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loop_logic.rs
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use std::cell::{Cell, RefCell};
use std::fmt::Debug;
use std::rc::{Rc, Weak};
use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::Arc;
use std::time::{Duration, Instant};
use std::{io, slice};
#[cfg(feature = "block_on")]
use std::future::Future;
#[cfg(unix)]
use std::os::unix::io::{AsFd, AsRawFd, BorrowedFd, RawFd};
#[cfg(windows)]
use std::os::windows::io::{AsHandle, AsRawHandle, AsSocket as AsFd, BorrowedHandle, RawHandle};
use polling::Poller;
use tracing::{trace, warn};
use crate::list::{SourceEntry, SourceList};
use crate::sources::{Dispatcher, EventSource, Idle, IdleDispatcher};
use crate::sys::{Notifier, PollEvent};
use crate::token::TokenInner;
use crate::{
AdditionalLifecycleEventsSet, InsertError, Poll, PostAction, Readiness, Token, TokenFactory,
};
type IdleCallback<'i, Data> = Rc<RefCell<dyn IdleDispatcher<Data> + 'i>>;
/// A token representing a registration in the [`EventLoop`].
///
/// This token is given to you by the [`EventLoop`] when an [`EventSource`] is inserted or
/// a [`Dispatcher`] is registered. You can use it to [disable](LoopHandle#method.disable),
/// [enable](LoopHandle#method.enable), [update`](LoopHandle#method.update),
/// [remove](LoopHandle#method.remove) or [kill](LoopHandle#method.kill) it.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct RegistrationToken {
inner: TokenInner,
}
impl RegistrationToken {
/// Create the RegistrationToken corresponding to the given raw key
/// This is needed because some methods use `RegistrationToken`s as
/// raw usizes within this crate
pub(crate) fn new(inner: TokenInner) -> Self {
Self { inner }
}
}
pub(crate) struct LoopInner<'l, Data> {
pub(crate) poll: RefCell<Poll>,
// The `Option` is used to keep slots of the slab occupied, to prevent id reuse
// while in-flight events might still refer to a recently destroyed event source.
pub(crate) sources: RefCell<SourceList<'l, Data>>,
pub(crate) sources_with_additional_lifecycle_events: RefCell<AdditionalLifecycleEventsSet>,
idles: RefCell<Vec<IdleCallback<'l, Data>>>,
pending_action: Cell<PostAction>,
}
/// A handle to an event loop
///
/// This handle allows you to insert new sources and idles in this event loop,
/// it can be cloned, and it is possible to insert new sources from within a source
/// callback.
pub struct LoopHandle<'l, Data> {
inner: Rc<LoopInner<'l, Data>>,
}
/// Weak variant of a [`LoopHandle`]
pub struct WeakLoopHandle<'l, Data> {
inner: Weak<LoopInner<'l, Data>>,
}
impl<Data> Debug for LoopHandle<'_, Data> {
#[cfg_attr(feature = "nightly_coverage", coverage(off))]
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.write_str("LoopHandle { ... }")
}
}
/// Manually implemented `Clone`.
///
/// The derived implementation adds a `Clone` bound on the generic parameter `Data`.
impl<Data> Clone for LoopHandle<'_, Data> {
#[cfg_attr(feature = "nightly_coverage", coverage(off))]
fn clone(&self) -> Self {
LoopHandle {
inner: self.inner.clone(),
}
}
}
impl<'l, Data> LoopHandle<'l, Data> {
/// Inserts a new event source in the loop.
///
/// The provided callback will be called during the dispatching cycles whenever the
/// associated source generates events, see `EventLoop::dispatch(..)` for details.
///
/// This function takes ownership of the event source. Use `register_dispatcher`
/// if you need access to the event source after this call.
pub fn insert_source<S, F>(
&self,
source: S,
callback: F,
) -> Result<RegistrationToken, InsertError<S>>
where
S: EventSource + 'l,
F: FnMut(S::Event, &mut S::Metadata, &mut Data) -> S::Ret + 'l,
{
let dispatcher = Dispatcher::new(source, callback);
self.register_dispatcher(dispatcher.clone())
.map_err(|error| InsertError {
error,
inserted: dispatcher.into_source_inner(),
})
}
/// Registers a `Dispatcher` in the loop.
