diff options
| -rw-r--r-- | Lib/concurrent/futures/_base.py | 8 | ||||
| -rw-r--r-- | Lib/test/test_concurrent_futures.py | 18 | ||||
| -rw-r--r-- | Misc/NEWS | 3 |
3 files changed, 25 insertions, 4 deletions
diff --git a/Lib/concurrent/futures/_base.py b/Lib/concurrent/futures/_base.py index 79b91d4..9f11f69 100644 --- a/Lib/concurrent/futures/_base.py +++ b/Lib/concurrent/futures/_base.py @@ -112,12 +112,14 @@ class _AllCompletedWaiter(_Waiter): def __init__(self, num_pending_calls, stop_on_exception): self.num_pending_calls = num_pending_calls self.stop_on_exception = stop_on_exception + self.lock = threading.Lock() super().__init__() def _decrement_pending_calls(self): - self.num_pending_calls -= 1 - if not self.num_pending_calls: - self.event.set() + with self.lock: + self.num_pending_calls -= 1 + if not self.num_pending_calls: + self.event.set() def add_result(self, future): super().add_result(future) diff --git a/Lib/test/test_concurrent_futures.py b/Lib/test/test_concurrent_futures.py index 372da27..2afa938 100644 --- a/Lib/test/test_concurrent_futures.py +++ b/Lib/test/test_concurrent_futures.py @@ -183,7 +183,9 @@ class ProcessPoolShutdownTest(ProcessPoolMixin, ExecutorShutdownTest): for p in processes: p.join() + class WaitTests(unittest.TestCase): + def test_first_completed(self): future1 = self.executor.submit(mul, 21, 2) future2 = self.executor.submit(time.sleep, 1.5) @@ -284,7 +286,21 @@ class WaitTests(unittest.TestCase): class ThreadPoolWaitTests(ThreadPoolMixin, WaitTests): - pass + + def test_pending_calls_race(self): + # Issue #14406: multi-threaded race condition when waiting on all + # futures. + event = threading.Event() + def future_func(): + event.wait() + oldswitchinterval = sys.getswitchinterval() + sys.setswitchinterval(1e-6) + try: + fs = {self.executor.submit(future_func) for i in range(100)} + event.set() + futures.wait(fs, return_when=futures.ALL_COMPLETED) + finally: + sys.setswitchinterval(oldswitchinterval) class ProcessPoolWaitTests(ProcessPoolMixin, WaitTests): @@ -31,6 +31,9 @@ Core and Builtins Library ------- +- Issue #14406: Fix a race condition when using ``concurrent.futures.wait( + return_when=ALL_COMPLETED)``. Patch by Matt Joiner. + - Issue #14409: IDLE now properly executes commands in the Shell window when it cannot read the normal config files on startup and has to use the built-in default key bindings. |