From f2694a642ed6d105e74518cf1a9439f3abf06a32 Mon Sep 17 00:00:00 2001
From: Tom Parker-Shemilt <palfrey@tevp.net>
Date: Wed, 27 Nov 2024 21:18:39 +0000
Subject: [PATCH] Explicit testing for tokio multi-thread

Because https://github.com/palfrey/serial_test/issues/121 flagged a possible issue
---
 Cargo.lock                  | 18 +++++++++++++++++
 serial_test_test/Cargo.toml |  3 ++-
 serial_test_test/src/lib.rs | 39 ++++++++++++++++++++++++++++++-------
 3 files changed, 52 insertions(+), 8 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 5b10e48..ec8fb00 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -168,6 +168,12 @@ dependencies = [
  "slab",
 ]
 
+[[package]]
+name = "hermit-abi"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d231dfb89cfffdbc30e7fc41579ed6066ad03abda9e567ccafae602b97ec5024"
+
 [[package]]
 name = "itertools"
 version = "0.10.5"
@@ -232,6 +238,16 @@ dependencies = [
  "windows-sys 0.48.0",
 ]
 
+[[package]]
+name = "num_cpus"
+version = "1.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4161fcb6d602d4d2081af7c3a45852d875a03dd337a6bfdd6e06407b61342a43"
+dependencies = [
+ "hermit-abi",
+ "libc",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.19.0"
@@ -366,6 +382,7 @@ dependencies = [
  "log",
  "once_cell",
  "parking_lot",
+ "scc",
  "scoped-tls",
  "serial_test",
  "tokio",
@@ -437,6 +454,7 @@ dependencies = [
  "autocfg",
  "libc",
  "mio",
+ "num_cpus",
  "parking_lot",
  "pin-project-lite",
  "signal-hook-registry",
diff --git a/serial_test_test/Cargo.toml b/serial_test_test/Cargo.toml
index 8f64aee..bb3787f 100644
--- a/serial_test_test/Cargo.toml
+++ b/serial_test_test/Cargo.toml
@@ -16,9 +16,10 @@ lock_api = { version="^0.4.7", default-features = false }
 wasm-bindgen-test = {version="0.3.20", optional=true, default-features = false }
 scoped-tls = { version="1", optional=true, default-features = false }
 log = { version = ">=0.4.4" , default-features = false }
+scc = { version = "2", default-features = false}
 
 [dev-dependencies]
-tokio = { version = "^1.27", features = ["macros", "rt"], default-features = false }
+tokio = { version = "^1.27", features = ["macros", "rt", "rt-multi-thread"], default-features = false }
 actix-rt = { version = "^2.8", features = ["macros"], default-features = false }
 futures-util = {version = "^0.3", default-features = false }
 
diff --git a/serial_test_test/src/lib.rs b/serial_test_test/src/lib.rs
index 5fa70d1..009c253 100644
--- a/serial_test_test/src/lib.rs
+++ b/serial_test_test/src/lib.rs
@@ -37,6 +37,8 @@
 //! ```
 
 use log::info;
+use once_cell::sync::OnceCell;
+use scc::HashMap;
 #[cfg(test)]
 use serial_test::{parallel, serial};
 use std::{
@@ -47,19 +49,24 @@ use std::{
     time::Duration,
 };
 
-static LOCK: AtomicUsize = AtomicUsize::new(0);
+static LOCKS: OnceCell<HashMap<String, AtomicUsize>> = OnceCell::new();
 
 fn init() {
     let _ = env_logger::builder().is_test(false).try_init();
 }
 
-pub fn test_fn(count: usize) {
+pub fn test_fn(key: &str, count: usize) {
     init();
+    let local_locks = LOCKS.get_or_init(HashMap::new);
+    let entry = local_locks
+        .entry(key.to_string())
+        .or_insert(AtomicUsize::new(0));
+    let local_lock = entry.get();
     info!("(non-fs) Start {}", count);
-    LOCK.store(count, Ordering::Relaxed);
+    local_lock.store(count, Ordering::Relaxed);
     thread::sleep(Duration::from_millis(1000 * (count as u64)));
     info!("(non-fs) End {}", count);
-    assert_eq!(LOCK.load(Ordering::Relaxed), count);
+    assert_eq!(local_lock.load(Ordering::Relaxed), count);
 }
 
 pub fn fs_test_fn(count: usize) {
@@ -134,19 +141,19 @@ mod tests {
     #[test]
     #[serial(alpha)]
     fn test_serial_1() {
-        test_fn(1)
+        test_fn("alpha", 1)
     }
 
     #[test]
     #[serial(alpha)]
     fn test_serial_2() {
-        test_fn(2)
+        test_fn("alpha", 2)
     }
 
     #[test]
     #[serial(alpha)]
     fn test_serial_3() {
-        test_fn(3)
+        test_fn("alpha", 3)
     }
 
     #[test]
@@ -394,4 +401,22 @@ mod tests {
     #[serial]
     #[wasm_bindgen_test]
     async fn wasm_works_second() {}
+
+    #[tokio::test(flavor = "multi_thread")]
+    #[serial(slt)]
+    async fn tokio_multi_1() {
+        test_fn("tokio", 1);
+    }
+
+    #[tokio::test(flavor = "multi_thread")]
+    #[serial(slt)]
+    async fn tokio_multi_2() {
+        test_fn("tokio", 2);
+    }
+
+    #[tokio::test(flavor = "multi_thread")]
+    #[serial(slt)]
+    async fn tokio_multi_3() {
+        test_fn("tokio", 3);
+    }
 }