amaranth/nmigen/sim/__init__.py

from .core import *


__all__ = ["Settle", "Delay", "Tick", "Passive", "Active", "Simulator"]
sim: split into base, core, and engines. Before this commit, each simulation engine (which is only pysim at the moment, but also cxxsim soon) was a subclass of SimulatorCore, and every simulation engine module would essentially duplicate the complete structure of a simulator, with code partially shared. This was a really bad idea: it was inconvenient to use, with downstream code having to branch between e.g. PySettle and CxxSettle; it had no well-defined external interface; it had multiple virtually identical entry points; and it had no separation between simulation algorithms and glue code. This commit completely rearranges simulation code. 1. sim._base defines internal simulation interfaces. The clarity of these internal interfaces is important because simulation engines mix and match components to provide a consistent API regardless of the chosen engine. 2. sim.core defines the external simulation interface: the commands and the simulator facade. The facade provides a single entry point and, when possible, validates or lowers user input. It also imports built-in simulation engines by their symbolic name, avoiding eager imports of pyvcd or ctypes. 3. sim.xxxsim (currently, only sim.pysim) defines the simulator implementation: time and state management, process scheduling, and waveform dumping. The new simulator structure has none of the downsides of the old one. See #324. 2020-08-27 04:17:02 -06:00			`from .core import *`


			`__all__ = ["Settle", "Delay", "Tick", "Passive", "Active", "Simulator"]`