add support for io-uring (#374)

Co-authored-by: Rob Ede <robjtede@icloud.com>

Author: fakeshadow

.cargo/config.toml

@@ -1,5 +1,23 @@
 [alias]
 chk = "check --workspace --all-features --tests --examples --bins"
 lint = "clippy --workspace --all-features --tests --examples --bins -- -Dclippy::todo"
-ci-test = "test --workspace --all-features --lib --tests --no-fail-fast -- --nocapture"
+
 ci-doctest = "test --workspace --all-features --doc --no-fail-fast -- --nocapture"
+
+# just check the library (without dev deps)
+ci-check-min = "hack --workspace check --no-default-features"
+ci-check-lib = "hack --workspace --feature-powerset --exclude-features io-uring check"
+ci-check-lib-linux = "hack --workspace --feature-powerset check"
+
+# check everything
+ci-check = "hack --workspace --feature-powerset --exclude-features io-uring check --tests --examples"
+ci-check-linux = "hack --workspace --feature-powerset check --tests --examples"
+
+# tests avoiding io-uring feature
+ci-test = "hack test --workspace --exclude=actix-rt --exclude=actix-server --all-features --lib --tests --no-fail-fast -- --nocapture"
+ci-test-rt = "    hack --feature-powerset --exclude-features io-uring test --package=actix-rt     --lib --tests --no-fail-fast -- --nocapture"
+ci-test-server = "hack --feature-powerset --exclude-features io-uring test --package=actix-server --lib --tests --no-fail-fast -- --nocapture"
+
+# test with io-uring feature
+ci-test-rt-linux = "    hack --feature-powerset test --package=actix-rt     --lib --tests --no-fail-fast -- --nocapture"
+ci-test-server-linux = "hack --feature-powerset test --package=actix-server --lib --tests --no-fail-fast -- --nocapture"

.github/workflows/ci.yml

@@ -75,36 +75,47 @@ jobs:
           command: install
           args: cargo-hack
 
-      - name: check minimal
+      - name: check lib
+        if: >
+          matrix.target.os != 'ubuntu-latest'
+          && matrix.target.triple != 'x86_64-pc-windows-gnu'
         uses: actions-rs/cargo@v1
-        with:
-          command: hack
-          args: check --workspace --no-default-features
-
-      - name: check minimal + tests
+        with: { command: ci-check-lib }
+      - name: check lib
+        if: matrix.target.os == 'ubuntu-latest'
         uses: actions-rs/cargo@v1
-        with:
-          command: hack
-          args: check --workspace --no-default-features --tests --examples
-
-      - name: check default
+        with: { command: ci-check-lib-linux }
+      - name: check lib
+        if: matrix.target.triple == 'x86_64-pc-windows-gnu'
         uses: actions-rs/cargo@v1
-        with:
-          command: check
-          args: --workspace --tests --examples
-
+        with: { command: ci-check-min }
+      
       - name: check full
         # TODO: compile OpenSSL and run tests on MinGW
-        if: matrix.target.triple != 'x86_64-pc-windows-gnu'
+        if: >
+          matrix.target.os != 'ubuntu-latest'
+          && matrix.target.triple != 'x86_64-pc-windows-gnu'
         uses: actions-rs/cargo@v1
-        with:
-          command: check
-          args: --workspace --all-features --tests --examples
+        with: { command: ci-check }
+      - name: check all
+        if: matrix.target.os == 'ubuntu-latest'
+        uses: actions-rs/cargo@v1
+        with: { command: ci-check-linux }
 
       - name: tests
-        if: matrix.target.triple != 'x86_64-pc-windows-gnu'
-        uses: actions-rs/cargo@v1
-        with: { command: ci-test }
+        if: >
+          matrix.target.os != 'ubuntu-latest'
+          && matrix.target.triple != 'x86_64-pc-windows-gnu'
+        run: |
+          cargo ci-test
+          cargo ci-test-rt
+          cargo ci-test-server
+      - name: tests
+        if: matrix.target.os == 'ubuntu-latest'
+        run: |
+          cargo ci-test
+          cargo ci-test-rt-linux
+          cargo ci-test-server-linux
 
       - name: Generate coverage file
         if: >
@@ -120,8 +131,7 @@ jobs:
           && matrix.version == 'stable'
           && github.ref == 'refs/heads/master'
         uses: codecov/codecov-action@v1
-        with:
-          file: cobertura.xml
+        with: { file: cobertura.xml }
 
       - name: Clear the cargo caches
         run: |

actix-rt/CHANGES.md

@@ -1,9 +1,11 @@
 # Changes
 
 ## Unreleased - 2021-xx-xx
+* Add `io-uring` feature for enabling async file I/O on linux. [#374]
 * The `spawn` method can now resolve with non-unit outputs. [#369]
 
 [#369]: https://github.com/actix/actix-net/pull/369
+[#374]: https://github.com/actix/actix-net/pull/374
 
 
 ## 2.2.0 - 2021-03-29

actix-rt/Cargo.toml

@@ -21,13 +21,17 @@ path = "src/lib.rs"
 [features]
 default = ["macros"]
 macros = ["actix-macros"]
+io-uring = ["tokio-uring"]
 
