From: Charles Mills <cmills@...>
Date: 2004-08-25T05:17:45+09:00
Subject: Re: Find the number of open files


On Aug 24, 2004, at 1:05 PM, Robert Klemme wrote:

>
> "Charles Mills" <cmills@freeshell.org> schrieb im Newsbeitrag
> news:267B9838-F607-11D8-93A8-000A95A27A10@freeshell.org...
>> On Aug 24, 2004, at 12:41 PM, Charles Mills wrote:
>>
>>> Is there an easy way to find out the number of open files held by a
>>> process (using C or Ruby)?
>>>
>> I think the way I phrased the question above makes the problem sound
>> harder than it is...
>> I am unittesting a C extension.  The extension opens files using
>> open().  I want to make sure that the extension closes all the files 
>> it
>> opens (when errors occur or whatever).
>>
>> So I figured getting a count of open file descriptors before the
>> extension code is called and after it is finished would enable me to 
>> do
>> this.
>
> IMHO this would not be safe unless you disable threading: another 
> thread
> could open or close files in the meantime.
>
Good point.
The unittests are pretty simple.  Basically more or less testing a C 
library (not multithreaded) wrapped in Ruby.
There is a point where all Ruby data gets converted to C 
types/structures and passed to the C library functions I am testing.  
However, the library functions handle opening and closing files 
themselves.
-Charlie

> Why don't you just create a customized class that does the bookkeeping?
> Alternatively you could hand in open IO objects, if the logic of your
> extension allows this.
>
> Kind regards
>
>     robert
>
>