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