Adjust input value to WaitEventSetWait() in ExecAppendAsyncEventWait().

Adjust the number of events given to WaitEventSetWait() so that it
doesn't exceed the maximum number of events in the WaitEventSet given
to that function (set->nevents_space) in hopes of making the buildfarm
green.

Per valgrind failure report from Tom Lane and the buildfarm.

Author: Etsuro Fujita
Discussion: https://postgr.es/m/3411577.1617289776%40sss.pgh.pa.us

diff --git a/src/backend/executor/nodeAppend.c b/src/backend/executor/nodeAppend.c
index 7da8ffe0652073895cd8902eee5d9a78012f1aaa..c25275726860c33d2d50a55d49c4de33d6e42145 100644 (file)
--- a/src/backend/executor/nodeAppend.c
+++ b/src/backend/executor/nodeAppend.c
@@ -1001,6 +1001,7 @@ ExecAppendAsyncEventWait(AppendState *node)
    long        timeout = node->as_syncdone ? -1 : 0;
    WaitEvent   occurred_event[EVENT_BUFFER_SIZE];
    int         noccurred;
+   int         nevents;
    int         i;
 
    /* We should never be called when there are no valid async subplans. */
@@ -1022,8 +1023,9 @@ ExecAppendAsyncEventWait(AppendState *node)
    }
 
    /* Wait for at least one event to occur. */
+   nevents = Min(node->as_nasyncplans + 1, EVENT_BUFFER_SIZE);
    noccurred = WaitEventSetWait(node->as_eventset, timeout, occurred_event,
-                                EVENT_BUFFER_SIZE, WAIT_EVENT_APPEND_READY);
+                                nevents, WAIT_EVENT_APPEND_READY);
    FreeWaitEventSet(node->as_eventset);
    node->as_eventset = NULL;
    if (noccurred == 0)