action.cc

   1 #include <stdio.h>
   2 #define __STDC_FORMAT_MACROS
   3 #include <inttypes.h>
   4 #include <vector>
   5
   6 #include "model.h"
   7 #include "action.h"
   8 #include "clockvector.h"
   9 #include "common.h"
  10
  11 ModelAction::ModelAction(action_type_t type, memory_order order, void *loc, uint64_t value) :
  12         type(type),
  13         order(order),
  14         location(loc),
  15         value(value),
  16         reads_from(NULL),
  17         cv(NULL)
  18 {
  19         Thread *t = thread_current();
  20         this->tid = t->get_id();
  21         this->seq_number = model->get_next_seq_num();
  22 }
  23
  24 ModelAction::~ModelAction()
  25 {
  26         if (cv)
  27                 delete cv;
  28 }
  29
  30 void ModelAction::copy_from_new(ModelAction *newaction) {
  31         seq_number=newaction->seq_number;
  32 }
  33
  34 bool ModelAction::is_mutex_op() const {
  35         return type == ATOMIC_LOCK || type == ATOMIC_TRYLOCK || type == ATOMIC_UNLOCK;
  36 }
  37
  38 bool ModelAction::is_lock() const {
  39         return type == ATOMIC_LOCK;
  40 }
  41
  42 bool ModelAction::is_unlock() const {
  43         return type == ATOMIC_UNLOCK;
  44 }
  45
  46 bool ModelAction::is_trylock() const {
  47         return type == ATOMIC_TRYLOCK;
  48 }
  49
  50 bool ModelAction::is_success_lock() const {
  51         return type == ATOMIC_LOCK || (type == ATOMIC_TRYLOCK && value == VALUE_TRYSUCCESS);
  52 }
  53
  54 bool ModelAction::is_failed_trylock() const {
  55         return (type == ATOMIC_TRYLOCK && value == VALUE_TRYFAILED);
  56 }
  57
  58 bool ModelAction::is_read() const
  59 {
  60         return type == ATOMIC_READ || type == ATOMIC_RMWR || type == ATOMIC_RMW;
  61 }
  62
  63 bool ModelAction::is_write() const
  64 {
  65         return type == ATOMIC_WRITE || type == ATOMIC_RMW || type == ATOMIC_INIT;
  66 }
  67
  68 bool ModelAction::is_rmwr() const
  69 {
  70         return type == ATOMIC_RMWR;
  71 }
  72
  73 bool ModelAction::is_rmw() const
  74 {
  75         return type == ATOMIC_RMW;
  76 }
  77
  78 bool ModelAction::is_rmwc() const
  79 {
  80         return type == ATOMIC_RMWC;
  81 }
  82
  83 bool ModelAction::is_fence() const
  84 {
  85         return type == ATOMIC_FENCE;
  86 }
  87
  88 bool ModelAction::is_initialization() const
  89 {
  90         return type == ATOMIC_INIT;
  91 }
  92
  93 bool ModelAction::is_acquire() const
  94 {
  95         switch (order) {
  96         case std::memory_order_acquire:
  97         case std::memory_order_acq_rel:
  98         case std::memory_order_seq_cst:
  99                 return true;
 100         default:
 101                 return false;
 102         }
 103 }
 104
 105 bool ModelAction::is_release() const
 106 {
 107         switch (order) {
 108         case std::memory_order_release:
 109         case std::memory_order_acq_rel:
 110         case std::memory_order_seq_cst:
 111                 return true;
 112         default:
 113                 return false;
 114         }
 115 }
 116
 117 bool ModelAction::is_seqcst() const
 118 {
 119         return order==std::memory_order_seq_cst;
 120 }
 121
 122 bool ModelAction::same_var(const ModelAction *act) const
 123 {
 124         return location == act->location;
 125 }
 126
 127 bool ModelAction::same_thread(const ModelAction *act) const
 128 {
 129         return tid == act->tid;
 130 }
 131
 132 void ModelAction::copy_typeandorder(ModelAction * act) {
 133         this->type=act->type;
 134         this->order=act->order;
 135 }
 136
 137 /** This method changes an existing read part of an RMW action into either:
 138  *  (1) a full RMW action in case of the completed write or
 139  *  (2) a READ action in case a failed action.
 140  * @todo  If the memory_order changes, we may potentially need to update our
 141  * clock vector.
 142  */
 143 void ModelAction::process_rmw(ModelAction * act) {
 144         this->order=act->order;
 145         if (act->is_rmwc())
 146                 this->type=ATOMIC_READ;
 147         else if (act->is_rmw()) {
 148                 this->type=ATOMIC_RMW;
 149                 this->value=act->value;
 150         }
 151 }
 152
 153 /** The is_synchronizing method should only explore interleavings if:
 154  *  (1) the operations are seq_cst and don't commute or
 155  *  (2) the reordering may establish or break a synchronization relation.
 156  *  Other memory operations will be dealt with by using the reads_from
 157  *  relation.
 158  *
 159  *  @param act is the action to consider exploring a reordering.
 160  *  @return tells whether we have to explore a reordering.