 [dependencies]
 actix-macros = { version = "0.2.0", optional = true }
 
 futures-core = { version = "0.3", default-features = false }
 tokio = { version = "1.3", features = ["rt", "net", "parking_lot", "signal", "sync", "time"] }
 
+[target.'cfg(target_os = "linux")'.dependencies]
+tokio-uring = { version = "0.1", optional = true }
+
 [dev-dependencies]
 tokio = { version = "1.2", features = ["full"] }
 hyper = { version = "0.14", default-features = false, features = ["server", "tcp", "http1"] }

actix-rt/src/arbiter.rs

@@ -9,12 +9,9 @@ use std::{
 };
 
 use futures_core::ready;
-use tokio::{sync::mpsc, task::LocalSet};
+use tokio::sync::mpsc;
 
-use crate::{
-    runtime::{default_tokio_runtime, Runtime},
-    system::{System, SystemCommand},
-};
+use crate::system::{System, SystemCommand};
 
 pub(crate) static COUNT: AtomicUsize = AtomicUsize::new(0);
 
@@ -98,16 +95,19 @@ impl Arbiter {
     ///
     /// # Panics
     /// Panics if a [System] is not registered on the current thread.
+    #[cfg(not(all(target_os = "linux", feature = "io-uring")))]
     #[allow(clippy::new_without_default)]
     pub fn new() -> Arbiter {
         Self::with_tokio_rt(|| {
-            default_tokio_runtime().expect("Cannot create new Arbiter's Runtime.")
+            crate::runtime::default_tokio_runtime()
+                .expect("Cannot create new Arbiter's Runtime.")
         })
     }
 
     /// Spawn a new Arbiter using the [Tokio Runtime](tokio-runtime) returned from a closure.
     ///
     /// [tokio-runtime]: tokio::runtime::Runtime
+    #[cfg(not(all(target_os = "linux", feature = "io-uring")))]
     #[doc(hidden)]
     pub fn with_tokio_rt<F>(runtime_factory: F) -> Arbiter
     where
@@ -127,7 +127,7 @@ impl Arbiter {
             .spawn({
                 let tx = tx.clone();
                 move || {
-                    let rt = Runtime::from(runtime_factory());
+                    let rt = crate::runtime::Runtime::from(runtime_factory());
                     let hnd = ArbiterHandle::new(tx);
 
                     System::set_current(sys);
@@ -159,15 +159,67 @@ impl Arbiter {
         Arbiter { tx, thread_handle }
     }
 
-    /// Sets up an Arbiter runner in a new System using the provided runtime local task set.
-    pub(crate) fn in_new_system(local: &LocalSet) -> ArbiterHandle {
+    /// Spawn a new Arbiter thread and start its event loop with `tokio-uring` runtime.
+    ///
+    /// # Panics
+    /// Panics if a [System] is not registered on the current thread.
+    #[cfg(all(target_os = "linux", feature = "io-uring"))]
+    #[allow(clippy::new_without_default)]
+    pub fn new() -> Arbiter {
+        let sys = System::current();
+        let system_id = sys.id();
+        let arb_id = COUNT.fetch_add(1, Ordering::Relaxed);
+
+        let name = format!("actix-rt|system:{}|arbiter:{}", system_id, arb_id);
+        let (tx, rx) = mpsc::unbounded_channel();
+
+        let (ready_tx, ready_rx) = std::sync::mpsc::channel::<()>();
+
+        let thread_handle = thread::Builder::new()
+            .name(name.clone())
+            .spawn({
+                let tx = tx.clone();
+                move || {
+                    let hnd = ArbiterHandle::new(tx);
+
+                    System::set_current(sys);
+
+                    HANDLE.with(|cell| *cell.borrow_mut() = Some(hnd.clone()));
+
+                    // register arbiter
+                    let _ = System::current()
+                        .tx()
+                        .send(SystemCommand::RegisterArbiter(arb_id, hnd));
+
+                    ready_tx.send(()).unwrap();
+
+                    // run arbiter event processing loop
+                    tokio_uring::start(ArbiterRunner { rx });
+
+                    // deregister arbiter
+                    let _ = System::current()
+                        .tx()
+                        .send(SystemCommand::DeregisterArbiter(arb_id));
+                }
+            })
+            .unwrap_or_else(|err| {
+                panic!("Cannot spawn Arbiter's thread: {:?}. {:?}", &name, err)
+            });
+
+        ready_rx.recv().unwrap();
+
+        Arbiter { tx, thread_handle }
+    }
+
+    /// Sets up an Arbiter runner in a new System using the environment's local set.
+    pub(crate) fn in_new_system() -> ArbiterHandle {
         let (tx, rx) = mpsc::unbounded_channel();
 
         let hnd = ArbiterHandle::new(tx);
 
         HANDLE.with(|cell| *cell.borrow_mut() = Some(hnd.clone()));
 
-        local.spawn_local(ArbiterRunner { rx });
+        crate::spawn(ArbiterRunner { rx });
 
         hnd
     }

actix-rt/src/lib.rs

@@ -32,13 +32,20 @@
 //! arbiter.stop();
 //! arbiter.join().unwrap();
 //! ```
+//!
+//! # `io-uring` Support
+//! There is experimental support for using io-uring with this crate by enabling the
+//! `io-uring` feature. For now, it is semver exempt.
 
