[Omp] A question about threadprivate

[Meadows, Lawrence F]

I think that the standard specifies what you expect in the first
example. It makes no guarantee about the second example.

-----Original Message-----
From: omp-bounces at openmp.org [mailto:omp-bounces at openmp.org] On Behalf
Of Marina Kraeva
Sent: Wednesday, April 11, 2007 9:16 AM
To: omp at openmp.org
Subject: [Omp] A question about threadprivate

Hello,

Could you please share your opinion on what will happen in the following

two small examples.

In the OpenMP API 2.5 (and in the earlier versions) it is said:
"The values of data in the threadprivate objects of threads other than 
the initial thread are guaranteed to persist between two consecutive 
active parallel regions only if all the following conditions hold:
* Neither parallel region is nested inside another parallel region..."


According to API, is it guaranteed that in the following example the 
values of 'i' will persist, so array will have values (0,1,2,3)?

int i,array(0:3)
threadprivate(i)
!$omp parallel num_threads(4)
	i=omp_get_thread_num()
	!$omp parallel num_threads(2)
		... ('i' is not referenced)
	!$omp end parallel
!$omp end parallel

!$omp parallel num_threads(4) shared(array)
	array(omp_get_thread_num())=i
!$omp end parallel



What if inside the nested parallel region 'i' was modified:

int i,array(0:3)
threadprivate(i)
!$omp parallel num_threads(4)
	i=omp_get_thread_num()
	!$omp parallel num_threads(2)
                i=-omp_get_thread_num()
	!$omp end parallel
!$omp end parallel

!$omp parallel num_threads(4) shared(array)
	array(omp_get_thread_num())=i
!$omp end parallel

Is it guaranteed, that array still will have values (0,1,2,3)?

Thank you!
Marina Kraeva.
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