 161  */
 162 bool ModelAction::is_synchronizing(const ModelAction *act) const
 163 {
 164         //Same thread can't be reordered
 165         if (same_thread(act))
 166                 return false;
 167
 168         // Different locations commute
 169         if (!same_var(act))
 170                 return false;
 171
 172         // Explore interleavings of seqcst writes to guarantee total order
 173         // of seq_cst operations that don't commute
 174         if (is_write() && is_seqcst() && act->is_write() && act->is_seqcst())
 175                 return true;
 176
 177         // Explore synchronizing read/write pairs
 178         if (is_read() && is_acquire() && act->is_write() && act->is_release())
 179                 return true;
 180         if (is_write() && is_release() && act->is_read() && act->is_acquire())
 181                 return true;
 182
 183         // Otherwise handle by reads_from relation
 184         return false;
 185 }
 186
 187 bool ModelAction::is_conflicting_lock(const ModelAction *act) const
 188 {
 189         //Must be different threads to reorder
 190         if (same_thread(act))
 191                 return false;
 192
 193         //Try to reorder a lock past a successful lock
 194         if (act->is_success_lock())
 195                 return true;
 196
 197         //Try to push a successful trylock past an unlock
 198         if (act->is_unlock() && is_trylock() && value == VALUE_TRYSUCCESS)
 199                 return true;
 200
 201         return false;
 202 }
 203
 204 void ModelAction::create_cv(const ModelAction *parent)
 205 {
 206         if (cv)
 207                 delete cv;
 208
 209         if (parent)
 210                 cv = new ClockVector(parent->cv, this);
 211         else
 212                 cv = new ClockVector(NULL, this);
 213 }
 214
 215 void ModelAction::set_try_lock(bool obtainedlock) {
 216         if (obtainedlock)
 217                 value=VALUE_TRYSUCCESS;
 218         else
 219                 value=VALUE_TRYFAILED;
 220 }
 221
 222 /** Update the model action's read_from action */
 223 void ModelAction::read_from(const ModelAction *act)
 224 {
 225         ASSERT(cv);
 226         reads_from = act;
 227         if (act != NULL && this->is_acquire()) {
 228                 rel_heads_list_t release_heads;
 229                 model->get_release_seq_heads(this, &release_heads);
 230                 for (unsigned int i = 0; i < release_heads.size(); i++)
 231                         synchronize_with(release_heads[i]);
 232         }
 233 }
 234
 235 /**
 236  * Synchronize the current thread with the thread corresponding to the
 237  * ModelAction parameter.
 238  * @param act The ModelAction to synchronize with
 239  */
 240 void ModelAction::synchronize_with(const ModelAction *act) {
 241         ASSERT(*act < *this || type == THREAD_JOIN || type == ATOMIC_LOCK );
 242         model->check_promises(cv, act->cv);
 243         cv->merge(act->cv);
 244 }
 245
 246 bool ModelAction::has_synchronized_with(const ModelAction *act) const
 247 {
 248         return cv->has_synchronized_with(act->cv);
 249 }
 250
 251 /**
 252  * Check whether 'this' happens before act, according to the memory-model's
 253  * happens before relation. This is checked via the ClockVector constructs.
 254  * @return true if this action's thread has synchronized with act's thread
 255  * since the execution of act, false otherwise.
 256  */
 257 bool ModelAction::happens_before(const ModelAction *act) const
 258 {
 259         return act->cv->synchronized_since(this);
 260 }
 261
 262 void ModelAction::print(void) const
 263 {
 264         const char *type_str, *mo_str;
 265         switch (this->type) {
 266         case THREAD_CREATE:
 267                 type_str = "thread create";
 268                 break;
 269         case THREAD_START:
 270                 type_str = "thread start";
 271                 break;
 272         case THREAD_YIELD:
 273                 type_str = "thread yield";
 274                 break;
 275         case THREAD_JOIN:
 276                 type_str = "thread join";
 277                 break;
 278         case THREAD_FINISH:
 279                 type_str = "thread finish";
 280                 break;
 281         case ATOMIC_READ:
 282                 type_str = "atomic read";
 283                 break;
 284         case ATOMIC_WRITE:
 285                 type_str = "atomic write";
 286                 break;
 287         case ATOMIC_RMW:
 288                 type_str = "atomic rmw";
 289                 break;
 290         case ATOMIC_FENCE:
 291                 type_str = "fence";
 292                 break;
 293         case ATOMIC_RMWR:
 294                 type_str = "atomic rmwr";
 295                 break;
 296         case ATOMIC_RMWC:
 297                 type_str = "atomic rmwc";
 298                 break;
 299         case ATOMIC_INIT:
 300                 type_str = "init atomic";
 301                 break;
 302         case ATOMIC_LOCK:
 303                 type_str = "lock";
 304                 break;
 305         case ATOMIC_UNLOCK:
 306                 type_str = "unlock";
 307                 break;
 308         case ATOMIC_TRYLOCK:
 309                 type_str = "trylock";
 310                 break;
 311         default:
 312                 type_str = "unknown type";
 313         }
 314
 315         uint64_t valuetoprint=type==ATOMIC_READ?(reads_from!=NULL?reads_from->value:VALUE_NONE):value;
 316
 317         switch (this->order) {
 318         case std::memory_order_relaxed:
 319                 mo_str = "relaxed";
 320                 break;
 321         case std::memory_order_acquire:
 322                 mo_str = "acquire";
 323                 break;
 324         case std::memory_order_release:
 325                 mo_str = "release";
 326                 break;
 327         case std::memory_order_acq_rel:
 328                 mo_str = "acq_rel";
 329                 break;
 330         case std::memory_order_seq_cst:
 331                 mo_str = "seq_cst";
 332                 break;
 333         default:
 334                 mo_str = "unknown";
 335                 break;
 336         }
 337
 338         printf("(%3d) Thread: %-2d   Action: %-13s   MO: %7s  Loc: %14p  Value: %-12" PRIu64,
 339                         seq_number, id_to_int(tid), type_str, mo_str, location, valuetoprint);
 340         if (is_read()) {
 341                 if (reads_from)
 342                         printf(" Rf: %d", reads_from->get_seq_number());
 343                 else
 344                         printf(" Rf: ?");
 345         }
 346         if (cv) {
 347                 printf("\t");
 348                 cv->print();
 349         } else
 350                 printf("\n");
 351 }