On May 11, 2007, at 12:05 PM, Michael Peters wrote:
This kind of thing happens all the time. Think of SAX XML parsers
or mod_perl
filters. It's not terribly difficult to parse something in chunks
like that.
I wasn't saying that it wouldn't be easier to have everything in
memory. Heck
I'
On 5/12/07, Lionel MARTIN <[EMAIL PROTECTED]> wrote:
Of course, I understand why $tmp value is reset during each call (the
lexical variable goes out of scope) but, as we can see, the address used
by
the variable is changing as well during each request, and this fact
doesn't
seem consistent w
On 5/12/07, Lionel MARTIN <[EMAIL PROTECTED]> wrote:
Of course, I understand why $tmp value is reset during each call (the
lexical variable goes out of scope) but, as we can see, the address used by
the variable is changing as well during each request, and this fact doesn't
seem consistent with w
> #**
> use strict;
> package mypack;
>
> my $tmp;
> $tmp .= 'a';
> print '$tmp value: ' . $tmp . ' - address: ' . \$tmp . "\n";
> #**
>
> I am running this script in a ModPerl::Registry environment.
>
> In this sit
Hi all (and Perrin),
I understand the concepts being discussed here.
However, no on replied one of my questions:
Let's conside this script:
#**
use strict;
package mypack;
my $tmp;
$tmp .= 'a';
print '$tmp value: ' . $tmp . ' - address: ' . \$tmp . "\n"
<[EMAIL PROTECTED]> writes:
> Why am I getting these emails even after unsubscribing?
I unsubscribed this person.
--
Joe Schaefer
Why am I getting these emails even after unsubscribing?
-Original Message-
From: [EMAIL PROTECTED] on behalf of Perrin Harkins
Sent: Fri 5/11/2007 8:53 PM
To: James. L
Cc: modperl@perl.apache.org
Subject:Re: After retrieving data from DB, the memory doesn't se
On 5/11/07, James. L <[EMAIL PROTECTED]> wrote:
sorry, i wasn't clear. I understand that memory
allocated by a lexical variable(not reference) can be
released to perl. as described by the practical
modperl link you posted.
I would expect that both behave the same however you
are saying a referen
--- Perrin Harkins <[EMAIL PROTECTED]> wrote:
> On 5/11/07, James. L <[EMAIL PROTECTED]> wrote:
> On 5/10/07, Andy Armstrong <[EMAIL PROTECTED]> wrote:
> > Unless I'm misunderstanding you that's not true.
> When a value's
> > reference count goes to zero the memory is freed -
> at least to Perl
bject: Re: After retrieving data from DB, the memory doesn't seem to
be freed up
On 5/11/07, James. L <[EMAIL PROTECTED]> wrote:
> hm. lexical variable release memory to perl. but
> reference doesn't..
No, that isn't what I was saying, and you're mixing separate c
On 5/11/07, James. L <[EMAIL PROTECTED]> wrote:
hm. lexical variable release memory to perl. but
reference doesn't..
No, that isn't what I was saying, and you're mixing separate concepts
together. A lexical variable can be a reference. You can have a
reference to a lexical variable. They are
--- Perrin Harkins <[EMAIL PROTECTED]> wrote:
> On 5/10/07, Andy Armstrong <[EMAIL PROTECTED]> wrote:
> > Unless I'm misunderstanding you that's not true.
> When a value's
> > reference count goes to zero the memory is freed -
> at least to Perl
> > if not to the OS.
>
> No, it's not. I know it'
On 11 May 2007, at 19:07, Lionel MARTIN wrote:
-another example hat comes to my mind is a project (implemented
in PHP) where I had to work. Part of the process was retrieving
cached HTML template pages from the server and do BB tags
parsing before serving the client. Of course, you would
-another example hat comes to my mind is a project (implemented in PHP)
where I had to work. Part of the process was retrieving cached HTML
template pages from the server and do BB tags parsing before serving the
client. Of course, you would tell me that I could retrieve the data
chunk by c
(sorry, I posted the message below from another email address hours ago, and
it didn't get publish - see below if anyone could reply)
On May 10, 2007, at 6:52 PM, Andy Armstrong wrote:
On 10 May 2007, at 23:48, Jonathan Vanasco wrote:
that also means that variables are sticky -- if you chang
> That's not really large data -- you're talking about dealing with
> 10-300k per request ( it should never go beyond that, because you'd
> be chunking stuff off the db for ease of download to the end user ).
>
> I've been under the impression ( and I'd imagine that others on this
> list ar
On May 11, 2007, at 12:57 PM, Lionel MARTIN wrote:
I don't have any clear situations right here in mind, but we could
imagine many:
-for example, a bulletin board system, where you are retrieving
posted message from a DB. Each message could weigh several dozens
of kilo. (especially if you
Lionel MARTIN wrote:
>
>> Lionel MARTIN wrote:
>>
- Don't load large amounts of data into scalars.
