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From Cliff Woolley <cliffwool...@yahoo.com>
Subject Re: apr_buckets_file.c:file_read + XTHREAD
Date Wed, 28 Nov 2001 05:26:44 GMT
On Tue, 27 Nov 2001, Ryan Bloom wrote:

> Not good.  The problem is that you will take the real chance that multiple
> filters will be converting to mmap, and then unmapping large files without
> making any changes.  Think of a large SSI file that does have any tags.
> You'll MMAP each piece, unmapping as you go, and then you'll do the
> same thing again in the next filter.

Um, why?  Once one filter mmap's the thing, it stays that way until the
bucket is deleted or the bucket gets sent out onto the network.  It's not
like mod_include says oh, I ended up not doing anything to that bucket, so
I can map it back down to a file, right?  So mod_include leaves it as an
mmap which it passes down the filter chain right away.  Only once it goes
out on the network do we munmap it.  Granted, we might then have to mmap
the next 4MB of the file when we return up the stack, but I don't see that
as a problem.

What am I missing?

--Cliff

--------------------------------------------------------------
   Cliff Woolley
   cliffwoolley@yahoo.com
   Charlottesville, VA



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