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From: Cyrill Gorcunov <gorcunov@gmail.com>
To: tml <tarantool-patches@dev.tarantool.org>
Cc: Vladislav Shpilevoy <v.shpilevoy@tarantool.org>
Subject: [Tarantool-patches] [PATCH 02/11] vclock: vclock_get - drop misleading masking
Date: Thu, 12 Nov 2020 22:51:12 +0300	[thread overview]
Message-ID: <20201112195121.191366-3-gorcunov@gmail.com> (raw)
In-Reply-To: <20201112195121.191366-1-gorcunov@gmail.com>

We rely heavily that VCLOCK_MAX is 32 bits wide
and using "VCLOCK_MAX - 1" as a mask for safe
access to the replica id is simply misleading.

Instead use assert here because we might change
the number of supported replicas one day and they
do not have to be pow2 value.

And no need for this completely useless comment.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
 src/lib/vclock/vclock.h | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/src/lib/vclock/vclock.h b/src/lib/vclock/vclock.h
index 5865f7443..fd4072c94 100644
--- a/src/lib/vclock/vclock.h
+++ b/src/lib/vclock/vclock.h
@@ -160,11 +160,7 @@ vclock_is_set(const struct vclock *vclock)
 static inline int64_t
 vclock_get(const struct vclock *vclock, uint32_t replica_id)
 {
-	/*
-	 * If replica_id does not fit in VCLOCK_MAX - 1 then
-	 * let result be undefined.
-	 */
-	replica_id &= VCLOCK_MAX - 1;
+	assert(replica_id < VCLOCK_MAX);
 	/* Evaluate a bitmask to avoid branching. */
 	int64_t mask = 0ULL - ((vclock->map >> replica_id) & 0x1);
 	return mask & vclock->lsn[replica_id];
-- 
2.26.2

  parent reply	other threads:[~2020-11-12 19:51 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-12 19:51 [Tarantool-patches] [PATCH 00/11] qsync: code refactoring Cyrill Gorcunov
2020-11-12 19:51 ` [Tarantool-patches] [PATCH 01/11] build: add more ignore paths for tags target Cyrill Gorcunov
2020-11-16 13:09   ` Cyrill Gorcunov
2020-11-20 23:55   ` Vladislav Shpilevoy
2020-11-21 12:09     ` Cyrill Gorcunov
2020-11-12 19:51 ` Cyrill Gorcunov [this message]
2020-11-12 19:51 ` [Tarantool-patches] [PATCH 03/11] vclock: vclock_inc -- add assert() to catch overflow Cyrill Gorcunov
2020-11-13  9:30   ` Serge Petrenko
2020-11-12 19:51 ` [Tarantool-patches] [PATCH 04/11] txn: txn_commit_async -- drop redundant variable Cyrill Gorcunov
2020-11-13  9:31   ` Serge Petrenko
2020-11-20 23:55   ` Vladislav Shpilevoy
2020-11-21 12:30     ` Cyrill Gorcunov
2020-11-21 13:29       ` Vladislav Shpilevoy
2020-11-21 16:14         ` Cyrill Gorcunov
2020-11-12 19:51 ` [Tarantool-patches] [PATCH 05/11] qsync: rename txn_limbo::instance_id to owner_id Cyrill Gorcunov
2020-11-13  9:37   ` Serge Petrenko
2020-11-12 19:51 ` [Tarantool-patches] [PATCH 06/11] qsync: txn_limbo_append -- use owner_id in argument name Cyrill Gorcunov
2020-11-13  9:43   ` Serge Petrenko
2020-11-13 10:11     ` Cyrill Gorcunov
2020-11-20 23:55   ` Vladislav Shpilevoy
2020-11-12 19:51 ` [Tarantool-patches] [PATCH 07/11] qsync: move limbo owner transition into separate helper Cyrill Gorcunov
2020-11-13  9:47   ` Serge Petrenko
2020-11-13 10:12     ` Cyrill Gorcunov
2020-11-20 23:55   ` Vladislav Shpilevoy
2020-11-12 19:51 ` [Tarantool-patches] [PATCH 08/11] qsync: txn_limbo_wait_confirm -- refactor code a bit Cyrill Gorcunov
2020-11-13  9:56   ` Serge Petrenko
2020-11-20 23:55   ` Vladislav Shpilevoy
2020-11-12 19:51 ` [Tarantool-patches] [PATCH 09/11] qsync: drop redundant type convention Cyrill Gorcunov
2020-11-13 10:11   ` Serge Petrenko
2020-11-13 10:13     ` Cyrill Gorcunov
2020-11-13 10:19       ` Serge Petrenko
2020-11-20 23:55   ` Vladislav Shpilevoy
2020-11-12 19:51 ` [Tarantool-patches] [PATCH 10/11] relay: use verbose names for fibers Cyrill Gorcunov
2020-11-13 10:17   ` Serge Petrenko
2020-11-13 10:28     ` Cyrill Gorcunov
2020-11-20 23:55   ` Vladislav Shpilevoy
2020-11-12 19:51 ` [Tarantool-patches] [PATCH 11/11] raft: drop redundant argument Cyrill Gorcunov
2020-11-13 10:18   ` Serge Petrenko
2020-11-20 23:54 ` [Tarantool-patches] [PATCH 00/11] qsync: code refactoring Vladislav Shpilevoy
2020-11-24 23:24   ` Vladislav Shpilevoy
2020-11-23 23:26 ` Vladislav Shpilevoy
2020-11-24  6:52   ` Cyrill Gorcunov
2020-11-24 21:41     ` Alexander V. Tikhonov

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