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Re: memory management question
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Re: memory management question


  • Subject: Re: memory management question
  • From: matt neuburg <email@hidden>
  • Date: Sat, 20 Mar 2004 13:28:47 -0800

On 3/20/04 at roughly 9:56 AM, thus spake Michael Rothwell
<email@hidden>:

>How about using something like this on the file descriptors?
>
>fcntl(fd, F_NOCACHE, 1);
>fcntl(fd, F_RDAHEAD, 1);
>
>.... it seems to work for me, on Panther.

That is absolutely perfect. I can't thank you enough. You've no idea how
much experimenting and tweaking I've done over the past couple of months
with this app, trying to change its memory-management behavior from within
Cocoa itself. It seemed hopeless, and I worried that the app would just
never be viable. You've breathed new life into the whole project. My client
is going to be reeeeeally happy. m.

PS I take it that there is no downside to this that I need to watch out for?
I'm not, with these fcntl() calls, altering anything that I need to reset
afterwards, am I? Presently I am just creating the NSFileHandle from a
pathname, making the fcntl() calls, reading all the data, then sending
-closeFile to the NSFileHandle and then letting the NSFileHandle get
released in the usual way.

>On Mar 20, 2004, at 11:05 AM, matt neuburg wrote:
>> Once a TIFF has been read from disk, it will not be read
>> again. The system is wrong to cache it; this is a false
>> optimization. Thus, I am looking for a way to get the
>> system to "give back" the RAM occupied by each TIFF
>> after I am done with it. m.
--
matt neuburg, phd = email@hidden, http://www.tidbits.com/matt/
pantes anthropoi tou eidenai oregontai phusei
AppleScript: the Definitive Guide! NOW SHIPPING...! (Finally.)
http://www.amazon.com/exec/obidos/ASIN/0596005571/somethingsbymatt
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References: 
 >Re: memory management question (From: Michael Rothwell <email@hidden>)

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