fortran について書きます。

Fortran2008 で導入された coArray 機能に対する本家からの批判

coArray Fortran 2.0

In our view, both Numrich and Reid's original design and the coarray extensions proposed for Fortran 2008, suffer from the following shortcomings:

  1. There is no support for processor subsets; for instance, coarrays must be allocated over all images.
  2. Coarrays must be declared as global variables; one cannot dynamically allocate a coarray into a locally scoped variable.
  3. The coarray extensions lack any notion of global pointers, which are essential for creating and manipulating any kind of linked data structure.
  4. Reliance on named critical sections for mutual exclusion hinders scalable parallelism by associating mutual exclusion with code regions rather than data objects.
  5. Fortran 2008's sync images statement doesn't provide a safe synchronization space. As a result, synchronization operations in user's code that are pending when a library call is made can interfere with synchronization in the library call.
  6. There are no mechanisms to avoid or tolerate latency when manipulating data on remote images.
  7. There is no support for collective communication.

Numerich の著作。もうすぐ出る新刊。