From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp46.i.mail.ru (smtp46.i.mail.ru [94.100.177.106]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dev.tarantool.org (Postfix) with ESMTPS id B7D7A44184B for ; Mon, 30 Mar 2020 14:04:28 +0300 (MSK) From: Serge Petrenko Date: Mon, 30 Mar 2020 14:04:08 +0300 Message-Id: <3162d52a68b95a43a0756dd2e03e4418dd80eafa.1585565637.git.sergepetrenko@tarantool.org> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [Tarantool-patches] [PATCH v5 1/4] vclock: add an ability to reset individual clock components List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: kostja.osipov@gmail.com, v.shpilevoy@tarantool.org Cc: tarantool-patches@dev.tarantool.org Anonymous replicas use 0th vclock component to sign local rows. vclock_reset will allow to zero-out 0th vclock component when an anonymous replica is promoted to a normal one and sends out its vclock to other joining instances, as to not pollute their own 0th vclock component. Also add a shortcut for vclcok_copy() + vclock_reset() for 0th clock component: vclock_copy_ignore0() Follow-up #3186 Prerequisite #4114 --- src/box/vclock.c | 15 +++++++++++++++ src/box/vclock.h | 24 ++++++++++++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/src/box/vclock.c b/src/box/vclock.c index 90ae27591..ac3e9fccd 100644 --- a/src/box/vclock.c +++ b/src/box/vclock.c @@ -37,6 +37,21 @@ #include "diag.h" #include "tt_static.h" +void +vclock_reset(struct vclock *vclock, uint32_t replica_id, int64_t lsn) +{ + assert(lsn >= 0); + assert(replica_id < VCLOCK_MAX); + vclock->signature -= vclock_get(vclock, replica_id); + if (lsn == 0) { + vclock->map &= ~(1 << replica_id); + return; + } + vclock->lsn[replica_id] = lsn; + vclock->map |= 1 << replica_id; + vclock->signature += lsn; +} + int64_t vclock_follow(struct vclock *vclock, uint32_t replica_id, int64_t lsn) { diff --git a/src/box/vclock.h b/src/box/vclock.h index 79e5a1bc0..2a3a29020 100644 --- a/src/box/vclock.h +++ b/src/box/vclock.h @@ -182,6 +182,19 @@ vclock_inc(struct vclock *vclock, uint32_t replica_id) return ++vclock->lsn[replica_id]; } +/** + * Set vclock component represented by replica id to the desired + * value. Can be used to decrease stored LSN value for the given + * replica id while maintaining a valid signature or in the same + * manner as vclock_follow. + * + * @param vclock Vector clock. + * @param replica_id Replica identifier. + * @param lsn Lsn to set + */ +void +vclock_reset(struct vclock *vclock, uint32_t replica_id, int64_t lsn); + static inline void vclock_copy(struct vclock *dst, const struct vclock *src) { @@ -194,6 +207,17 @@ vclock_copy(struct vclock *dst, const struct vclock *src) sizeof(*dst->lsn) * max_pos); } +/** + * A shortcut for vclock_copy() + vclock_reset() for 0th clock + * component. + */ +static inline void +vclock_copy_ignore0(struct vclock *dst, const struct vclock *src) +{ + vclock_copy(dst, src); + vclock_reset(dst, 0, 0); +} + static inline uint32_t vclock_size(const struct vclock *vclock) { -- 2.21.1 (Apple Git-122.3)