Struct Signal

pub struct Signal { /* private fields */ }

A semaphore-like asynchronous inter-process communication primitive.

Each signal has 32-bit-wide bitfields. Updating the bitfields wakes up waiting processes. You can update the bitfields multiple times before it is cleared, but it can’t tell how many times it was updated. In other words, it guarantees bitfields are set at least once.

Signal vs. Channel

While Signal cannot carry data more than bitfields, it is more lightweight and faster than Channel.

Use Signal when you need to notify other processes of an event, especially when you just want to wake up a sleeping process.

Implementations

impl Signal

pub fn create() -> Result<Signal, FtlError>

Creates a new signal.

pub fn from_handle(handle: OwnedHandle) -> Signal

Instantiates the object from the given handle.

pub fn handle(&self) -> &OwnedHandle

Returns the handle.

pub fn update(&self, value: SignalBits) -> Result<(), FtlError>

Updates the signal. Non-blocking.

This bit-wise ORs the given value to the signal, and wakes up waiting processes if any.

pub fn clear(&self) -> Result<SignalBits, FtlError>

Clears the signal, and returns the previous value. Non-blocking.

Trait Implementations

impl Debug for Signal

fn fmt(&self, _f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.