1
0
forked from ROMEO/nexosim
2024-09-12 15:35:31 +02:00

985 lines
30 KiB
Rust

//! Scheduling functions and types.
use std::error::Error;
use std::future::Future;
use std::hash::{Hash, Hasher};
use std::pin::Pin;
use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::{Arc, Mutex};
use std::task::{Context, Poll};
use std::time::Duration;
use std::{fmt, ptr};
use pin_project_lite::pin_project;
use recycle_box::{coerce_box, RecycleBox};
use crate::channel::Sender;
use crate::executor::Executor;
use crate::model::Model;
use crate::ports::InputFn;
use crate::simulation::Address;
use crate::time::{AtomicTimeReader, MonotonicTime};
use crate::util::priority_queue::PriorityQueue;
/// Scheduler.
#[derive(Clone)]
pub struct Scheduler {
scheduler_queue: Arc<Mutex<SchedulerQueue>>,
time: AtomicTimeReader,
}
impl Scheduler {
pub(crate) fn new(scheduler_queue: Arc<Mutex<SchedulerQueue>>, time: AtomicTimeReader) -> Self {
Self {
scheduler_queue,
time,
}
}
/// Returns the current simulation time.
///
/// # Examples
///
/// ```
/// use asynchronix::simulation::Scheduler;
/// use asynchronix::time::MonotonicTime;
///
/// fn is_third_millenium(scheduler: &Scheduler) -> bool {
/// let time = scheduler.time();
/// time >= MonotonicTime::new(978307200, 0).unwrap()
/// && time < MonotonicTime::new(32535216000, 0).unwrap()
/// }
/// ```
pub fn time(&self) -> MonotonicTime {
self.time.try_read().expect("internal simulation error: could not perform a synchronized read of the simulation time")
}
/// Schedules an action at a future time.
///
/// An error is returned if the specified time is not in the future of the
/// current simulation time.
///
/// If multiple actions send events at the same simulation time to the same
/// model, these events are guaranteed to be processed according to the
/// scheduling order of the actions.
pub fn schedule(&self, deadline: impl Deadline, action: Action) -> Result<(), SchedulingError> {
let mut scheduler_queue = self.scheduler_queue.lock().unwrap();
let now = self.time();
let time = deadline.into_time(now);
if now >= time {
return Err(SchedulingError::InvalidScheduledTime);
}
// The channel ID is set to the same value for all actions. This
// ensures that the relative scheduling order of all source events is
// preserved, which is important if some of them target the same models.
// The value 0 was chosen as it prevents collisions with channel IDs as
// the latter are always non-zero.
scheduler_queue.insert((time, 0), action);
Ok(())
}
/// Schedules an event at a future time.
///
/// An error is returned if the specified time is not in the future of the
/// current simulation time.
///
/// Events scheduled for the same time and targeting the same model are
/// guaranteed to be processed according to the scheduling order.
///
/// See also: [`LocalScheduler::schedule_event`](LocalScheduler::schedule_event).
pub fn schedule_event<M, F, T, S>(
&self,
deadline: impl Deadline,
func: F,
arg: T,
address: impl Into<Address<M>>,
) -> Result<(), SchedulingError>
where
M: Model,
F: for<'a> InputFn<'a, M, T, S>,
T: Send + Clone + 'static,
S: Send + 'static,
{
let mut scheduler_queue = self.scheduler_queue.lock().unwrap();
let now = self.time();
let time = deadline.into_time(now);
if now >= time {
return Err(SchedulingError::InvalidScheduledTime);
}
let sender = address.into().0;
let channel_id = sender.channel_id();
let action = Action::new(OnceAction::new(process_event(func, arg, sender)));
scheduler_queue.insert((time, channel_id), action);
Ok(())
}
/// Schedules a cancellable event at a future time and returns an event key.
///
/// An error is returned if the specified time is not in the future of the
/// current simulation time.
///
/// Events scheduled for the same time and targeting the same model are
/// guaranteed to be processed according to the scheduling order.
