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