[issue21645] test_read_all_from_pipe_reader() of test_asyncio hangs on FreeBSD 9
STINNER Victor added the comment: I created a new repository just for this issue: http://hg.python.org/sandbox/issue21645 I added a lot of debug. It looks like a race condition: the SIGCHLD signal is handled in a thread B (a C thread, not a Python), whereas the asyncio event loop is running in a thread A (the main thread, a Python thread). Debug of the test which blocks: --- PIPE: (7, 8) threads [_MainThread(MainThread, started 34384933888)] [pid 78351] _run_once: thread=34384933888 Execute Handle Task._step() created at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/tasks.py:74 [pid 78351] _run_once: thread=34384933888 Execute Handle StreamReaderProtocol.connection_made(_UnixReadPipeTransport fd=7 polling) created at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/unix_events.py:287 Execute Handle Future._set_result_unless_cancelled(None) created at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/unix_events.py:290 [pid 78351] _run_once: thread=34384933888 Execute Handle Task._wakeup(Future finished result=None) created at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/futures.py:239 Read pipe 7 connected: (_UnixReadPipeTransport fd=7 polling, asyncio.streams.StreamReaderProtocol object at 0x806e257a8) [pid 78351] _run_once: thread=34384933888 Execute Handle _raise_stop_error(Task finished coro=BaseEventLoop.connect_read_pipe() done, defined at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/base_events.py:767 created at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/base_events.py:258 result=(_UnixReadPipeTransport fd=7 polling, asyncio.streams.StreamReaderProtocol object at 0x806e257a8)) at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/base_events.py:95 created at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/futures.py:239 Execute Handle _raise_stop_error(Task finished coro=BaseEventLoop.connect_read_pipe() done, defined at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/base_events.py:767 created at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/base_events.py:258 result=(_UnixReadPipeTransport fd=7 polling, asyncio.streams.StreamReaderProtocol object at 0x806e257a8)) at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/base_events.py:95 created at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/futures.py:239: FAIL! _StopError() add_signal_handler(Signals.SIGCHLD, bound method SafeChildWatcher._sig_chld of asyncio.unix_events.SafeChildWatcher object at 0x806e25810, ()) PY signal.signal(Signals.SIGCHLD) [pid 78351] _run_once: thread=34384933888 Execute Handle Task._step() created at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/tasks.py:74 execute program '/usr/home/buildbot/buildarea/custom.krah-freebsd/build/python' process '/usr/home/buildbot/buildarea/custom.krah-freebsd/build/python' created: pid 78390 execute program '/usr/home/buildbot/buildarea/custom.krah-freebsd/build/python': _UnixSubprocessTransport pid=78390 [pid 78351] _run_once: thread=34384933888 Execute Handle SubprocessStreamProtocol.connection_made(_UnixSubprocessTransport pid=78390) created at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/base_subprocess.py:121 [pid 78351] _run_once: thread=34384933888 Execute Handle Task._wakeup(Future finished result=None) created at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/futures.py:239 [pid 78351] _run_once: thread=34384933888 Execute Handle _raise_stop_error(Task finished coro=create_subprocess_exec() done, defined at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/subprocess.py:208 created at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/base_events.py:258 result=Process 78390) at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/base_events.py:95 created at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/futures.py:239 Execute Handle _raise_stop_error(Task finished coro=create_subprocess_exec() done, defined at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/subprocess.py:208 created at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/base_events.py:258 result=Process 78390) at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/base_events.py:95 created at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/futures.py:239: FAIL! _StopError() [pid 78351] _run_once: thread=34384933888 Execute Handle Task._step() created at /usr/home/buildbot/buildarea/custom.krah-freebsd/build/Lib/asyncio/tasks.py:74 [pid 78351] _run_once: thread=34384933888 select(None) (1) import (2) dump traceback select(None) - [(SelectorKey(fileobj=7, fd=7, events=1, data=(Handle _UnixReadPipeTransport._read_ready() created
[issue21645] test_read_all_from_pipe_reader() of test_asyncio hangs on FreeBSD 9
STINNER Victor added the comment: I'm running tests on the buildbot AMD64 FreeBSD 9.0 custom: http://buildbot.python.org/all/builders/AMD64%20FreeBSD%209.0%20custom/builds/27/steps/test/logs/stdio -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue21645 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue21645] test_read_all_from_pipe_reader() of test_asyncio hangs on FreeBSD 9
STINNER Victor added the comment: (1) the thread B gets the SIGCHLD signal: it writes a byte into the self pipe of the event loop C signal_handler: sig_num=20, thread=34468857856 trip_signal(20): write() (2) in the main thread, the event loop is awaken by the write in the pipe... but there is nothing to do _read_from_self - b'\x14', thread=34384933888 (3) the thread B schedules the callback Py_AddPendingCall(checksignals_witharg), thread=34468857856 (I modified the output a little bit for readability.) IMO the problem is that asyncio relies on two events: * signal number written in the self pipe of the event loop * callback scheduled by the C handler A solution would be to schedule the callback in the event loop. Since Python 3.3, the C signal handler writes the signal number, which should be enough to find and schedule the Python callback. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue21645 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue21645] test_read_all_from_pipe_reader() of test_asyncio hangs on FreeBSD 9
