[issue10348] multiprocessing: use SysV semaphores on FreeBSD
Charles-François Natali neolo...@free.fr added the comment: -1 IMHO, implementing SysV semaphores would be a step backwards, plus the API is a real pain. I think there's no reason to complicate the code to accomodate such corner cases, especially since the systems that don't support POSIX semaphores will eventually die out... -- nosy: +neologix ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10348 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10348] multiprocessing: use SysV semaphores on FreeBSD
Antoine Pitrou pit...@free.fr added the comment: Agreed with Charles-François. -- nosy: +pitrou ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10348 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10348] multiprocessing: use SysV semaphores on FreeBSD
Jesse Noller jnol...@gmail.com added the comment: Charles and Antoine's votes match my own, therefore closing the bug wont fix -- resolution: - wont fix status: open - closed ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10348 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10348] multiprocessing: use SysV semaphores on FreeBSD
STINNER Victor victor.stin...@haypocalc.com added the comment: Martin fixed test_concurrent_futures (#10798), this issue can be implemented later. -- type: - feature request versions: +Python 3.3 -Python 3.2 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10348 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10348] multiprocessing: use SysV semaphores on FreeBSD
STINNER Victor victor.stin...@haypocalc.com added the comment: More info about FreeBSD. sysctl p1003_1b.sem_nsems_max gives the maximum number of POSIX semaphores (per process? system wide?). Since FreeBSD 8.1, sudo sysctl -w p1003_1b.sem_nsems_max=256 can be used to change this limit at runtime. Before FreeBSD 8.1, SEM_MAX constant should be changed in the kernel source code, and the kernel have to be recompiled. (p1003_1b.sem_nsems_max is not configurable in /etc/sysctl.conf, it is an hardcoded limit). Before FreeBSD 8.0, the POSIX semaphores are disabled by default: the kernel have to be compiled using P1003_1B_SEMAPHORES option. Extract of sys/conf/NOTES: # # POSIX P1003.1B # Real time extensions added in the 1993 POSIX # _KPOSIX_PRIORITY_SCHEDULING: Build in _POSIX_PRIORITY_SCHEDULING options _KPOSIX_PRIORITY_SCHEDULING # p1003_1b_semaphores are very experimental, # user should be ready to assist in debugging if problems arise. options P1003_1B_SEMAPHORES # POSIX message queue options P1003_1B_MQUEUE # -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10348 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10348] multiprocessing: use SysV semaphores on FreeBSD
STINNER Victor victor.stin...@haypocalc.com added the comment: NetBSD. Extract of the sem_close() manpage http://www.daemon-systems.org/man/sem_close.3.html --- STANDARDS The sem_open(), sem_close(), and sem_unlink() functions conform to ISO/IEC 9945-1:1996 (``POSIX.1''). HISTORY Support for named semaphores first appeared in NetBSD 2.0. --- Martin wrote on the mailing list: --- According to http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/kern/uipc_sem.c?rev=1.22content-type=text/x-cvsweb-markuponly_with_tag=MAIN SEM_MAX is 128 since 2007, and dynamically adjustable (no reboot). --- It looks like the sysctl (read/write) option is kern.posix.semmax. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10348 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10348] multiprocessing: use SysV semaphores on FreeBSD
STINNER Victor victor.stin...@haypocalc.com added the comment: Darwin (Mac OS X). According to the following email (July 2010), Darwin supports POSIX semaphores and the default limit is 10,000 semaphores. http://osdir.com/ml/darwin-dev/2010-07/msg00012.html The limit is configurable via sysctl as kern.posix.sem.max. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10348 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10348] multiprocessing: use SysV semaphores on FreeBSD
STINNER Victor victor.stin...@haypocalc.com added the comment: OpenBSD. According to Martin, OpenBSD doesn't implement POSIX semaphores. --- I don't have an installation of OpenBSD, but... In FreeBSD, POSIX semaphores are implemented in sys/kern/uipc_sem.c. In http://www.openbsd.org/cgi-bin/cvsweb/src/sys/kern/ that file doesn't exist. Also, in FreeBSD's limits.h, _POSIX_SEM_NSEMS_MAX is defined (surprisingly to 256); in http://www.openbsd.org/cgi-bin/cvsweb/~checkout~/src/include/limits.h?rev=1.15;content-type=text/plain this constant doesn't appear. So ISTM that OpenBSD doesn't implement POSIX semaphores. IIUC, this means that the multiprocessing module won't be fully functional, and its tests (and the concurrent.futures tests) will be skipped. --- -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10348 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10348] multiprocessing: use SysV semaphores on FreeBSD
Jesse Noller jnol...@gmail.com added the comment: Adding, or moving, to SYSV semaphores is very low on the list of things to do. If someone were to provide a patch, I'm sure we could consider it. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10348 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10348] multiprocessing: use SysV semaphores on FreeBSD
STINNER Victor victor.stin...@haypocalc.com added the comment: Informations about SysV semaphores: - functions: semget(), semop(), semctl(), ftok() - http://perldoc.perl.org/IPC/SysV.html - http://beej.us/guide/bgipc/output/html/multipage/semaphores.html -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10348 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10348] multiprocessing: use SysV semaphores on FreeBSD
STINNER Victor victor.stin...@haypocalc.com added the comment: Examples of programs using SysV semaphores: http://firebird.cvs.sourceforge.net/viewvc/firebird/firebird2/src/jrd/isc_sync.cpp?revision=HEADview=markup (Firebird, search #ifdef USE_SYS5SEMAPHORE sections) https://github.com/mono/mono/blob/master/mono/io-layer/shared.c#L501 (Mono) -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10348 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10348] multiprocessing: use SysV semaphores on FreeBSD
STINNER Victor victor.stin...@haypocalc.com added the comment: See also #5725. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10348 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10348] multiprocessing: use SysV semaphores on FreeBSD
STINNER Victor victor.stin...@haypocalc.com added the comment: See also http://semanchuk.com/philip/sysv_ipc/: System V IPC for Python - Semaphores, Shared Memory and Message Queues -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10348 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10348] multiprocessing: use SysV semaphores on FreeBSD
Changes by Antoine Pitrou pit...@free.fr: -- nosy: +asksol ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10348 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10348] multiprocessing: use SYSV semaphores on FreeBSD
New submission from STINNER Victor victor.stin...@haypocalc.com: Support POSIX semaphore on FreeBSD is recent, optional (eg. disabled by default in FreeBSD 7) and limited (30 semaphores). SYSV should be used instead because they are less limited or more adjustable (at runtime: POSIX semaphore requires to recompile the kernel!). This issue should fix test_concurrent_futures on FreeBSD 7.2 and 8.0: many tests use more than 30 semaphores. The maximum is test_all_completed_some_already_completed: 52 semaphores. -- components: Library (Lib) keywords: buildbot messages: 120705 nosy: db3l, haypo priority: normal severity: normal status: open title: multiprocessing: use SYSV semaphores on FreeBSD versions: Python 3.2 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10348 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10348] multiprocessing: use SysV semaphores on FreeBSD
STINNER Victor victor.stin...@haypocalc.com added the comment: It looks like SysV semaphores are also preferred on Darwin. So I suppose that Mac OS X would also benefit of this issue. Maybe also other OSes (Solaris?). See also issue #7272. -- nosy: +jnoller title: multiprocessing: use SYSV semaphores on FreeBSD - multiprocessing: use SysV semaphores on FreeBSD ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue10348 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
