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11.10 Implementing PARALLEL construct

  #pragma omp parallel
  {
    body;
  }

becomes

  void subfunction (void *data)
  {
    use data;
    body;
  }

  setup data;
  GOMP_parallel_start (subfunction, &data, num_threads);
  subfunction (&data);
  GOMP_parallel_end ();
  void GOMP_parallel_start (void (*fn)(void *), void *data, unsigned num_threads)

The FN argument is the subfunction to be run in parallel.

The DATA argument is a pointer to a structure used to communicate data in and out of the subfunction, as discussed above with respect to FIRSTPRIVATE et al.

The NUM_THREADS argument is 1 if an IF clause is present and false, or the value of the NUM_THREADS clause, if present, or 0.

The function needs to create the appropriate number of threads and/or launch them from the dock. It needs to create the team structure and assign team ids.

  void GOMP_parallel_end (void)

Tears down the team and returns us to the previous omp_in_parallel() state.