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authorAlex Auvolat <alex@adnab.me>2021-03-18 19:27:02 +0100
committerAlex Auvolat <alex@adnab.me>2021-03-18 19:27:02 +0100
commit4348bde180887f5185ca6da6024476e8e8fb2fe6 (patch)
tree8a35f0e4229d15665af7673eebcaa1b3d75a73cb /src/util/background.rs
parent5b659b28ce6bef15072d2fc93f777aa8ff73b2d8 (diff)
parent4eb16e886388f35d2bdee52b16922421004cf132 (diff)
downloadgarage-4348bde180887f5185ca6da6024476e8e8fb2fe6.tar.gz
garage-4348bde180887f5185ca6da6024476e8e8fb2fe6.zip
Merge branch 'dev-0.2'
Diffstat (limited to 'src/util/background.rs')
-rw-r--r--src/util/background.rs185
1 files changed, 105 insertions, 80 deletions
diff --git a/src/util/background.rs b/src/util/background.rs
index 937062dd..b5eb8bc8 100644
--- a/src/util/background.rs
+++ b/src/util/background.rs
@@ -1,12 +1,11 @@
use core::future::Future;
use std::pin::Pin;
+use std::sync::Arc;
+use std::time::Duration;
-use futures::future::join_all;
+use futures::future::*;
use futures::select;
-use futures_util::future::*;
-use std::sync::Arc;
-use tokio::sync::Mutex;
-use tokio::sync::{mpsc, watch, Notify};
+use tokio::sync::{mpsc, watch, Mutex};
use crate::error::Error;
@@ -14,54 +13,106 @@ type JobOutput = Result<(), Error>;
type Job = Pin<Box<dyn Future<Output = JobOutput> + Send>>;
pub struct BackgroundRunner {
- n_runners: usize,
pub stop_signal: watch::Receiver<bool>,
queue_in: mpsc::UnboundedSender<(Job, bool)>,
- queue_out: Mutex<mpsc::UnboundedReceiver<(Job, bool)>>,
- job_notify: Notify,
-
- workers: Mutex<Vec<tokio::task::JoinHandle<()>>>,
+ worker_in: mpsc::UnboundedSender<tokio::task::JoinHandle<()>>,
}
impl BackgroundRunner {
- pub fn new(n_runners: usize, stop_signal: watch::Receiver<bool>) -> Arc<Self> {
+ pub fn new(
+ n_runners: usize,
+ stop_signal: watch::Receiver<bool>,
+ ) -> (Arc<Self>, tokio::task::JoinHandle<()>) {
+ let (worker_in, mut worker_out) = mpsc::unbounded_channel();
+
+ let stop_signal_2 = stop_signal.clone();
+ let await_all_done = tokio::spawn(async move {
+ loop {
+ let wkr = {
+ select! {
+ item = worker_out.recv().fuse() => {
+ match item {
+ Some(x) => x,
+ None => break,
+ }
+ }
+ _ = tokio::time::sleep(Duration::from_secs(5)).fuse() => {
+ if *stop_signal_2.borrow() {
+ break;
+ } else {
+ continue;
+ }
+ }
+ }
+ };
+ if let Err(e) = wkr.await {
+ error!("Error while awaiting for worker: {}", e);
+ }
+ }
+ });
+
let (queue_in, queue_out) = mpsc::unbounded_channel();
- Arc::new(Self {
- n_runners,
- stop_signal,
- queue_in,
- queue_out: Mutex::new(queue_out),
- job_notify: Notify::new(),
- workers: Mutex::new(Vec::new()),
- })
- }
+ let queue_out = Arc::new(Mutex::new(queue_out));
- pub async fn run(self: Arc<Self>) {
- let mut workers = self.workers.lock().await;
- for i in 0..self.n_runners {
- workers.push(tokio::spawn(self.clone().runner(i)));
- }
- drop(workers);
+ for i in 0..n_runners {
+ let queue_out = queue_out.clone();
+ let stop_signal = stop_signal.clone();
- let mut stop_signal = self.stop_signal.clone();
- while let Some(exit_now) = stop_signal.recv().await {
- if exit_now {
- let mut workers = self.workers.lock().await;
- let workers_vec = workers.drain(..).collect::<Vec<_>>();
- join_all(workers_vec).await;
- return;
- }
+ worker_in
+ .send(tokio::spawn(async move {
+ loop {
+ let (job, cancellable) = {
+ select! {
+ item = wait_job(&queue_out).fuse() => match item {
+ // We received a task, process it
+ Some(x) => x,
+ // We received a signal that no more tasks will ever be sent
+ // because the sending side was dropped. Exit now.
