On 16 January 2013 19:39, Roberto De Ioris <[email protected]> wrote: > >> I actually found that flock has, for some reason, no effect whatsoever >> when daemonize is used. (Is that fd inadvertently closed?) >> >> This is on an ext4 filesystem. The related test configs: (the asdf >> lockfile was pre-created) >> >> $ cat x.ini >> [uwsgi] >> flock=asdf >> socket=/tmp/test.sock >> daemonize=foo.log >> >> $ cat x-nodaemon.ini >> [uwsgi] >> flock=asdf >> socket=/tmp/test.sock >> >> First session, showing two daemonized uWSGIs and one non-daemonized uWSGI >> starting concurrently with the same flock file: >> >> $ uwsgi-1.4.3 x.ini >> [uWSGI] getting INI configuration from x.ini >> >> $ uwsgi-1.4.3 x.ini >> [uWSGI] getting INI configuration from x.ini >> >> $ ps aux | grep x.ini >> 21943 ... uwsgi-1.4.3 x.ini >> 21947 ... uwsgi-1.4.3 x.ini >> >> $ uwsgi-1.4.3 x-nodaemon.ini >> [uWSGI] getting INI configuration from x-nodaemon.ini >> *** Starting uWSGI 1.4.3 (64bit) on [Tue Jan 15 09:50:39 2013] *** >> >> And a second session, with two non-daemonized uWSGIs with the same >> lockfile: >> >> (shell 1) $ uwsgi-1.4.3 x-nodaemon.ini >> [uWSGI] getting INI configuration from x-nodaemon.ini >> *** Starting uWSGI 1.4.3 (64bit) on [Tue Jan 15 09:51:23 2013] *** >> >> (shell 2) $ uwsgi-1.4.3 x-nodaemon.ini >> [uWSGI] getting INI configuration from x-nodaemon.ini >> uWSGI ERROR: asdf is locked by another instance >> (shell 2) $ >> >> Strange... >> >> - > > it is the expected behaviour. > > If you fork() after a flock(), the lock is lost.
This is confusing. The flock(2) manpage says the opposite: <quote> Locks created by flock() are associated with an open file table entry. This means that duplicate file descriptors (created by, for example, fork(2) or dup(2)) refer to the same lock, and this lock may be modified or released using any of these descriptors. Furthermore, the lock is released either by an explicit LOCK_UN operation on any of these duplicate descriptors, or when all such descriptors have been closed. </quote> I regularly flock and fork and do not lose the lock in child processes. Generally in Perl, but whatever, it uses fork(), and flock() internally. What am I missing? Are you describing uWSGI specific behavior? cheers, Yves -- perl -Mre=debug -e "/just|another|perl|hacker/" _______________________________________________ uWSGI mailing list [email protected] http://lists.unbit.it/cgi-bin/mailman/listinfo/uwsgi
