Add a function which returns the number of running instances

[ouuan]

Feature request: Add a function which returns the number of running instances. (In fact, I only want to know if one instance is the only running instance.)

This is helpful if you want to behave differently on different number of instances.

My actual need is described in cpeditor/cpeditor#131, if you are interested in where this feature is useful.

[ouuan]

Just read the source codes, it seems that what I need is inst->primary + inst->secondary.

UPD: No, inst->secondary is not reduced when a secondary instance closes.

[itay-grudev]

Yhea. inst->secondary is used just to generate a unique identifier. It can't be used for counting,=.

[ouuan]

Here's a solution:

#91 (comment)

But I'm not familiar with it, I hope someone else could implement it, thanks in advance!

[itay-grudev]

@ouuan I really appreciate your effort. When I have some more free time I will consider implementing it, but it may be a while as my schedule is really packed right now.