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  1. MariaDB Server
  2. MDEV-4926

[PATCH] Remove division-using-subtraction implementation from semi-sync plugin

        Details

        • Type: Bug
        • Status: Closed
        • Priority: Major
        • Resolution: Fixed
        • Affects Version/s: 10.0.4, 5.5.32
        • Fix Version/s: 10.0.5, 5.5.33
        • Component/s: None
        • Labels:
          None

          Description

          Apparently the person who included our semi-sync code into MariaDB (or MySQL) assumed that semi-sync timeout will always be less than a second or on the order of a few seconds. With a very big timeout this algorithm doesn't work well.
          The following patch fixes this:

          --- a/plugin/semisync/semisync_master.cc
+++ b/plugin/semisync/semisync_master.cc
@@ -677,9 +677,11 @@ int ReplSemiSyncMaster::commitTrx(const char* trx_wait_binlog_name,
       }
 
       /* Calcuate the waiting period. */
+      unsigned long diff_secs = wait_timeout_ / TIME_THOUSAND;
       unsigned long long diff_nsecs =
-        start_ts.tv_nsec + (unsigned long long)wait_timeout_ * TIME_MILLION;
-      abstime.tv_sec = start_ts.tv_sec;
+        start_ts.tv_nsec + (unsigned long long)wait_timeout_ * TIME_MILLION
+                         - diff_secs * TIME_BILLION;
+      abstime.tv_sec = start_ts.tv_sec + diff_secs;
       while (diff_nsecs >= TIME_BILLION)
       {
         abstime.tv_sec++;

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                http://lists.askmonty.org/pipermail/commits/2013-September/005341.html

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                wlad Vladislav Vaintroub added a comment - http://lists.askmonty.org/pipermail/commits/2013-September/005341.html

                  People

                  • Assignee:
                    wlad Vladislav Vaintroub
                    Reporter:
                    pivanof Pavel Ivanov
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                      Updated:
                      Resolved:

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