Developing and Porting C and C++ Applications on AIX

9.4. Parallel region construct

The following directive defines a parallel region, which is a region of the program that is to be executed by multiple threads in parallel. This is the fundamental construct that starts parallel execution:

#pragma omp parallel [clause[ [, ]clause] ...] new-line
       structured-block

The clause is one of the following:

• if(scalar-expression)

• private(variable-list)

• firstprivate(variable-list)

• default(shared | none)

• shared(variable-list)

• copyin(variable-list)

• reduction(operator: variable-list)

• num_threads(integer-expression)

For a detailed description of the clauses, see 9.9, “Data-sharing attribute clauses” on page 355.

When a thread encounters a parallel construct, a team of threads is created if one of the following cases ...