///
/// Use this function if you need access to the event source after its insertion in the loop.
///
/// See also `insert_source`.
#[cfg_attr(feature = "nightly_coverage", coverage(off))] // Contains a branch we can't hit w/o OOM
pub fn register_dispatcher<S>(
&self,
dispatcher: Dispatcher<'l, S, Data>,
) -> crate::Result<RegistrationToken>
where
S: EventSource + 'l,
{
let mut sources = self.inner.sources.borrow_mut();
let mut poll = self.inner.poll.borrow_mut();
// Find an empty slot if any
let slot = sources.vacant_entry();
slot.source = Some(dispatcher.clone_as_event_dispatcher());
trace!(source = slot.token.get_id(), "Inserting new source");
let ret = slot.source.as_ref().unwrap().register(
&mut poll,
&mut self
.inner
.sources_with_additional_lifecycle_events
.borrow_mut(),
&mut TokenFactory::new(slot.token),
);
if let Err(error) = ret {
slot.source = None;
return Err(error);
}
Ok(RegistrationToken { inner: slot.token })
}
/// Inserts an idle callback.
///
/// This callback will be called during a dispatching cycle when the event loop has
/// finished processing all pending events from the sources and becomes idle.
pub fn insert_idle<'i, F: FnOnce(&mut Data) + 'l + 'i>(&self, callback: F) -> Idle<'i> {
let mut opt_cb = Some(callback);
let callback = Rc::new(RefCell::new(Some(move |data: &mut Data| {
if let Some(cb) = opt_cb.take() {
cb(data);
}
})));
self.inner.idles.borrow_mut().push(callback.clone());
Idle { callback }
}
/// Enables this previously disabled event source.
///
/// This previously disabled source will start generating events again.
///
/// **Note:** this cannot be done from within the source callback.
pub fn enable(&self, token: &RegistrationToken) -> crate::Result<()> {
if let &SourceEntry {
token: entry_token,
source: Some(ref source),
} = self.inner.sources.borrow().get(token.inner)?
{
trace!(source = entry_token.get_id(), "Registering source");
source.register(
&mut self.inner.poll.borrow_mut(),
&mut self
.inner
.sources_with_additional_lifecycle_events
.borrow_mut(),
&mut TokenFactory::new(entry_token),
)
} else {
Err(crate::Error::InvalidToken)
}
}
/// Makes this source update its registration.
///
/// If after accessing the source you changed its parameters in a way that requires
/// updating its registration.
pub fn update(&self, token: &RegistrationToken) -> crate::Result<()> {
if let &SourceEntry {
token: entry_token,
source: Some(ref source),
} = self.inner.sources.borrow().get(token.inner)?
{
trace!(
source = entry_token.get_id(),
"Updating registration of source"
);
if !source.reregister(
&mut self.inner.poll.borrow_mut(),
&mut self
.inner
.sources_with_additional_lifecycle_events
.borrow_mut(),
&mut TokenFactory::new(entry_token),
)? {
trace!(
source = entry_token.get_id(),
"Can't update registration withing a callback, storing for later."
);
// we are in a callback, store for later processing
self.inner.pending_action.set(PostAction::Reregister);
}
Ok(())
} else {
Err(crate::Error::InvalidToken)
}
}
/// Disables this event source.
///
/// The source remains in the event loop, but it'll no longer generate events
pub fn disable(&self, token: &RegistrationToken) -> crate::Result<()> {
if let &SourceEntry {
token: entry_token,
source: Some(ref source),
} = self.inner.sources.borrow().get(token.inner)?
{
if !token.inner.same_source_as(entry_token) {
// The token provided by the user is no longer valid
return Err(crate::Error::InvalidToken);
}
trace!(source = entry_token.get_id(), "Unregistering source");
if !source.unregister(
&mut self.inner.poll.borrow_mut(),
&mut self
.inner
.sources_with_additional_lifecycle_events
.borrow_mut(),
*token,
)? {
trace!(
source = entry_token.get_id(),
"Cannot unregister source in callback, storing for later."
