action.cc

   1 #include <stdio.h>
   2 #define __STDC_FORMAT_MACROS
   3 #include <inttypes.h>
   4
   5 #include "model.h"
   6 #include "action.h"
   7 #include "clockvector.h"
   8 #include "common.h"
   9
  10 ModelAction::ModelAction(action_type_t type, memory_order order, void *loc, uint64_t value) :
  11         type(type),
  12         order(order),
  13         location(loc),
  14         value(value),
  15         reads_from(NULL),
  16         cv(NULL)
  17 {
  18         Thread *t = thread_current();
  19         this->tid = t->get_id();
  20         this->seq_number = model->get_next_seq_num();
  21 }
  22
  23 ModelAction::~ModelAction()
  24 {
  25         if (cv)
  26                 delete cv;
  27 }
  28
  29 bool ModelAction::is_read() const
  30 {
  31         return type == ATOMIC_READ || type == ATOMIC_RMWR || type == ATOMIC_RMW;
  32 }
  33
  34 bool ModelAction::is_write() const
  35 {
  36         return type == ATOMIC_WRITE || type == ATOMIC_RMW || type == ATOMIC_INIT;
  37 }
  38
  39 bool ModelAction::is_rmwr() const
  40 {
  41         return type == ATOMIC_RMWR;
  42 }
  43
  44 bool ModelAction::is_rmw() const
  45 {
  46         return type == ATOMIC_RMW;
  47 }
  48
  49 bool ModelAction::is_rmwc() const
  50 {
  51         return type == ATOMIC_RMWC;
  52 }
  53
  54 bool ModelAction::is_initialization() const
  55 {
  56         return type == ATOMIC_INIT;
  57 }
  58
  59 bool ModelAction::is_acquire() const
  60 {
  61         switch (order) {
  62         case std::memory_order_acquire:
  63         case std::memory_order_acq_rel:
  64         case std::memory_order_seq_cst:
  65                 return true;
  66         default:
  67                 return false;
  68         }
  69 }
  70
  71 bool ModelAction::is_release() const
  72 {
  73         switch (order) {
  74         case std::memory_order_release:
  75         case std::memory_order_acq_rel:
  76         case std::memory_order_seq_cst:
  77                 return true;
  78         default:
  79                 return false;
  80         }
  81 }
  82
  83 bool ModelAction::is_seqcst() const
  84 {
  85         return order==std::memory_order_seq_cst;
  86 }
  87
  88 bool ModelAction::same_var(const ModelAction *act) const
  89 {
  90         return location == act->location;
  91 }
  92
  93 bool ModelAction::same_thread(const ModelAction *act) const
  94 {
  95         return tid == act->tid;
  96 }
  97
  98 void ModelAction::copy_typeandorder(ModelAction * act) {
  99         this->type=act->type;
 100         this->order=act->order;
 101 }
 102
 103 void ModelAction::process_rmw(ModelAction * act) {
 104         this->order=act->order;
 105         if (act->is_rmwc())
 106                 this->type=ATOMIC_READ;
 107         else if (act->is_rmw()) {
 108                 this->type=ATOMIC_RMW;
 109                 this->value=act->value;
 110         }
 111 }
 112
 113 /** The is_synchronizing method should only explore interleavings if:
 114  *  (1) the operations are seq_cst and don't commute or
 115  *  (2) the reordering may establish or break a synchronization relation.
 116  *  Other memory operations will be dealt with by using the reads_from
 117  *  relation.
 118  *
 119  *  @param act is the action to consider exploring a reordering.
 120  *  @return tells whether we have to explore a reordering.
 121  */
 122
 123 bool ModelAction::is_synchronizing(const ModelAction *act) const
 124 {
 125         //Same thread can't be reordered
 126         if (same_thread(act))
 127                 return false;
 128
 129         // Different locations commute
 130         if (!same_var(act))
 131                 return false;
 132
 133         // Explore interleavings of seqcst writes to guarantee total order
 134         // of seq_cst operations that don't commute
 135         if (is_write() && is_seqcst() && act->is_write() && act->is_seqcst())
 136                 return true;
 137
 138         // Explore synchronizing read/write pairs
 139         if (is_read() && is_acquire() && act->is_write() && act->is_release())
 140                 return true;
 141         if (is_write() && is_release() && act->is_read() && act->is_acquire())
 142                 return true;
 143
 144         // Otherwise handle by reads_from relation
 145         return false;
 146 }
 147
 148 void ModelAction::create_cv(const ModelAction *parent)
 149 {
 150         ASSERT(cv == NULL);
 151
 152         if (parent)
 153                 cv = new ClockVector(parent->cv, this);
 154         else
 155                 cv = new ClockVector(NULL, this);
 156 }
 157
 158 void ModelAction::read_from(const ModelAction *act)
 159 {
 160         ASSERT(cv);
 161         if (act->is_release() && this->is_acquire())
 162                 cv->merge(act->cv);
 163         reads_from = act;
 164 }
 165
 166 /**
 167  * Check whether 'this' happens before act, according to the memory-model's
 168  * happens before relation. This is checked via the ClockVector constructs.
 169  * @return true if this action's thread has synchronized with act's thread
 170  * since the execution of act, false otherwise.
 171  */
 172 bool ModelAction::happens_before(const ModelAction *act) const
 173 {
 174         return act->cv->synchronized_since(this);
 175 }
 176
 177 void ModelAction::print(void) const
 178 {
 179         const char *type_str;
 180         switch (this->type) {
 181         case THREAD_CREATE:
 182                 type_str = "thread create";
 183                 break;
 184         case THREAD_START:
 185                 type_str = "thread start";
 186                 break;
 187         case THREAD_YIELD:
 188                 type_str = "thread yield";
 189                 break;
 190         case THREAD_JOIN:
 191                 type_str = "thread join";
 192                 break;
 193         case ATOMIC_READ:
 194                 type_str = "atomic read";
 195                 break;
 196         case ATOMIC_WRITE:
 197                 type_str = "atomic write";
 198                 break;
 199         case ATOMIC_RMW:
 200                 type_str = "atomic rmw";
 201                 break;
 202         case ATOMIC_RMWR:
 203                 type_str = "atomic rmwr";
 204                 break;
 205         case ATOMIC_RMWC:
 206                 type_str = "atomic rmwc";
 207                 break;
 208         case ATOMIC_INIT:
 209                 type_str = "init atomic";
 210                 break;
 211         default:
 212                 type_str = "unknown type";
 213         }
 214
 215         uint64_t valuetoprint=type==ATOMIC_READ?(reads_from!=NULL?reads_from->value:VALUE_NONE):value;
 216
 217         printf("(%3d) Thread: %-2d    Action: %-13s    MO: %d    Loc: %14p    Value: %-12" PRIu64,
 218                         seq_number, id_to_int(tid), type_str, order, location, valuetoprint);
 219         if (reads_from)
 220                 printf(" Rf: %d", reads_from->get_seq_number());
 221         if (cv) {
 222                 printf("\t");
 223                 cv->print();
 224         } else
 225                 printf("\n");
 226 }