source: CIVL/examples/omp/transform/DRB028_manual_transform.cvl@ 7d77e64

/* Manually transformed CIVL-C code for the openMP data race benchmakr
   028 example.
*/
/* 
tmp should be annotated as private to avoid race condition.
Data race pairs: tmp@65:5 vs. tmp@66:12
                 tmp@65:5 vs. tmp@65:5
*/

/*  
###############################
######  Origianl program ######

#include <stdlib.h>
#include <stdio.h>
int main(int argc, char* argv[])
{
  int i;
  int tmp;
  int len=100;
  int a[100];
  for (i=0;i<len;i++)
    a[i]=i;

#pragma omp parallel for
  for (i=0;i<len;i++)
  {
    tmp =a[i]+i;
    a[i] = tmp;
  }

  printf("a[50]=%d\n", a[50]);
  return 0;
}
###############################
*/
#include<stdio.h>
#include<mem.cvh>
#include<civl-omp.cvh>

#ifndef NTHREADS 
#define NTHREADS 10
#endif

 /*  Eventually these two sets shall be stored in $omp_team locally.
  */
$mem reads[NTHREADS], writes[NTHREADS];

 /*@ executes_when \true;
   @ depends_on \nothing;
  */
void capture_start(int tid);

 /*@ executes_when \true;
   @ depends_on \nothing;
  */
void capture_end(int tid);

 /*@ executes_when \true;
   @ depends_on \nothing;
  */
void check_data_race();

int main() {
  int i;
  int tmp;
  int len=100;
  int a[100];
  for (i=0;i<len;i++)
    a[i]=i;
  
  $omp_gteam gteam = $omp_gteam_create($here, NTHREADS);
  
  // translation of "parallel"
  $parfor (int _tid : 0 .. NTHREADS-1) {
    $local_start();
    $omp_team team = $omp_team_create($here, gteam, _tid);
    // translation of "for":
    $domain loop_domain = ($domain(1)){0 .. len-1};
    $domain(1) my_iters = ($domain(1))$omp_arrive_loop(team, 0, loop_domain, ROUND_ROBIN);

    // original loop-body:
    capture_start(_tid); // start monitoring
    $for (int i : my_iters) {
      tmp = a[i]+i;
      a[i] = tmp;
    }
    capture_end(_tid);                  // end monitoring
    $barrier_call(team->barrier);       // implicit at end of parallel region
    $local_end(); 
    if (_tid == 0)
      check_data_race();
    $omp_team_destroy(team);
  }
  
  printf("a[50]=%d\n", a[50]);
  $omp_gteam_destroy(gteam);
}


void capture_start(int tid) {
  $read_set_push();$write_set_push();
}

void capture_end(int tid) {
  $mem mr = $read_set_pop();
  $mem mw = $write_set_pop();

  reads[tid] = mr; 
  writes[tid] = mw;
}

void check_data_race() {
  for (int i = 0; i < NTHREADS; i++)
    for (int j = i+1; j < NTHREADS; j++) {
      $mem mr_i = reads[i];
      $mem mw_j = writes[j];
      $mem out_i, out_j;
      _Bool no_race = $mem_no_intersect(mr_i, mw_j, &out_i, &out_j);

      if (no_race)
        continue;
      $assert(no_race, "%p read by thread %d intersects %p written by thread %d\n",
              out_i, i, out_j, j);
    } 
}