diff options
Diffstat (limited to 'Lib/asyncio/tasks.py')
| -rw-r--r-- | Lib/asyncio/tasks.py | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/Lib/asyncio/tasks.py b/Lib/asyncio/tasks.py index aa5269a..7eb647b 100644 --- a/Lib/asyncio/tasks.py +++ b/Lib/asyncio/tasks.py @@ -813,6 +813,7 @@ def gather(*coros_or_futures, return_exceptions=False): children = [] nfuts = 0 nfinished = 0 + done_futs = [] loop = None outer = None # bpo-46672 for arg in coros_or_futures: @@ -829,7 +830,10 @@ def gather(*coros_or_futures, return_exceptions=False): nfuts += 1 arg_to_fut[arg] = fut - fut.add_done_callback(_done_callback) + if fut.done(): + done_futs.append(fut) + else: + fut.add_done_callback(_done_callback) else: # There's a duplicate Future object in coros_or_futures. @@ -838,6 +842,13 @@ def gather(*coros_or_futures, return_exceptions=False): children.append(fut) outer = _GatheringFuture(children, loop=loop) + # Run done callbacks after GatheringFuture created so any post-processing + # can be performed at this point + # optimization: in the special case that *all* futures finished eagerly, + # this will effectively complete the gather eagerly, with the last + # callback setting the result (or exception) on outer before returning it + for fut in done_futs: + _done_callback(fut) return outer |