Migrate to Rust 2021 (#15)

Signed-off-by: John Nunley <dev@notgull.net>

.github/workflows/ci.yml

@@ -1,5 +1,8 @@
 name: CI
 
+permissions:
+  contents: read
+
 on:
   pull_request:
   push:
@@ -10,6 +13,7 @@ on:
 
 env:
   CARGO_INCREMENTAL: 0
+  CARGO_NET_GIT_FETCH_WITH_CLI: true
   CARGO_NET_RETRY: 10
   CARGO_TERM_COLOR: always
   RUST_BACKTRACE: 1
@@ -30,7 +34,7 @@ jobs:
         os: [ubuntu-latest]
         rust: [nightly, beta, stable]
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install Rust
         run: rustup update ${{ matrix.rust }} && rustup default ${{ matrix.rust }}
       - run: cargo build --all --all-features --all-targets
@@ -45,9 +49,9 @@ jobs:
       matrix:
         # When updating this, the reminder to update the minimum supported
         # Rust version in Cargo.toml.
-        rust: ['1.35']
+        rust: ['1.63']
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install Rust
         run: rustup update ${{ matrix.rust }} && rustup default ${{ matrix.rust }}
       - run: cargo build
@@ -55,7 +59,7 @@ jobs:
   clippy:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install Rust
         run: rustup update stable
       - run: cargo clippy --all-features --all-targets
@@ -63,7 +67,7 @@ jobs:
   fmt:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install Rust
         run: rustup update stable
       - run: cargo fmt --all --check
@@ -71,7 +75,7 @@ jobs:
   miri:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install Rust
         run: rustup toolchain install nightly --component miri && rustup default nightly
       - run: cargo miri test
@@ -80,9 +84,13 @@ jobs:
           RUSTFLAGS: ${{ env.RUSTFLAGS }} -Z randomize-layout
 
   security_audit:
+    permissions:
+      checks: write
+      contents: read
+      issues: write
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       # https://github.com/rustsec/audit-check/issues/2
       - uses: rustsec/audit-check@master
         with:

.github/workflows/release.yml

@@ -1,5 +1,8 @@
 name: Release
 
+permissions:
+  contents: write
+
 on:
   push:
     tags:
@@ -10,7 +13,7 @@ jobs:
     if: github.repository_owner == 'smol-rs'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: taiki-e/create-gh-release-action@v1
         with:
           changelog: CHANGELOG.md

CHANGELOG.md

@@ -1,3 +1,7 @@
+# Version 3.3.1
+
+- Reimplement using 100% safe code. (#11)
+
 # Version 3.3.0
 
 - Add `Parallel::collect()` and `Parallel::finish_in()` to allow for generic containers. (#9)

Cargo.toml

@@ -3,10 +3,10 @@ name = "easy-parallel"
 # When publishing a new version:
 # - Update CHANGELOG.md
 # - Create "v3.x.y" git tag
-version = "3.3.0"
+version = "3.3.1"
 authors = ["Stjepan Glavina <stjepang@gmail.com>"]
-edition = "2018"
-rust-version = "1.35"
+edition = "2021"
+rust-version = "1.63"
 description = "Run closures in parallel"
 license = "Apache-2.0 OR MIT"
 repository = "https://github.com/smol-rs/easy-parallel"

src/lib.rs

@@ -57,12 +57,17 @@
 //! ```
 
 #![warn(missing_docs, missing_debug_implementations, rust_2018_idioms)]
+#![forbid(unsafe_code)]
+#![doc(
+    html_favicon_url = "https://raw.githubusercontent.com/smol-rs/smol/master/assets/images/logo_fullsize_transparent.png"
+)]
+#![doc(
+    html_logo_url = "https://raw.githubusercontent.com/smol-rs/smol/master/assets/images/logo_fullsize_transparent.png"
+)]
 
 use std::fmt;
-use std::iter::{self, FromIterator};
-use std::mem;
+use std::iter;
 use std::panic;
-use std::process;
 use std::sync::mpsc;
 use std::thread;
 
@@ -256,58 +261,50 @@ impl<'a, T> Parallel<'a, T> {
         T: Send + 'a,
         C: FromIterator<T>,
     {
-        // Set up a guard that aborts on panic.
-        let guard = NoPanic;
+        // Set up a new thread scope.
+        thread::scope(|scope| {
+            // Join handles for spawned threads.
+            let mut handles = Vec::new();
 