 #![deny(rust_2018_idioms, nonstandard_style)]
 #![allow(clippy::type_complexity)]
 #![warn(missing_docs)]
 #![doc(html_logo_url = "https://actix.rs/img/logo.png")]
 #![doc(html_favicon_url = "https://actix.rs/favicon.ico")]
 
+#[cfg(all(not(target_os = "linux"), feature = "io-uring"))]
+compile_error!("io_uring is a linux only feature.");
+
 use std::future::Future;
 
 use tokio::task::JoinHandle;

actix-rt/src/runtime.rs

@@ -31,11 +31,6 @@ impl Runtime {
         })
     }
 
-    /// Reference to local task set.
-    pub(crate) fn local_set(&self) -> &LocalSet {
-        &self.local
-    }
-
     /// Offload a future onto the single-threaded runtime.
     ///
     /// The returned join handle can be used to await the future's result.

actix-rt/src/system.rs

@@ -54,7 +54,7 @@ impl System {
         let (sys_tx, sys_rx) = mpsc::unbounded_channel();
 
         let rt = Runtime::from(runtime_factory());
-        let sys_arbiter = Arbiter::in_new_system(rt.local_set());
+        let sys_arbiter = rt.block_on(async { Arbiter::in_new_system() });
         let system = System::construct(sys_tx, sys_arbiter.clone());
 
         system

actix-rt/tests/tests.rs

@@ -1,10 +1,6 @@
 use std::{
     future::Future,
-    sync::{
-        atomic::{AtomicBool, Ordering},
-        mpsc::channel,
-        Arc,
-    },
+    sync::mpsc::channel,
     thread,
     time::{Duration, Instant},
 };
@@ -221,8 +217,8 @@ fn system_stop_stops_arbiters() {
     System::current().stop();
     sys.run().unwrap();
 
-    // account for slightly slow thread de-spawns (only observed on windows)
-    thread::sleep(Duration::from_millis(100));
+    // account for slightly slow thread de-spawns
+    thread::sleep(Duration::from_millis(500));
 
     // arbiter should be dead and return false
     assert!(!Arbiter::current().spawn_fn(|| {}));
@@ -231,6 +227,7 @@ fn system_stop_stops_arbiters() {
     arb.join().unwrap();
 }
 
+#[cfg(not(feature = "io-uring"))]
 #[test]
 fn new_system_with_tokio() {
     let (tx, rx) = channel();
@@ -263,8 +260,14 @@ fn new_system_with_tokio() {
     assert_eq!(rx.recv().unwrap(), 42);
 }
 
+#[cfg(not(feature = "io-uring"))]
 #[test]
 fn new_arbiter_with_tokio() {
+    use std::sync::{
+        atomic::{AtomicBool, Ordering},
+        Arc,
+    };
+
     let _ = System::new();
 
     let arb = Arbiter::with_tokio_rt(|| {
@@ -323,3 +326,32 @@ fn spawn_local() {
         h(actix_rt::spawn(async { 1 }));
     })
 }
+
+#[cfg(all(target_os = "linux", feature = "io-uring"))]
+#[test]
+fn tokio_uring_arbiter() {
+    let system = System::new();
+    let (tx, rx) = std::sync::mpsc::channel();
+
+    Arbiter::new().spawn(async move {
+        let handle = actix_rt::spawn(async move {
+            let f = tokio_uring::fs::File::create("test.txt").await.unwrap();
+            let buf = b"Hello World!";
+
+            let (res, _) = f.write_at(&buf[..], 0).await;
+            assert!(res.is_ok());
+
+            f.sync_all().await.unwrap();
+            f.close().await.unwrap();
+
+            std::fs::remove_file("test.txt").unwrap();
+        });
+
+        handle.await.unwrap();
+        tx.send(true).unwrap();
+    });
+
+    assert!(rx.recv().unwrap());
+
+    drop(system);
+}

actix-server/CHANGES.md

@@ -3,11 +3,13 @@
 ## Unreleased - 2021-xx-xx
 * Remove `config` module. `ServiceConfig`, `ServiceRuntime` public types are removed due to this change. [#349]
 * Remove `ServerBuilder::configure` [#349]
+* Add `io-uring` feature for enabling async file I/O on linux. [#374]
 * Server no long listens to SIGHUP signal.
   It actually did not take any action when receiving SIGHUP, the only thing SIGHUP did was to stop
   the Server from receiving any future signal, because the `Signals` future stops on the first
   signal received [#389]
 
+[#374]: https://github.com/actix/actix-net/pull/374
 [#349]: https://github.com/actix/actix-net/pull/349
 [#389]: https://github.com/actix/actix-net/pull/389