Roundup Robot added the comment: New changeset a0e6a370755f by Victor Stinner in branch 'default': Issue #21645: Add debug code to analyze a failure on FreeBSD 9 http://hg.python.org/cpython/rev/a0e6a370755f -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue21645 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue21645] test_read_all_from_pipe_reader() of test_asyncio hangs on FreeBSD 9
Roundup Robot added the comment: New changeset dbf991650441 by Victor Stinner in branch 'default': Issue #21645: test_asyncio, log debug trace into sys.__stderr__, not in http://hg.python.org/cpython/rev/dbf991650441 -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue21645 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue21645] test_read_all_from_pipe_reader() of test_asyncio hangs on FreeBSD 9
STINNER Victor added the comment: Buildbot where the issue occurs: http://buildbot.python.org/all/builders/AMD64%20FreeBSD%209.0%203.x/ -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue21645 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue21645] test_read_all_from_pipe_reader() of test_asyncio hangs on FreeBSD 9
Roundup Robot added the comment: New changeset 69d474dab479 by Victor Stinner in branch 'default': Issue #21645: asyncio: add a watchdog in test_read_all_from_pipe_reader() for http://hg.python.org/cpython/rev/69d474dab479 -- nosy: +python-dev ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue21645 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue21645] test_read_all_from_pipe_reader() of test_asyncio hangs on FreeBSD 9
Changes by Giampaolo Rodola' g.rod...@gmail.com: -- components: +Asyncio ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue21645 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue21645] test_read_all_from_pipe_reader() of test_asyncio hangs on FreeBSD 9
New submission from STINNER Victor: http://buildbot.python.org/all/builders/AMD64%20FreeBSD%209.0%203.4/builds/191/steps/test/logs/stdio [ 8/389] test_asyncio Timeout (1:00:00)! Thread 0x000801407400 (most recent call first): File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/selectors.py, line 494 in select File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/asyncio/base_events.py, line 795 in _run_once File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/asyncio/base_events.py, line 184 in run_forever File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/asyncio/base_events.py, line 203 in run_until_complete File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/test/test_asyncio/test_streams.py, line 617 in test_read_all_from_pipe_reader File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/unittest/case.py, line 577 in run File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/unittest/case.py, line 625 in __call__ File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/unittest/suite.py, line 125 in run File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/unittest/suite.py, line 87 in __call__ File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/unittest/suite.py, line 125 in run File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/unittest/suite.py, line 87 in __call__ File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/unittest/suite.py, line 125 in run File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/unittest/suite.py, line 87 in __call__ File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/unittest/runner.py, line 168 in run File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/test/support/__init__.py, line 1724 in _run_suite File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/test/support/__init__.py, line 1758 in run_unittest File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/test/test_asyncio/__init__.py, line 29 in test_main File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/test/regrtest.py, line 1278 in runtest_inner File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/test/regrtest.py, line 967 in runtest File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/test/regrtest.py, line 763 in main File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/test/regrtest.py, line 1562 in main_in_temp_cwd File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/test/__main__.py, line 3 in module File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/runpy.py, line 85 in _run_code File /usr/home/buildbot/buildarea/3.4.krah-freebsd/build/Lib/runpy.py, line 170 in _run_module_as_main -- components: Tests keywords: buildbot messages: 219647 nosy: giampaolo.rodola, gvanrossum, haypo, pitrou, yselivanov priority: normal severity: normal status: open title: test_read_all_from_pipe_reader() of test_asyncio hangs on FreeBSD 9 versions: Python 3.4 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue21645 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue21645] test_read_all_from_pipe_reader() of test_asyncio hangs on FreeBSD 9
Guido van Rossum added the comment: Maybe see Tulip issue 168? That test was added to support that. Maybe the fix doesn't work for this platform? -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue21645 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