);
// we are in a callback, store for later processing
self.inner.pending_action.set(PostAction::Disable);
}
Ok(())
} else {
Err(crate::Error::InvalidToken)
}
}
/// Removes this source from the event loop.
pub fn remove(&self, token: RegistrationToken) {
if let Ok(&mut SourceEntry {
token: entry_token,
ref mut source,
}) = self.inner.sources.borrow_mut().get_mut(token.inner)
{
if let Some(source) = source.take() {
trace!(source = entry_token.get_id(), "Removing source");
if let Err(e) = source.unregister(
&mut self.inner.poll.borrow_mut(),
&mut self
.inner
.sources_with_additional_lifecycle_events
.borrow_mut(),
token,
) {
warn!("Failed to unregister source from the polling system: {e:?}");
}
}
}
}
/// Wrap an IO object into an async adapter
///
/// This adapter turns the IO object into an async-aware one that can be used in futures.
/// The readiness of these futures will be driven by the event loop.
///
/// The produced futures can be polled in any executor, and notably the one provided by
/// calloop.
pub fn adapt_io<F: AsFd>(&self, fd: F) -> crate::Result<crate::io::Async<'l, F>> {
crate::io::Async::new(self.inner.clone(), fd)
}
/// Create a weak reference to this loop data.
///
/// # Examples
///
/// ```
/// use calloop::timer::{TimeoutAction, Timer};
/// use calloop::EventLoop;
///
/// let event_loop: EventLoop<()> = EventLoop::try_new().unwrap();
/// let weak_handle = event_loop.handle().downgrade();
///
/// event_loop
/// .handle()
/// .insert_source(Timer::immediate(), move |_, _, _| {
/// // Hold its weak handle in the event loop's callback to break the reference cycle.
/// let handle = weak_handle.upgrade().unwrap();
///
/// // Use the upgraded handle later...
///
/// TimeoutAction::Drop
/// })
/// .unwrap();
/// ```
pub fn downgrade(&self) -> WeakLoopHandle<'l, Data> {
WeakLoopHandle {
inner: Rc::downgrade(&self.inner),
}
}
}
impl<Data> Debug for WeakLoopHandle<'_, Data> {
#[cfg_attr(feature = "nightly_coverage", coverage(off))]
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.write_str("WeakLoopHandle { ... }")
}
}
/// Manually implemented `Clone`.
///
/// The derived implementation adds a `Clone` bound on the generic parameter `Data`.
impl<Data> Clone for WeakLoopHandle<'_, Data> {
#[cfg_attr(feature = "nightly_coverage", coverage(off))]
fn clone(&self) -> Self {
WeakLoopHandle {
inner: self.inner.clone(),
}
}
}
/// Manually implemented `Default`.
///
/// The derived implementation adds a `Default` bound on the generic parameter `Data`.
impl<Data> Default for WeakLoopHandle<'_, Data> {
#[cfg_attr(feature = "nightly_coverage", coverage(off))]
fn default() -> Self {
WeakLoopHandle {
inner: Weak::default(),
}
}
}
impl<'l, Data> WeakLoopHandle<'l, Data> {
/// Try to get a [`LoopHandle`] from this weak reference.
///
/// Returns [`None`] if the loop data has been dropped.
pub fn upgrade(&self) -> Option<LoopHandle<'l, Data>> {
self.inner.upgrade().map(|inner| LoopHandle { inner })
}
/// Check if the loop data has been dropped.
pub fn expired(&self) -> bool {
self.inner.strong_count() == 0
}
}
/// An event loop
///
/// This loop can host several event sources, that can be dynamically added or removed.
pub struct EventLoop<'l, Data> {
#[allow(dead_code)]
poller: Arc<Poller>,
handle: LoopHandle<'l, Data>,
signals: Arc<Signals>,
// A caching vector for synthetic poll events
synthetic_events: Vec<PollEvent>,
}
impl<Data> Debug for EventLoop<'_, Data> {
#[cfg_attr(feature = "nightly_coverage", coverage(off))]
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.write_str("EventLoop { ... }")
}
}
/// Signals related to the event loop.
struct Signals {
/// Signal to stop the event loop.
stop: AtomicBool,
/// Signal that the future is ready.