///
/// See also: [`LocalScheduler::schedule_keyed_event`](LocalScheduler::schedule_keyed_event).
pub fn schedule_keyed_event<M, F, T, S>(
&self,
deadline: impl Deadline,
func: F,
arg: T,
address: impl Into<Address<M>>,
) -> Result<ActionKey, SchedulingError>
where
M: Model,
F: for<'a> InputFn<'a, M, T, S>,
T: Send + Clone + 'static,
S: Send + 'static,
{
let mut scheduler_queue = self.scheduler_queue.lock().unwrap();
let now = self.time();
let time = deadline.into_time(now);
if now >= time {
return Err(SchedulingError::InvalidScheduledTime);
}
let event_key = ActionKey::new();
let sender = address.into().0;
let channel_id = sender.channel_id();
let action = Action::new(KeyedOnceAction::new(
|ek| send_keyed_event(ek, func, arg, sender),
event_key.clone(),
));
scheduler_queue.insert((time, channel_id), action);
Ok(event_key)
}
/// Schedules a periodically recurring event at a future time.
///
/// An error is returned if the specified time is not in the future of the
/// current simulation time or if the specified period is null.
///
/// Events scheduled for the same time and targeting the same model are
/// guaranteed to be processed according to the scheduling order.
///
/// See also: [`LocalScheduler::schedule_periodic_event`](LocalScheduler::schedule_periodic_event).
pub fn schedule_periodic_event<M, F, T, S>(
&self,
deadline: impl Deadline,
period: Duration,
func: F,
arg: T,
address: impl Into<Address<M>>,
) -> Result<(), SchedulingError>
where
M: Model,
F: for<'a> InputFn<'a, M, T, S> + Clone,
T: Send + Clone + 'static,
S: Send + 'static,
{
let mut scheduler_queue = self.scheduler_queue.lock().unwrap();
let now = self.time();
let time = deadline.into_time(now);
if now >= time {
return Err(SchedulingError::InvalidScheduledTime);
}
if period.is_zero() {
return Err(SchedulingError::NullRepetitionPeriod);
}
let sender = address.into().0;
let channel_id = sender.channel_id();
let action = Action::new(PeriodicAction::new(
|| process_event(func, arg, sender),
period,
));
scheduler_queue.insert((time, channel_id), action);
Ok(())
}
/// Schedules a cancellable, periodically recurring event at a future time
/// and returns an event key.
///
/// An error is returned if the specified time is not in the future of the
/// current simulation time or if the specified period is null.
///
/// Events scheduled for the same time and targeting the same model are
/// guaranteed to be processed according to the scheduling order.
///
/// See also: [`LocalScheduler::schedule_keyed_periodic_event`](LocalScheduler::schedule_keyed_periodic_event).
pub fn schedule_keyed_periodic_event<M, F, T, S>(
&self,
deadline: impl Deadline,
period: Duration,
func: F,
arg: T,
address: impl Into<Address<M>>,
) -> Result<ActionKey, SchedulingError>
where
M: Model,
F: for<'a> InputFn<'a, M, T, S> + Clone,
T: Send + Clone + 'static,
S: Send + 'static,
{
let mut scheduler_queue = self.scheduler_queue.lock().unwrap();
let now = self.time();
let time = deadline.into_time(now);
if now >= time {
return Err(SchedulingError::InvalidScheduledTime);
}
if period.is_zero() {
return Err(SchedulingError::NullRepetitionPeriod);
}
let event_key = ActionKey::new();
let sender = address.into().0;
let channel_id = sender.channel_id();
let action = Action::new(KeyedPeriodicAction::new(
|ek| send_keyed_event(ek, func, arg, sender),
period,
event_key.clone(),
));
scheduler_queue.insert((time, channel_id), action);
Ok(event_key)
}
}
impl fmt::Debug for Scheduler {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("Scheduler")
.field("time", &self.time())
.finish_non_exhaustive()
}
}
/// Local scheduler.
pub struct LocalScheduler<M: Model> {
pub(crate) scheduler: Scheduler,
address: Address<M>,
}
impl<M: Model> LocalScheduler<M> {
pub(crate) fn new(scheduler: Scheduler, address: Address<M>) -> Self {
Self { scheduler, address }
}
/// Returns the current simulation time.
