in reply to Re: Lots of memory usage with fork&copy
in thread Lots of memory usage with fork&copy

Here is a image of resources usage:
http://img266.imageshack.us/img266/6838/perlfh2.png
The memory grows until I suspend the process (or windows says: Enough memory, Rest in Peace! ;) ).

The "use Win32;" follows: http://img266.imageshack.us/my.php?image=perlokvu7.png

As i said before "I run this scripts with perl v5.8.8 on Windows XP. (Binary build 817, ActiveState, 20 Mar 2006)."

I've tried it with both an empty file and a 49MB file. With and empty file the memory usage grows faster because it forks faster.

I've run the scripts on local files.

Edit: g0n - linkified web links

  • Comment on Re^2: Lots of memory usage with fork&copy

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Re^3: Lots of memory usage with fork&copy
by BrowserUk (Patriarch) on Apr 27, 2007 at 16:12 UTC

    FYI: The use of a fileshare and File::Copy are both incidental to the problem. The following one-liner demonstrates the memory growth under both 5.8.8 and 5.9.5.

    The second one-liner also demonstrates that use Win32; definitely has the effect of slowing the growth rate: 

    ## leaks rapidly. The sleep just avoids a fork bomb.
\as817\perl\bin\perl.exe -le"while(Win32::Sleep 10){$p=fork and waitpi
+d($p,0) or print(qq[kid:$$]),exit}"

## This leaks more slowly
\as817\perl\bin\perl.exe -mWin32 -le"while(Win32::Sleep 10){$p=fork an
+d waitpid($p,0) or print(qq[kid:$$]),exit}"

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      With waitpid (used in that form) you won't create a fork bomb so there's no need for sleep. I'll test on monday with an older perl if I'll found an installation kit on the internet.
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Re^3: Lots of memory usage with fork&copy
by BrowserUk (Patriarch) on Apr 27, 2007 at 15:03 UTC

    Sorry. That's the problem with coming to the party late, you tend to miss what has gone before. In this case, the reference to 5.8.8/AS817. I was using AS811/5.8.6 which I have stuck with in preference to 5.8.8 as I have encountered several anomolies with the latter.

    I just repeated my tests using AS817 and replicated your results exactly. I also tried it with 5.9.5 (current - 10 days), and found that it produces similar results to 5.8.8, so it looks like bug introduced since 5.8.6 is responsible. Worth raising a perl-bug report I think.

    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
    "Science is about questioning the status quo. Questioning authority".
    In the absence of evidence, opinion is indistinguishable from prejudice.
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