#[cfg(feature = "block_on")]
future_ready: AtomicBool,
}
impl<'l, Data> EventLoop<'l, Data> {
/// Create a new event loop
///
/// Fails if the initialization of the polling system failed.
pub fn try_new() -> crate::Result<Self> {
let poll = Poll::new()?;
let poller = poll.poller.clone();
let handle = LoopHandle {
inner: Rc::new(LoopInner {
poll: RefCell::new(poll),
sources: RefCell::new(SourceList::new()),
idles: RefCell::new(Vec::new()),
pending_action: Cell::new(PostAction::Continue),
sources_with_additional_lifecycle_events: Default::default(),
}),
};
Ok(EventLoop {
handle,
signals: Arc::new(Signals {
stop: AtomicBool::new(false),
#[cfg(feature = "block_on")]
future_ready: AtomicBool::new(false),
}),
poller,
synthetic_events: vec![],
})
}
/// Retrieve a loop handle
pub fn handle(&self) -> LoopHandle<'l, Data> {
self.handle.clone()
}
fn dispatch_events(
&mut self,
mut timeout: Option<Duration>,
data: &mut Data,
) -> crate::Result<()> {
let now = Instant::now();
{
let mut extra_lifecycle_sources = self
.handle
.inner
.sources_with_additional_lifecycle_events
.borrow_mut();
let sources = &self.handle.inner.sources.borrow();
for source in &mut *extra_lifecycle_sources.values {
if let Ok(SourceEntry {
source: Some(disp), ..
}) = sources.get(source.inner)
{
if let Some((readiness, token)) = disp.before_sleep()? {
// Wake up instantly after polling if we recieved an event
timeout = Some(Duration::ZERO);
self.synthetic_events.push(PollEvent { readiness, token });
}
} else {
unreachable!()
}
}
}
let events = {
let poll = self.handle.inner.poll.borrow();
loop {
let result = poll.poll(timeout);
match result {
Ok(events) => break events,
Err(crate::Error::IoError(err)) if err.kind() == io::ErrorKind::Interrupted => {
// Interrupted by a signal. Update timeout and retry.
if let Some(to) = timeout {
let elapsed = now.elapsed();
if elapsed >= to {
return Ok(());
} else {
timeout = Some(to - elapsed);
}
}
}
Err(err) => return Err(err),
};
}
};
{
let mut extra_lifecycle_sources = self
.handle
.inner
.sources_with_additional_lifecycle_events
.borrow_mut();
if !extra_lifecycle_sources.values.is_empty() {
for source in &mut *extra_lifecycle_sources.values {
if let Ok(SourceEntry {
source: Some(disp), ..
}) = self.handle.inner.sources.borrow().get(source.inner)
{
let iter = EventIterator {
inner: events.iter(),
registration_token: *source,
};
disp.before_handle_events(iter);
} else {
unreachable!()
}
}
}
}
for event in self.synthetic_events.drain(..).chain(events) {
// Get the registration token associated with the event.