///
/// # Examples
///
/// ```
/// use asynchronix::model::Model;
/// use asynchronix::simulation::LocalScheduler;
/// use asynchronix::time::MonotonicTime;
///
/// fn is_third_millenium<M: Model>(scheduler: &LocalScheduler<M>) -> bool {
/// let time = scheduler.time();
/// time >= MonotonicTime::new(978307200, 0).unwrap()
/// && time < MonotonicTime::new(32535216000, 0).unwrap()
/// }
/// ```
pub fn time(&self) -> MonotonicTime {
self.scheduler.time()
}
/// Schedules an event at a future time.
///
/// An error is returned if the specified deadline is not in the future of
/// the current simulation time.
///
/// # Examples
///
/// ```
/// use std::time::Duration;
///
/// use asynchronix::model::{Context, Model};
///
/// // A timer.
/// pub struct Timer {}
///
/// impl Timer {
/// // Sets an alarm [input port].
/// pub fn set(&mut self, setting: Duration, context: &Context<Self>) {
/// if context.scheduler.schedule_event(setting, Self::ring, ()).is_err() {
/// println!("The alarm clock can only be set for a future time");
/// }
/// }
///
/// // Rings [private input port].
/// fn ring(&mut self) {
/// println!("Brringggg");
/// }
/// }
///
/// impl Model for Timer {}
/// ```
pub fn schedule_event<F, T, S>(
&self,
deadline: impl Deadline,
func: F,
arg: T,
) -> Result<(), SchedulingError>
where
F: for<'a> InputFn<'a, M, T, S>,
T: Send + Clone + 'static,
S: Send + 'static,
{
self.scheduler
.schedule_event(deadline, func, arg, &self.address)
}
/// Schedules a cancellable event at a future time and returns an action
/// key.
///
/// An error is returned if the specified deadline is not in the future of
/// the current simulation time.
///
/// # Examples
///
/// ```
/// use asynchronix::model::{Context, Model};
/// use asynchronix::simulation::ActionKey;
/// use asynchronix::time::MonotonicTime;
///
/// // An alarm clock that can be cancelled.
/// #[derive(Default)]
/// pub struct CancellableAlarmClock {
/// event_key: Option<ActionKey>,
/// }
///
/// impl CancellableAlarmClock {
/// // Sets an alarm [input port].
/// pub fn set(&mut self, setting: MonotonicTime, context: &Context<Self>) {
/// self.cancel();
/// match context.scheduler.schedule_keyed_event(setting, Self::ring, ()) {
/// Ok(event_key) => self.event_key = Some(event_key),
/// Err(_) => println!("The alarm clock can only be set for a future time"),
/// };
/// }
///
/// // Cancels the current alarm, if any [input port].
/// pub fn cancel(&mut self) {
/// self.event_key.take().map(|k| k.cancel());
/// }
///
/// // Rings the alarm [private input port].
/// fn ring(&mut self) {
/// println!("Brringggg!");
/// }
/// }
///
/// impl Model for CancellableAlarmClock {}
/// ```
pub fn schedule_keyed_event<F, T, S>(
&self,
deadline: impl Deadline,
func: F,
arg: T,
) -> Result<ActionKey, SchedulingError>
where
F: for<'a> InputFn<'a, M, T, S>,
T: Send + Clone + 'static,
S: Send + 'static,
{
let event_key = self
.scheduler
.schedule_keyed_event(deadline, func, arg, &self.address)?;
Ok(event_key)
}
/// Schedules a periodically recurring event at a future time.
///
/// An error is returned if the specified deadline is not in the future of
/// the current simulation time or if the specified period is null.
///
/// # Examples
///
/// ```
/// use std::time::Duration;
///
/// use asynchronix::model::{Context, Model};
/// use asynchronix::time::MonotonicTime;
///
/// // An alarm clock beeping at 1Hz.
/// pub struct BeepingAlarmClock {}
///
/// impl BeepingAlarmClock {
/// // Sets an alarm [input port].
