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Continue previous threading issue
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‎python_issue.py‎

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import resource
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import sys
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import os
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import threading
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import time
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import traceback
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import gc
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# To Compile Python
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"""
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mkdir -p /home/odoo/Documents/Pythons/py12 &&
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./configure --prefix=/home/odoo/Documents/Pythons/py12 --enable-optimizations &&
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make --quiet clean &&
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make --quiet -j 10 &&
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make --quiet altinstall
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"""
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"""
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./configure --enable-optimizations &&
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make --quiet clean &&
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make --quiet -j 10
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"""
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"""
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Current explaination:
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When one `handler` Thread is hard kill between after `_start_new_thread` and before `_started.set()` (inside `_bootstrap_inner`):
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Two issues happens
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- The first issue, is that `threading.enumerate` returns it, but it shouldn't since it is not alive:
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That's because `_limbo` is not clean if hard kill (finally clause of `_bootstrap_inner` is bypass). Weird but not blocking
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When one `handler` Thread is killed (not enough memory) between after starting the new thread (thread_run C code)
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and before `_started.set()` Python (inside `_bootstrap_inner` or just before in the C threaded code):
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Leading into deadlock situation the serving Thread wait the `_started` to be set, but
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it will never be since the specific Thread is dead... Also if this dead Thread remains in
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the _limbo dictionary (small inconsistency since it will be return in case of threading.enumarate()).
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When the thread is killed inside before `_started.set()`, we always get this weird error message:
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"Exception ignored in thread started by: <A method>"
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This comes from the `thread_run` (C code) calling `_PyErr_WriteUnraisableMsg`
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At first glance, it seems that the ignored Exception is a MemoryError that skip part of the `_bootstrap_inner` method
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What we tried:
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- Increasing the stack_size to force Python to only accept create new Thread when more
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memory is available on the stack. That's doesn't seems to work even with a hug number...
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Does this method even work ?? Signature is odd and the doc is incomplete ??
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- Catch the MemoryError, to sleep + gc after in order to force free memory => doesn't work better
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- Biscept on stable version, but is is reproductible:
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- Python 3.8.0b1: Reproductible but seems more rare?
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- Our version 3.12.3: Reproductible
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- Python 3.12.11+: Reproductible
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- Python 3.13.7+: Reproductible
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- Python 3.14.0rc2+: Reproductible
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- Python main/3.15.0a0: Reproductible
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- The Thread of `serving` is stuck waiting that self._started of the killed Thread becomes free, but it will never be ...
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- Find a magic solution to bypass `self._started.wait()`. The only 'working' solution is to add
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a timeout (1 sec) on it that recheck the status of the Thread. But is fragile, because a timeout
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is always a trade-off (after 1 sec is long and still not ensure that the Thread has been effectively
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killed).
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Deadlock traceback
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------------------
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File "/home/odoo/Documents/Pythons/py12_11/lib/python3.12/threading.py", line 1033, in _bootstrap
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self._bootstrap_inner()
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File "/home/odoo/Documents/Pythons/py12_11/lib/python3.12/threading.py", line 1078, in _bootstrap_inner
@@ -30,103 +78,59 @@
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File "/home/odoo/Documents/Pythons/py12_11/lib/python3.12/threading.py", line 355, in wait
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waiter.acquire()
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Because the Thread is hard kill by the OS, should it release his lock and then setting _started ???
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TODO:
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- Check inside the ignored Exception with a debugger C
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- Check works stack_size
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-
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"""
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threading.stack_size(33000)
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print("PID: ", os.getpid(), " Stack Size ", threading.stack_size())
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# print("Sleep 10 sec")
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# time.sleep(10)
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print("PID: ", os.getpid())
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print("Sleep 10 sec")
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time.sleep(1)
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#
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resource.setrlimit(resource.RLIMIT_AS, (1_000_000_000, 1_500_000_000))
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def memory_error():
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memory_issue_list = []
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while True:
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memory_issue_list.append("a" * 10_000)
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memory_issue_list.append("a" * 150_000)
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def handler():
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time.sleep(0.001)
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try:
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memory_error()
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except MemoryError:
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print("MemoryError - stop")
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print(f"MemoryError in {threading.current_thread()}")
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# gc.collect()
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# time.sleep(0.1)
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def serving():
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for _ in range(100):
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t = threading.Thread(target=handler)
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print('Start Sub-Thread')
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t.start()
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try:
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t = threading.Thread(target=handler)
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print(f'Start Thread: {t}')
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t.start()
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except RuntimeError:
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print('RuntimeError', {t})
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print('Start Serving')
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serving_thread = threading.Thread(target=serving, daemon=True)
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serving_thread.start()
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time.sleep(10)
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while serving_thread.is_alive():
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time.sleep(2)
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for alive_thread in threading.enumerate():
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print(alive_thread, alive_thread.is_alive(), alive_thread.ident, alive_thread.native_id)
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if not alive_thread.is_alive() and serving_thread.is_alive():
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print(f"Serving thread info: {serving_thread._started=} | {serving_thread._started._flag=}")
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print(f"Alive but dead thread: {alive_thread._started=} | {alive_thread._started._flag=}")
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frames_serving_thread = sys._current_frames()[serving_thread.ident]
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traceback.print_stack(frames_serving_thread)
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# File "/home/odoo/Documents/Pythons/py14/lib/python3.14/threading.py", line 1043, in _bootstrap
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# self._bootstrap_inner()
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# File "/home/odoo/Documents/Pythons/py14/lib/python3.14/threading.py", line 1081, in _bootstrap_inner
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# self._context.run(self.run)
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# File "/home/odoo/Documents/Pythons/py14/lib/python3.14/threading.py", line 1023, in run
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# self._target(*self._args, **self._kwargs)
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# File "/home/odoo/Documents/dev/./odoo_scripts/python_issue.py", line 17, in serving
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# t.start()
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# File "/home/odoo/Documents/Pythons/py14/lib/python3.14/threading.py", line 1010, in start
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# self._started.wait() # Will set ident and native_id
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# File "/home/odoo/Documents/Pythons/py14/lib/python3.14/threading.py", line 669, in wait
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# signaled = self._cond.wait(timeout)
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# File "/home/odoo/Documents/Pythons/py14/lib/python3.14/threading.py", line 369, in wait
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# waiter.acquire()
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"""
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git checkout main &&
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mkdir -p /home/odoo/Documents/Pythons/pymain &&
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make --quiet clean &&
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./configure --prefix=/home/odoo/Documents/Pythons/pymain --enable-optimizations &&
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make --quiet -j 10 &&
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make --quiet altinstall
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"""
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"""
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make --quiet clean &&
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./configure --enable-optimizations &&
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make --quiet -j 10
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"""
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# ./configure --prefix=/home/odoo/Documents/Pythons/py14 --enable-optimizations
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# Python 3.8.0b1: Reproductible but seems more rare?
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# Our version 3.12.3: Reproductible
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# Python 3.12.11+: Reproductible
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# Python 3.13.7+: Reproductible
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# Python 3.14.0rc2+: Reproductible
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# Python main/3.15.0a0: Reproductible
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if serving_thread.ident in sys._current_frames():
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frames_serving_thread = sys._current_frames()[serving_thread.ident]
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traceback.print_stack(frames_serving_thread)
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time.sleep(10)

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