/*
* @@name:	nestable_lock.1c
* @@type:	C
* @@compilable:	yes
* @@linkable:	no
* @@expect:	success
*/
#include <omp.h>
typedef struct {
      int a,b;
      omp_nest_lock_t lck; } pair;

int work1();
int work2();
int work3();
void incr_a(pair *p, int a)
{
  /* Called only from incr_pair, no need to lock. */
  p->a += a;
}
void incr_b(pair *p, int b)
{
  /* Called both from incr_pair and elsewhere, */
  /* so need a nestable lock. */

  omp_set_nest_lock(&p->lck);
  p->b += b;
  omp_unset_nest_lock(&p->lck);
}
void incr_pair(pair *p, int a, int b)
{
  omp_set_nest_lock(&p->lck);
  incr_a(p, a);
  incr_b(p, b);
  omp_unset_nest_lock(&p->lck);
}
void nestlock(pair *p)
{
  #pragma omp parallel sections
  {
    #pragma omp section
      incr_pair(p, work1(), work2());
    #pragma omp section
      incr_b(p, work3());
  }
}