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RANDOM: Rewrite seed numbers handling.

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The array of seed numbers makes sense only when OpenMP is used. With
MPI on, the length of seed vector on each MPI process is equal to the
number of OpenMP threads. For no OpenMP, only one seed number per MPI
process is used.

Signed-off-by: Grzegorz Kowal <grzegorz@amuncode.org>
This commit is contained in:
Grzegorz Kowal 2018-02-09 16:44:19 -02:00
parent 56ec194862
commit eef631de50
2 changed files with 28 additions and 47 deletions
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5
src/driver.F90
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@ -308,9 +308,10 @@ program amun
!
call setup_mpi(div(:), per(:), .false.)
! initialize the random number generator
! initialize the random number generator (passes the number of OpenMP threads
! and the current thread number)
!
call initialize_random(nprocs, nproc)
call initialize_random(1, 0)
! initialize geometry modules and print info
!

50
src/random.F90
View File

@ -80,7 +80,7 @@ module random
!
!===============================================================================
!
subroutine initialize_random(nprocs, nproc)
subroutine initialize_random(nthreads, nthread)
! obtain required variables from other modules
!
@ -92,7 +92,7 @@ module random
! subroutine arguments
!
integer, intent(in) :: nprocs, nproc
integer, intent(in) :: nthreads, nthread
! local variables
!
@ -112,9 +112,9 @@ module random
call start_timer(iri)
#endif /* PROFILE */
! set the processor number
! set the thread number
!
kp = nproc
kp = nthread
! obtain the generator type
!
@ -122,7 +122,7 @@ module random
! calculate the number of seeds
!
nseeds = 2 * nprocs
nseeds = nthreads
lseed = nseeds - 1
! allocate seeds for random number generator
@ -138,12 +138,8 @@ module random
seeds(i) = 123456789 * r
end do
case default
call random_number(r)
do i = 0, nprocs - 1
seeds(i) = 123456789 * r
end do
call random_number(r)
do i = nprocs, lseed
r = 0.1234567890123456789
do i = 0, lseed
seeds(i) = 123456789 * r
end do
end select
@ -204,7 +200,7 @@ module random
!
!===============================================================================
!
subroutine set_seeds(np, seed)
subroutine set_seeds(np, nseeds)
! declare all variables as implicit
!
@ -213,7 +209,7 @@ module random
! input arguments
!
integer , intent(in) :: np
integer(kind=4), dimension(0:np-1), intent(in) :: seed
integer(kind=4), dimension(np), intent(in) :: nseeds
! local variables
!
@ -230,18 +226,10 @@ module random
! set the seeds only if the input array and seeds have the same sizes
!
if (np == nseeds) then
seeds(0:lseed) = seed(0:lseed)
else
! if the input array and seeds have different sizes, expand or shrink seeds
!
l = min(lseed, np - 1)
seeds(0:l) = seed(1:l+1)
select case(gentype)
case('random')
l = min(lseed, np - 1)
seeds(0:l) = seed(0:l)
if (l < lseed) then
do i = l + 1, lseed
call random_number(r)
@ -249,17 +237,9 @@ module random
end do
end if
case default
l = nseeds / 2
do i = 0, l - 1
seeds(i) = seed(0)
end do
do i = l, lseed
seeds(i) = seed(np-1)
end do
seeds(l+1:lseed) = seeds(0)
end select
end if
#ifdef PROFILE
! stop accounting time for the random number generator
!
@ -279,7 +259,7 @@ module random
!
!===============================================================================
!
subroutine get_seeds(seed)
subroutine get_seeds(rseeds)
! declare all variables as implicit
!
@ -287,7 +267,7 @@ module random
! output arguments
!
integer(kind=4), dimension(0:lseed), intent(out) :: seed
integer(kind=4), dimension(nseeds), intent(out) :: rseeds
!
!-------------------------------------------------------------------------------
!
@ -297,7 +277,7 @@ module random
call start_timer(iri)
#endif /* PROFILE */
seed(0:lseed) = seeds(0:lseed)
rseeds(1:nseeds) = seeds(0:lseed)
#ifdef PROFILE
! stop accounting time for the random number generator