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