use tokio::task::spawn_blocking as threadpool

actix-threadpool/Cargo.toml

@@ -18,10 +18,4 @@ name = "actix_threadpool"
 path = "src/lib.rs"
 
 [dependencies]
-derive_more = "0.99.2"
+tokio = { version = "1", features = ["parking_lot", "rt"] }
-futures-channel = "0.3.7"
-parking_lot = "0.11"
-lazy_static = "1.3"
-log = "0.4"
-num_cpus = "1.10"
-threadpool = "1.7"

actix-threadpool/src/lib.rs

@@ -9,49 +9,24 @@ use std::future::Future;
 use std::pin::Pin;
 use std::task::{Context, Poll};
 
-use derive_more::Display;
+use tokio::task::JoinHandle;
-use futures_channel::oneshot;
-use parking_lot::Mutex;
-use threadpool::ThreadPool;
-
-/// Env variable for default cpu pool size.
-const ENV_CPU_POOL_VAR: &str = "ACTIX_THREADPOOL";
-
-lazy_static::lazy_static! {
-    pub(crate) static ref DEFAULT_POOL: Mutex<ThreadPool> = {
-        let num = std::env::var(ENV_CPU_POOL_VAR)
-            .map_err(|_| ())
-            .and_then(|val| {
-                val.parse().map_err(|_| log::warn!(
-                    "Can not parse {} value, using default",
-                    ENV_CPU_POOL_VAR,
-                ))
-            })
-            .unwrap_or_else(|_| num_cpus::get() * 5);
-        Mutex::new(
-            threadpool::Builder::new()
-                .thread_name("actix-web".to_owned())
-                .num_threads(num)
-                .build(),
-        )
-    };
-}
-
-thread_local! {
-    static POOL: ThreadPool = {
-        DEFAULT_POOL.lock().clone()
-    };
-}
 
 /// Blocking operation execution error
-#[derive(Debug, Display)]
+#[derive(Debug)]
 pub enum BlockingError<E: fmt::Debug> {
-    #[display(fmt = "{:?}", _0)]
     Error(E),
-    #[display(fmt = "Thread pool is gone")]
     Canceled,
 }
 
+impl<E: fmt::Debug> fmt::Display for BlockingError<E> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match *self {
+            Self::Error(ref e) => write!(f, "{:?}", e),
+            Self::Canceled => write!(f, "Thread pool is gone"),
+        }
+    }
+}
+
 impl<E: fmt::Debug> std::error::Error for BlockingError<E> {}
 
 /// Execute blocking function on a thread pool, returns future that resolves
@@ -62,35 +37,25 @@ where
     I: Send + 'static,
     E: Send + fmt::Debug + 'static,
 {
-    let (tx, rx) = oneshot::channel();
+    let handle = tokio::task::spawn_blocking(f);
-    POOL.with(|pool| {
-        pool.execute(move || {
-            if !tx.is_canceled() {
-                let _ = tx.send(f());
-            }
-        })
-    });
 
-    CpuFuture { rx }
+    CpuFuture { handle }
 }
 
 /// Blocking operation completion future. It resolves with results
 /// of blocking function execution.
 pub struct CpuFuture<I, E> {
-    rx: oneshot::Receiver<Result<I, E>>,
+    handle: JoinHandle<Result<I, E>>,
 }
 
 impl<I, E: fmt::Debug> Future for CpuFuture<I, E> {
     type Output = Result<I, BlockingError<E>>;
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let rx = Pin::new(&mut self.rx);
+        match Pin::new(&mut self.handle).poll(cx) {
-        let res = match rx.poll(cx) {
+            Poll::Pending => Poll::Pending,
-            Poll::Pending => return Poll::Pending,
+            Poll::Ready(Ok(res)) => Poll::Ready(res.map_err(BlockingError::Error)),
-            Poll::Ready(res) => res
+            Poll::Ready(Err(_)) => Poll::Ready(Err(BlockingError::Canceled)),
-                .map_err(|_| BlockingError::Canceled)
+        }
-                .and_then(|res| res.map_err(BlockingError::Error)),
-        };
-        Poll::Ready(res)
     }
 }