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NNTP-Posting-Date: Fri, 02 Dec 2011 09:55:17 -0600
From: Mark <i@dontgetlotsofspamanymore.net>
Newsgroups: comp.lang.java.programmer
Subject: Re: java.io.File
Date: Fri, 02 Dec 2011 15:55:17 +0000
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On Fri, 2 Dec 2011 07:25:02 -0800 (PST), Lew <lewbloch@gmail.com>
wrote:

>Mark wrote:
>> Can a java.io.File object use a OS file descriptor?  I am trying to
>> find the source of a fd leak in a[n] application.
>
>At some point, depending on the operations performed by the 'File' instance, 
>there may be a file descriptor involved, and then the 'File' instance certainly
>does use it, at least indirectly via JVM system calls that proxy to OS system
>calls.
>
>From a Java perspective you should look for unclosed I/O streams/channels and 
>packratted 'File' instances rather than file descriptors.

I've done a code inspection and the streams are all explicitly closed.
There are a number of File objects used and I notice that File does
not have a close() method so we have to rely on GC.

>Of course I'm shooting in the dark since you've said absolutely nothing about
>your application, much less provided an http://sscce.org/.

I know.  It would be difficult to produce an example since I cannot
reproduce the problem myself - it happens in production only and I
don't have any access there.

I get the exception:
java.io.IOException: Cannot run program "/path/to/script":
java.io.IOException: error=24, Too many open files

The script is called via ProcessBuilder object and I don't see any
obvious problems there.