init futures module

glib/src/futures/mod.rs

@@ -0,0 +1,277 @@
+use futures_task::FutureObj;
+use futures_task::LocalFutureObj;
+use futures_task::LocalSpawn;
+use futures_task::Poll;
+use futures_task::Spawn;
+use futures_util::future::Either;
+use futures_util::future::Select;
+use futures_util::pin_mut;
+
+use crate::FutureWithTimeoutError;
+use crate::JoinHandle;
+use crate::MainContext;
+use crate::Priority;
+use crate::SpawnWithinJoinHandle;
+use std::future::{Future, IntoFuture};
+use std::{pin::Pin, time::Duration};
+
+#[derive(Default, Debug, Eq, PartialEq)]
+pub enum SchedulingPrecision {
+    #[default]
+    Millisecond,
+    Second,
+}
+
+#[derive(Default, Debug, Eq, PartialEq)]
+pub struct Sleep {
+    duration: Duration,
+    priority: Priority,
+    precision: SchedulingPrecision,
+}
+
+impl IntoFuture for Sleep {
+    type Output = ();
+
+    type IntoFuture = Pin<Box<dyn Future<Output = ()> + Send + 'static>>;
+
+    fn into_future(self) -> Self::IntoFuture {
+        use SchedulingPrecision::*;
+        match self.precision {
+            Millisecond => crate::timeout_future_with_priority(self.priority, self.duration),
+            Second => crate::timeout_future_seconds_with_priority(
+                self.priority,
+                self.duration.as_secs_f32().round() as u32,
+            ),
+        }
+    }
+}
+
+impl Sleep {
+    pub fn priority(mut self, priority: Priority) -> Self {
+        self.priority = priority;
+        self
+    }
+    pub fn precision(mut self, precision: SchedulingPrecision) -> Self {
+        self.precision = precision;
+        self
+    }
+}
+
+pub fn sleep(duration: Duration) -> Sleep {
+    Sleep {
+        priority: crate::PRIORITY_DEFAULT,
+        duration,
+        precision: SchedulingPrecision::Millisecond,
+    }
+}
+
+/// Options to build a future that will run until the specified `duration` passes.
+#[derive(Default, Debug, Eq, PartialEq)]
+pub struct Timeout<F: Future> {
+    duration: Duration,
+    priority: Priority,
+    precision: SchedulingPrecision,
+    future: F,
+}
+pub struct TimeoutFuture<F> {
+    select: Select<F, Pin<Box<dyn Future<Output = ()> + Send + 'static>>>,
+}
+
+impl<F: Future + Unpin> Future for TimeoutFuture<F> {
+    type Output = Result<F::Output, FutureWithTimeoutError>;
+
+    fn poll(
+        mut self: Pin<&mut Self>,
+        cx: &mut futures_task::Context<'_>,
+    ) -> futures_task::Poll<Self::Output> {
+        let select = &mut self.as_mut().select;
+        pin_mut!(select);
+        match select.poll(cx) {
+            Poll::Ready(res) => match res {
+                Either::Left(value) => Poll::Ready(Ok(value.0)),
+                Either::Right(_timedout) => Poll::Ready(Err(FutureWithTimeoutError)),
+            },
+            Poll::Pending => Poll::Pending,
+        }
+    }
+}
+
+impl<F: Future + std::marker::Unpin + 'static> IntoFuture for Timeout<F> {
+    type Output = Result<F::Output, FutureWithTimeoutError>;
+
+    type IntoFuture = TimeoutFuture<F>;
+
+    fn into_future(self) -> Self::IntoFuture {
+        let sleep = Sleep {
+            duration: self.duration,
+            precision: self.precision,
+            priority: self.priority,
+        };
+        TimeoutFuture {
+            select: futures_util::future::select(self.future, sleep.into_future()),
+        }
+    }
+}
+
+impl<F: Future> Timeout<F> {
+    pub fn priority(mut self, priority: Priority) -> Self {
+        self.priority = priority;
+        self
+    }
+    pub fn precision(mut self, precision: SchedulingPrecision) -> Self {
+        self.precision = precision;
+        self
+    }
+}
+
+pub fn timeout<F: Future>(
+    duration: Duration,
+    future: F,
+) -> Timeout<impl Future<Output = F::Output>> {
+    Timeout {
+        duration,
+        priority: crate::PRIORITY_DEFAULT,
+        future: Box::pin(future),
+        precision: SchedulingPrecision::Millisecond,
+    }
+}
+
+#[derive(Default, Debug, Eq, PartialEq)]