/// pub fn set(&mut self, setting: MonotonicTime, context: &Context<Self>) {
/// if context.scheduler.schedule_periodic_event(
/// setting,
/// Duration::from_secs(1), // 1Hz = 1/1s
/// Self::beep,
/// ()
/// ).is_err() {
/// println!("The alarm clock can only be set for a future time");
/// }
/// }
///
/// // Emits a single beep [private input port].
/// fn beep(&mut self) {
/// println!("Beep!");
/// }
/// }
///
/// impl Model for BeepingAlarmClock {}
/// ```
pub fn schedule_periodic_event<F, T, S>(
&self,
deadline: impl Deadline,
period: Duration,
func: F,
arg: T,
) -> Result<(), SchedulingError>
where
F: for<'a> InputFn<'a, M, T, S> + Clone,
T: Send + Clone + 'static,
S: Send + 'static,
{
self.scheduler
.schedule_periodic_event(deadline, period, func, arg, &self.address)
}
/// Schedules a cancellable, periodically recurring event at a future time
/// and returns an action key.
///
/// An error is returned if the specified deadline is not in the future of
/// the current simulation time or if the specified period is null.
///
/// # Examples
///
/// ```
/// use std::time::Duration;
///
/// use asynchronix::model::{Context, Model};
/// use asynchronix::simulation::ActionKey;
/// use asynchronix::time::MonotonicTime;
///
/// // An alarm clock beeping at 1Hz that can be cancelled before it sets off, or
/// // stopped after it sets off.
/// #[derive(Default)]
/// pub struct CancellableBeepingAlarmClock {
/// event_key: Option<ActionKey>,
/// }
///
/// impl CancellableBeepingAlarmClock {
/// // Sets an alarm [input port].
/// pub fn set(&mut self, setting: MonotonicTime, context: &Context<Self>) {
/// self.cancel();
/// match context.scheduler.schedule_keyed_periodic_event(
/// setting,
/// Duration::from_secs(1), // 1Hz = 1/1s
/// Self::beep,
/// ()
/// ) {
/// Ok(event_key) => self.event_key = Some(event_key),
/// Err(_) => println!("The alarm clock can only be set for a future time"),
/// };
/// }
///
/// // Cancels or stops the alarm [input port].
/// pub fn cancel(&mut self) {
/// self.event_key.take().map(|k| k.cancel());
/// }
///
/// // Emits a single beep [private input port].
/// fn beep(&mut self) {
/// println!("Beep!");
/// }
/// }
///
/// impl Model for CancellableBeepingAlarmClock {}
/// ```
pub fn schedule_keyed_periodic_event<F, T, S>(
&self,
deadline: impl Deadline,
period: Duration,
func: F,
arg: T,
) -> Result<ActionKey, SchedulingError>
where
F: for<'a> InputFn<'a, M, T, S> + Clone,
T: Send + Clone + 'static,
S: Send + 'static,
{
let event_key = self.scheduler.schedule_keyed_periodic_event(
deadline,
period,
func,
arg,
&self.address,
)?;
Ok(event_key)
}
}
impl<M: Model> Clone for LocalScheduler<M> {
fn clone(&self) -> Self {
Self {
scheduler: self.scheduler.clone(),
address: self.address.clone(),
}
}
}
impl<M: Model> fmt::Debug for LocalScheduler<M> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("LocalScheduler")
.field("time", &self.time())
.field("address", &self.address)
.finish_non_exhaustive()
}
}
/// Shorthand for the scheduler queue type.
// Why use both time and channel ID as the key? The short answer is that this
// ensures that events targeting the same model are sent in the order they were
// scheduled. More precisely, this ensures that events targeting the same model
// are ordered contiguously in the priority queue, which in turns allows the
// event loop to easily aggregate such events into single futures and thus
// control their relative order of execution.
pub(crate) type SchedulerQueue = PriorityQueue<(MonotonicTime, usize), Action>;
/// Trait abstracting over time-absolute and time-relative deadlines.
