[PATCH] Refactor common code from nscd's two main poll loops.

[Andreas Jaeger]

On 02/07/2013 11:02 PM, Carlos O'Donell wrote:
> Team,
>
> While working on some nscd issues I caused myself some grief
> by not noticing that we have quite a bit of duplicate code
> in both the main_loop_poll and main_loop_epoll functions.
>
> This patch does two things:
> (1) Adds more comments.
> (2) Refactors two chunks of identical code out of the
>      two main poll loops.
>
> The resulting code is easier to review and maintain.
>
> No regressions on x86-64, tested the resulting nscd locally
> with no issues. Verified that the produced object files
> show both functions inlined into main_loop_*poll and
> equivalent object code produced.
>
> OK to checkin?
>
> 2013-02-07  Carlos O'Donell  <carlos@redhat.com>
>
> 	* nscd/connection.c (register_traced_file): Comment function.
> 	[HAVE_INOTIFY] (union __inev): Define.
> 	[HAVE_INOTIFY] (inotify_check_files): New function.
> 	[HAVE_INOTIFY] (clear_db_cache): Likewise.
> 	[HAVE_INOTIFY] (main_loop_poll): Call inotify_check_files and
> 	clear_db_cache.
> 	[HAVE_INOTIFY] (main_loop_epoll): Likewise.
>
> diff --git a/nscd/connections.c b/nscd/connections.c
> index f6e2328..44a8bfb 100644
> --- a/nscd/connections.c
> +++ b/nscd/connections.c
> @@ -976,9 +976,25 @@ cannot change socket to nonblocking mode: %s"),
>   }
>
>
> +/* Register the file in FINFO as a traced file for the database DBS[DBIX].
> +
> +   We support registering multiple files per database. Each call to
> +   register_traced_file adds to the list of registered files.
> +
> +   When we prune the database, either through timeout or a request to
> +   invalidate, we will check to see if any of the registered files has changed.
> +   When we accept new connections to handle a cache request we will also
> +   check to see if any of the registered files has changed.
> +
> +   If we have inotify support then we install an inotify fd to notify us of
> +   file deletion or modification, both of which will require we invalidate
> +   the cache for the database.  Without inotify support we stat the file and
> +   store st_mtime to determine if the file has been modified.  */
>   void
>   register_traced_file (size_t dbidx, struct traced_file *finfo)
>   {
> +  /* If the database is disabled or file checking is disabled
> +     then ignore the registration.  */
>     if (! dbs[dbidx].enabled || ! dbs[dbidx].check_file)
>       return;
>
> @@ -1870,6 +1886,63 @@ restart_p (time_t now)
>   /* Array for times a connection was accepted.  */
>   static time_t *starttime;
>
> +#ifdef HAVE_INOTIFY
> +/* Inotify event for changed file.  */
> +union __inev
> +{
> +  struct inotify_event i;
> +# ifndef PATH_MAX
> +#  define PATH_MAX 1024
> +# endif
> +  char buf[sizeof (struct inotify_event) + PATH_MAX];
> +};
> +
> +/* Process the inotify event in INEV. If the event matches any of the files
> +   registered with a database then mark that database as requiring its cache
> +   to be cleared. We indicate the cache needs clearing by setting
> +   TO_CLEAR[DBCNT] to true for the matching database.  */
> +static inline void
> +inotify_check_files(bool *to_clear, union __inev *inev)

A space before the opening parenthesis.

Ok with this change,

Andreas
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  Andreas Jaeger aj@{suse.com,opensuse.org} Twitter/Identica: jaegerandi
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