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forked from ROMEO/nexosim
2024-05-10 14:32:07 +02:00

510 lines
15 KiB
Rust

use std::fmt;
use std::sync::{Arc, Mutex};
use std::time::Duration;
use crate::channel::Sender;
use crate::executor::Executor;
use crate::ports::InputFn;
use crate::simulation::{
self, schedule_event_at_unchecked, schedule_keyed_event_at_unchecked,
schedule_periodic_event_at_unchecked, schedule_periodic_keyed_event_at_unchecked, ActionKey,
Deadline, Mailbox, SchedulerQueue, SchedulingError,
};
use crate::time::{MonotonicTime, TearableAtomicTime};
use crate::util::sync_cell::SyncCellReader;
use super::Model;
/// A local context for models.
///
/// A `Context` is a handle to the global context associated to a model
/// instance. It can be used by the model to retrieve the simulation time or
/// schedule delayed actions on itself.
///
/// ### Caveat: self-scheduling `async` methods
///
/// Due to a current rustc issue, `async` methods that schedule themselves will
/// not compile unless an explicit `Send` bound is added to the returned future.
/// This can be done by replacing the `async` signature with a partially
/// desugared signature such as:
///
/// ```ignore
/// fn self_scheduling_method<'a>(
/// &'a mut self,
/// arg: MyEventType,
/// context: &'a Context<Self>
/// ) -> impl Future<Output=()> + Send + 'a {
/// async move {
/// /* implementation */
/// }
/// }
/// ```
///
/// Self-scheduling methods which are not `async` are not affected by this
/// issue.
///
/// # Examples
///
/// A model that sends a greeting after some delay.
///
/// ```
/// use std::time::Duration;
/// use asynchronix::model::{Context, Model};
/// use asynchronix::ports::Output;
///
/// #[derive(Default)]
/// pub struct DelayedGreeter {
/// msg_out: Output<String>,
/// }
///
/// impl DelayedGreeter {
/// // Triggers a greeting on the output port after some delay [input port].
/// pub async fn greet_with_delay(&mut self, delay: Duration, context: &Context<Self>) {
/// let time = context.time();
/// let greeting = format!("Hello, this message was scheduled at: {:?}.", time);
///
/// if delay.is_zero() {
/// self.msg_out.send(greeting).await;
/// } else {
/// context.schedule_event(delay, Self::send_msg, greeting).unwrap();
/// }
/// }
///
/// // Sends a message to the output [private input port].
/// async fn send_msg(&mut self, msg: String) {
/// self.msg_out.send(msg).await;
/// }
/// }
/// impl Model for DelayedGreeter {}
/// ```
// The self-scheduling caveat seems related to this issue:
// https://github.com/rust-lang/rust/issues/78649
pub struct Context<M: Model> {
name: String,
sender: Sender<M>,
scheduler_queue: Arc<Mutex<SchedulerQueue>>,
time: SyncCellReader<TearableAtomicTime>,
}
impl<M: Model> Context<M> {
/// Creates a new local context.
pub(crate) fn new(
name: String,
sender: Sender<M>,
scheduler_queue: Arc<Mutex<SchedulerQueue>>,
time: SyncCellReader<TearableAtomicTime>,
) -> Self {
Self {
name,
sender,
scheduler_queue,
time,
}
}
/// Returns the model instance name.
pub fn name(&self) -> &str {
&self.name
}
/// Returns the current simulation time.
///
/// # Examples
///
/// ```
/// use asynchronix::model::{Context, Model};
/// use asynchronix::time::MonotonicTime;
///
/// fn is_third_millenium<M: Model>(context: &Context<M>) -> bool {
/// let time = context.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 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.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,
{
let now = self.time();
let time = deadline.into_time(now);
if now >= time {
return Err(SchedulingError::InvalidScheduledTime);
}
let sender = self.sender.clone();
schedule_event_at_unchecked(time, func, arg, sender, &self.scheduler_queue);
Ok(())
}
/// 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.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 now = self.time();
let time = deadline.into_time(now);
if now >= time {
return Err(SchedulingError::InvalidScheduledTime);
}
let sender = self.sender.clone();
let event_key =
schedule_keyed_event_at_unchecked(time, func, arg, sender, &self.scheduler_queue);
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.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,
{
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 = self.sender.clone();
schedule_periodic_event_at_unchecked(
time,
period,
func,
arg,
sender,
&self.scheduler_queue,
);
Ok(())
}
/// 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.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 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 = self.sender.clone();
let event_key = schedule_periodic_keyed_event_at_unchecked(
time,
period,
func,
arg,
sender,
&self.scheduler_queue,
);
Ok(event_key)
}
}
impl<M: Model> fmt::Debug for Context<M> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("Context").finish_non_exhaustive()
}
}
/// A setup context for models.
///
/// A `SetupContext` can be used by models during the setup stage to
/// create submodels and add them to the simulation bench.
///
/// # Examples
///
/// A model that contains two connected submodels.
///
/// ```
/// use std::time::Duration;
/// use asynchronix::model::{Model, SetupContext};
/// use asynchronix::ports::Output;
/// use asynchronix::simulation::Mailbox;
///
/// #[derive(Default)]
/// pub struct SubmodelA {
/// out: Output<u32>,
/// }
///
/// impl Model for SubmodelA {}
///
/// #[derive(Default)]
/// pub struct SubmodelB {}
///
/// impl SubmodelB {
/// pub async fn input(&mut self, value: u32) {
/// println!("Received {}", value);
/// }
/// }
///
/// impl Model for SubmodelB {}
///
/// #[derive(Default)]
/// pub struct Parent {}
///
/// impl Model for Parent {
/// fn setup(
/// &mut self,
/// setup_context: &SetupContext<Self>) {
/// let mut a = SubmodelA::default();
/// let b = SubmodelB::default();
/// let a_mbox = Mailbox::new();
/// let b_mbox = Mailbox::new();
/// let a_name = setup_context.name().to_string() + "::a";
/// let b_name = setup_context.name().to_string() + "::b";
///
/// a.out.connect(SubmodelB::input, &b_mbox);
///
/// setup_context.add_model(a, a_mbox, a_name);
/// setup_context.add_model(b, b_mbox, b_name);
/// }
/// }
///
/// ```
#[derive(Debug)]
pub struct SetupContext<'a, M: Model> {
/// Mailbox of the model.
pub mailbox: &'a Mailbox<M>,
context: &'a Context<M>,
executor: &'a Executor,
}
impl<'a, M: Model> SetupContext<'a, M> {
/// Creates a new local context.
pub(crate) fn new(
mailbox: &'a Mailbox<M>,
context: &'a Context<M>,
executor: &'a Executor,
) -> Self {
Self {
mailbox,
context,
executor,
}
}
/// Returns the model instance name.
pub fn name(&self) -> &str {
&self.context.name
}
/// Adds a new model and its mailbox to the simulation bench.
///
/// The `name` argument needs not be unique (it can be an empty string) and
/// is used for convenience for model instance identification (e.g. for
/// logging purposes).
pub fn add_model<N: Model>(&self, model: N, mailbox: Mailbox<N>, name: impl Into<String>) {
let mut submodel_name = name.into();
if !self.context.name().is_empty() && !submodel_name.is_empty() {
submodel_name = self.context.name().to_string() + "." + &submodel_name;
}
simulation::add_model(
model,
mailbox,
submodel_name,
self.context.scheduler_queue.clone(),
self.context.time.clone(),
self.executor,
);
}
}