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::upgrade_rmw(ModelAction * act) {
  99         ASSERT(is_read());
 100         ASSERT(act->is_rmw());
 101         //Upgrade our type to the act's type
 102         this->type=act->type;
 103         this->order=act->order;
 104         this->value=act->value;
 105 }
 106
 107 /** The is_synchronizing method should only explore interleavings if:
 108  *  (1) the operations are seq_cst and don't commute or
 109  *  (2) the reordering may establish or break a synchronization relation.
 110  *  Other memory operations will be dealt with by using the reads_from
 111  *  relation.
 112  *
 113  *  @param act is the action to consider exploring a reordering.
 114  *  @return tells whether we have to explore a reordering.
 115  */
 116
 117 bool ModelAction::is_synchronizing(const ModelAction *act) const
 118 {
 119         //Same thread can't be reordered
 120         if (same_thread(act))
 121                 return false;
 122
 123         // Different locations commute
 124         if (!same_var(act))
 125                 return false;
 126
 127         // Explore interleavings of seqcst writes to guarantee total order
 128         // of seq_cst operations that don't commute
 129         if (is_write() && is_seqcst() && act->is_write() && act->is_seqcst())
 130                 return true;
 131
 132         // Explore synchronizing read/write pairs
 133         if (is_read() && is_acquire() && act->is_write() && act->is_release())
 134                 return true;
 135         if (is_write() && is_release() && act->is_read() && act->is_acquire())
 136                 return true;
 137
 138         // Otherwise handle by reads_from relation
 139         return false;
 140 }
 141
 142 void ModelAction::create_cv(const ModelAction *parent)
 143 {
 144         ASSERT(cv == NULL);
 145
 146         if (parent)
 147                 cv = new ClockVector(parent->cv, this);
 148         else
 149                 cv = new ClockVector(NULL, this);
 150 }
 151
 152 void ModelAction::read_from(const ModelAction *act)
 153 {
 154         ASSERT(cv);
 155         if (act->is_release() && this->is_acquire())
 156                 cv->merge(act->cv);
 157         reads_from = act;
 158 }
 159
 160 /**
 161  * Check whether 'this' happens before act, according to the memory-model's
 162  * happens before relation. This is checked via the ClockVector constructs.
 163  * @return true if this action's thread has synchronized with act's thread
 164  * since the execution of act, false otherwise.
 165  */
 166 bool ModelAction::happens_before(const ModelAction *act) const
 167 {
 168         return act->cv->synchronized_since(this);
 169 }
 170
 171 void ModelAction::print(void) const
 172 {
 173         const char *type_str;
 174         switch (this->type) {
 175         case THREAD_CREATE:
 176                 type_str = "thread create";
 177                 break;
 178         case THREAD_START:
 179                 type_str = "thread start";
 180                 break;
 181         case THREAD_YIELD:
 182                 type_str = "thread yield";
 183                 break;
 184         case THREAD_JOIN:
 185                 type_str = "thread join";
 186                 break;
 187         case ATOMIC_READ:
 188                 type_str = "atomic read";
 189                 break;
 190         case ATOMIC_WRITE:
 191                 type_str = "atomic write";
 192                 break;
 193         case ATOMIC_RMW:
 194                 type_str = "atomic rmw";
 195                 break;
 196         case ATOMIC_RMWR:
 197                 type_str = "atomic rmwr";
 198                 break;
 199         case ATOMIC_RMWC:
 200                 type_str = "atomic rmwc";
 201                 break;
 202         case ATOMIC_INIT:
 203                 type_str = "init atomic";
 204                 break;
 205         default:
 206                 type_str = "unknown type";
 207         }
 208
 209         uint64_t valuetoprint=type==ATOMIC_READ?reads_from->value:value;
 210
 211         printf("(%3d) Thread: %-2d    Action: %-13s    MO: %d    Loc: %14p    Value: %-12" PRIu64,
 212                         seq_number, id_to_int(tid), type_str, order, location, valuetoprint);
 213         if (reads_from)
 214                 printf(" Rf: %d", reads_from->get_seq_number());
 215         if (cv) {
 216                 printf("\t");
 217                 cv->print();
 218         } else
 219                 printf("\n");
 220 }