Intel(R) Fortran Language Reference (online version)

Directive Enhanced Compilation 14
c$OMP BARRIER
c
Is one of the following: C (or c), !, or * (see “Syntax Rules for Compiler Directives”).
The BARRIER directive must be encountered by all threads in a team or by none at all. It must
also be encountered in the same order by all threads in a team.
Example
The directive binding rules call for a BARRIER directive to bind to the closest enclosing
PARALLEL directive. In the following example, the BARRIER directive ensures that all threads
have executed the first loop and that it is safe to execute the second loop:
c$OMP PARALLEL
c$OMP DO PRIVATE(i)
DO i = 1, 100
b(i) = i
END DO
c$OMP BARRIER
c$OMP DO PRIVATE(i)
DO i = 1, 100
a(i) = b(101-i)
END DO
c$OMP END PARALLEL
See Also
“Nesting and Binding Rules” for details about directive binding
CRITICAL Directive
The CRITICAL directive restricts access to a block of code to only one thread at a time. It takes
the following form:
c$OMP CRITICAL [(name)]
block
c$OMP END CRITICAL [(name)]
c
Is one of the following: C (or c), !, or * (see “Syntax Rules for Compiler Directives”).
name
Is the name of the critical section.
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