undef a Module

jai_dgl has asked for the wisdom of the Perl Monks concerning the following question:

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Re: undef a Module by talexb (Chancellor) on Jan 21, 2010 at 16:15 UTC
I'm using many Perl modules in my script, my concern is while compile the process memory keeps growing drastically. I want to undef some module once after its done. I'm trying to understand the problem before I suggest a solution. Are you saying while the script's compiling, and before it starts to run, it uses a lot of memory? Or are you saying that when it runs (and compiles first) it uses a lot of memory? Is this a long-running script, or a daemon? Is it processing large files that are getting read into memory? Is it processing large XML files? Is this a real performance problem? Are you running this script on a machine that's underpowered? Can you get more memory for the machine? If you can explain what's going on in a little more detail, perhaps we can make better suggestions. Alex / talexb / Toronto Team website: Forex Chart Monkey, Forex Technical Analysis and Pickpocket Prevention "Groklaw is the open-source mentality applied to legal research" ~ Linus Torvalds	[reply]
Re: undef a Module by Anonymous Monk on Jan 21, 2010 at 14:28 UTC
Its possible (see Symbol::delete_package] , but not very useful.	[reply]
Re: undef a Module by steve (Deacon) on Jan 21, 2010 at 17:49 UTC
Can you post some code as well? Which modules are you trying to use? What makes you suspect that the compile process is the cause of the increase in the allocated memory size? You may benefit from looking into Mini-Tutorial: Perl's Memory Management, Memory reusability, etc. There are a lot of well written posts here on perlmonks about memory management. You may also try looking into roles (for example: http://www.modernperlbooks.com/mt/2009/04/the-why-of-perl-roles.html, http://www.scwn.net/2009/05/duck-typing-and-roles-in-object-oriented-programming/) in order to minimize what you are compiling from the modules in question.	[reply]
Re: undef a Module by turo (Friar) on Jan 21, 2010 at 15:49 UTC
I don't know if it helps, but have you tried simply to make the following?: `use MyLib1; use MyLib2; <my code here> no MyLib1; <my code here> no MyLib2; <more code here>` [download] Regards, turo `perl -Te 'print map { chr((ord)-((10,20,2,7)[$i++])) } split //,"turo"'`	[reply] [d/l] [select]
Re^2: undef a Module by chromatic (Archbishop) on Jan 21, 2010 at 19:52 UTC
I'm unaware of any modules where that would help. `no` calls the given module's `unimport()` method, which (in theory) could free a lot of memory, but that's likely to be minimal (usually it toggles some lexical hints at compilation time) and it'll free that memory back to Perl, not the OS.	[reply] [d/l] [select]
Re: undef a Module by Khen1950fx (Canon) on Jan 22, 2010 at 10:56 UTC
I'm working on a project right now that uses a lot of modules. What I did was to tuck the modules that weren't used constantly into subs. Then you can call them as methods when you need them, and you won't get out of memory warnings. As for undef, each module will probably have its own procedure for undef or exit, so check that module's documentation to see how its done. There's a lot of modules that don't have a method for undef, but if you're using subs, you may not need to undef them.	[reply]