Properly check interrupts in execScan.c.

anarazel · anarazel · commit 253c8afc9eb1 · 2017-09-14T02:02:20.000-07:00
During the development of d47cfef the CFI()s in ExecScan() were moved back and forth, ending up in the wrong place. Thus queries that largely spend their time in ExecScan(), and have neither projection nor a qual, can't be cancelled in a timely manner. Reported-By: Jeff Janes Author: Andres Freund Discussion: https://postgr.es/m/CAMkU=1weDXp8eLLPt9SO1LEUsJYYK9cScaGhLKpuN+WbYo9b5g@mail.gmail.com Backpatch: 10, as d47cfef
diff --git a/src/backend/executor/execScan.c b/src/backend/executor/execScan.c
@@ -27,7 +27,7 @@ static bool tlist_matches_tupdesc(PlanState *ps, List *tlist, Index varno, Tuple
 
 
 /*
- * ExecScanFetch -- fetch next potential tuple
+ * ExecScanFetch -- check interrupts & fetch next potential tuple
  *
  * This routine is concerned with substituting a test tuple if we are
  * inside an EvalPlanQual recheck.  If we aren't, just execute
@@ -40,6 +40,8 @@ ExecScanFetch(ScanState *node,
 {
 	EState	   *estate = node->ps.state;
 
+	CHECK_FOR_INTERRUPTS();
+
 	if (estate->es_epqTuple != NULL)
 	{
 		/*
@@ -133,6 +135,8 @@ ExecScan(ScanState *node,
 	projInfo = node->ps.ps_ProjInfo;
 	econtext = node->ps.ps_ExprContext;
 
+	/* interrupt checks are in ExecScanFetch */
+
 	/*
 	 * If we have neither a qual to check nor a projection to do, just skip
 	 * all the overhead and return the raw scan tuple.
@@ -157,8 +161,6 @@ ExecScan(ScanState *node,
 	{
 		TupleTableSlot *slot;
 
-		CHECK_FOR_INTERRUPTS();
-
 		slot = ExecScanFetch(node, accessMtd, recheckMtd);
 
 		/*
