Merged race condition fix, cut down on some repetition

Author: Andrew J Westlake

src/generic.rs

@@ -315,34 +315,16 @@ fn done(future: &PyAny) -> PyResult<bool> {
 }
 
 #[pyclass]
-struct CheckedSetResult();
+struct CheckedCompletor;
 
 #[pymethods]
-impl CheckedSetResult {
-    fn __call__(&self, future: &PyAny, value: PyObject) -> PyResult<()> {
+impl CheckedCompletor {
+    fn __call__(&self, future: &PyAny, complete: &PyAny, value: &PyAny) -> PyResult<()> {
         if done(future)? {
             return Ok(());
         }
 
-        let set_result = future.getattr("set_result")?;
-        set_result.call1((value,))?;
-
-        Ok(())
-    }
-}
-
-#[pyclass]
-struct CheckedSetException();
-
-#[pymethods]
-impl CheckedSetException {
-    fn __call__(&self, future: &PyAny, exception: PyObject) -> PyResult<()> {
-        if done(future)? {
-            return Ok(());
-        }
-
-        let set_exception = future.getattr("set_exception")?;
-        set_exception.call1((exception,))?;
+        complete.call1((value,))?;
 
         Ok(())
     }
@@ -352,13 +334,11 @@ fn set_result(event_loop: &PyAny, future: &PyAny, result: PyResult<PyObject>) ->
     let py = event_loop.py();
     let none = py.None().into_ref(py);
 
-    let checked_set_result = CheckedSetResult().into_py(py).into_ref(py);
-    let checked_set_exception = CheckedSetException().into_py(py).into_ref(py);
-
-    match result {
-        Ok(val) => call_soon_threadsafe(event_loop, none, (checked_set_result, future, val))?,
-        Err(err) => call_soon_threadsafe(event_loop, none, (checked_set_exception, future, err))?,
-    }
+    let (complete, val) = match result {
+        Ok(val) => (future.getattr("set_result")?, val.into_py(py)),
+        Err(err) => (future.getattr("set_exception")?, err.into_py(py)),
+    };
+    call_soon_threadsafe(event_loop, none, (CheckedCompletor, future, complete, val))?;
 
     Ok(())
 }