Accsessing data from another image

[abhimodak]

Hi

I think this is novice-level question in Co-Array usage.

The test program below crashes...What am I missing? If the lines printing the variable OBJ from different imagesare commented out, it works. Thus, the bounds can be accessed and printed but not the values.

Abhi


=========

[fortran]      Program Test
         
         Implicit None
         
         Type Base
            Integer, Allocatable :: M(:)
         End Type Base
         Type(Base) :: OBJ

         Integer :: myImageNum
         Integer :: is(1), ie(1)
         Integer :: i, n
         
         myImageNum = THIS_IMAGE()
         is(1) = myImageNum; ie(1) = myImageNum+1
         Allocate(OBJ%M(is(1):ie(1)))
         SYNC ALL
         
         do i=is(1),ie(1)
            OBJ%M(i) = 10*myImageNum + i*i
            !print *, THIS_IMAGE(), i, OBJ%M(i)
         end do
         
         SYNC ALL

         if (myImageNum == 1) then
            do n=1,NUM_IMAGES()
               is = LBOUND(OBJ%M); ie = UBOUND(OBJ%M)
               print *, is(1), ie(1)
               do i=is(1),ie(1)
                  print *, OBJ%M(i)
               end do
            end do
         end if
         
         SYNC ALL
         
         DeAllocate(OBJ%M)
         
      End Program Test[/fortran]

[Steven_L_Intel1]

In the compiler release notes section on Coarrays, there is a list of features known to not work. One of them is:

Coarrays of derived type where the type contains an ultimate component that is ALLOCATABLE or POINTER

You have coarray OBJ which is of derived type with an ultimate ALLOCATABLE component, and are running into this problem. Some aspects of it may work, others do not.

While your program doesn't quite do this, another feature listed as not working is:

Output (WRITE, PRINT, etc.) of an array slice of a coarray referencing another image. A whole array reference, or a single element works.

This will be resolved in a future version - we apologize for the inconvenience.

[abhimodak]

Oops. Thanks and my sincere apologies, Steve,for not reading the release notes first. It is very good that IVF is putting in the CoArrays.

Abhi

[abhimodak]

Hi

As per the release notes of update 6 I thought that this will work. However, it does not.

If I replace the print out inside the do loop to "print *, OBJ%M" i.e whole-array statement it works (as mentioned in the release note". However, as is i.e. referencing an element does not work.

Also, no matter which way I do the above, the program seems to crash. That is, I get "program has stopped working" dialogue pops up.

Did I mistakenly assume that this issue was fixed by update 6?

Abhi

[Steven_L_Intel1]

I too would have thought this should work. I'll let the developers know.

I find that the results are unpredictable. In tests I did, sometimes it would work, sometimes I'd get zero values and sometimes the processes would go CPU bound. This was with either the whole array or elements. Escalated as DPD200173725.

[Steven_L_Intel1]

I am told that this is fixed for an update later this year, probably October.