benchmarks/checkfence/dekker/dekker-fences.c.in

   1 #include "lsl_protos.h"
   2 /*
   3  * Dekker's critical section algorithm, implemented with fences.
   4  *
   5  * URL:
   6  *   http://www.justsoftwaresolutions.co.uk/threading/
   7  */
   8
   9
  10 int flag0, flag1;
  11 int turn;
  12
  13 int var = 0;
  14
  15 void p0() {
  16         flag0 = 1;
  17
  18         while (flag1) {
  19                 if (turn != 0) {
  20                         flag0=0;
  21                         while (turn != 0) {
  22                                 lsl_assume(false);
  23                         }
  24                         flag0=1;
  25                 } else {
  26                                 lsl_assume(false);
  27                 }
  28         }
  29
  30         // critical section
  31         var=1;
  32
  33         turn=1;
  34         flag0=0;
  35 }
  36
  37 void p1() {
  38         flag1=1;
  39
  40         while (flag0) {
  41                 if (turn != 1) {
  42                         flag1=0;
  43                         while (turn!=1) {
  44                                 lsl_assume(false);
  45                         }
  46                         flag1=1;
  47                 } else {
  48                                 lsl_assume(false);
  49                 }
  50         }
  51         // critical section
  52         var=2;
  53         turn=0;
  54         flag1=0;
  55 }
  56
  57 void init() {
  58         flag0=0;
  59         flag1=0;
  60         turn=0;
  61 }
  62
  63 void p0l() {
  64         int i;
  65         for(i=0;i<PROBLEMSIZE;i++) {
  66                 p0();
  67         }
  68 }
  69
  70 void p1l() {
  71         int i;
  72         for(i=0;i<PROBLEMSIZE;i++) {
  73                 p1();
  74         }
  75 }