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) :
35 seq_number(ACTION_INITIAL_CLOCK),
39 /* References to NULL atomic variables can end up here */
40 ASSERT(loc || type == MODEL_FIXUP_RELSEQ);
42 Thread *t = thread ? thread : thread_current();
43 this->tid = t->get_id();
46 /** @brief ModelAction destructor */
47 ModelAction::~ModelAction()
50 * We can't free the clock vector:
51 * Clock vectors are snapshotting state. When we delete model actions,
52 * they are at the end of the node list and have invalid old clock
53 * vectors which have already been rolled back to an unallocated state.
61 void ModelAction::copy_from_new(ModelAction *newaction)
63 seq_number = newaction->seq_number;
66 void ModelAction::set_seq_number(modelclock_t num)
68 ASSERT(seq_number == ACTION_INITIAL_CLOCK);
72 bool ModelAction::is_relseq_fixup() const
74 return type == MODEL_FIXUP_RELSEQ;
77 bool ModelAction::is_mutex_op() const
79 return type == ATOMIC_LOCK || type == ATOMIC_TRYLOCK || type == ATOMIC_UNLOCK || type == ATOMIC_WAIT || type == ATOMIC_NOTIFY_ONE || type == ATOMIC_NOTIFY_ALL;
82 bool ModelAction::is_lock() const
84 return type == ATOMIC_LOCK;
87 bool ModelAction::is_wait() const {
88 return type == ATOMIC_WAIT;
91 bool ModelAction::is_notify() const {
92 return type==ATOMIC_NOTIFY_ONE || type==ATOMIC_NOTIFY_ALL;
95 bool ModelAction::is_notify_one() const {
96 return type==ATOMIC_NOTIFY_ONE;
99 bool ModelAction::is_unlock() const
101 return type == ATOMIC_UNLOCK;
104 bool ModelAction::is_trylock() const
106 return type == ATOMIC_TRYLOCK;
109 bool ModelAction::is_success_lock() const
111 return type == ATOMIC_LOCK || (type == ATOMIC_TRYLOCK && value == VALUE_TRYSUCCESS);
114 bool ModelAction::is_failed_trylock() const
116 return (type == ATOMIC_TRYLOCK && value == VALUE_TRYFAILED);
119 bool ModelAction::is_read() const
121 return type == ATOMIC_READ || type == ATOMIC_RMWR || type == ATOMIC_RMW;
124 bool ModelAction::is_write() const
126 return type == ATOMIC_WRITE || type == ATOMIC_RMW || type == ATOMIC_INIT;
129 bool ModelAction::could_be_write() const
131 return is_write() || is_rmwr();
134 bool ModelAction::is_rmwr() const
136 return type == ATOMIC_RMWR;
139 bool ModelAction::is_rmw() const
141 return type == ATOMIC_RMW;
144 bool ModelAction::is_rmwc() const
146 return type == ATOMIC_RMWC;
149 bool ModelAction::is_fence() const
151 return type == ATOMIC_FENCE;
154 bool ModelAction::is_initialization() const
156 return type == ATOMIC_INIT;
159 bool ModelAction::is_acquire() const
162 case std::memory_order_acquire:
163 case std::memory_order_acq_rel:
164 case std::memory_order_seq_cst:
171 bool ModelAction::is_release() const
174 case std::memory_order_release:
175 case std::memory_order_acq_rel:
176 case std::memory_order_seq_cst:
183 bool ModelAction::is_seqcst() const
185 return order==std::memory_order_seq_cst;
188 bool ModelAction::same_var(const ModelAction *act) const
190 return location == act->location;
193 bool ModelAction::same_thread(const ModelAction *act) const
195 return tid == act->tid;
198 void ModelAction::copy_typeandorder(ModelAction * act) {
199 this->type = act->type;
200 this->order = act->order;
203 /** This method changes an existing read part of an RMW action into either:
204 * (1) a full RMW action in case of the completed write or
205 * (2) a READ action in case a failed action.
206 * @todo If the memory_order changes, we may potentially need to update our
209 void ModelAction::process_rmw(ModelAction * act) {
210 this->order=act->order;
212 this->type=ATOMIC_READ;
213 else if (act->is_rmw()) {
214 this->type=ATOMIC_RMW;
215 this->value=act->value;
219 /** The is_synchronizing method should only explore interleavings if:
220 * (1) the operations are seq_cst and don't commute or
221 * (2) the reordering may establish or break a synchronization relation.
222 * Other memory operations will be dealt with by using the reads_from
225 * @param act is the action to consider exploring a reordering.
226 * @return tells whether we have to explore a reordering.