///
/// This trait is implemented by [`std::time::Duration`] and
/// [`MonotonicTime`].
pub trait Deadline {
/// Make this deadline into an absolute timestamp, using the provided
/// current time as a reference.
fn into_time(self, now: MonotonicTime) -> MonotonicTime;
}
impl Deadline for Duration {
#[inline(always)]
fn into_time(self, now: MonotonicTime) -> MonotonicTime {
now + self
}
}
impl Deadline for MonotonicTime {
#[inline(always)]
fn into_time(self, _: MonotonicTime) -> MonotonicTime {
self
}
}
/// Managed handle to a scheduled action.
///
/// An `AutoActionKey` is a managed handle to a scheduled action that cancels
/// action on drop.
#[derive(Debug)]
#[must_use = "managed action key shall be used"]
pub struct AutoActionKey {
is_cancelled: Arc<AtomicBool>,
}
impl Drop for AutoActionKey {
fn drop(&mut self) {
self.is_cancelled.store(true, Ordering::Relaxed);
}
}
/// Handle to a scheduled action.
///
/// An `ActionKey` can be used to cancel a scheduled action.
#[derive(Clone, Debug)]
#[must_use = "prefer unkeyed scheduling methods if the action is never cancelled"]
pub struct ActionKey {
is_cancelled: Arc<AtomicBool>,
}
impl ActionKey {
/// Creates a key for a pending action.
pub(crate) fn new() -> Self {
Self {
is_cancelled: Arc::new(AtomicBool::new(false)),
}
}
/// Checks whether the action was cancelled.
pub(crate) fn is_cancelled(&self) -> bool {
self.is_cancelled.load(Ordering::Relaxed)
}
/// Cancels the associated action.
pub fn cancel(self) {
self.is_cancelled.store(true, Ordering::Relaxed);
}
/// Converts action key to a managed key.
pub fn into_auto(self) -> AutoActionKey {
AutoActionKey {
is_cancelled: self.is_cancelled,
}
}
}
impl PartialEq for ActionKey {
/// Implements equality by considering clones to be equivalent, rather than
/// keys with the same `is_cancelled` value.
fn eq(&self, other: &Self) -> bool {
ptr::eq(&*self.is_cancelled, &*other.is_cancelled)
}
}
impl Eq for ActionKey {}
impl Hash for ActionKey {
/// Implements `Hash`` by considering clones to be equivalent, rather than
/// keys with the same `is_cancelled` value.
fn hash<H>(&self, state: &mut H)
where
H: Hasher,
{
ptr::hash(&*self.is_cancelled, state)
}
}
/// Error returned when the scheduled time or the repetition period are invalid.
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
pub enum SchedulingError {
/// The scheduled time does not lie in the future of the current simulation
/// time.
InvalidScheduledTime,
/// The repetition period is zero.
NullRepetitionPeriod,
}
impl fmt::Display for SchedulingError {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
Self::InvalidScheduledTime => write!(
fmt,
"the scheduled time should be in the future of the current simulation time"
),
Self::NullRepetitionPeriod => write!(fmt, "the repetition period cannot be zero"),
}
}
}
impl Error for SchedulingError {}
/// A possibly periodic, possibly cancellable action that can be scheduled or
/// processed immediately.
pub struct Action {
inner: Box<dyn ActionInner>,
}
impl Action {
/// Creates a new `Action` from an `ActionInner`.
pub(crate) fn new<S: ActionInner>(s: S) -> Self {
Self { inner: Box::new(s) }
}
/// Reports whether the action was cancelled.
pub(crate) fn is_cancelled(&self) -> bool {
self.inner.is_cancelled()
}
/// If this is a periodic action, returns a boxed clone of this action and
/// its repetition period; otherwise returns `None`.
pub(crate) fn next(&self) -> Option<(Action, Duration)> {
self.inner
.next()
.map(|(inner, period)| (Self { inner }, period))
}
/// Returns a boxed future that performs the action.
pub(crate) fn into_future(self) -> Pin<Box<dyn Future<Output = ()> + Send>> {
self.inner.into_future()
}
/// Spawns the future that performs the action onto the provided executor.
