| msg133908 - (view) |
Author: STINNER Victor (vstinner) *  |
Date: 2011-04-16 22:57 |
| test_interrupted_write_text() of test_io failed of Python 3.3 on FreeBSD 7.2: ----------------------------------------------- [250/354] test_io Exception in thread Thread-1316: Traceback (most recent call last): File "/usr/home/db3l/buildarea/3.x.bolen-freebsd7/build/Lib/threading.py", line 735, in _bootstrap_inner self.run() File "/usr/home/db3l/buildarea/3.x.bolen-freebsd7/build/Lib/threading.py", line 688, in run self._target(*self._args, **self._kwargs) File "/usr/home/db3l/buildarea/3.x.bolen-freebsd7/build/Lib/test/test_io.py", line 2630, in _read s = os.read(r, 1) OSError: [Errno 4] Interrupted system call Timeout (1:00:00)! Thread 0x28401040: File "/usr/home/db3l/buildarea/3.x.bolen-freebsd7/build/Lib/test/test_io.py", line 2651 in check_interrupted_write File "/usr/home/db3l/buildarea/3.x.bolen-freebsd7/build/Lib/test/test_io.py", line 2672 in test_interrupted_write_text File "/usr/home/db3l/buildarea/3.x.bolen-freebsd7/build/Lib/unittest/case.py", line 387 in _executeTestPart File "/usr/home/db3l/buildarea/3.x.bolen-freebsd7/build/Lib/unittest/case.py", line 442 in run File "/usr/home/db3l/buildarea/3.x.bolen-freebsd7/build/Lib/unittest/case.py", line 494 in __call__ File "/usr/home/db3l/buildarea/3.x.bolen-freebsd7/build/Lib/unittest/suite.py", line 105 in run File "/usr/home/db3l/buildarea/3.x.bolen-freebsd7/build/Lib/unittest/suite.py", line 67 in __call__ File "/usr/home/db3l/buildarea/3.x.bolen-freebsd7/build/Lib/unittest/suite.py", line 105 in run File "/usr/home/db3l/buildarea/3.x.bolen-freebsd7/build/Lib/unittest/suite.py", line 67 in __call__ File "/usr/home/db3l/buildarea/3.x.bolen-freebsd7/build/Lib/test/support.py", line 1078 in run File "/usr/home/db3l/buildarea/3.x.bolen-freebsd7/build/Lib/test/support.py", line 1166 in _run_suite File "/usr/home/db3l/buildarea/3.x.bolen-freebsd7/build/Lib/test/support.py", line 1192 in run_unittest File "/usr/home/db3l/buildarea/3.x.bolen-freebsd7/build/Lib/test/test_io.py", line 2845 in test_main File "./Lib/test/regrtest.py", line 1041 in runtest_inner File "./Lib/test/regrtest.py", line 835 in runtest File "./Lib/test/regrtest.py", line 659 in main File "./Lib/test/regrtest.py", line 1619 in *** Error code 1 Stop in /usr/home/db3l/buildarea/3.x.bolen-freebsd7/build. program finished with exit code 1 elapsedTime=8703.824572 ----------------------------------------------- http://www.python.org/dev/buildbot/all/builders/x86%20FreeBSD%207.2%203.x/builds/1695/steps/test/logs/stdio |
|
|
| msg133909 - (view) |
Author: STINNER Victor (vstinner) * |
Date: 2011-04-16 23:17 |
| I already read somewhere that on FreeBSD, any thread can receive a signal, not only the main thread. I suppose that it should be the same on Linux, but Linux tries maybe to send a signal to the main thread if the main thread and other threads are calling a system call. In this case, "_read" thread gets the SIGARLM signal and so its os.read() system call is interrupted. It means that os.read() is blocked at least one second, whereas wio.write() is supposed to send data to unblock _read() thread. |
|
|
| msg133910 - (view) |
Author: STINNER Victor (vstinner) * |
Date: 2011-04-16 23:23 |
| One solution to fix this problem is to use pthread_sigmask() on the _read() thread to not handle SIGARLM. For example, the faulthandler uses the following code to not handle any thread in its timeout thread: #ifdef HAVE_PTHREAD_H sigset_t set; /* we don't want to receive any signal */ sigfillset(&set); #if defined(HAVE_PTHREAD_SIGMASK) && !defined(HAVE_BROKEN_PTHREAD_SIGMASK) pthread_sigmask(SIG_SETMASK, &set, NULL); #else sigprocmask(SIG_SETMASK, &set, NULL); #endif #endif |
|
|
| msg133923 - (view) |
Author: Antoine Pitrou (pitrou) * |
Date: 2011-04-17 13:30 |
| Agreed with your analysis. The problem is that the signal module doesn't expose pthread_sigmask. We could grab Jean-Paul's implementation from http://bazaar.launchpad.net/~exarkun/python-signalfd/trunk/view/head:/signalfd/_signalfd.c (although I'm not sure why the method is called "sigprocmask" while it calls pthread_sigmask). |
|
|
| msg134863 - (view) |
Author: STINNER Victor (vstinner) * |
Date: 2011-04-30 13:23 |
| New changeset 28b9702a83d1 by Victor Stinner in branch 'default': Issue #8407, issue #11859: Add signal.pthread_sigmask() function to fetch http://hg.python.org/cpython/rev/28b9702a83d1 |
|
|
| msg134940 - (view) |
Author: STINNER Victor (vstinner) * |
Date: 2011-05-01 22:47 |
| The issue is race condition and was rare (I only saw it once on FreeBSD 7.2 3.x buildbot). I suppose that it is fixed, I'm unable to check (I am unable to reproduce the bug in my FreeBSD 8 VM). Reopen the issue if it is not fixed yet. |
|
|