William A. Rowe, Jr. wrote:
>Here's my take on the dir_merge patch I offered up. Please review for sanity.
>
Thanks! This looks clear and complete to me.
There's one point at the end where I disagree, though it may be due to
a bad assumption on my part. Here's the item in question:
[...]
>Caching Considerations
>----------------------
>
>The key point within Apache is; a given per-dir config cannot be trusted after a
>subsequent merge_dir_configs callback in the same pool.
>
I wouldn't have drawn this conclusion. If your per-dir config is being
passed as
the 'base' to a subsequent merge_dir_config callback, it should be
unharmed afterward
because the callback must treat the base as const. It's okay for the
callback to
use a very liberal definition of constness if needed for performance
reasons; e.g.,
it can increment a reference count in the base in support of
copy-on-write logic.
But from the perspective of the caller, passing a cached per-dir config
as the
base to a merge_dir_configs callback shouldn't change the semantics of
the data
in that per-dir config.
What am I missing?
Thanks,
--Brian