///
/// This method is typically more efficient that spawning the boxed future
/// from `into_future` since it can directly spawn the unboxed future.
pub(crate) fn spawn_and_forget(self, executor: &Executor) {
self.inner.spawn_and_forget(executor)
}
}
impl fmt::Debug for Action {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("SchedulableEvent").finish_non_exhaustive()
}
}
/// Trait abstracting over the inner type of an action.
pub(crate) trait ActionInner: Send + 'static {
/// Reports whether the action was cancelled.
fn is_cancelled(&self) -> bool;
/// If this is a periodic action, returns a boxed clone of this action and
/// its repetition period; otherwise returns `None`.
fn next(&self) -> Option<(Box<dyn ActionInner>, Duration)>;
/// Returns a boxed future that performs the action.
fn into_future(self: Box<Self>) -> Pin<Box<dyn Future<Output = ()> + Send>>;
/// Spawns the future that performs the action onto the provided executor.
///
/// This method is typically more efficient that spawning the boxed future
/// from `into_future` since it can directly spawn the unboxed future.
fn spawn_and_forget(self: Box<Self>, executor: &Executor);
}
pin_project! {
/// An object that can be converted to a future performing a single
/// non-cancellable action.
///
/// Note that this particular action is in fact already a future: since the
/// future cannot be cancelled and the action does not need to be cloned,
/// there is no need to defer the construction of the future. This makes
/// `into_future` a trivial cast, which saves a boxing operation.
pub(crate) struct OnceAction<F> {
#[pin]
fut: F,
}
}
impl<F> OnceAction<F>
where
F: Future<Output = ()> + Send + 'static,
{
/// Constructs a new `OnceAction`.
pub(crate) fn new(fut: F) -> Self {
OnceAction { fut }
}
}
impl<F> Future for OnceAction<F>
where
F: Future,
{
type Output = F::Output;
#[inline(always)]
fn poll(self: std::pin::Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
self.project().fut.poll(cx)
}
}
impl<F> ActionInner for OnceAction<F>
where
F: Future<Output = ()> + Send + 'static,
{
fn is_cancelled(&self) -> bool {
false
}
fn next(&self) -> Option<(Box<dyn ActionInner>, Duration)> {
None
}
fn into_future(self: Box<Self>) -> Pin<Box<dyn Future<Output = ()> + Send>> {
// No need for boxing, type coercion is enough here.
Box::into_pin(self)
}
fn spawn_and_forget(self: Box<Self>, executor: &Executor) {
executor.spawn_and_forget(*self);
}
}
/// An object that can be converted to a future performing a non-cancellable,
/// periodic action.
pub(crate) struct PeriodicAction<G, F>
where
G: (FnOnce() -> F) + Clone + Send + 'static,
F: Future<Output = ()> + Send + 'static,
{
/// A clonable generator for the associated future.
gen: G,
/// The action repetition period.
period: Duration,
}
impl<G, F> PeriodicAction<G, F>
where
G: (FnOnce() -> F) + Clone + Send + 'static,
F: Future<Output = ()> + Send + 'static,
{
/// Constructs a new `PeriodicAction`.
pub(crate) fn new(gen: G, period: Duration) -> Self {
Self { gen, period }
}
}
impl<G, F> ActionInner for PeriodicAction<G, F>
where
G: (FnOnce() -> F) + Clone + Send + 'static,
F: Future<Output = ()> + Send + 'static,
{
fn is_cancelled(&self) -> bool {
false
}
fn next(&self) -> Option<(Box<dyn ActionInner>, Duration)> {
let event = Box::new(Self::new(self.gen.clone(), self.period));
Some((event, self.period))
}
fn into_future(self: Box<Self>) -> Pin<Box<dyn Future<Output = ()> + Send>> {
Box::pin((self.gen)())
}
fn spawn_and_forget(self: Box<Self>, executor: &Executor) {
executor.spawn_and_forget((self.gen)());
}
}
/// An object that can be converted to a future performing a single, cancellable
/// action.
pub(crate) struct KeyedOnceAction<G, F>
where
G: (FnOnce(ActionKey) -> F) + Send + 'static,
F: Future<Output = ()> + Send + 'static,
{
/// A generator for the associated future.
gen: G,
/// The event cancellation key.
