IO::Select Memory Hog?

rapier1 has asked for the wisdom of the Perl Monks concerning the following question:

I'm writing a nonforking blockign server that is making use of IO::Select's can_read function. Specifcially:

foreach $client ($select->can_read(0)) {
   dostuff
}
[download]

When I run top the memory usage on this script approaches 98% which seems a little excessive to me. I'm starting to think this is having some negative effects on the functionality of the server. Does it? Should I be concerned? Are there alternatives? All the examples of a nonforking server I've seen use can_read.

Also, who do I have to kill to keep this text from being centered? It makes it difficult as hell to read the code.

Comment on IO::Select Memory Hog? Download Code

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Re: IO::Select Memory Hog? by kjherron (Pilgrim) on Aug 23, 2001 at 23:56 UTC
s/memory/cpu/ noted... The loop you show looks fine, but you understand that can_read(0) doesn't block? It returns immediately, whether any handles are ready or not. If the surrounding code is essentially: `while(1) { foreach $client ($select->can_read(0)) { dostuff } }` [download] then you're going to keep calling can_read() just as fast as you can, rather than truly blocking until a file handle becomes ready. If you want can_read() to block as long as necessary, then you shouldn't pass a timeout argument. IF you need can_read() to return every so often, then you should pass some timeout other than 0. Only use 0 for the timeout if you don't want the call to block.	[reply] [d/l]
Re: Re: IO::Select Memory Hog? by rapier1 (Novice) on Aug 24, 2001 at 21:31 UTC
Yeah, unfortunately I need it not to block. Once it gets a client connection it has to spit out data as fast as possible. I can't fork and I can't use threads so I guess I'm entirely screwed.	[reply]
Re: IO::Select Memory Hog? by rapier1 (Novice) on Aug 23, 2001 at 23:20 UTC
s/memory/cpu/g I am a dork sometimes...	[reply]
Re: IO::Select Memory Hog? by jlongino (Parson) on Aug 24, 2001 at 08:14 UTC
As for the centering, I understand that it is because you are using IE 6.0. You might want to go back a version or switch to NS. I read about it somewhere on this site but can't find it via search. Update: Check the node Re: Everything is centered. If the code and the comments disagree, then both* are probably wrong.* -- Norm Schryer	[reply]