4.10 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.