From 45a43de3e11e58a59c20d72239e9a20cfa69b593 Mon Sep 17 00:00:00 2001
From: CJP10 <cjpet10@gmail.com>
Date: Sun, 18 Aug 2024 18:21:05 -0400
Subject: [PATCH] use loom for concurrency testing

---
 Cargo.toml          |  3 +++
 src/experimental.rs | 47 ++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 268d9eb..175e733 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,6 +15,9 @@ license = "MIT/Apache-2.0"
 [dependencies]
 parking_lot = "0.12.3"
 
+[target.'cfg(loom)'.dependencies]
+loom = "0.7"
+
 [dev-dependencies]
 criterion = "0.5.1"
 criterion-plot = "0.5.0"
diff --git a/src/experimental.rs b/src/experimental.rs
index 97c6872..8e9b302 100644
--- a/src/experimental.rs
+++ b/src/experimental.rs
@@ -3,12 +3,15 @@ use std::{
     iter::FromIterator,
     mem::ManuallyDrop,
     ops::{Deref, DerefMut},
-    sync::atomic::{
-        AtomicU64,
-        Ordering::{Acquire, Relaxed, Release},
-    },
+    sync::atomic::Ordering::{Acquire, Relaxed, Release},
 };
 
+#[cfg(not(loom))]
+use std::sync::atomic::AtomicU64;
+
+#[cfg(loom)]
+use loom::sync::atomic::AtomicU64;
+
 const U64_BITS: usize = u64::BITS as usize;
 
 pub struct Pool<T> {
@@ -139,7 +142,6 @@ impl AtomicBitSet {
 #[cfg(test)]
 mod tests {
     use crate::experimental::Pool;
-    use std::iter::FromIterator;
     use std::sync::atomic::Ordering::Relaxed;
 
     #[test]
@@ -191,3 +193,38 @@ mod tests {
         }
     }
 }
+
+#[cfg(loom)]
+mod loom_tests {
+    use crate::experimental::Pool;
+    use loom::sync::Arc;
+
+    #[test]
+    fn concurrent_pull_sum() {
+        loom::model(|| {
+            const N: usize = 2;
+            let p: Pool<usize> = (0..N).map(|_| 0).collect();
+            let p = Arc::new(p);
+
+            let handles: Vec<_> = (0..N)
+                .map(|_| {
+                    let p1 = p.clone();
+                    loom::thread::spawn(move || {
+                        *p1.pull().unwrap() += 1;
+                    })
+                })
+                .collect();
+
+            for handle in handles {
+                handle.join().unwrap();
+            }
+
+            unsafe {
+                assert_eq!(
+                    p.objects.iter().map(|x| (*x.get()).unwrap()).sum::<usize>(),
+                    N
+                );
+            }
+        });
+    }
+}