From d2ab11fd4aeba6c1de469a81a2033d7e70c5e2e7 Mon Sep 17 00:00:00 2001
From: Alan Fleming <>
Date: Sat, 25 Apr 2026 11:12:36 +1000
Subject: [PATCH] Refactor Caller.as_completed.

---
 src/async_kernel/caller.py | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/async_kernel/caller.py b/src/async_kernel/caller.py
index cd98d3d7..a8fc0901 100644
--- a/src/async_kernel/caller.py
+++ b/src/async_kernel/caller.py
@@ -1003,7 +1003,7 @@ async def as_completed(
             -  `Caller.MAX_IDLE_POOL_INSTANCES`
         """
         resume = noop
-        queue: SingleAsyncQueue[Pending[T]] = SingleAsyncQueue()
+        done: SingleAsyncQueue[Pending[T]] = SingleAsyncQueue()
         unfinished: set[Pending[T]] = set()
         pen_current = self.current_pending()
         if isinstance(items, set | list | tuple):
@@ -1015,40 +1015,42 @@ async def scheduler():
             nonlocal resume
             gen = items if isinstance(items, AsyncGenerator) else iter(items)
             is_async = isinstance(gen, AsyncGenerator)
-            while not queue.stopped and (pen := await anext(gen, None) if is_async else next(gen, None)) is not None:
+            while not done.stopped and (pen := await anext(gen, None) if is_async else next(gen, None)) is not None:
                 if pen is pen_current:
-                    queue.stop()
+                    done.stop()
                     msg = "Waiting for the pending in which it is running would result in deadlock!"
                     raise RuntimeError(msg)
                 if not isinstance(pen, Pending):
                     pen = cast("Pending[T]", self.call_soon(await_for, pen))
                 if not pen.done():
                     unfinished.add(pen)
+                    pen.add_done_callback(done.append)
                     if max_concurrent_ and len(unfinished) == max_concurrent_:
                         event = create_async_event()
                         resume = event.set
                         if len(unfinished) == max_concurrent_:
                             await event
                         resume = noop
-                pen.add_done_callback(queue.append)
-            if not queue.queue and not unfinished:
-                queue.stop()
+                else:
+                    done.append(pen)
+            if not done.queue and not unfinished:
+                done.stop()
 
         pen_ = self.call_soon(scheduler)
         try:
-            async for pen in queue:
+            async for pen in done:
                 unfinished.discard(pen)
                 yield pen
-                if pen_.done() and not unfinished and not queue.queue:
+                if pen_.done() and not unfinished and not done.queue:
                     break
                 else:
                     if max_concurrent_ and len(unfinished) < max_concurrent_:
                         resume()
             pen_.result()
         finally:
-            queue.stop()
+            done.stop()
             for pen in unfinished:
-                pen.remove_done_callback(queue.append)
+                pen.remove_done_callback(done.append)
                 if cancel_unfinished:
                     pen.cancel("Cancelled by as_completed")
             await pen_.cancel_wait(shield=True)
@@ -1084,6 +1086,7 @@ async def wait(
             if isinstance(item, Pending):
                 done.add(item) if item.done() else pending.add(item)
             else:
+                assert inspect.isawaitable(item)
                 pending.add(self.call_soon(await_for, item))
         if done:
             if return_when == "FIRST_COMPLETED":