Upgrade rust/crates/tokio to 1.12.0

Test: make
Change-Id: I4b0bd405c0b615f886e5a6606e0bf7c0ac7c6699

1 files changed, 128 insertions, 3 deletions

diff --git a/src/runtime/builder.rs b/src/runtime/builder.rs
index 51bf8c8..91c365f 100644
--- a/src/runtime/builder.rs
+++ b/src/runtime/builder.rs
@@ -70,6 +70,12 @@ pub struct Builder {
     /// To run before each worker thread stops
     pub(super) before_stop: Option<Callback>,
 
+    /// To run before each worker thread is parked.
+    pub(super) before_park: Option<Callback>,
+
+    /// To run after each thread is unparked.
+    pub(super) after_unpark: Option<Callback>,
+
     /// Customizable keep alive timeout for BlockingPool
     pub(super) keep_alive: Option<Duration>,
 }
@@ -135,6 +141,8 @@ impl Builder {
             // No worker thread callbacks
             after_start: None,
             before_stop: None,
+            before_park: None,
+            after_unpark: None,
 
             keep_alive: None,
         }
@@ -374,6 +382,120 @@ impl Builder {
         self
     }
 
+    /// Executes function `f` just before a thread is parked (goes idle).
+    /// `f` is called within the Tokio context, so functions like [`tokio::spawn`](crate::spawn)
+    /// can be called, and may result in this thread being unparked immediately.
+    ///
+    /// This can be used to start work only when the executor is idle, or for bookkeeping
+    /// and monitoring purposes.
+    ///
+    /// Note: There can only be one park callback for a runtime; calling this function
+    /// more than once replaces the last callback defined, rather than adding to it.
+    ///
+    /// # Examples
+    ///
+    /// ## Multithreaded executor
+    /// ```
+    /// # use std::sync::Arc;
+    /// # use std::sync::atomic::{AtomicBool, Ordering};
+    /// # use tokio::runtime;
+    /// # use tokio::sync::Barrier;
+    /// # pub fn main() {
+    /// let once = AtomicBool::new(true);
+    /// let barrier = Arc::new(Barrier::new(2));
+    ///
+    /// let runtime = runtime::Builder::new_multi_thread()
+    ///     .worker_threads(1)
+    ///     .on_thread_park({
+    ///         let barrier = barrier.clone();
+    ///         move || {
+    ///             let barrier = barrier.clone();
+    ///             if once.swap(false, Ordering::Relaxed) {
+    ///                 tokio::spawn(async move { barrier.wait().await; });
+    ///            }
+    ///         }
+    ///     })
+    ///     .build()
+    ///     .unwrap();
+    ///
+    /// runtime.block_on(async {
+    ///    barrier.wait().await;
+    /// })
+    /// # }
+    /// ```
+    /// ## Current thread executor
+    /// ```
+    /// # use std::sync::Arc;
+    /// # use std::sync::atomic::{AtomicBool, Ordering};
+    /// # use tokio::runtime;
+    /// # use tokio::sync::Barrier;
+    /// # pub fn main() {
+    /// let once = AtomicBool::new(true);
+    /// let barrier = Arc::new(Barrier::new(2));
+    ///
+    /// let runtime = runtime::Builder::new_current_thread()
+    ///     .on_thread_park({
+    ///         let barrier = barrier.clone();
+    ///         move || {
+    ///             let barrier = barrier.clone();
+    ///             if once.swap(false, Ordering::Relaxed) {
+    ///                 tokio::spawn(async move { barrier.wait().await; });
+    ///            }
+    ///         }
+    ///     })
+    ///     .build()
+    ///     .unwrap();
+    ///
+    /// runtime.block_on(async {
+    ///    barrier.wait().await;
+    /// })
+    /// # }
+    /// ```
+    #[cfg(not(loom))]
+    pub fn on_thread_park<F>(&mut self, f: F) -> &mut Self
+    where
+        F: Fn() + Send + Sync + 'static,
+    {
+        self.before_park = Some(std::sync::Arc::new(f));
+        self
+    }
+
+    /// Executes function `f` just after a thread unparks (starts executing tasks).
+    ///
+    /// This is intended for bookkeeping and monitoring use cases; note that work
+    /// in this callback will increase latencies when the application has allowed one or
+    /// more runtime threads to go idle.
+    ///
+    /// Note: There can only be one unpark callback for a runtime; calling this function
+    /// more than once replaces the last callback defined, rather than adding to it.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use tokio::runtime;
+    ///
+    /// # pub fn main() {
+    /// let runtime = runtime::Builder::new_multi_thread()
+    ///     .on_thread_unpark(|| {
+    ///         println!("thread unparking");
+    ///     })
+    ///     .build();
+    ///
+    /// runtime.unwrap().block_on(async {
+    ///    tokio::task::yield_now().await;
+    ///    println!("Hello from Tokio!");
+    /// })
+    /// # }
+    /// ```
+    #[cfg(not(loom))]
+    pub fn on_thread_unpark<F>(&mut self, f: F) -> &mut Self
+    where
+        F: Fn() + Send + Sync + 'static,
+    {
+        self.after_unpark = Some(std::sync::Arc::new(f));
+        self
+    }
+
     /// Creates the configured `Runtime`.
     ///
     /// The returned `Runtime` instance is ready to spawn tasks.
@@ -441,7 +563,8 @@ impl Builder {
         // there are no futures ready to do something, it'll let the timer or
         // the reactor to generate some new stimuli for the futures to continue
         // in their life.
-        let scheduler = BasicScheduler::new(driver);
+        let scheduler =
+            BasicScheduler::new(driver, self.before_park.clone(), self.after_unpark.clone());
         let spawner = Spawner::Basic(scheduler.spawner().clone());
 
         // Blocking pool
@@ -546,7 +669,7 @@ cfg_rt_multi_thread! {
 
             let (driver, resources) = driver::Driver::new(self.get_cfg())?;
 
-            let (scheduler, launch) = ThreadPool::new(core_threads, Parker::new(driver));
+            let (scheduler, launch) = ThreadPool::new(core_threads, Parker::new(driver), self.before_park.clone(), self.after_unpark.clone());
             let spawner = Spawner::ThreadPool(scheduler.spawner().clone());
 
             // Create the blocking pool
@@ -587,7 +710,9 @@ impl fmt::Debug for Builder {
             )
             .field("thread_stack_size", &self.thread_stack_size)
             .field("after_start", &self.after_start.as_ref().map(|_| "..."))
-            .field("before_stop", &self.after_start.as_ref().map(|_| "..."))
+            .field("before_stop", &self.before_stop.as_ref().map(|_| "..."))
+            .field("before_park", &self.before_park.as_ref().map(|_| "..."))
+            .field("after_unpark", &self.after_unpark.as_ref().map(|_| "..."))
             .finish()
     }
 }