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