+ None => break,
+ },
+ _ = tokio::time::sleep(Duration::from_secs(5)).fuse() => {
+ if *stop_signal.borrow() {
+ // Nothing has been going on for 5 secs, and we are shutting
+ // down. Exit now.
+ break;
+ } else {
+ // Nothing is going on but we don't want to exit.
+ continue;
+ }
+ }
+ }
+ };
+ if cancellable && *stop_signal.borrow() {
+ continue;
+ }
+ if let Err(e) = job.await {
+ error!("Job failed: {}", e)
+ }
+ }
+ info!("Background worker {} exiting", i);
+ }))
+ .unwrap();
}
+
+ let bgrunner = Arc::new(Self {
+ stop_signal,
+ queue_in,
+ worker_in,
+ });
+ (bgrunner, await_all_done)
}
+ // Spawn a task to be run in background
pub fn spawn<T>(&self, job: T)
where
T: Future<Output = JobOutput> + Send + 'static,
{
let boxed: Job = Box::pin(job);
- let _: Result<_, _> = self.queue_in.clone().send((boxed, false));
- self.job_notify.notify();
+ self.queue_in
+ .send((boxed, false))
+ .map_err(|_| "could not put job in queue")
+ .unwrap();
}
pub fn spawn_cancellable<T>(&self, job: T)
@@ -69,56 +120,30 @@ impl BackgroundRunner {
T: Future<Output = JobOutput> + Send + 'static,
{
let boxed: Job = Box::pin(job);
- let _: Result<_, _> = self.queue_in.clone().send((boxed, true));
- self.job_notify.notify();
+ self.queue_in
+ .send((boxed, true))
+ .map_err(|_| "could not put job in queue")
+ .unwrap();
}
- pub async fn spawn_worker<F, T>(&self, name: String, worker: F)
+ pub fn spawn_worker<F, T>(&self, name: String, worker: F)
where
F: FnOnce(watch::Receiver<bool>) -> T + Send + 'static,
- T: Future<Output = JobOutput> + Send + 'static,
+ T: Future<Output = ()> + Send + 'static,
{
- let mut workers = self.workers.lock().await;
let stop_signal = self.stop_signal.clone();
- workers.push(tokio::spawn(async move {
- if let Err(e) = worker(stop_signal).await {
- error!("Worker stopped with error: {}, error: {}", name, e);
- } else {
- info!("Worker exited successfully: {}", name);
- }
- }));
- }
-
- async fn runner(self: Arc<Self>, i: usize) {
- let mut stop_signal = self.stop_signal.clone();
- loop {
- let must_exit: bool = *stop_signal.borrow();
- if let Some(job) = self.dequeue_job(must_exit).await {
- if let Err(e) = job.await {
- error!("Job failed: {}", e)
- }
- } else {
- if must_exit {
- info!("Background runner {} exiting", i);
- return;
- }
- select! {
- _ = self.job_notify.notified().fuse() => (),
- _ = stop_signal.recv().fuse() => (),
- }
- }
- }
+ let task = tokio::spawn(async move {
+ info!("Worker started: {}", name);
+ worker(stop_signal).await;
+ info!("Worker exited: {}", name);
+ });
+ self.worker_in
+ .send(task)
+ .map_err(|_| "could not put job in queue")
+ .unwrap();
}
+}
- async fn dequeue_job(&self, must_exit: bool) -> Option<Job> {
- let mut queue = self.queue_out.lock().await;
- while let Ok((job, cancellable)) = queue.try_recv() {
- if cancellable && must_exit {
- continue;
- } else {
- return Some(job);
- }
- }
- None
- }
+async fn wait_job(q: &Mutex<mpsc::UnboundedReceiver<(Job, bool)>>) -> Option<(Job, bool)> {
+ q.lock().await.recv().await
}