Add spawn_blocking() api

msim-tokio/src/sim/runtime.rs

@@ -6,7 +6,7 @@ use std::time::Duration;
 use msim::runtime as ms_runtime;
 use msim::task::JoinHandle;
 
-use tracing::debug;
+use tracing::{debug, warn};
 
 #[derive(Clone)]
 pub struct Handle {
@@ -48,6 +48,18 @@ impl Handle {
     {
         ms_runtime::NodeHandle::current().spawn(future)
     }
+
+    pub fn spawn_blocking<F, R>(&self, f: F) -> JoinHandle<R>
+    where
+        F: FnOnce() -> R + Send + 'static,
+        R: Send + 'static,
+    {
+        warn!(
+            "spawn_blocking() call in simulator may cause deadlocks if spawned task \
+            attempts to do I/O"
+        );
+        ms_runtime::NodeHandle::current().spawn_blocking(f)
+    }
 }
 
 pub struct EnterGuard<'a>(ms_runtime::EnterGuard, std::marker::PhantomData<&'a Handle>);

msim/src/sim/runtime/mod.rs

@@ -364,6 +364,15 @@ impl NodeHandle {
         self.task.spawn(future)
     }
 
+    /// Spawn a blocking task.
+    pub fn spawn_blocking<F, R>(&self, f: F) -> JoinHandle<R>
+    where
+        F: FnOnce() -> R + Send + 'static,
+        R: Send + 'static,
+    {
+        self.task.spawn(async move { f() })
+    }
+
     /// Join the node.
     /// TODO: unimplemented
     pub fn join(self) -> Result<(), ()> {