Re: Modules Executed Twice
* Perrin Harkins [EMAIL PROTECTED] [2002-12-30 19:07]: Explanations and other suggested approaches to handling this problem will be most welcome. My suggestion in the past has been to PerlRequire a startup.pl that does a use on your modules, instead of pulling them in with PerlModule. I believe that if you have custom directives, you need to PerlModule your module -- a simple 'use Foo;' line within a PerlRequire'd script is not sufficient. (darren) -- Do you realize how many holes there could be if people would just take the time to take the dirt out of them?
Modules Executed Twice
Hi All,
I'm developing a new module for mod_perl 1.27, and I'm noticing that
some code is getting executed twice when the Apache server starts up.
Here's a simple example. Say I have two modules in separate files:
package DoubleTest;
use strict;
my $seen;
sub test_seen {
$seen++;
warn Seen: $seen\n
}
1;
package TestSeen;
use strict;
use DoubleTest;
DoubleTest::test_seen();
1;
Then I have an httpd.conf with these two lines:
PerlModule DoubleTest
PerlModule TestSeen
When I start up Apache, I see Seen: 1 print to the terminal, and then
I see Seen: 2 in the error log. For some reason, TestSeen is getting
executed twice!
I did a quick search on perl.apache.org, and found this item:
http://perl.apache.org/docs/1.0/guide/
config.html#Apache_Restarts_Twice_On_Start
However, this seems to indicate that, first, modules will be executed
twice on restart but not on start, and second, that it doesn't affect
PerlModule directives. What I'm seeing above doesn't seem to bear this
out.
Thanks to that item in the guide, I did figure out how to circumvent
the problem by checking $Apache::Server::Starting in
DoubleTest::test_seen():
sub test_seen {
return if $Apache::Server::Starting;
$seen++;
warn Seen: $seen\n
}
So I'm fine with this workaround, but not sure why it's necessary. I
could also change TestSeen.pm to only call test_seen() in a BEGIN block
or something (since the modules seems to be compiled only once, but run
twice), but since the module I'm actually writing is the equivalent of
DoubleTest with TestSeen as the client, I'd rather not impose that on
the users of my module.
Explanations and other suggested approaches to handling this problem
will be most welcome.
TIA,
David
--
David Wheeler AIM: dwTheory
[EMAIL PROTECTED] ICQ: 15726394
http://david.wheeler.net/ Yahoo!: dew7e
Jabber: [EMAIL PROTECTED]
Re: Modules Executed Twice
David Wheeler wrote:
Hi All,
I'm developing a new module for mod_perl 1.27, and I'm noticing that
some code is getting executed twice when the Apache server starts up.
It was supposed to be fixed in 1.25_01:
=item 1.25_01 - July 6, 2001
...
fix double-loading bug of Perl{Require,Module}s at startup time
Here is the diff:
Index: Apache/Apache.pm
===
RCS file: /home/cvs/modperl/Apache/Apache.pm,v
retrieving revision 1.62
retrieving revision 1.63
diff -u -r1.62 -r1.63
--- Apache/Apache.pm29 Jan 2001 16:07:08 - 1.62
+++ Apache/Apache.pm26 Apr 2001 05:30:45 - 1.63
@@ -30,7 +30,10 @@
sub httpd_conf {
shift;
-push @Apache::ReadConfig::PerlConfig,
+no strict 'refs';
+#use a symbolic reference so %Apache::ReadConfig::
+#is empty at compile time
+push @{Apache::ReadConfig::PerlConfig},
map $_\n, @_;
}
[...]
sub test_seen {
return if $Apache::Server::Starting;
$seen++;
warn Seen: $seen\n
}
Indeed, that's the workaround that was added originaly to cure the above
problem. Perhaps you can play with httpd_conf and see why it doesn't
work for you. I know that several people have reported that they still
had this problem since 1.26 was released.
__
Stas BekmanJAm_pH -- Just Another mod_perl Hacker
http://stason.org/ mod_perl Guide --- http://perl.apache.org
mailto:[EMAIL PROTECTED] http://use.perl.org http://apacheweek.com
http://modperlbook.org http://apache.org http://ticketmaster.com
Re: Modules Executed Twice
On Monday, December 30, 2002, at 02:45 PM, Stas Bekman wrote:
David Wheeler wrote:
Hi All,
I'm developing a new module for mod_perl 1.27, and I'm noticing that
some code is getting executed twice when the Apache server starts up.
It was supposed to be fixed in 1.25_01:
=item 1.25_01 - July 6, 2001
...
fix double-loading bug of Perl{Require,Module}s at startup time
Hrm, interesting. I wonder what the problem is?
Indeed, that's the workaround that was added originaly to cure the
above problem. Perhaps you can play with httpd_conf and see why it
doesn't work for you. I know that several people have reported that
they still had this problem since 1.26 was released.
I have a better workaround, now. I found that I could make the problem
go away by reversing the order in which the modules are loaded in
httpd.conf:
PerlModule TestSeen
PerlModule DoubleTest
Not exactly sure why that makes a difference, though.
Is httpd_conf() documented somewhere? I can't see what's supposed to be
passed to it.
