Rename variable for code clarity

When tracking IO timing for WAL, the duration is what we calculate
based on the start and end timestamps, it's not what the variable
contains. Rename the timestamp variable to end to better communicate
what it contains.  Original patch by Krishnakumar with additional
hacking to fix another occurrence by me.

Author: Krishnakumar R <[email protected]>
Discussion: https://postgr.es/m/CAPMWgZ9f9o8awrQpjo8oxnNQ=bMDVPx00NE0QcDzvHD_ZrdLPw@mail.gmail.com

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 725a308debb79e96a3f92eb6bb1301b661f90981..fcbde10529b17bf3b57ea6436f5ad56868ca8aa0 100644 (file)
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -2226,10 +2226,10 @@ XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible)
                 */
                if (track_wal_io_timing)
                {
-                   instr_time  duration;
+                   instr_time  end;
 
-                   INSTR_TIME_SET_CURRENT(duration);
-                   INSTR_TIME_ACCUM_DIFF(PendingWalStats.wal_write_time, duration, start);
+                   INSTR_TIME_SET_CURRENT(end);
+                   INSTR_TIME_ACCUM_DIFF(PendingWalStats.wal_write_time, end, start);
                }
 
                PendingWalStats.wal_write++;
@@ -8252,10 +8252,10 @@ issue_xlog_fsync(int fd, XLogSegNo segno, TimeLineID tli)
     */
    if (track_wal_io_timing)
    {
-       instr_time  duration;
+       instr_time  end;
 
-       INSTR_TIME_SET_CURRENT(duration);
-       INSTR_TIME_ACCUM_DIFF(PendingWalStats.wal_sync_time, duration, start);
+       INSTR_TIME_SET_CURRENT(end);
+       INSTR_TIME_ACCUM_DIFF(PendingWalStats.wal_sync_time, end, start);
    }
 
    PendingWalStats.wal_sync++;