OpenMP-Examples/tasking/sources/task_dep.4b.f90
2022-11-04 09:35:42 -07:00

48 lines
1.0 KiB
Fortran

! @@name: task_dep.4b
! @@type: F-free
! @@operation: compile
! @@expect: success
! @@version: omp_5.1
subroutine task_dep(N)
implicit none
integer :: N
integer :: i, v, R
integer, external :: f
!$omp parallel private(i,v) shared(R)
!$omp single
!! CASE 1: tasks with inout dependence type.
!! tasks are serialized here.
R = 0
do i = 1, N
!$omp task depend(inout: R) !! T1
v = f(i)
R = R + v
!$omp end task
end do
!$omp task depend(in: R) !! T2
print *, "result is ", R
!$omp end task
!$omp taskwait !! to avoid race with CASE 2
!! CASE 2: tasks with inoutset dependence type.
!! tasks are executed concurrently.
R = 0
do i = 1, N
!$omp task depend(inoutset: R) !! T3
v = f(i)
!$omp atomic
R = R + v
!$omp end task
end do
!$omp task depend(in: R) !! T4
print *, "result is ", R
!$omp end task
!$omp end single
!$omp end parallel
end subroutine