>>> Fine. Now I know why. But sometimes, you don't have the choice.
>>
>> I'd like to know what situations you encounter where you are forced to
>> load
>> large amounts of data into scalars. I
On 11 May 2007, at 17:57, Lionel MARTIN wrote:
Lionel MARTIN wrote:
- Don't load large amounts of data into scalars.
Fine. Now I know why. But sometimes, you don't have the choice.
I'd like to know what situations you encounter where you are
forced to load
large amounts of data into scala
Lionel MARTIN wrote:
- Don't load large amounts of data into scalars.
Fine. Now I know why. But sometimes, you don't have the choice.
I'd like to know what situations you encounter where you are forced to
load
large amounts of data into scalars. I can't think of any.
I don't have any cl
Lionel MARTIN wrote:
> I'll see what I can do when the problem arises, but of course, I now
> know I should better avoid loading too much data in RAM at once, because
> of data persistance.
Not to be too picky, but just so it's clear to everyone and to future readers of
the archives:
The issue w
Hi again,
If you have a lot of scripts that, for
example, load large data files, make a module with a sub that you call
to load the files and use it from all your scripts. Pass the data by
reference to the calling scripts. Then you will isolate the large
lexical in that one module.
Better ye
On 5/11/07, Lionel MARTIN <[EMAIL PROTECTED]> wrote:
For example, instead of using a "my $bigdata" in 50 different script, that
could this result in big memory allocation, I would use a unique
$mypack::bigdata in each script, so that each script would share the same
memory address for this potent
Lionel MARTIN wrote:
>> - Don't load large amounts of data into scalars.
> Fine. Now I know why. But sometimes, you don't have the choice.
I'd like to know what situations you encounter where you are forced to load
large amounts of data into scalars. I can't think of any.
--
Michael Peters
Deve
Hi Perrin,
No, if the message you're getting is to use globals instead of
lexicals then you've got it all wrong.
- Use lexicals for everything, unless you actually want the value to
persist across requests.
I was thinking, for large amounts of data, about using globals.
Indeed, imagine you hav
I would even say PER THREAD or PER PERL INTERPRETER.
Indeed, I'm running Per/mod perl under Windows, and there's one unique
Apache process (except the parent one) hosting all perl interpreters.
Something to ask about modperl and memory in Windows. I know modperl uses
threads in Windows. But do
On 5/10/07, Lionel MARTIN <[EMAIL PROTECTED]> wrote:
If my website is made of hundreds of different pages, then, I should better
ensure that lexical variables are properly freed up.
Even if that's not good programming practive, at least, with global
variables, we are sure that the same memory lo
I would even say PER THREAD or PER PERL INTERPRETER.
Indeed, I'm running Per/mod perl under Windows, and there's one unique
Apache process (except the parent one) hosting all perl interpreters.
Something to ask about modperl and memory in Windows. I know modperl
uses threads in Windows. But
On May 10, 2007, at 6:52 PM, Andy Armstrong wrote:
On 10 May 2007, at 23:48, Jonathan Vanasco wrote:
that also means that variables are sticky -- if you change
something from $a= "b" to $a.= "b" , you'll see the var appending
b on every iteration
No you don't:
sub frog {
my $x;
Thanks for this.
well, to complicate things, this behavior is PER CHILD...
meaning:
if you run test1.pl 2x and they are both served by the same apache child,
then the memory will be reused.
if you run test1.pl 2x and they are both served by the different apache
children, then the memory wi
On 10 May 2007, at 23:48, Jonathan Vanasco wrote:
that also means that variables are sticky -- if you change
something from $a= "b" to $a.= "b" , you'll see the var appending
b on every iteration
No you don't:
sub frog {
my $x;
$x .= 'x';
return $x;
}
print frog(),
On May 10, 2007, at 6:25 PM, Lionel MARTIN wrote:
So, to sum up, if I have got 10 different scripts in a mod perl
environment (let's call them test1.pltest10.pl), and using
lexical variables there.
If I first run test1.pl and then, run test2.pl, the only way for
test2.p to get access to
- Original Message -
From: "Andy Armstrong" <[EMAIL PROTECTED]>
To: "Lionel MARTIN" <[EMAIL PROTECTED]>
Cc:
Sent: Friday, May 11, 2007 12:34 AM
Subject: Re: After retrieving data from DB, the memory doesn't seem to be
freed up
On 10 May 2007
MAIL PROTECTED]>
Cc:
Sent: Friday, May 11, 2007 12:29 AM
Subject: Re: After retrieving data from DB, the memory doesn't seem to be
freed up
On 5/10/07, Lionel MARTIN <[EMAIL PROTECTED]> wrote:
So, to sum up, if I have got 10 different scripts in a mod perl
environment
(let&
On 10 May 2007, at 23:25, Lionel MARTIN wrote:
OK, fine.
