Hi Jon, My code actually needed to run other shell commands. I just used the `date` function as a simple example to demonstrate the problem.
David On Sat, 2012-01-07 at 02:44 -0700, Jon wrote: > Hello All, > > > Ok, maybe I'm missing the whole point of this thread, but why is this > solution better than using the built-in perl `date` function? > > > Personally, I think using the system 'date' function provides too many > variables [read: problems] when attempting cross-platform continuity. > > > > Maybe I have misunderstood the whole point of this thread, but it > seems to me that everyone is over-engineering the problem... (i've > only been a Perl programmer for like three years, so I still have > ton's to learn... hopefully I can learn from this if I'm way off > base) > > > Thanks, > Jon A > > On Tue, Jan 3, 2012 at 8:38 PM, David Booth <da...@dbooth.org> wrote: > Thanks for the suggestion. I tried it with prefork and the > problem > still occurred. HOWEVER, I then decided to remove all modules > down to a > minimal example, and discovered that the mere inclusion of the > following > module: > > use Test::MockObject; > > was causing the segmentation fault after several successful > requests, > even though no functions whatsoever were called. Since this > appears to > be a bug in Test::MockObject, I reported the bug here: > https://rt.cpan.org/Public/Bug/Display.html?id=73723 > > The bug report shows the exact minimal handler code that I > used to > reproduce the bug. > > Best wishes, > David > > > On Tue, 2012-01-03 at 17:26 -0500, Daniel Risacher wrote: > > I think I've been bitten by this too, years ago. > > > > I *think* I solved it by switching to mpm_prefork, which was > > unsatisfying, but adequate for my needs. > > > > On Tue, Jan 3, 2012 at 5:21 PM, David Booth > <da...@dbooth.org> wrote: > > > I tried redirecting stderr to /dev/null and it did not > help: > > > system("date >> $f 2> /dev/null"); > > > > > > I am using the worker processing model. Does it work for > you (or anyone > > > else) without causing periodic child process segmentation > faults? > > > > > > > > > On Tue, 2012-01-03 at 16:29 -0500, Daniel Risacher wrote: > > >> It's been a while since I looked at doing this, but IIRC > it's fairly > > >> dependent on the processing model that Apache is using. > Are you > > >> mpm_prefork, or mpm_worker? > > >> > > >> Also, I found it was important to redirect stderr > to /dev/null: > > >> > > >> sub play { > > >> system "/usr/bin/xmms -t 2> /dev/null"; > > >> } > > >> > > >> > > >> On Tue, Jan 3, 2012 at 12:48 PM, David Booth > <da...@dbooth.org> wrote: > > >> > I am trying to run a shell command from a mod_perl2 > response handler. > > >> > It works properly for some number of HTTP requests, but > sometimes it > > >> > fails (somewhat randomly) and I see in my Apache2 error > log that one of > > >> > the Apache2 child processes has died with a > segmentation fault. > > >> > For example, /var/log/apache2/error.log shows: > > >> > > > >> > [Tue Jan 03 12:16:10 2012] [notice] child pid 3538 exit > signal Segmentation fault (11) > > >> > > > >> > Is this normal? How does one normally run a shell > command from a > > >> > response handler? I do not want to return the > command's output to the > > >> > client. > > >> > > > >> > Here is a trivial example response handler that > exhibits this behavior: > > >> > > > >> > sub handler > > >> > { > > >> > my $r = shift || die; > > >> > my $f = $ENV{DOCUMENT_ROOT} . "/date.txt"; > > >> > system("date >> $f"); > > >> > $r->internal_redirect("/date.txt"); > > >> > return Apache2::Const::OK; > > >> > } > > >> > > > >> > Can anyone provide any guidance? Does this work for > you? > > >> > > > >> > Note that you may not notice the problem if you don't > carefully watch > > >> > the Apache2 error log (e.g., with "tail > -f /var/log/apache2/error.log"), > > >> > because Apache2 automatically spawns new children > processes as needed, > > >> > and client (such as Firefox or wget, though not curl) > seem to > > >> > automatically re-try the request when it fails, thus > giving the illusion > > >> > of succeeding. > > >> > > > >> > P.S. I have posted about this on perlmonks, but thus > far have not found > > >> > a solution: > > >> > http://www.perlmonks.org/?node_id=945947 > > >> > > > >> > > > >> > -- > > >> > David Booth, Ph.D. > > >> > http://dbooth.org/ > > >> > > > >> > Opinions expressed herein are those of the author and > do not necessarily > > >> > reflect those of his employer. > > >> > > > >> > > >> > > > > > > -- > > > David Booth, Ph.D. > > > http://dbooth.org/ > > > > > > Opinions expressed herein are those of the author and do > not necessarily > > > reflect those of his employer. > > > > > > > > > -- > David Booth, Ph.D. > http://dbooth.org/ > > Opinions expressed herein are those of the author and do not > necessarily > reflect those of his employer. > > > > > > > -- > Best Regards, > Jonathan David > > > Please excuse any brevity or typos as this e-mail is most likely sent > from a mobile device. > > -- David Booth, Ph.D. http://dbooth.org/ Opinions expressed herein are those of the author and do not necessarily reflect those of his employer.
