Struct devices::utils::event_loop::EventLoop

pub struct EventLoop {
    fail_handle: Option<Arc<dyn FailHandle>>,
    poll_ctx: Arc<WaitContext<Descriptor>>,
    handlers: Arc<Mutex<BTreeMap<Descriptor, Weak<dyn EventHandler>>>>,
    stop_evt: Event,
}

EventLoop is an event loop blocked on a set of fds. When a monitered events is triggered, event loop will invoke the mapped handler.

Fields

fail_handle: Option<Arc<dyn FailHandle>>

poll_ctx: Arc<WaitContext<Descriptor>>

handlers: Arc<Mutex<BTreeMap<Descriptor, Weak<dyn EventHandler>>>>

stop_evt: Event

Implementations

impl EventLoop

pub fn start( name: String, fail_handle: Option<Arc<dyn FailHandle>> ) -> Result<(EventLoop, JoinHandle<()>), Error>

Start an event loop. An optional fail handle could be passed to the event loop.

pub fn add_event( &self, descriptor: &dyn AsRawDescriptor, event_type: EventType, handler: Weak<dyn EventHandler> ) -> Result<(), Error>

Add a new event to event loop. The event handler will be invoked when event happens on descriptor.

If the same descriptor is added multiple times, the old handler will be replaced. EventLoop will not keep handler alive, if handler is dropped when event is triggered, the event will be removed.

pub fn remove_event_for_descriptor( &self, descriptor: &dyn AsRawDescriptor ) -> Result<(), Error>

Removes event for this descriptor. This function is safe to call even when the descriptor is not actively being polled because it’s been paused.

EventLoop does not guarantee all events for descriptor is handled.

pub fn pause_event_for_descriptor( &self, descriptor: &dyn AsRawDescriptor ) -> Result<(), Error>

Pauses polling on the given descriptor. It keeps a reference to the descriptor and its handler so it can be resumed by calling resume_event_for_descriptor().

pub fn resume_event_for_descriptor( &self, descriptor: &dyn AsRawDescriptor, event_type: EventType ) -> Result<(), Error>

Resumes polling on the given descriptor with the previously-provided handler. If descriptor was not paused beforehand, this function does nothing. If descriptor does not exist in the event loop, it returns an error. event_type does not need to match the previously registered event type.

pub fn stop(&self)

Stops this event loop asynchronously. Previous events might not be handled.