes.
24 * @param thread (optional) The Thread in which this action occurred. If NULL
25 * (default), then a Thread is assigned according to the scheduler.
27 ModelAction::ModelAction(action_type_t type, memory_order order, void *loc,
28 uint64_t value, Thread *thread) :
34 last_fence_release(NULL),
36 seq_number(ACTION_INITIAL_CLOCK),
40 /* References to NULL atomic variables can end up here */
41 ASSERT(loc || type == ATOMIC_FENCE || type == MODEL_FIXUP_RELSEQ);
43 Thread *t = thread ? thread : thread_current();
44 this->tid = t->get_id();
47 /** @brief ModelAction destructor */
48 ModelAction::~ModelAction()
51 * We can't free the clock vector:
52 * Clock vectors are snapshotting state. When we delete model actions,
53 * they are at the end of the node list and have invalid old clock
54 * vectors which have already been rolled back to an unallocated state.
62 void ModelAction::copy_from_new(ModelAction *newaction)
64 seq_number = newaction->seq_number;
67 void ModelAction::set_seq_number(modelclock_t num)
69 /* ATOMIC_UNINIT actions should never have non-zero clock */
70 ASSERT(!is_uninitialized());
71 ASSERT(seq_number == ACTION_INITIAL_CLOCK);
75 bool ModelAction::is_thread_start() const
77 return type == THREAD_START;
80 bool ModelAction::is_relseq_fixup() const
82 return type == MODEL_FIXUP_RELSEQ;
85 bool ModelAction::is_mutex_op() const
87 return type == ATOMIC_LOCK || type == ATOMIC_TRYLOCK || type == ATOMIC_UNLOCK || type == ATOMIC_WAIT || type == ATOMIC_NOTIFY_ONE || type == ATOMIC_NOTIFY_ALL;
90 bool ModelAction::is_lock() const
92 return type == ATOMIC_LOCK;
95 bool ModelAction::is_wait() const {
96 return type == ATOMIC_WAIT;
99 bool ModelAction::is_notify() const {
100 return type==ATOMIC_NOTIFY_ONE || type==ATOMIC_NOTIFY_ALL;
103 bool ModelAction::is_notify_one() const {
104 return type==ATOMIC_NOTIFY_ONE;
107 bool ModelAction::is_unlock() const
109 return type == ATOMIC_UNLOCK;
112 bool ModelAction::is_trylock() const
114 return type == ATOMIC_TRYLOCK;
117 bool ModelAction::is_success_lock() const
119 return type == ATOMIC_LOCK || (type == ATOMIC_TRYLOCK && value == VALUE_TRYSUCCESS);
122 bool ModelAction::is_failed_trylock() const
124 return (type == ATOMIC_TRYLOCK && value == VALUE_TRYFAILED);
127 bool ModelAction::is_uninitialized() const
129 return type == ATOMIC_UNINIT;
132 bool ModelAction::is_read() const
134 return type == ATOMIC_READ || type == ATOMIC_RMWR || type == ATOMIC_RMW;
137 bool ModelAction::is_write() const
139 return type == ATOMIC_WRITE || type == ATOMIC_RMW || type == ATOMIC_INIT || type == ATOMIC_UNINIT;
142 bool ModelAction::could_be_write() const
144 return is_write() || is_rmwr();
147 bool ModelAction::is_rmwr() const
149 return type == ATOMIC_RMWR;
152 bool ModelAction::is_rmw() const
154 return type == ATOMIC_RMW;
157 bool ModelAction::is_rmwc() const
159 return type == ATOMIC_RMWC;
162 bool ModelAction::is_fence() const
164 return type == ATOMIC_FENCE;
167 bool ModelAction::is_initialization() const
169 return type == ATOMIC_INIT;
172 bool ModelAction::is_relaxed() const
174 return order == std::memory_order_relaxed;
177 bool ModelAction::is_acquire() const
180 case std::memory_order_acquire:
181 case std::memory_order_acq_rel:
182 case std::memory_order_seq_cst:
189 bool ModelAction::is_release() const
192 case std::memory_order_release:
193 case std::memory_order_acq_rel:
194 case std::memory_order_seq_cst:
201 bool ModelAction::is_seqcst() const
203 return order==std::memory_order_seq_cst;
206 bool ModelAction::same_var(const ModelAction *act) const
208 if ( act->is_wait() || is_wait() ) {
209 if ( act->is_wait() && is_wait() ) {
210 if ( ((void *)value) == ((void *)act->value) )
212 } else if ( is_wait() ) {
213 if ( ((void *)value) == act->location )
215 } else if ( act->is_wait() ) {
216 if ( location == ((void *)act->value) )
221 return location == act->location;
224 bool ModelAction::same_thread(const ModelAction *act) const
226 return tid == act->tid;
229 void ModelAction::copy_typeandorder(ModelAction * act) {
230 this->type = act->type;
231 this->order = act->order;
234 /** This method changes an existing read part of an RMW action into either:
235 * (1) a full RMW action in case of the completed write or
236 * (2) a READ action in case a failed action.
237 * @todo If the memory_order changes, we may potentially need to update our
240 void ModelAction::process_rmw(ModelAction * act) {
241 this->order=act->order;
243 this->type=ATOMIC_READ;
244 else if (act->is_rmw()) {
245 this->type=ATOMIC_RMW;
246 this->value=act->value;
250 /** The is_synchronizing method should only explore interleavings if:
251 * (1) the operations are seq_cst and don't commute or
252 * (2) the reordering may establish or break a synchronization relation.
253 * Other memory operations will be dealt with by using the reads_from
256 * @param act is the action to consider exploring a reordering.
