Commit 169c843a authored by Tim Bird's avatar Tim Bird Committed by Greg Kroah-Hartman
Browse files

staging: android: logger: clarify code in clock_interval 



Add commentary, rename the function and make the code easier to read.

Signed-off-by: default avatarTim Bird <tim.bird@am.sony.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c76c7ca3

drivers/staging/android/logger.c

+20 −8
Original line number Diff line number Diff line
@@ -242,16 +242,28 @@ static size_t get_next_entry(struct logger_log *log, size_t off, size_t len) 
}



/*

 * clock_interval - is a < c < b in mod-space? Put another way, does the line

 * from a to b cross c?

 * is_between - is a < c < b, accounting for wrapping of a, b, and c

 *    positions in the buffer

 *

 * That is, if a<b, check for c between a and b

 * and if a>b, check for c outside (not between) a and b

 *

 * |------- a xxxxxxxx b --------|

 *               c^

 *

 * |xxxxx b --------- a xxxxxxxxx|

 *    c^

 *  or                    c^

 */

static inline int clock_interval(size_t a, size_t b, size_t c)

static inline int is_between(size_t a, size_t b, size_t c)

{

	if (b < a) {

		if (a < c || b >= c)

	if (a < b) {

		/* is c between a and b? */

		if (a < c && c <= b)

			return 1;

	} else {

		if (a < c && b >= c)

		/* is c outside of b through a? */

		if (c <= b || a < c)

			return 1;

	}
@@ -272,11 +284,11 @@ static void fix_up_readers(struct logger_log *log, size_t len) 
	size_t new = logger_offset(log, old + len);

	struct logger_reader *reader;



	if (clock_interval(old, new, log->head))

	if (is_between(old, new, log->head))

		log->head = get_next_entry(log, log->head, len);



	list_for_each_entry(reader, &log->readers, list)

		if (clock_interval(old, new, reader->r_off))

		if (is_between(old, new, reader->r_off))

			reader->r_off = get_next_entry(log, reader->r_off, len);

}