Rodrigo Arias
79d17b5b0c
Allows mkdocs to discover broken links when the pointed document has moved.
40 lines
1.6 KiB
Markdown
40 lines
1.6 KiB
Markdown
# Patch bay
|
|
|
|
The patch bay (or simply bay) allows [channels](channels.md) to be registered
|
|
with their name so they are visible to all parts of the emulator and provides a
|
|
way to run callbacks when the channels update their values.
|
|
|
|
The name follows from the [patch bay](https://en.wikipedia.org/wiki/Patch_panel)
|
|
used to connect audio channels:
|
|
|
|
|
|
|
|
## Registering channels
|
|
|
|
Channels are registered with `bay_register()`, using the channel name as a
|
|
unique identifier. It is an error to register multiple channels with the same
|
|
name.
|
|
|
|
The register step sets the channel callback function, so the bay can detect
|
|
which channel become dirty and act upon them.
|
|
|
|
## Callbacks
|
|
|
|
After registering a channel in the bay, multiple callbacks can be registered
|
|
with `bay_add_cb()` and will be called in same order they were added.
|
|
|
|
The callbacks are executed in the propagation phase, when `bay_propagate()` is
|
|
called. There are two types of callbacks: *dirty* and *emit*.
|
|
|
|
All dirty callbacks are called first, for all the channels that are dirty.
|
|
Executing the dirty callbacks may cause other channels to become dirty too,
|
|
which will be added to the list of dirty channels. Channels that are already
|
|
dirty cannot be modified, so we prevent an infinite updating loop.
|
|
|
|
Then the emit callbacks are called for each dirty channel in the same way. The
|
|
emit callbacks are generally used to write the values of the channels in the
|
|
output traces. These callbacks cannot cause any new channel to become dirty.
|
|
|
|
Finally, all channels are flushed by calling `chan_flush()`, clearing the dirty
|
|
flag and leaving them ready for the next input event.
|