let reg_token = event.token.inner.forget_sub_id();
let opt_disp = self
.handle
.inner
.sources
.borrow()
.get(reg_token)
.ok()
.and_then(|entry| entry.source.clone());
if let Some(disp) = opt_disp {
trace!(source = reg_token.get_id(), "Dispatching events for source");
let mut ret = disp.process_events(event.readiness, event.token, data)?;
// if the returned PostAction is Continue, it may be overwritten by a user-specified pending action
let pending_action = self
.handle
.inner
.pending_action
.replace(PostAction::Continue);
if let PostAction::Continue = ret {
ret = pending_action;
}
match ret {
PostAction::Reregister => {
trace!(
source = reg_token.get_id(),
"Postaction reregister for source"
);
disp.reregister(
&mut self.handle.inner.poll.borrow_mut(),
&mut self
.handle
.inner
.sources_with_additional_lifecycle_events
.borrow_mut(),
&mut TokenFactory::new(reg_token),
)?;
}
PostAction::Disable => {
trace!(
source = reg_token.get_id(),
"Postaction unregister for source"
);
disp.unregister(
&mut self.handle.inner.poll.borrow_mut(),
&mut self
.handle
.inner
.sources_with_additional_lifecycle_events
.borrow_mut(),
RegistrationToken::new(reg_token),
)?;
}
PostAction::Remove => {
trace!(source = reg_token.get_id(), "Postaction remove for source");
if let Ok(entry) = self.handle.inner.sources.borrow_mut().get_mut(reg_token)
{
entry.source = None;
}
}
PostAction::Continue => {}
}
if self
.handle
.inner
.sources
.borrow()
.get(reg_token)
.ok()
.map(|entry| entry.source.is_none())
.unwrap_or(true)
{
// the source has been removed from within its callback, unregister it
let mut poll = self.handle.inner.poll.borrow_mut();
if let Err(e) = disp.unregister(
&mut poll,
&mut self
.handle
.inner
.sources_with_additional_lifecycle_events
.borrow_mut(),
RegistrationToken::new(reg_token),
) {
warn!("Failed to unregister source from the polling system: {e:?}",);
}
}
} else {
warn!(?reg_token, "Received an event for non-existence source");
}
}
Ok(())
}
fn dispatch_idles(&mut self, data: &mut Data) {
let idles = std::mem::take(&mut *self.handle.inner.idles.borrow_mut());
for idle in idles {
idle.borrow_mut().dispatch(data);
}
}
/// Dispatch pending events to their callbacks
///
/// If some sources have events available, their callbacks will be immediately called.
/// Otherwise, this will wait until an event is received or the provided `timeout`
/// is reached. If `timeout` is `None`, it will wait without a duration limit.
///
/// Once pending events have been processed or the timeout is reached, all pending
/// idle callbacks will be fired before this method returns.
pub fn dispatch<D: Into<Option<Duration>>>(
&mut self,
timeout: D,
data: &mut Data,
) -> crate::Result<()> {
self.dispatch_events(timeout.into(), data)?;
self.dispatch_idles(data);
Ok(())
}
/// Get a signal to stop this event loop from running
///
/// To be used in conjunction with the `run()` method.
pub fn get_signal(&self) -> LoopSignal {
LoopSignal {
signal: self.signals.clone(),
notifier: self.handle.inner.poll.borrow().notifier(),
}
}
/// Run this event loop
///
/// This will repeatedly try to dispatch events (see the `dispatch()` method) on
/// this event loop, waiting at most `timeout` every time.
///
/// Between each dispatch wait, your provided callback will be called.
///
/// You can use the `get_signal()` method to retrieve a way to stop or wakeup
/// the event loop from anywhere.
pub fn run<F, D: Into<Option<Duration>>>(
&mut self,
timeout: D,
data: &mut Data,
mut cb: F,
) -> crate::Result<()>
where
F: FnMut(&mut Data),
{
let timeout = timeout.into();
self.signals.stop.store(false, Ordering::Release);
while !self.signals.stop.load(Ordering::Acquire) {
self.dispatch(timeout, data)?;
cb(data);
}
Ok(())
}
/// Block a future on this event loop.
///
/// This will run the provided future on this event loop, blocking until it is
/// resolved.
///
/// If [`LoopSignal::stop()`] is called before the future is resolved, this function returns
/// `None`.
