Re: Prototype Mismatch in ModPerl::PerlRun

Ed, thanks for your response!

I had already tried most of your suggestions: Putting the module load in 
the startup (with or without the import) didn't make a difference (still 
get the prototype mismatch on the second and subsequent runs of the 
script); and yah, importing nothing and referring to the sub directly 
via Time::HiRes::time() makes the error go away (presumably because 
nothing is imported).

I had originally thought it would warn on any import, but after reading 
your message I did a little more experimenting. It's true that not all 
modules/routines will trigger the warning; as a test I just tried use 
Digest::SHA qw(sha256) and it did not trigger the warning. However it 
looks like it does happen for more than just overwritten CORE routines. 
For example I can trigger the warning with use JSON qw(to_json); and use 
Fcntl qw(:flock) generates the warning separately for each symbol imported.

Prototype mismatch: sub 
ModPerl::ROOT::ModPerl::PerlRunPrefork::var_www_test_test5_2epl::LOCK_SH: none 
vs () at /var/www/test/test5.pl line 8.
Prototype mismatch: sub 
ModPerl::ROOT::ModPerl::PerlRunPrefork::var_www_test_test5_2epl::LOCK_NB: none 
vs () at /var/www/test/test5.pl line 8.
Prototype mismatch: sub 
ModPerl::ROOT::ModPerl::PerlRunPrefork::var_www_test_test5_2epl::LOCK_UN: none 
vs () at /var/www/test/test5.pl line 8.
Prototype mismatch: sub 
ModPerl::ROOT::ModPerl::PerlRunPrefork::var_www_test_test5_2epl::LOCK_EX: none 
vs () at /var/www/test/test5.pl line 8.

Cheers!

Dan

On 5/14/2021 5:23 PM, Edward J. Sabol wrote:
> Hi, Daniel. This error can happen even under regular Perl in some circumstances when a package redefines a core function ((like what importing Time::HiRes does here with time).
> 
> I would change "use Time::HiRes qw(time);" to "use Time::HiRes ();" and then change "time()" on line 13 to "Time::HiRes::time()." Does that make the message go away?
> 
> Even better would be to move or add "use Time::HiRes ();" to your startup.pl. I think it's generally a good idea (I want to say "best practice" even) to not import any functions or variables in your startup.pl, so I always add " ()" to my "use" statements there. You can then *usually* import specific functions with "use Whatever qw(func);" in your scripts. The problem here though is that the import is redefining the core function, and I think that can just be problematic.
> 
> I think the moral here is that ModPerl::PerlRun* is not a perfect drop-in replacement for a Perl CGI. With mod_perl, there's usually something you need to tweak (like how global variables and things like that) slightly in order to get it working as intended, but the changes are usually minor and make sense once you wrap your head around how mod_perl works.
> 
> Hope this helps!
> 
> Regards,
> Ed
> 
> On May 14, 2021, at 9:36 AM, Daniel Ragle <[email protected]> wrote:
>> I'm investigating short term solutions for site performance (long term is a full rewrite of the app) and I'm working for the first time with ModPerl::PerlRun (and ModPerl::PerlRunPrefork, both seem to exhibit the same behavior) and feel like I'm missing something obvious.
>>
>> I have this reduction (as test2.pl):
>>
>> ####################
>> #!/usr/bin/perl
>>
>> use strict;
>> use warnings;
>>
>> use Time::HiRes qw(time);
>>
>> use CGI;
>> my $cgi = CGI->new();
>>
>> print $cgi->header();
>> print "<h1>Hello World</h1>\n";
>> print "<h1>HiRes time is: ", time(), "</h1>\n";
>> #####################
>>
>> The script runs properly as far as I can see, but I'm getting Prototype Mismatch warnings in the log with each hit after the first one:
>>
>> Prototype mismatch: sub ModPerl::ROOT::ModPerl::PerlRunPrefork::var_www_test_test2_2epl::time: none vs () at /var/www/test/test2.pl line 6.
> 
>