+pub struct SpawnOptions {
+    priority: Priority,
+    context: Option<crate::MainContext>,
+}
+
+impl SpawnOptions {
+    pub fn new() -> Self {
+        SpawnOptions {
+            priority: crate::PRIORITY_DEFAULT,
+            context: None,
+        }
+    }
+    pub fn priority(&mut self, priority: Priority) -> &mut Self {
+        self.priority = priority;
+        self
+    }
+    pub fn context(&mut self, context: MainContext) -> &mut Self {
+        self.context = Some(context);
+        self
+    }
+    pub fn spawn_local<F: Future + 'static>(&self, future: F) -> JoinHandle<<F as Future>::Output> {
+        self.context
+            .as_ref()
+            .unwrap_or(&MainContext::default())
+            .spawn_local_with_priority(self.priority, future)
+    }
+    pub fn spawn<R: Send + 'static, F: Future<Output = R> + Send + 'static>(
+        &self,
+        future: F,
+    ) -> JoinHandle<R> {
+        self.context
+            .as_ref()
+            .unwrap_or(&MainContext::default())
+            .spawn_with_priority(self.priority, future)
+    }
+    pub fn spawn_from_within<F: Future + 'static>(
+        &self,
+        func: impl FnOnce() -> F + Send + 'static,
+    ) -> SpawnWithinJoinHandle<<F as Future>::Output> {
+        self.context
+            .as_ref()
+            .unwrap_or(&MainContext::default())
+            .spawn_from_within_with_priority(self.priority, func)
+    }
+}
+
+impl From<MainContext> for SpawnOptions {
+    fn from(value: MainContext) -> Self {
+        let mut opts = SpawnOptions::new();
+        opts.context(value);
+        opts
+    }
+}
+
+// The following trait implementations will reuse the methods from `SpawnOptions`, so the spawned
+// futures will have the correct priority chosen by the user.
+// This is an improvement compared to `MainContext::spawn_obj`, which doesn't let you specify the
+// priority.
+impl Spawn for SpawnOptions {
+    fn spawn_obj(&self, future: FutureObj<'static, ()>) -> Result<(), futures_task::SpawnError> {
+        self.spawn(future);
+        Ok(())
+    }
+}
+impl LocalSpawn for SpawnOptions {
+    fn spawn_local_obj(
+        &self,
+        future: LocalFutureObj<'static, ()>,
+    ) -> Result<(), futures_task::SpawnError> {
+        self.spawn_local(future);
+        Ok(())
+    }
+}
+
+#[test]
+fn test_sleep() {
+    use crate::MainContext;
+
+    let c = MainContext::new();
+
+    c.block_on(async {
+        sleep(Duration::from_millis(10)).await;
+        sleep(Duration::from_secs(1))
+            .priority(crate::PRIORITY_HIGH)
+            .precision(SchedulingPrecision::Second)
+            .await;
+    });
+}
+
+#[test]
+fn test_timeout() {
+    use crate::{MainContext, MainLoop};
+    use std::future::ready;
+
+    let c = MainContext::new();
+    let l = MainLoop::new(Some(&c), false);
+
+    let tt = timeout(Duration::from_millis(10), ready(()));
+    let l_clone = l.clone();
+    c.spawn_local(async move {
+        tt.await.unwrap();
+        l_clone.quit();
+    });
+    l.run();
+
+    let tt = timeout(Duration::from_millis(10), async move { 2 }).priority(crate::PRIORITY_HIGH);
+    let l_clone = l.clone();
+    c.spawn(async move {
+        tt.await.unwrap();
+        l_clone.quit();
+    });
+    l.run();
+}
+
+#[test]
+fn spawn() {
+    use crate::{MainContext, MainLoop};
+
+    let c = MainContext::new();
+    let l = MainLoop::new(Some(&c), false);
+
+    let l_clone = l.clone();
+    SpawnOptions::new().spawn(async move {
+        2;
+        l_clone.quit();
+    });
+    l.run();
+
+    let l_clone = l.clone();
+    SpawnOptions::new()
+        .context(c)
+        .priority(crate::PRIORITY_HIGH)
+        .spawn_local(async move {
+            2;
+            l_clone.quit();
+        });
+    l.run();
+}

glib/src/lib.rs

@@ -130,6 +130,7 @@ mod convert;
 pub use self::convert::*;
 mod enums;
 mod functions;
+pub mod futures;
 pub use self::functions::*;
 mod key_file;
 pub mod prelude;