source: CIVL/examples/pthread/cprover/10_fmaxsym_cas_true.c@ 1aaefd4

#include <pthread.h>

#define assume(e) __VERIFIER_assume(e)
#define assert(e) { if(!(e)) { ERROR: goto ERROR; (void)0; } }

#define WORKPERTHREAD 2
#define THREADSMAX 3
volatile int max = 0x80000000;

int storage[WORKPERTHREAD*THREADSMAX];

void __VERIFIER_atomic_CAS(
  volatile int *v,
  int e,
  int u,
  int *r)
{
        if(*v == e)
        {
                *v = u, *r = 1;
        }
        else
        {
                *r = 0;
        }
}

inline void findMax(int offset){
        int i;
        int e;
        int c; 
        int cret;

        for(i = offset; i < offset+WORKPERTHREAD; i++) {
                e = storage[i];

                while(1){
                        c = max;
                        if(e > c){
                                __VERIFIER_atomic_CAS(&max,c,e,&cret);
                                if(cret){
                                        break;
                                }
                        }else{
                                break;
                        }
                }

                assert(e <= max);
        }
}

void* thr1(void* arg) {
        int offset;

        assume(offset % WORKPERTHREAD == 0 && offset >= 0 && offset < WORKPERTHREAD*THREADSMAX);
        //assume(offset < WORKPERTHREAD && offset >= 0 && offset < WORKPERTHREAD*THREADSMAX);

        findMax(offset);

  return 0;
}

int main(){
  pthread_t t;

        while(1) { pthread_create(&t, 0, thr1, 0); }
}