"Too Many Files Open" problem

cr8josh has asked for the wisdom of the Perl Monks concerning the following question:

Greetings!

I am using Audio::WAV to both read and write several WAV files through an iterative process. After generating a bunch of files, I get the following:

Background Error: Can't locate C:/Perl64/site/lib/auto/Tk/Error.al:   
+Too many open files at C:/Perl64/site/lib/Tk.pm line 423
[download]

I have checked and I believe I am properly finishing each WAV file I write with write->finish, and in any case the Audio WAV docs specify that finish is "not entirely neccessary as finish is done in DESTROY now (if the file hasn't been finished already)."

I am also reading WAV files iteratively but I don't see any way to close them after reading. I don't know if the 'too many files open' is about reading or writing, but I suspect the former.

Any advice? Many thanks in advance.

Comment on "Too Many Files Open" problem Download Code

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Re: "Too Many Files Open" problem by Marshall (Canon) on Jan 07, 2012 at 04:43 UTC
It appears to me that you are hitting an OS restriction on open files (not only OS specific, but also installation specific of that OS). But in any event it appears that you have too many open file handles - but I guess you know that. From Audio::Wav `use Audio::Wav; my $wav = new Audio::Wav; my $read = $wav -> read( 'input.wav' );` [download] If you somehow keep track of this $wav object via a reference to it an array of hash or array of array or whatever, I would assume that the file handle to 'input.wav' remains open. $wav=undef; would cause that complete object to be destroyed and the file handle freed - right Now! - not when Perl exits. Perl will destroy objects upon exit, but sometimes it is necessary to "take control" and do that for yourself. Maybe undef'ing the $read variable is all you need? It would be very helpful if you could provide some actual code.	[reply] [d/l]
Re: "Too Many Files Open" problem by ikegami (Patriarch) on Jan 07, 2012 at 05:38 UTC
I am also reading WAV files iteratively but I don't see any way to close them after reading. Destroy the object returned by `read`. Do this by losing all references to the object.	[reply] [d/l]
Re: "Too Many Files Open" problem by Eliya (Vicar) on Jan 07, 2012 at 01:56 UTC
Maybe you could try handle -p ... to narrow down on what file handles are leaking. Also, the error message shows that Tk is involved somehow. Are you sure the Tk part is ok? Perhaps try running the Audio::WAV code without the GUI (for debugging purposes).	[reply]
Re: "Too Many Files Open" problem by cr8josh (Sexton) on Jan 07, 2012 at 06:57 UTC
THANK YOU ALL! I've simplified the code greatly. See below. After 2045 files I get this: `WAV/j_Wah.wav: unable to open file (Too many open files)` [download] I used the 'handle' program and indeed the read files are staying open. Any thoughts? Thanks! `use Audio::Wav; my @wavs = glob ("WAV\/*.wav"); while (1) { for my $wav (@wavs) { print "$wav\n"; my $readwav = new Audio::Wav; my $read = $readwav -> read( "$wav" ); my $src_details = $read -> details(); $readwav = undef; $read = undef; } }` [download]	[reply] [d/l] [select]
Re^2: "Too Many Files Open" problem by Anonymous Monk on Jan 07, 2012 at 08:14 UTC
Hi Read more... (4 kB) I'd offer a fix, but I'm just so disgusted, report to author :) as a workaround you can use `$read->{handle}->close;` in your loop my `Audio-Wav-0.12\xt\bug.filehandles.t` based on your program Read more... (1129 Bytes)	[reply] [d/l] [select]
Re^3: "Too Many Files Open" problem by Anonymous Monk on Jan 07, 2012 at 15:58 UTC
That did it! You have my deepest thanks. I spent a long time banging my head against a wall thinking I must be missing something really dumb. I never would have solved this without your help...	[reply]
Re: "Too Many Files Open" problem by Anonymous Monk on Jan 07, 2012 at 02:43 UTC
Hi, You could try creating the WAV object in a scope that you leave within each iteration. Does that make sense? J.C.	[reply]
Re: "Too Many Files Open" problem by Anonymous Monk on Jan 07, 2012 at 02:01 UTC
Any advice? Post code that replicates the problem ddg://Too many open files site:perlmonks.org Perl limits on number of open files? How to debug "Too Many Open Files" Error How to test for open file handles? Performance Trap - Opening/Closing Files Inside a Loop Too many open files error with DBD Oracle Opening too many files? FileCache	[reply]
Re: "Too Many Files Open" problem by cavac (Prior) on Jan 07, 2012 at 13:26 UTC
As posted by others, Audio::WAV seems to have a bug. If you still run into problems with the number of open files (maybe you actually need to have more open files than permited for whatever you are doing), try this link for Linux or this link for Windows 200/XP/2003 or this link for Windows 7. "Believe me, Mike, I calculated the odds of this succeeding against the odds I was doing something incredibly stupid… and I went ahead anyway." (Crow in "MST3K The Movie")	[reply]