Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757301Ab2BHCc1 (ORCPT ); Tue, 7 Feb 2012 21:32:27 -0500 Received: from db3ehsobe005.messaging.microsoft.com ([213.199.154.143]:50681 "EHLO DB3EHSOBE003.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756556Ab2BHCcZ (ORCPT ); Tue, 7 Feb 2012 21:32:25 -0500 X-SpamScore: 0 X-BigFish: VPS0(zzzz1202hzz8275bhz2fh668h839h93fh) X-Forefront-Antispam-Report: CIP:160.33.98.74;KIP:(null);UIP:(null);IPV:NLI;H:mail7.fw-bc.sony.com;RD:mail7.fw-bc.sony.com;EFVD:NLI Message-ID: <4F31DEA2.7000702@am.sony.com> Date: Tue, 7 Feb 2012 18:32:02 -0800 From: Tim Bird User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.12) Gecko/20100907 Fedora/3.0.7-1.fc12 Thunderbird/3.0.7 MIME-Version: 1.0 To: Greg KH , linux-embedded , linux kernel , Brian Swetland , Dima Zavin , Andrew Morton Subject: [PATCH 4/5] logger: clarify code in clock_interval References: <4F31DC31.6040303@am.sony.com> In-Reply-To: <4F31DC31.6040303@am.sony.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-OriginatorOrg: am.sony.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2133 Lines: 68 Add commentary, rename the function and make the code easier to read. Signed-off-by: Tim Bird --- drivers/staging/android/logger.c | 28 ++++++++++++++++++++-------- 1 files changed, 20 insertions(+), 8 deletions(-) diff --git a/drivers/staging/android/logger.c b/drivers/staging/android/logger.c index 54b7cdf..8d9d4f1 100644 --- a/drivers/staging/android/logger.c +++ b/drivers/staging/android/logger.c @@ -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 ab, 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); } -- 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/