Refine resource's queue discipline

[Enchufa2]

• Add priorities.
• Preemption?

[Bart6114]

ideally different levels of priorities
where a higher "level number" equals a higher priority

e.g.

t0<-
  create_trajectory() %>%
  seize("operator", 1, priority=2) %>%
  timeout(3) %>%
  release("operator", 1)

[Bart6114]

woops, didn't mean to close it 😬

[Bart6114]

check https://github.com/Bart6114/simmer/blob/c3007cfc4adedd5fd9a857199bd0f0570859cace/tests/testthat/test-simmer-resource.R for an example

[Enchufa2]

Nice! BTW, merge the latest developments of the master branch in your tree, please. For instance, I introduced the Boost library and I created a new header devoted to standardise the use of efficient containers (vector, queues, map, set...) through macros.

[Bart6114]

nice^2

I'll try to do the merge this evening

[Bart6114]

check 8a23121 for a start with testing FIFO processing (and implementation)

[Bart6114]

moved compare func into the struct (tx, a lot more elegant) e2d2822

haven't had time to look into in in detail but couldn't get your suggestion working on the simple FIFO ordering when priorities are equal (for example, std::sort also doesn't guarantee preserving order of equal elements).

[Enchufa2]

You are right. Definitely, we need the arrived_at secondary key (and my tests suggest that the priority queue performs similarly to the previous FIFO queue 👍). As a consequence, I had to use priorities to ensure that releases go before seizes (see ac74e22 and this test).

Now, what about preemption? It is a far more complex task. 😬 I'm going to merge the current changes into the master branch before continuing with this.

[Bart6114]

Let's close this and discuss the preemption (which will be a far bigger challenge 😀) in #34