intel / rohd

The Rapid Open Hardware Development (ROHD) framework is a framework for describing and verifying hardware in the Dart programming language.
https://intel.github.io/rohd-website
BSD 3-Clause "New" or "Revised" License
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A way to dispose of unnecessary `Simulator` subscriptions #516

Open mkorbel1 opened 1 month ago

mkorbel1 commented 1 month ago

Motivation

When running many tests, it may be necessary to build many versions of the same or different Modules, each with a variety of their own Logics. The _Wires within Logics have automation to re-subscribe to Simulator events after a Simulator.reset so that they still functionally work (e.g. for reusing same hardware between tests/simulator resets). However, if you are "throwing away" the old reference to some DUT, and you don't want to simulate with it anymore, you don't care that the Logics within are properly simulating and triggering events like changed. In this case, each time you throw away hardware, you're paying a penalty for future simulations on Simulator events.

One of the most problematic issues is that Simulator.resetRequested is re-subscribed every time. Then, if you have a tearDown where Simulator.reset() is called, the call will get progressively slower as it has to restart more and more subscriptions each test.

This only really impacts test files with many Simulator.reset calls (many tests, many DUTs, etc.).

Desired solution

Some mechanism to signal that Simulator subscriptions should be disposed of, rather than just restarted. A way to clean up all the old hardware between tests.

Alternatives considered

Additional details

No response

mkorbel1 commented 1 month ago

Maybe, if possible, it would be nice to generate these Simulator subscriptions the first time a signal glitches (after reset)? Then there's no special "dispose" required and hardware that loses references would just go away like one would expected