event_key: ActionKey,
}
impl<G, F> KeyedOnceAction<G, F>
where
G: (FnOnce(ActionKey) -> F) + Send + 'static,
F: Future<Output = ()> + Send + 'static,
{
/// Constructs a new `KeyedOnceAction`.
pub(crate) fn new(gen: G, event_key: ActionKey) -> Self {
Self { gen, event_key }
}
}
impl<G, F> ActionInner for KeyedOnceAction<G, F>
where
G: (FnOnce(ActionKey) -> F) + Send + 'static,
F: Future<Output = ()> + Send + 'static,
{
fn is_cancelled(&self) -> bool {
self.event_key.is_cancelled()
}
fn next(&self) -> Option<(Box<dyn ActionInner>, Duration)> {
None
}
fn into_future(self: Box<Self>) -> Pin<Box<dyn Future<Output = ()> + Send>> {
Box::pin((self.gen)(self.event_key))
}
fn spawn_and_forget(self: Box<Self>, executor: &Executor) {
executor.spawn_and_forget((self.gen)(self.event_key));
}
}
/// An object that can be converted to a future performing a periodic,
/// cancellable action.
pub(crate) struct KeyedPeriodicAction<G, F>
where
G: (FnOnce(ActionKey) -> F) + Clone + Send + 'static,
F: Future<Output = ()> + Send + 'static,
{
/// A clonable generator for associated future.
gen: G,
/// The repetition period.
period: Duration,
/// The event cancellation key.
event_key: ActionKey,
}
impl<G, F> KeyedPeriodicAction<G, F>
where
G: (FnOnce(ActionKey) -> F) + Clone + Send + 'static,
F: Future<Output = ()> + Send + 'static,
{
/// Constructs a new `KeyedPeriodicAction`.
pub(crate) fn new(gen: G, period: Duration, event_key: ActionKey) -> Self {
Self {
gen,
period,
event_key,
}
}
}
impl<G, F> ActionInner for KeyedPeriodicAction<G, F>
where
G: (FnOnce(ActionKey) -> F) + Clone + Send + 'static,
F: Future<Output = ()> + Send + 'static,
{
fn is_cancelled(&self) -> bool {
self.event_key.is_cancelled()
}
fn next(&self) -> Option<(Box<dyn ActionInner>, Duration)> {
let event = Box::new(Self::new(
self.gen.clone(),
self.period,
self.event_key.clone(),
));
Some((event, self.period))
}
fn into_future(self: Box<Self>) -> Pin<Box<dyn Future<Output = ()> + Send>> {
Box::pin((self.gen)(self.event_key))
}
fn spawn_and_forget(self: Box<Self>, executor: &Executor) {
executor.spawn_and_forget((self.gen)(self.event_key));
}
}
/// Asynchronously sends a non-cancellable event to a model input.
pub(crate) async fn process_event<M, F, T, S>(func: F, arg: T, sender: Sender<M>)
where
M: Model,
F: for<'a> InputFn<'a, M, T, S>,
T: Send + 'static,
{
let _ = sender
.send(
move |model: &mut M,
scheduler,
recycle_box: RecycleBox<()>|
-> RecycleBox<dyn Future<Output = ()> + Send + '_> {
let fut = func.call(model, arg, scheduler);
coerce_box!(RecycleBox::recycle(recycle_box, fut))
},
)
.await;
}
/// Asynchronously sends a cancellable event to a model input.
pub(crate) async fn send_keyed_event<M, F, T, S>(
event_key: ActionKey,
func: F,
arg: T,
sender: Sender<M>,
) where
M: Model,
F: for<'a> InputFn<'a, M, T, S>,
T: Send + Clone + 'static,
{
let _ = sender
.send(
move |model: &mut M,
scheduler,
recycle_box: RecycleBox<()>|
-> RecycleBox<dyn Future<Output = ()> + Send + '_> {
let fut = async move {
// Only perform the call if the event wasn't cancelled.
if !event_key.is_cancelled() {
func.call(model, arg, scheduler).await;
}
};
coerce_box!(RecycleBox::recycle(recycle_box, fut))
},
)
.await;
}