#[cfg(feature = "block_on")]
pub fn block_on<R>(
&mut self,
future: impl Future<Output = R>,
data: &mut Data,
mut cb: impl FnMut(&mut Data),
) -> crate::Result<Option<R>> {
use std::task::{Context, Poll, Wake, Waker};
/// A waker that will wake up the event loop when it is ready to make progress.
struct EventLoopWaker(LoopSignal);
impl Wake for EventLoopWaker {
fn wake(self: Arc<Self>) {
// Set the waker.
self.0.signal.future_ready.store(true, Ordering::Release);
self.0.notifier.notify().ok();
}
fn wake_by_ref(self: &Arc<Self>) {
// Set the waker.
self.0.signal.future_ready.store(true, Ordering::Release);
self.0.notifier.notify().ok();
}
}
// Pin the future to the stack.
pin_utils::pin_mut!(future);
// Create a waker that will wake up the event loop when it is ready to make progress.
let waker = {
let handle = EventLoopWaker(self.get_signal());
Waker::from(Arc::new(handle))
};
let mut context = Context::from_waker(&waker);
// Begin running the loop.
let mut output = None;
self.signals.stop.store(false, Ordering::Release);
self.signals.future_ready.store(true, Ordering::Release);
while !self.signals.stop.load(Ordering::Acquire) {
// If the future is ready to be polled, poll it.
if self.signals.future_ready.swap(false, Ordering::AcqRel) {
// Poll the future and break the loop if it's ready.
if let Poll::Ready(result) = future.as_mut().poll(&mut context) {
output = Some(result);
break;
}
}
// Otherwise, block on the event loop.
self.dispatch_events(None, data)?;
self.dispatch_idles(data);
cb(data);
}
Ok(output)
}
}
#[cfg(unix)]
impl<Data> AsRawFd for EventLoop<'_, Data> {
/// Get the underlying raw-fd of the poller.
///
/// This could be used to create [`Generic`] source out of the current loop
/// and inserting into some other [`EventLoop`]. It's recommended to clone `fd`
/// before doing so.
///
/// [`Generic`]: crate::generic::Generic
fn as_raw_fd(&self) -> RawFd {
self.poller.as_raw_fd()
}
}
#[cfg(unix)]
impl<Data> AsFd for EventLoop<'_, Data> {
/// Get the underlying fd of the poller.
///
/// This could be used to create [`Generic`] source out of the current loop
/// and inserting into some other [`EventLoop`].
///
/// [`Generic`]: crate::generic::Generic
fn as_fd(&self) -> BorrowedFd<'_> {
self.poller.as_fd()
}
}
#[cfg(windows)]
impl<Data> AsRawHandle for EventLoop<'_, Data> {
fn as_raw_handle(&self) -> RawHandle {
self.poller.as_raw_handle()
}
}
#[cfg(windows)]
impl<Data> AsHandle for EventLoop<'_, Data> {
fn as_handle(&self) -> BorrowedHandle<'_> {
self.poller.as_handle()
}
}
#[derive(Clone, Debug)]
/// The EventIterator is an `Iterator` over the events relevant to a particular source
/// This type is used in the [`EventSource::before_handle_events`] methods for
/// two main reasons:
///
/// - To avoid dynamic dispatch overhead
/// - Secondly, it is to allow this type to be `Clone`, which is not
/// possible with dynamic dispatch
pub struct EventIterator<'a> {
inner: slice::Iter<'a, PollEvent>,
registration_token: RegistrationToken,
}
impl Iterator for EventIterator<'_> {
type Item = (Readiness, Token);
fn next(&mut self) -> Option<Self::Item> {
for next in self.inner.by_ref() {
if next
.token
.inner
.same_source_as(self.registration_token.inner)
{
return Some((next.readiness, next.token));
}
}
None
}
}
/// A signal that can be shared between thread to stop or wakeup a running
/// event loop
#[derive(Clone)]
pub struct LoopSignal {
signal: Arc<Signals>,
notifier: Notifier,
}
impl Debug for LoopSignal {
#[cfg_attr(feature = "nightly_coverage", coverage(off))]
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.write_str("LoopSignal { ... }")
}
}
impl LoopSignal {
/// Stop the event loop
///
/// Once this method is called, the next time the event loop has finished
/// waiting for events, it will return rather than starting to wait again.
