wafer

v0.1.0

wafer v0.1.0 Wafer.InterruptRegistry

This module provides Wafer's interrupt registry. This allows multiple subscribers to be subscribed to interrupts from many different pins.

It is used by Driver.Circuits.GPIO.Dispatcher and Driver.ElixirALE.GPIO.Dispatcher and you should probably use it if you're writing your own driver which supports sending interrupts to subscribers.

Link to this section Summary

Types

key()

Functions

count_subscriptions(key)

Count the number of active subscriptions for key.

count_subscriptions(key, pin_condition)

Count the number of active subscriptions for key and pin_condition.

publish(key, pin_condition)

Publish an interrupt to subscribers that are interested in key and pin_condition.

subscribe(key, pin_condition, conn)

Subscribe the calling process to interrupts for the specified pin_condition using the provided key.

subscribe(key, pin_condition, conn, metadata)

Subscribe the calling process to interrupts for the specified pin_condition using the provided key.

subscribers?(key)

Are there any subscribers to key?

subscribers?(key, pin_condition)

Are there any subscribers to key and pin_condition?

subscriptions(key)

Returns a list of all subscriptions to key.

subscriptions(key, pin_condition)

Returns a list of all subscriptions key and pin_condition.

unsubscribe(key, pin_condition, conn)

Remove all subscriptions for key, pin_condition and conn.

Link to this section Types

Link to this type

key()

key() :: any()

Link to this section Functions

Link to this function

count_subscriptions(key)

count_subscriptions(key()) :: non_neg_integer()

Count the number of active subscriptions for key.

Link to this function

count_subscriptions(key, pin_condition)

count_subscriptions(key(), Wafer.GPIO.pin_condition()) :: non_neg_integer()

Count the number of active subscriptions for key and pin_condition.

Link to this function

publish(key, pin_condition)

publish(key(), :rising | :falling) :: {:ok, non_neg_integer()}

Publish an interrupt to subscribers that are interested in key and pin_condition.

Searches the registry for all subscribers to are subscribed to pin_condition or :both and publishes the interrupt message to them. The interrupt message takes the form {:interrupt, Conn.t(), :rising | :falling, metadata :: any}.

Link to this function

subscribe(key, pin_condition, conn)

subscribe(key(), Wafer.GPIO.pin_condition(), Wafer.Conn.t()) :: :ok

Subscribe the calling process to interrupts for the specified pin_condition using the provided key.

See subscribe/4 for more information.

Example 

iex> subscribe({MCP230017.Pin, 13}, :rising, conn)
:ok
Link to this function

subscribe(key, pin_condition, conn, metadata)

subscribe(key(), Wafer.GPIO.pin_condition(), Wafer.Conn.t(), any()) :: :ok

Subscribe the calling process to interrupts for the specified pin_condition using the provided key.

Arguments

  • key a key which uniquely describes the pin. Probably a combination of device name and pin.
  • pin_condition either :rising, :falling or :both.
  • conn the receiver's connection to the pin, sent back to them in the interrupt message.
  • metadata arbitrary data which will be sent to the receiver process in the interrupt message. Defaults to nil.
Link to this function

subscribers?(key)

subscribers?(key()) :: boolean()

Are there any subscribers to key?

Link to this function

subscribers?(key, pin_condition)

subscribers?(key(), Wafer.GPIO.pin_condition()) :: boolean()

Are there any subscribers to key and pin_condition?

Link to this function

subscriptions(key)

subscriptions(key()) :: [
  {Wafer.GPIO.pin_condition(), Wafer.Conn.t(), metadata :: any(),
   receiver :: pid()}
]

Returns a list of all subscriptions to key.

Link to this function

subscriptions(key, pin_condition)

subscriptions(key(), Wafer.GPIO.pin_condition()) :: [
  {Wafer.GPIO.pin_condition(), Wafer.Conn.t(), metadata :: any(),
   receiver :: pid()}
]

Returns a list of all subscriptions key and pin_condition.

Link to this function

unsubscribe(key, pin_condition, conn)

unsubscribe(key(), Wafer.GPIO.pin_condition(), Wafer.Conn.t()) :: :ok

Remove all subscriptions for key, pin_condition and conn.