257 * @return tells whether we have to explore a reordering.
259 bool ModelAction::could_synchronize_with(const ModelAction *act) const
261 //Same thread can't be reordered
262 if (same_thread(act))
265 // Different locations commute
269 // Explore interleavings of seqcst writes/fences to guarantee total
270 // order of seq_cst operations that don't commute
271 if ((could_be_write() || act->could_be_write() || is_fence() || act->is_fence())
272 && is_seqcst() && act->is_seqcst())
275 // Explore synchronizing read/write/fence pairs
276 if (is_acquire() && act->is_release() && (is_read() || is_fence()) &&
277 (act->could_be_write() || act->is_fence()))
280 //lock just released...we can grab lock
281 if ((is_lock() ||is_trylock()) && (act->is_unlock()||act->is_wait()))
284 //lock just acquired...we can fail to grab lock
285 if (is_trylock() && act->is_success_lock())
288 //other thread stalling on lock...we can release lock
289 if (is_unlock() && (act->is_trylock()||act->is_lock()))
292 if (is_trylock() && (act->is_unlock()||act->is_wait()))
295 if ( is_notify() && act->is_wait() )
298 if ( is_wait() && act->is_notify() )
301 // Otherwise handle by reads_from relation
305 bool ModelAction::is_conflicting_lock(const ModelAction *act) const
307 //Must be different threads to reorder
308 if (same_thread(act))
311 //Try to reorder a lock past a successful lock
312 if (act->is_success_lock())
315 //Try to push a successful trylock past an unlock
316 if (act->is_unlock() && is_trylock() && value == VALUE_TRYSUCCESS)
319 //Try to push a successful trylock past a wait
320 if (act->is_wait() && is_trylock() && value == VALUE_TRYSUCCESS)
327 * Create a new clock vector for this action. Note that this function allows a
328 * user to clobber (and leak) a ModelAction's existing clock vector. A user
329 * should ensure that the vector has already either been rolled back
330 * (effectively "freed") or freed.
332 * @param parent A ModelAction from which to inherit a ClockVector
334 void ModelAction::create_cv(const ModelAction *parent)
337 cv = new ClockVector(parent->cv, this);
339 cv = new ClockVector(NULL, this);
342 void ModelAction::set_try_lock(bool obtainedlock) {
344 value=VALUE_TRYSUCCESS;
346 value=VALUE_TRYFAILED;
349 /** @return The Node associated with this ModelAction */
350 Node * ModelAction::get_node() const
352 /* UNINIT actions do not have a Node */
353 ASSERT(!is_uninitialized());
358 * Update the model action's read_from action
359 * @param act The action to read from; should be a write
361 void ModelAction::set_read_from(const ModelAction *act)
364 if (act && act->is_uninitialized())
365 model->assert_bug("May read from uninitialized atomic\n");
369 * Synchronize the current thread with the thread corresponding to the
370 * ModelAction parameter.
371 * @param act The ModelAction to synchronize with
372 * @return True if this is a valid synchronization; false otherwise
374 bool ModelAction::synchronize_with(const ModelAction *act) {
375 if (*this < *act && type != THREAD_JOIN && type != ATOMIC_LOCK)
377 model->check_promises(act->get_tid(), cv, act->cv);
382 bool ModelAction::has_synchronized_with(const ModelAction *act) const
384 return cv->synchronized_since(act);
388 * Check whether 'this' happens before act, according to the memory-model's
389 * happens before relation. This is checked via the ClockVector constructs.
390 * @return true if this action's thread has synchronized with act's thread
391 * since the execution of act, false otherwise.
393 bool ModelAction::happens_before(const ModelAction *act) const
395 return act->cv->synchronized_since(this);
398 /** @brief Print nicely-formatted info about this ModelAction */
399 void ModelAction::print() const
401 const char *type_str, *mo_str;
402 switch (this->type) {
403 case MODEL_FIXUP_RELSEQ:
404 type_str = "relseq fixup";
407 type_str = "thread create";
410 type_str = "thread start";
413 type_str = "thread yield";
416 type_str = "thread join";
419 type_str = "thread finish";
422 type_str = "uninitialized";
425 type_str = "atomic read";
428 type_str = "atomic write";
431 type_str = "atomic rmw";
437 type_str = "atomic rmwr";
440 type_str = "atomic rmwc";
443 type_str = "init atomic";
452 type_str = "trylock";
457 case ATOMIC_NOTIFY_ONE:
458 type_str = "notify one";
460 case ATOMIC_NOTIFY_ALL:
461 type_str = "notify all";
464 type_str = "unknown type";
467 uint64_t valuetoprint=type==ATOMIC_READ?(reads_from!=NULL?reads_from->value:VALUE_NONE):value;
469 switch (this->order) {
470 case std::memory_order_relaxed:
473 case std::memory_order_acquire:
476 case std::memory_order_release:
479 case std::memory_order_acq_rel:
482 case std::memory_order_seq_cst:
490 model_print("(%4d) Thread: %-2d Action: %-13s MO: %7s Loc: %14p Value: %-#18" PRIx64,
491 seq_number, id_to_int(tid), type_str, mo_str, location, valuetoprint);
494 model_print(" Rf: %-3d", reads_from->get_seq_number());
496 model_print(" Rf: ? ");
508 /** @brief Print nicely-formatted info about this ModelAction */
509 unsigned int ModelAction::hash() const
511 unsigned int hash=(unsigned int) this->type;
512 hash^=((unsigned int)this->order)<<3;
514 hash ^= id_to_int(tid) << 6;
518 hash^=reads_from->get_seq_number();