///
/// This is only useful if you are using the `EventLoop::run()` method.
pub fn stop(&self) {
self.signal.stop.store(true, Ordering::Release);
}
/// Wake up the event loop
///
/// This sends a dummy event to the event loop to simulate the reception
/// of an event, making the wait return early. Called after `stop()`, this
/// ensures the event loop will terminate quickly if you specified a long
/// timeout (or no timeout at all) to the `dispatch` or `run` method.
pub fn wakeup(&self) {
self.notifier.notify().ok();
}
}
#[cfg(test)]
mod tests {
use std::{cell::Cell, rc::Rc, time::Duration};
use crate::{
channel::{channel, Channel},
ping::*,
timer, EventIterator, EventSource, Poll, PostAction, Readiness, RegistrationToken, Token,
TokenFactory,
};
#[cfg(unix)]
use crate::{generic::Generic, Dispatcher, Interest, Mode};
use super::EventLoop;
#[test]
fn dispatch_idle() {
let mut event_loop = EventLoop::try_new().unwrap();
let mut dispatched = false;
event_loop.handle().insert_idle(|d| {
*d = true;
});
event_loop
.dispatch(Some(Duration::ZERO), &mut dispatched)
.unwrap();
assert!(dispatched);
}
#[test]
fn cancel_idle() {
let mut event_loop = EventLoop::try_new().unwrap();
let mut dispatched = false;
let handle = event_loop.handle();
let idle = handle.insert_idle(move |d| {
*d = true;
});
idle.cancel();
event_loop
.dispatch(Duration::ZERO, &mut dispatched)
.unwrap();
assert!(!dispatched);
}
#[test]
fn wakeup() {
let mut event_loop = EventLoop::try_new().unwrap();
let signal = event_loop.get_signal();
::std::thread::spawn(move || {
::std::thread::sleep(Duration::from_millis(500));
signal.wakeup();
});
// the test should return
event_loop.dispatch(None, &mut ()).unwrap();
}
#[test]
fn wakeup_stop() {
let mut event_loop = EventLoop::try_new().unwrap();
let signal = event_loop.get_signal();
::std::thread::spawn(move || {
::std::thread::sleep(Duration::from_millis(500));
signal.stop();
signal.wakeup();
});
// the test should return
event_loop.run(None, &mut (), |_| {}).unwrap();
}
#[test]
fn additional_events() {
let mut event_loop: EventLoop<'_, Lock> = EventLoop::try_new().unwrap();
let mut lock = Lock {
lock: Rc::new((
// Whether the lock is locked
Cell::new(false),
// The total number of events processed in process_events
Cell::new(0),
// The total number of events processed in before_handle_events
// This is used to ensure that the count seen in before_handle_events is expected
Cell::new(0),
)),
};
let (sender, channel) = channel();
let token = event_loop
.handle()
.insert_source(
LockingSource {
channel,
lock: lock.clone(),
},
|_, _, lock| {
lock.lock();
lock.unlock();
},
)
.unwrap();
sender.send(()).unwrap();
event_loop.dispatch(None, &mut lock).unwrap();
// We should have been locked twice so far
assert_eq!(lock.lock.1.get(), 2);
// And we should have received one event
assert_eq!(lock.lock.2.get(), 1);
event_loop.handle().disable(&token).unwrap();
event_loop
.dispatch(Some(Duration::ZERO), &mut lock)
.unwrap();
assert_eq!(lock.lock.1.get(), 2);
event_loop.handle().enable(&token).unwrap();
event_loop
.dispatch(Some(Duration::ZERO), &mut lock)
.unwrap();
assert_eq!(lock.lock.1.get(), 3);
event_loop.handle().remove(token);
event_loop
.dispatch(Some(Duration::ZERO), &mut lock)
.unwrap();
assert_eq!(lock.lock.1.get(), 3);
assert_eq!(lock.lock.2.get(), 1);
#[derive(Clone)]
struct Lock {
lock: Rc<(Cell<bool>, Cell<u32>, Cell<u32>)>,
}
impl Lock {
fn lock(&self) {
if self.lock.0.get() {
panic!();
}
// Increase the count
self.lock.1.set(self.lock.1.get() + 1);