Thanks,
David
--
David Wheeler AIM: dwTheory
[EMAIL PROTECTED] ICQ: 15726394
http://david.wheeler.net/ Yahoo!: dew7e
Jabber: [EMAIL PROTECTED]
Re: Modules Executed Twice
David Wheeler wrote:
On Monday, December 30, 2002, at 02:45 PM, Stas Bekman wrote:
David Wheeler wrote:
Hi All,
I'm developing a new module for mod_perl 1.27, and I'm noticing that
some code is getting executed twice when the Apache server starts up.
It was supposed to be fixed in 1.25_01:
=item 1.25_01 - July 6, 2001
...
fix double-loading bug of Perl{Require,Module}s at startup time
Hrm, interesting. I wonder what the problem is?
Indeed, that's the workaround that was added originaly to cure the
above problem. Perhaps you can play with httpd_conf and see why it
doesn't work for you. I know that several people have reported that
they still had this problem since 1.26 was released.
I have a better workaround, now. I found that I could make the problem
go away by reversing the order in which the modules are loaded in
httpd.conf:
PerlModule TestSeen
PerlModule DoubleTest
Not exactly sure why that makes a difference, though.
Because $seen wasn't reset yet on reload.
Is httpd_conf() documented somewhere? I can't see what's supposed to be
passed to it.
It's an internal thing. You can add debug prints and Carp::cluck, to see
who calls it with what args. Hopefully someone will be able to track the
problem down and finally cure it for good.
__
Stas BekmanJAm_pH -- Just Another mod_perl Hacker
http://stason.org/ mod_perl Guide --- http://perl.apache.org
mailto:[EMAIL PROTECTED] http://use.perl.org http://apacheweek.com
http://modperlbook.org http://apache.org http://ticketmaster.com
RE: Modules Executed Twice
Is anyone getting duplicates (i.e. 2 of the same email) of this thread? It just
started happening today.
Brian
-Original Message-
From: Stas Bekman [mailto:[EMAIL PROTECTED]]
Sent: Monday, December 30, 2002 5:06 PM
To: David Wheeler
Cc: [EMAIL PROTECTED]
Subject: Re: Modules Executed Twice
David Wheeler wrote:
On Monday, December 30, 2002, at 02:45 PM, Stas Bekman wrote:
David Wheeler wrote:
Hi All,
I'm developing a new module for mod_perl 1.27, and I'm noticing that
some code is getting executed twice when the Apache server starts up.
It was supposed to be fixed in 1.25_01:
=item 1.25_01 - July 6, 2001
...
fix double-loading bug of Perl{Require,Module}s at startup time
Hrm, interesting. I wonder what the problem is?
Indeed, that's the workaround that was added originaly to cure the
above problem. Perhaps you can play with httpd_conf and see why it
doesn't work for you. I know that several people have reported that
they still had this problem since 1.26 was released.
I have a better workaround, now. I found that I could make the problem
go away by reversing the order in which the modules are loaded in
httpd.conf:
PerlModule TestSeen
PerlModule DoubleTest
Not exactly sure why that makes a difference, though.
Because $seen wasn't reset yet on reload.
Is httpd_conf() documented somewhere? I can't see what's supposed to be
passed to it.
It's an internal thing. You can add debug prints and Carp::cluck, to see
who calls it with what args. Hopefully someone will be able to track the
problem down and finally cure it for good.
__
Stas BekmanJAm_pH -- Just Another mod_perl Hacker
http://stason.org/ mod_perl Guide --- http://perl.apache.org
mailto:[EMAIL PROTECTED] http://use.perl.org http://apacheweek.com
http://modperlbook.org http://apache.org http://ticketmaster.com
Re: Modules Executed Twice
Hann, Brian wrote: Is anyone getting duplicates (i.e. 2 of the same email) of this thread? It just started happening today. I can't tell, since I never receive dups because of the procmail rule: :0 Wh: msgid.lock | formail -D 8192 saved/msgid.cache hint, hint ;) __ Stas BekmanJAm_pH -- Just Another mod_perl Hacker http://stason.org/ mod_perl Guide --- http://perl.apache.org mailto:[EMAIL PROTECTED] http://use.perl.org http://apacheweek.com http://modperlbook.org http://apache.org http://ticketmaster.com
Re: Modules Executed Twice
Explanations and other suggested approaches to handling this problem will be most welcome. My suggestion in the past has been to PerlRequire a startup.pl that does a use on your modules, instead of pulling them in with PerlModule. Of course, if you turn PerlFreshRestart on then this is the intended behavior. - Perrin
Re: Modules Executed Twice
On Monday, December 30, 2002, at 04:09 PM, Perrin Harkins wrote: My suggestion in the past has been to PerlRequire a startup.pl that does a use on your modules, instead of pulling them in with PerlModule. Of course, if you turn PerlFreshRestart on then this is the intended behavior. That's exactly what I do, too. But I want to give users the flexibility to do both. Thanks, David -- David Wheeler AIM: dwTheory [EMAIL PROTECTED] ICQ: 15726394 http://david.wheeler.net/ Yahoo!: dew7e Jabber: [EMAIL PROTECTED]
