hpx::vector partitions are not easily extendable by applications

[sithhell]

The different partitions one can specify for hpx::vector can not be easily extended by external applications. It would be nice to have that ability.

[hkaiser]

What do you mean by 'extended by the application'?

[sithhell]

How about this:

class my_cool_distribution_policy
{
    // Whatever needs to go there ...
};

hpx::vector<T> v(..., my_cool_distribution_policy());

I don't think this is easily possible at the moment, but please enlighten me.

[gbibek]

l think customizing the distribution policy as per user's need is good idea too.

[hkaiser]

From an discussion on IRC:

[14:30] hkaiser: heller: what would you like to change with such a distribution policy?
[14:30] heller: hkaiser: the partitioning of the data
[14:30] hkaiser: well sure, but which parameters?
[14:30] heller: hkaiser: and where to place what
[14:31] hkaiser: heller: currently those don't support a lot of customization, we wuld need concrete use cases to extend the existing capabilities
[14:31] heller: hkaiser: non uniform sized partitions, for example
[14:31] hkaiser: uhh
[14:31] hkaiser: for symmetric runs?
[14:32] heller: hkaiser: choosing the size of a partition based on some historic data stored in database
[14:32] heller: yup. for example
[14:33] hkaiser: heller: so it's mainly partition sizes you're interested in changing?
[14:33] heller: symmetric runs, heterogeneous work load per element, you name it
[14:33] heller: and *where* they are put
[14:33] hkaiser: ok, so an interface which returns the partition size for a given locality
[14:34] heller: i might want to have more than one partition per locality
[14:34] hkaiser: sure
[14:35] hkaiser: so an interface returning the number of partitions to create for a given locality as well

[sithhell]

Moving this to the next milestone as it requires further discussions and design.

[hkaiser]

This has been fixed by merging #1468