2.4.3 single Construct
The single directive identifies a construct that specifies that the associated structured block is executed by only one thread in the team (not necessarily the master thread). The syntax of the single directive is as follows:
#pragma omp single [clause[[,] clause] ...] new-line structured-block
The clause is one of the following:
There is an implicit barrier after the single construct unless a nowait clause is specified.
Restrictions to the single directive are as follows:
Only a single nowait clause can appear on a single directive.
The copyprivate clause must not be used with the nowait clause.