OpenMP private variable initialization

[Tobias Burnus]

MARGUINAUD Philippe wrote:
> I have a problem with the initialization of a private variable in an
> OpenMP loop. I do not know whether this is really a bug, but I would
> have expected a different behaviour.
>
> TYPE TA
>    INTEGER :: ILMESS = 1024
> END TYPE
>
> TYPE (TA) :: YA
>
> !$OMP PARALLEL PRIVATE (YA)
>     PRINT *, YA%ILMESS
> !$OMP END PARALLEL

The OpenMP 3.1 specification states in "2.9.3.3 private clause" (in the 
"Fortran" block, not the last sentence):

"A new list item of the same type is allocated once for each implicit 
task in the parallel region, or for each task generated by a task 
construct, if the construct references the list item in any statement. 
The initial value of the new list item is undefined."

See http://www.openmp.org/mp-documents/OpenMP3.1.pdf page 96 (= 104 page 
in the PDF)


The "firstprivate" clause, mentioned by Arjen, states (2.9.3.4, page 98 
(p.106)):

"The firstprivate clause declares one or more list items to be private 
to a task, and initializes each of them with the value that the 
corresponding original item has when the construct is encountered."

Tobias