add Executor::is_empty and LocalExecutor::is_empty

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>

src/lib.rs

@@ -214,6 +214,11 @@ impl<'a> Executor<'a> {
         future.or(run_forever).await
     }
 
+    /// Checks if the executor is empty and has no pending tasks to run.
+    pub fn is_empty(&self) -> bool {
+        self.state().active.lock().unwrap().is_empty()
+    }
+
     /// Returns a function that schedules a runnable task when it gets woken up.
     fn schedule(&self) -> impl Fn(Runnable) + Send + Sync + 'static {
         let state = self.state().clone();
@@ -393,6 +398,11 @@ impl<'a> LocalExecutor<'a> {
         self.inner().run(future).await
     }
 
+    /// Checks if the executor is empty and has no pending tasks to run.
+    pub fn is_empty(&self) -> bool {
+        self.inner().is_empty()
+    }
+
     /// Returns a function that schedules a runnable task when it gets woken up.
     fn schedule(&self) -> impl Fn(Runnable) + Send + Sync + 'static {
         let state = self.inner().state().clone();