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bpo-33097: Fix submit accepting callable after executor shutdown by interpreter exit #6144

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Merged
pitrou merged 8 commits into from
Apr 10, 2018
Merged

bpo-33097: Fix submit accepting callable after executor shutdown by interpreter exit #6144

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b1133c8
bpo-33097: Fix submit accepting callable after executor shutdown by i…
mrknmc Mar 18, 2018
10fb3c0
Replace submitted lambda: None with id, None
mrknmc Mar 24, 2018
bc31b41
Add explicit RuntimeError for when interpreter is shutting down
mrknmc Mar 24, 2018
47e72fc
Add explicit submit and result to submit after interpreter shutdown test
mrknmc Mar 24, 2018
546ec80
Mark ProcessPoolExecutor shutdown from queue management thread if shu…
mrknmc Mar 25, 2018
a1853a6
Mark ThreadPoolExecutor shutdown from worker thread if shutting down
mrknmc Mar 25, 2018
6b78fc2
Replace empty string check with implicit bool check in
mrknmc Apr 8, 2018
2ba6378
Replace assertTrue with assertIn in test_submit_after_interpreter_shu…
mrknmc Apr 9, 2018
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7 changes: 7 additions & 0 deletions Lib/concurrent/futures/process.py
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Original file line number Diff line number Diff line change
Expand Up @@ -421,6 +421,10 @@ def shutdown_worker():
# - The executor that owns this worker has been shutdown.
if shutting_down():
try:
# Flag the executor as shutting down as early as possible if it
# is not gc-ed yet.
if executor is not None:
executor._shutdown_thread = True
# Since no new work items can be added, it is safe to shutdown
# this thread if there are no pending work items.
if not pending_work_items:
Expand Down Expand Up @@ -593,6 +597,9 @@ def submit(self, fn, *args, **kwargs):
raise BrokenProcessPool(self._broken)
if self._shutdown_thread:
raise RuntimeError('cannot schedule new futures after shutdown')
if _global_shutdown:
raise RuntimeError('cannot schedule new futures after '
'interpreter shutdown')

f = _base.Future()
w = _WorkItem(f, fn, args, kwargs)
Expand Down
7 changes: 7 additions & 0 deletions Lib/concurrent/futures/thread.py
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Original file line number Diff line number Diff line change
Expand Up @@ -87,6 +87,10 @@ def _worker(executor_reference, work_queue, initializer, initargs):
# - The executor that owns the worker has been collected OR
# - The executor that owns the worker has been shutdown.
if _shutdown or executor is None or executor._shutdown:
# Flag the executor as shutting down as early as possible if it
# is not gc-ed yet.
if executor is not None:
executor._shutdown = True
# Notice other workers
work_queue.put(None)
return
Expand Down Expand Up @@ -145,6 +149,9 @@ def submit(self, fn, *args, **kwargs):

if self._shutdown:
raise RuntimeError('cannot schedule new futures after shutdown')
if _shutdown:
raise RuntimeError('cannot schedule new futures after'
'interpreter shutdown')

f = _base.Future()
w = _WorkItem(f, fn, args, kwargs)
Expand Down
28 changes: 28 additions & 0 deletions Lib/test/test_concurrent_futures.py
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Expand Up @@ -303,6 +303,34 @@ def test_interpreter_shutdown(self):
self.assertFalse(err)
self.assertEqual(out.strip(), b"apple")

def test_submit_after_interpreter_shutdown(self):
# Test the atexit hook for shutdown of worker threads and processes
rc, out, err = assert_python_ok('-c', """if 1:
import atexit
@atexit.register
def run_last():
try:
t.submit(id, None)
except RuntimeError:
print("runtime-error")
raise
from concurrent.futures import {executor_type}
if __name__ == "__main__":
context = '{context}'
if not context:
t = {executor_type}(5)
else:
from multiprocessing import get_context
context = get_context(context)
t = {executor_type}(5, mp_context=context)

@tomMoral tomMoral Mar 24, 2018

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Here, the executor is not started before the call in atexit. This causes another set of problem as the sub{Process,Thread} are not started and cleaned properly. For your proposed test, I would add a t.submit(id, 42).result() to be sure that the executor has been started before the atexit calls.

@mrknmc mrknmc Mar 24, 2018

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Added t.submit(id, 42).result() to the test in d5c28194a0b842833ac4729f5f333ce718120201

t.submit(id, 42).result()
""".format(executor_type=self.executor_type.__name__,
context=getattr(self, "ctx", "")))
# Errors in atexit hooks don't change the process exit code, check
# stderr manually.
self.assertIn("RuntimeError: cannot schedule new futures", err.decode())
self.assertEqual(out.strip(), b"runtime-error")

def test_hang_issue12364(self):
fs = [self.executor.submit(time.sleep, 0.1) for _ in range(50)]
self.executor.shutdown()
Expand Down
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Library/2018-03-18-16-48-23.bpo-33097.Yl4gI2.rst
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Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
Raise RuntimeError when ``executor.submit`` is called during interpreter
shutdown.