228 bool ModelAction::could_synchronize_with(const ModelAction *act) const
230 //Same thread can't be reordered
231 if (same_thread(act))
234 // Different locations commute
238 // Explore interleavings of seqcst writes to guarantee total order
239 // of seq_cst operations that don't commute
240 if ((could_be_write() || act->could_be_write()) && is_seqcst() && act->is_seqcst())
243 // Explore synchronizing read/write pairs
244 if (is_read() && is_acquire() && act->could_be_write() && act->is_release())
247 // Otherwise handle by reads_from relation
251 bool ModelAction::is_conflicting_lock(const ModelAction *act) const
253 //Must be different threads to reorder
254 if (same_thread(act))
257 //Try to reorder a lock past a successful lock
258 if (act->is_success_lock())
261 //Try to push a successful trylock past an unlock
262 if (act->is_unlock() && is_trylock() && value == VALUE_TRYSUCCESS)
265 //Try to push a successful trylock past a wait
266 if (act->is_wait() && is_trylock() && value == VALUE_TRYSUCCESS)
273 * Create a new clock vector for this action. Note that this function allows a
274 * user to clobber (and leak) a ModelAction's existing clock vector. A user
275 * should ensure that the vector has already either been rolled back
276 * (effectively "freed") or freed.
278 * @param parent A ModelAction from which to inherit a ClockVector
280 void ModelAction::create_cv(const ModelAction *parent)
283 cv = new ClockVector(parent->cv, this);
285 cv = new ClockVector(NULL, this);
288 void ModelAction::set_try_lock(bool obtainedlock) {
290 value=VALUE_TRYSUCCESS;
292 value=VALUE_TRYFAILED;
296 * Update the model action's read_from action
297 * @param act The action to read from; should be a write
298 * @return True if this read established synchronization
300 bool ModelAction::read_from(const ModelAction *act)
304 if (act != NULL && this->is_acquire()) {
305 rel_heads_list_t release_heads;
306 model->get_release_seq_heads(this, &release_heads);
307 int num_heads = release_heads.size();
308 for (unsigned int i = 0; i < release_heads.size(); i++)
309 if (!synchronize_with(release_heads[i])) {
310 model->set_bad_synchronization();
313 return num_heads > 0;
319 * Synchronize the current thread with the thread corresponding to the
320 * ModelAction parameter.
321 * @param act The ModelAction to synchronize with
322 * @return True if this is a valid synchronization; false otherwise
324 bool ModelAction::synchronize_with(const ModelAction *act) {
325 if (*this < *act && type != THREAD_JOIN && type != ATOMIC_LOCK)
327 model->check_promises(act->get_tid(), cv, act->cv);
332 bool ModelAction::has_synchronized_with(const ModelAction *act) const
334 return cv->has_synchronized_with(act->cv);
338 * Check whether 'this' happens before act, according to the memory-model's
339 * happens before relation. This is checked via the ClockVector constructs.
340 * @return true if this action's thread has synchronized with act's thread
341 * since the execution of act, false otherwise.
343 bool ModelAction::happens_before(const ModelAction *act) const
345 return act->cv->synchronized_since(this);
348 /** @brief Print nicely-formatted info about this ModelAction */
349 void ModelAction::print() const
351 const char *type_str, *mo_str;
352 switch (this->type) {
353 case MODEL_FIXUP_RELSEQ:
354 type_str = "relseq fixup";
357 type_str = "thread create";
360 type_str = "thread start";
363 type_str = "thread yield";
366 type_str = "thread join";
369 type_str = "thread finish";
372 type_str = "atomic read";
375 type_str = "atomic write";
378 type_str = "atomic rmw";
384 type_str = "atomic rmwr";
387 type_str = "atomic rmwc";
390 type_str = "init atomic";
399 type_str = "trylock";
402 type_str = "unknown type";
405 uint64_t valuetoprint=type==ATOMIC_READ?(reads_from!=NULL?reads_from->value:VALUE_NONE):value;
407 switch (this->order) {
408 case std::memory_order_relaxed:
411 case std::memory_order_acquire:
414 case std::memory_order_release:
417 case std::memory_order_acq_rel:
420 case std::memory_order_seq_cst:
428 printf("(%4d) Thread: %-2d Action: %-13s MO: %7s Loc: %14p Value: %-#18" PRIx64,
429 seq_number, id_to_int(tid), type_str, mo_str, location, valuetoprint);
432 printf(" Rf: %-3d", reads_from->get_seq_number());
446 /** @brief Print nicely-formatted info about this ModelAction */
447 unsigned int ModelAction::hash() const
449 unsigned int hash=(unsigned int) this->type;
450 hash^=((unsigned int)this->order)<<3;
456 hash^=reads_from->get_seq_number();