HPCC-32933 Track lookahead time for loop activity

Signed-off-by: Shamser Ahmed <shamser.ahmed@lexisnexis.com>
hpcc-systems · Jan 7, 2025 · f7ea184 · f7ea184
1 parent 1751abf
commit f7ea184
Showing 1 changed file with 25 additions and 5 deletions.
diff --git a/thorlcr/activities/loop/thloopslave.cpp b/thorlcr/activities/loop/thloopslave.cpp
@@ -304,12 +304,32 @@ class CLoopSlaveActivity : public CLoopSlaveActivityBase
             {
                 while (!abortSoon)
                 {
-                    OwnedConstThorRow ret = (void *)curInput->nextRow();
-                    if (!ret)
+                    OwnedConstThorRow ret;
                     {
-                        ret.setown(curInput->nextRow()); // more cope with groups somehow....
-                        if (!ret)
-                            break;
+                        if (loopCounter==1)
+                        {
+                            // The disk reads occur in the first iteration only so track lookahead time
+                            // in the first iteration only. In subsequent iterations, it is reading the
+                            // output from previous iterations.
+                            LookAheadTimer t(slaveTimerStats, timeActivities);
+                            ret.setown(curInput->nextRow());
+                            if (!ret)
+                            {
+                                ret.setown(curInput->nextRow()); // more cope with groups somehow....
+                                if (!ret)
+                                    break;
+                            }
+                        }
+                        else
+                        {
+                            ret.setown(curInput->nextRow());
+                            if (!ret)
+                            {
+                                ret.setown(curInput->nextRow()); // more cope with groups somehow....
+                                if (!ret)
+                                    break;
+                            }
+                        }
                     }
 
                     if (finishedLooping ||