Merge pull request #283 from japaric/rm-scoped_threadpool

use std:🧵:scope instead of scoped_threadpool

Cargo.toml

@@ -27,9 +27,6 @@ mpmc_large = []
 # This flag has no version guarantee, the `defmt` dependency can be updated in a patch release
 defmt-impl = ["defmt"]
 
-[target.'cfg(not(target_os = "none"))'.dev-dependencies]
-scoped_threadpool = "0.1.8"
-
 [target.thumbv6m-none-eabi.dependencies]
 atomic-polyfill = { version = "0.1.2", optional = true }
 
@@ -65,5 +62,8 @@ version = "0.1"
 version = ">=0.2.0,<0.4"
 optional = true
 
+[build-dependencies]
+rustc_version = "0.4.0"
+
 [package.metadata.docs.rs]
 all-features = true

build.rs

@@ -2,6 +2,8 @@
 
 use std::{env, error::Error};
 
+use rustc_version::Channel;
+
 fn main() -> Result<(), Box<dyn Error>> {
     let target = env::var("TARGET")?;
 
@@ -66,5 +68,12 @@ fn main() -> Result<(), Box<dyn Error>> {
         _ => {}
     }
 
+    if !matches!(
+        rustc_version::version_meta().unwrap().channel,
+        Channel::Stable | Channel::Beta
+    ) {
+        println!("cargo:rustc-cfg=unstable_channel");
+    }
+
     Ok(())
 }

suppressions.txt

@@ -1,7 +1,7 @@
-# false positives in thread::spawn (?)
-race:*dealloc
-race:*drop_slow*
-race:__call_tls_dtors
+race:std::panic::catch_unwind
+race:std::thread::scope
 
-# false positives in scoped_threadpool (?)
-race:*drop*
+# std::thread::spawn false positive; seen on Ubuntu 20.04 but not on Arch Linux (2022-04-29)
+race:drop_in_place*JoinHandle
+race:alloc::sync::Arc<*>::drop_slow
+race:__call_tls_dtors

tests/tsan.rs

@@ -1,11 +1,11 @@
+#![cfg_attr(unstable_channel, feature(scoped_threads))]
 #![deny(rust_2018_compatibility)]
 #![deny(rust_2018_idioms)]
 #![deny(warnings)]
 
-use std::{sync::mpsc, thread};
+use std::thread;
 
-use heapless::{mpmc::Q64, spsc};
-use scoped_threadpool::Pool;
+use heapless::spsc;
 
 #[test]
 fn once() {
@@ -51,6 +51,7 @@ fn twice() {
 }
 
 #[test]
+#[cfg(unstable_channel)]
 fn scoped() {
     let mut rb: spsc::Queue<i32, 5> = spsc::Queue::new();
 
@@ -59,12 +60,12 @@ fn scoped() {
     {
         let (mut p, mut c) = rb.split();
 
-        Pool::new(2).scoped(move |scope| {
-            scope.execute(move || {
+        thread::scope(move |scope| {
+            scope.spawn(move || {
                 p.enqueue(1).unwrap();
             });
 
-            scope.execute(move || {
+            scope.spawn(move || {
                 c.dequeue().unwrap();
             });
         });
@@ -75,6 +76,7 @@ fn scoped() {
 
 #[test]
 #[cfg_attr(miri, ignore)] // too slow
+#[cfg(unstable_channel)]
 fn contention() {
     const N: usize = 1024;
 
@@ -83,8 +85,8 @@ fn contention() {
     {
         let (mut p, mut c) = rb.split();
 
-        Pool::new(2).scoped(move |scope| {
-            scope.execute(move || {
+        thread::scope(move |scope| {
+            scope.spawn(move || {
                 let mut sum: u32 = 0;
 
                 for i in 0..(2 * N) {
@@ -95,7 +97,7 @@ fn contention() {
                 println!("producer: {}", sum);
             });
 
-            scope.execute(move || {
+            scope.spawn(move || {
                 let mut sum: u32 = 0;
 
                 for _ in 0..(2 * N) {
@@ -120,15 +122,20 @@ fn contention() {
 
 #[test]
 #[cfg_attr(miri, ignore)] // too slow
+#[cfg(unstable_channel)]
 fn mpmc_contention() {
+    use std::sync::mpsc;
+
+    use heapless::mpmc::Q64;
+
     const N: u32 = 64;
 
     static Q: Q64<u32> = Q64::new();
 
     let (s, r) = mpsc::channel();
-    Pool::new(2).scoped(|scope| {
+    thread::scope(|scope| {
         let s1 = s.clone();
-        scope.execute(move || {
+        scope.spawn(move || {
             let mut sum: u32 = 0;
 
             for i in 0..(16 * N) {
@@ -141,7 +148,7 @@ fn mpmc_contention() {
         });
 
         let s2 = s.clone();
-        scope.execute(move || {
+        scope.spawn(move || {
             let mut sum: u32 = 0;
 
             for _ in 0..(16 * N) {
@@ -166,6 +173,7 @@ fn mpmc_contention() {
 
 #[test]
 #[cfg_attr(miri, ignore)] // too slow
+#[cfg(unstable_channel)]
 fn unchecked() {
     const N: usize = 1024;
 
@@ -178,14 +186,14 @@ fn unchecked() {
     {
         let (mut p, mut c) = rb.split();
 
-        Pool::new(2).scoped(move |scope| {
-            scope.execute(move || {
+        thread::scope(move |scope| {
+            scope.spawn(move || {
                 for _ in 0..N / 2 - 1 {
                     p.enqueue(2).unwrap();
                 }
             });
 
-            scope.execute(move || {
+            scope.spawn(move || {
                 let mut sum: usize = 0;
 
                 for _ in 0..N / 2 - 1 {
@@ -246,8 +254,8 @@ fn pool() {
 
     A::grow(unsafe { &mut M });
 
-    Pool::new(2).scoped(move |scope| {
-        scope.execute(move || {
+    thread::scope(move |scope| {
+        scope.spawn(move || {
             for _ in 0..N / 4 {
                 let a = A::alloc().unwrap();
                 let b = A::alloc().unwrap();
@@ -257,7 +265,7 @@ fn pool() {
             }
         });
 
-        scope.execute(move || {
+        scope.spawn(move || {
             for _ in 0..N / 2 {
                 let a = A::alloc().unwrap();
                 let a = a.init([2; 8]);