-        // Join handles for spawned threads.
-        let mut handles = Vec::new();
+            // Channels to collect results from spawned threads.
+            let mut receivers = Vec::new();
 
-        // Channels to collect results from spawned threads.
-        let mut receivers = Vec::new();
+            for f in self.closures.into_iter() {
+                // Wrap into a closure that sends the result back.
+                let (sender, receiver) = mpsc::channel();
+                let f = move || sender.send(f()).unwrap();
 
-        // Spawn a thread for each closure after the first one.
-        for f in self.closures.into_iter() {
-            // Wrap into a closure that sends the result back.
-            let (sender, receiver) = mpsc::channel();
-            let f = move || sender.send(f()).unwrap();
-
-            // Erase the `'a` lifetime.
-            let f: Box<dyn FnOnce() + Send + 'a> = Box::new(f);
-            let f: Box<dyn FnOnce() + Send + 'static> = unsafe { mem::transmute(f) };
-
-            // Spawn a thread for the closure.
-            handles.push(thread::spawn(f));
-            receivers.push(receiver);
-        }
-
-        let mut last_err = None;
-
-        // Run the main closure on the main thread.
-        let res = panic::catch_unwind(panic::AssertUnwindSafe(f));
-
-        // Join threads and save the last panic if there was one.
-        for h in handles {
-            if let Err(err) = h.join() {
-                last_err = Some(err);
+                // Spawn it on the scope.
+                handles.push(scope.spawn(f));
+                receivers.push(receiver);
             }
-        }
 
-        // Drop the guard because we may resume a panic now.
-        drop(guard);
+            let mut last_err = None;
 
-        // If a thread has panicked, resume the last collected panic.
-        if let Some(err) = last_err {
-            panic::resume_unwind(err);
-        }
+            // Run the main closure on the main thread.
+            let res = panic::catch_unwind(panic::AssertUnwindSafe(f));
 
-        // Collect the results from threads.
-        let results = receivers.into_iter().map(|r| r.recv().unwrap()).collect();
+            // Join threads and save the last panic if there was one.
+            for h in handles {
+                if let Err(err) = h.join() {
+                    last_err = Some(err);
+                }
+            }
 
-        // If the main closure panicked, resume its panic.
-        match res {
-            Ok(r) => (results, r),
-            Err(err) => panic::resume_unwind(err),
-        }
+            // If a thread has panicked, resume the last collected panic.
+            if let Some(err) = last_err {
+                panic::resume_unwind(err);
+            }
+
+            // Collect the results from threads.
+            let results = receivers.into_iter().map(|r| r.recv().unwrap()).collect();
+
+            // If the main closure panicked, resume its panic.
+            match res {
+                Ok(r) => (results, r),
+                Err(err) => panic::resume_unwind(err),
+            }
+        })
     }
 }
 
@@ -324,14 +321,3 @@ impl<T> Default for Parallel<'_, T> {
         Self::new()
     }
 }
-
-/// Aborts the process if dropped while panicking.
-struct NoPanic;
-
-impl Drop for NoPanic {
-    fn drop(&mut self) {
-        if thread::panicking() {
-            process::abort();
-        }
-    }
-}

tests/smoke.rs

@@ -5,7 +5,7 @@ use easy_parallel::Parallel;
 #[test]
 fn smoke() {
     let m = Mutex::new(0);
-    let v = vec![2, 3, 5, 7, 11];
+    let v = [2, 3, 5, 7, 11];
 
     Parallel::new()
         .add(|| *m.lock().unwrap() += 10)
@@ -18,7 +18,7 @@ fn smoke() {
 
 #[test]
 fn squares() {
-    let v = vec![10, 20, 30];
+    let v = [10, 20, 30];
 
     let squares = Parallel::new().each(0..v.len(), |i| v[i] * v[i]).run();
 
@@ -27,7 +27,7 @@ fn squares() {
 
 #[test]
 fn finish() {
-    let v = vec![10, 20, 30];
+    let v = [10, 20, 30];
 
     let (squares, len) = Parallel::new()
         .each(0..v.len(), |i| v[i] * v[i])