1 files changed, 59 insertions, 23 deletions
diff --git a/src/backend/executor/execProcnode.c b/src/backend/executor/execProcnode.c
index 3f2ebff173..b7ac08eead 100644
--- a/src/backend/executor/execProcnode.c
+++ b/src/backend/executor/execProcnode.c
@@ -77,6 +77,7 @@
  */
 #include "postgres.h"
 
+#include "executor/execAsync.h"
 #include "executor/executor.h"
 #include "executor/nodeAgg.h"
 #include "executor/nodeAppend.h"
@@ -368,24 +369,14 @@ ExecInitNode(Plan *node, EState *estate, PlanState *parent, int eflags)
 
 
 /* ----------------------------------------------------------------
- *		ExecProcNode
+ *		ExecDispatchNode
  *
- *		Execute the given node to return a(nother) tuple.
+ *		Invoke the given node's dispatch function.
  * ----------------------------------------------------------------
  */
-TupleTableSlot *
-ExecProcNode(PlanState *node)
+void
+ExecDispatchNode(PlanState *node)
 {
-	TupleTableSlot *result;
-
-	CHECK_FOR_INTERRUPTS();
-
-	/* mark any previous result as having been consumed */
-	node->result_ready = false;
-
-	if (node->chgParam != NULL) /* something changed */
-		ExecReScan(node);		/* let ReScan handle this */
-
 	if (node->instrument)
 		InstrStartNode(node->instrument);
 
@@ -539,22 +530,67 @@ ExecProcNode(PlanState *node)
 
 		default:
 			elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node));
-			result = NULL;
 			break;
 	}
 
-	/* We don't support asynchronous execution yet. */
-	Assert(node->result_ready);
+	if (node->instrument)
+	{
+		double	nTuples = 0.0;
 
-	/* Result should be a TupleTableSlot, unless it's NULL. */
-	Assert(node->result == NULL || IsA(node->result, TupleTableSlot));
+		if (node->result_ready && node->result != NULL &&
+			IsA(node->result, TupleTableSlot))
+			nTuples = 1.0;
 
-	result = (TupleTableSlot *) node->result;
+		InstrStopNode(node->instrument, nTuples);
+	}
+}
 
-	if (node->instrument)
-		InstrStopNode(node->instrument, TupIsNull(result) ? 0.0 : 1.0);
 
-	return result;
+/* ----------------------------------------------------------------
+ *		ExecExecuteNode
+ *
+ *		Request the next tuple from the given node.  Note that
+ *		if the node supports asynchrony, result_ready may not be
+ *		set on return (use ExecProcNode if you need that, or call
+ *		ExecAsyncWaitForNode).
+ * ----------------------------------------------------------------
+ */
+void
+ExecExecuteNode(PlanState *node)
+{
+	node->result_ready = false;
+	ExecDispatchNode(node);
+}
+
+
+/* ----------------------------------------------------------------
+ *		ExecProcNode
+ *
+ *		Get the next tuple from the given node.  If the node is
+ *		asynchronous, wait for a tuple to be ready before
+ *		returning.
+ * ----------------------------------------------------------------
+ */
+TupleTableSlot *
+ExecProcNode(PlanState *node)
+{
+	CHECK_FOR_INTERRUPTS();
+
+	/* mark any previous result as having been consumed */
+	node->result_ready = false;
+
+	if (node->chgParam != NULL) /* something changed */
+		ExecReScan(node);		/* let ReScan handle this */
+
+	ExecDispatchNode(node);
+
+	if (!node->result_ready)
+		ExecAsyncWaitForNode(node);
+
+	/* Result should be a TupleTableSlot, unless it's NULL. */
+	Assert(node->result == NULL || IsA(node->result, TupleTableSlot));
+
+	return (TupleTableSlot *) node->result;
 }