Call reducers on the blocking pool. (#2737)

Author: jsdt

crates/core/src/host/module_host.rs

@@ -592,11 +592,13 @@ impl ModuleHost {
         // compiler that `dyn ModuleInstance` is unwind safe.
         // If a reducer call panics, we **must** ensure to call `self.on_panic`
         // so that the module is discarded by the host controller.
-        let result = tokio::spawn(async move { f(&mut *inst) }).await.unwrap_or_else(|e| {
-            log::warn!("reducer {reducer} panicked");
-            (self.on_panic)();
-            std::panic::resume_unwind(e.into_panic());
-        });
+        let result = tokio::task::spawn_blocking(move || f(&mut *inst))
+            .await
+            .unwrap_or_else(|e| {
+                log::warn!("reducer {reducer} panicked");
+                (self.on_panic)();
+                std::panic::resume_unwind(e.into_panic());
+            });
         Ok(result)
     }