Claude runtime review

lib/runtime/src/platform/linux_x86_64/driver.rs

@@ -2,7 +2,7 @@
 
 use std::cell::Cell;
 use std::cell::RefCell;
-use std::collections::BTreeMap;
+use std::collections::HashMap;
 use std::io;
 use std::os::fd::RawFd;
 use std::sync::Arc;
@@ -90,7 +90,7 @@ pub struct Driver {
     active_timer_token: Cell<Option<u64>>,
     pending_wakes: Cell<u64>,
     pending_timers: Cell<u64>,
-    completions: RefCell<BTreeMap<u64, CompletionHandler>>,
+    completions: RefCell<HashMap<u64, CompletionHandler>>,
 }
 
 /// Creates a new driver and its paired [`ThreadNotifier`].
@@ -123,7 +123,7 @@ pub fn create_driver() -> io::Result<(Driver, ThreadNotifier)> {
             active_timer_token: Cell::new(None),
             pending_wakes: Cell::new(0),
             pending_timers: Cell::new(0),
-            completions: RefCell::new(BTreeMap::new()),
+            completions: RefCell::new(HashMap::new()),
         },
         ThreadNotifier { inner: notifier },
     ))