The number of files that are getting written is always less than the number of threads. Logically for me, when I can have 4 threads and the CPU is working at 400%, I was expecting the number of files to be 4 (one each corresponding to every single thread). I don't know if there is a problem with my code or this is how it is supposed to work. The code is as follows:
!!!!!!!! module
module common
use iso_fortran_env
implicit none
integer,parameter:: dp=real64
real(dp):: aa,bb
contains
subroutine evolve(y,yevl)
implicit none
integer(dp),parameter:: id=2
real(dp),intent(in):: y(id)
real(dp),intent(out):: yevl(id)
yevl(1)=y(2)+1.d0-aa*y(1)**2
yevl(2)=bb*y(1)
end subroutine evolve
end module common
use common
implicit none
integer(dp):: iii,iter,i
integer(dp),parameter:: id=2
real(dp),allocatable:: y(:),yt(:)
integer(dp):: OMP_GET_THREAD_NUM, IXD
allocate(y(id)); allocate(yt(id)); y=0.d0; yt=0.d0; bb=0.3d0
!$OMP PARALLEL PRIVATE(iii,iter,y,i,yt) SHARED(bb)
IXD=OMP_GET_THREAD_NUM()
!$OMP DO
do iii=1,20000; print*,iii !! EXPECTED THREADS TO BE OF 5000 ITERATIONS EACH
aa=1.d0+dfloat(iii-1)*0.4d0/80000.d0
loop1: do iter=1,10 !! THE INITIAL CONDITION LOOP
call random_number(y)!! RANDOM INITIALIZATION OF THE VARIABLE
loop2: do i=1,70000 !! ITERATION OF THE SYSTEM
call evolve(y,yt)
y=yt
enddo loop2 !! END OF SYSTEM ITERATION
write(IXD+1,*)aa,yt !!! WRITING FILE CORRESPONDING TO EACH THREAD
enddo loop1 !!INITIAL CONDITION ITERATION DONE
enddo
!$OMP ENDDO
!$OMP END PARALLEL
end
Is this behavior resulting from some race issue in the code? The code compiles and executes just fine without any warnings or errors with ifort version 13.1.0 on ubuntu. Thanks a bunch for any comments or suggestions.
The variable IXD should be explicitely declared as private to make sure every thread has an own copy of it. Changing the line(s)
!$OMP PARALLEL PRIVATE(iii,iter,y,i,yt) SHARED(bb)
IXD=OMP_GET_THREAD_NUM()
to
!$OMP PARALLEL PRIVATE(iii,iter,y,i,yt,ixd) SHARED(bb)
IXD=OMP_GET_THREAD_NUM()
solves the problem.