# Fortran OpenMP parallelization and writing in multiple files.

1. Aug 8, 2012

### eleteroboltz

Hello.

I'm attempting to write some data in different files (each thread write in each file), but I'm getting an error saying: 'File already opened in another unit'. I'm using the function OMP_get_thread_num() from OpenMP library in order to open individual files in individual threads.

Code (Text):

!$OMP PARALLEL DEFAULT(PRIVATE) SHARED(PeVet,num,eta,xi,p) FIRSTPRIVATE(Temp,Told) !$OMP DO
DO q=1,5
Pe = PeVet(q)

WRITE(FileName,'(a,i4.4,a,i4.4,a,i2.1,a)') 'Velocity-Imax',Imax,'Jmax',Jmax,'Kn',p,'.dat'

DO j=1,jmax
ud(j)= (3.d0/2.d0)*(1.d0+8*Kn*bV-eta(j)**2)/(1.d0+12*Kn*bV)
END DO
END DO
!$OMP END DO !$OMP END PARALLEL

I don't know what I'm doing wrong...

Last edited: Aug 8, 2012
2. Aug 8, 2012

### gsal

It looks like the error is meaningful, isn't it?

I mean, you may be making sure that the unit number is different in every thread, but it does not look like you are making sure that the file name become different....in other words, it looks like you open the file the first time around from the first thread that gets there...and THEN, you are attempting to open the same file from another thread with a different unit number....follow?

are you trying to write to different files or the same? or what?

3. Aug 8, 2012

### eleteroboltz

Gsal, you are totally right.

Thank you