fix: make sleep wait for at least 1ms (#199)

Signed-off-by: Runji Wang <wangrunji0408@163.com>

CHANGELOG.md

@@ -6,6 +6,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## madsim [0.2.26] - 2024-03-18
+
+### Fixed
+
+- `sleep` and `sleep_until` now sleep for at least 1ms to be consistent with tokio's behavior.
+
 ## rdkafka [0.3.3] - 2024-02-28
 
 ### Changed

madsim/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "madsim"
-version = "0.2.25"
+version = "0.2.26"
 edition = "2021"
 authors = ["Runji Wang <wangrunji0408@163.com>"]
 description = "Deterministic Simulator for distributed systems."
@@ -62,7 +62,7 @@ tokio-util = { version = "0.7", features = ["codec"] }
 [dev-dependencies]
 criterion = "0.5"
 structopt = "0.3"
-tokio = { version = "1", features = ["rt-multi-thread", "macros"] }
+tokio = { version = "1", features = ["rt-multi-thread", "macros", "io-util"] }
 
 [[bench]]
 name = "rpc"

madsim/src/sim/time/mod.rs

@@ -106,15 +106,20 @@ impl TimeHandle {
     }
 
     /// Waits until `duration` has elapsed.
+    ///
+    /// It will sleep for at least 1ms to be consistent with the behavior of `tokio::time::sleep`.
     pub fn sleep(&self, duration: Duration) -> Sleep {
         self.sleep_until(self.clock.now_instant() + duration)
     }
 
     /// Waits until `deadline` is reached.
+    ///
+    /// It will sleep for at least 1ms to be consistent with the behavior of `tokio::time::sleep_until`.
     pub fn sleep_until(&self, deadline: Instant) -> Sleep {
+        let min_deadline = self.clock.now_instant() + Duration::from_millis(1);
         Sleep {
             handle: self.clone(),
-            deadline,
+            deadline: deadline.max(min_deadline),
         }
     }
 
@@ -233,6 +238,15 @@ mod tests {
     fn time() {
         let runtime = Runtime::new();
         runtime.block_on(async {
+            // sleep for at least 1ms
+            let t0 = Instant::now();
+            sleep(Duration::default()).await;
+            assert!(t0.elapsed() >= Duration::from_millis(1));
+
+            let t0 = Instant::now();
+            sleep_until(t0).await;
+            assert!(t0.elapsed() >= Duration::from_millis(1));
+
             let t0 = Instant::now();
 
             sleep(Duration::from_secs(1)).await;