So, to sum up, if I have got 10 different scripts in a mod perl
environment (let's call them test1.pltest10.pl), and using
lexical variables there.
If I first run test1.pl and then, run test2.pl, the only way for
test2.p to get
On 5/10/07, Lionel MARTIN <[EMAIL PROTECTED]> wrote:
So, to sum up, if I have got 10 different scripts in a mod perl environment
(let's call them test1.pltest10.pl), and using lexical variables there.
If I first run test1.pl and then, run test2.pl, the only way for test2.p to
get access to th
unning the script twice in a mod perl environment)?
Lionel.
- Original Message -
From: "Perrin Harkins" <[EMAIL PROTECTED]>
To: "Lionel MARTIN" <[EMAIL PROTECTED]>
Cc:
Sent: Friday, May 11, 2007 12:17 AM
Subject: Re: After retrieving data from DB, the memor
On 5/10/07, Lionel MARTIN <[EMAIL PROTECTED]> wrote:
> There's really no difference in the way globals behave under mod_perl.
> You just don't notice it under CGI because the process quits right
> after the request has been served.
[...]
So, this clearly shows that the global variables sticks i
On 10 May 2007, at 22:59, Lionel MARTIN wrote:
I would have believed the same, and that's why I believed that
$tmp = [0..10];
followed by
$tmp = 1;
would free memory (no more reference to the anonymous array), but
Perrin is telling me this is not the case.
Perl hangs on to the memory u
On 10 May 2007, at 23:00, Tom Schindl wrote:
Right: http://www.nntp.perl.org/group/perl.perl5.porters/2006/03/
msg111095.html
Yeah, that's lexicals - not things referred to by lexicals. The
example was a reference to an array.
--
Andy Armstrong, hexten.net
-I'll try to use, in my Perl scripts, lexical variables instead of global
variables, so that I'm sure the used memory can be resued for later
requests
(global variables, on the other hand, stick in memory, due to mod perl
way
of operating)
Not really. In terms of memory, there's no differenc
When the array goes out of scope its reference count is decremented. If
the reference count goes to zero (implying there are no more references)
the memory is released.
I would have believed the same, and that's why I believed that
$tmp = [0..10];
followed by
$tmp = 1;
would free memor
Right:
http://www.nntp.perl.org/group/perl.perl5.porters/2006/03/msg111095.html
Tom
Perrin Harkins schrieb:
On 5/10/07, Andy Armstrong <[EMAIL PROTECTED]> wrote:
Unless I'm misunderstanding you that's not true. When a value's
reference count goes to zero the memory is freed - at least to Perl
On 5/10/07, Andy Armstrong <[EMAIL PROTECTED]> wrote:
Unless I'm misunderstanding you that's not true. When a value's
reference count goes to zero the memory is freed - at least to Perl
if not to the OS.
No, it's not. I know it's counter-intutive, but this is a feature of
Perl, and the behavio
On 5/10/07, Lionel MARTIN <[EMAIL PROTECTED]> wrote:
-I'll try avoid using large chunks of data so that interpreters memory
footprint don't grow too big.
Yes.
-I'll try to use, in my Perl scripts, lexical variables instead of global
variables, so that I'm sure the used memory can be resued fo
On 10 May 2007, at 22:30, Lionel MARTIN wrote:
No. Those are two different things. If you explicitly undef it, the
memory gets handed back to Perl:
undef $foo;
If it just goes out of scope, the memory stays allocated to that
variable.
Unless I'm misunderstanding you that's not true. When
D]>
Cc:
Sent: Thursday, May 10, 2007 7:57 PM
Subject: Re: After retrieving data from DB, the memory doesn't seem to be
freed up
On 5/10/07, Lionel MARTIN <[EMAIL PROTECTED]> wrote:
On Windows XP, it seems to me that Perl never gves back memory to the OS,
even after I undef variable
On 5/10/07, Lionel MARTIN <[EMAIL PROTECTED]> wrote:
On Windows XP, it seems to me that Perl never gves back memory to the OS,
even after I undef variables or after they go out of scope.
That's pretty common. Perl will be able to use the memory for other
variables though.
But then, I'm wonde
ng large amounts
of data, I should undef if possible the variables before allocating others,
so that processes don't grow too big?
Thanks,
Lionel.
- Original Message -
From: "Perrin Harkins" <[EMAIL PROTECTED]>
To: "Lionel MARTIN" <[EMAIL PROTECTE
On 5/10/07, Lionel MARTIN <[EMAIL PROTECTED]> wrote:
I suspect that this is coming from data retrieved from my DB not being well
freed.
That's right. There are two things you need to understand here.
The first is that Perl doesn't free memory from variables unless you
tell it to, even when th
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