From 750816971b35270971dd77f37ed1e9655fce4ed9 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Tue, 9 Dec 2025 13:34:22 -0600
Subject: [PATCH] Add ParallelSlotSetIdle().

This commit refactors the code for marking a ParallelSlot as idle
to a new static inline function.  This can be used to mark a slot
that was obtained via ParallelSlotGetIdle() but that we don't
intend to actually use for a query as idle again.

This is preparatory work for a follow-up commit that will add a
--dry-run option to vacuumdb.

Reviewed-by: Corey Huinker <corey.huinker@gmail.com>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com
Discussion: https://postgr.es/m/CADkLM%3DckHkX7Of5SrK7g0LokPUwJ%3Dkk8JU1GXGF5pZ1eBVr0%3DQ%40mail.gmail.com
---
 src/fe_utils/parallel_slot.c         | 6 ++----
 src/include/fe_utils/parallel_slot.h | 7 +++++++
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/fe_utils/parallel_slot.c b/src/fe_utils/parallel_slot.c
index 253a840865e..1b9bc8b0da8 100644
--- a/src/fe_utils/parallel_slot.c
+++ b/src/fe_utils/parallel_slot.c
@@ -269,8 +269,7 @@ wait_on_slots(ParallelSlotArray *sa)
 			else
 			{
 				/* This connection has become idle */
-				sa->slots[i].inUse = false;
-				ParallelSlotClearHandler(&sa->slots[i]);
+				ParallelSlotSetIdle(&sa->slots[i]);
 				break;
 			}
 		}
@@ -509,8 +508,7 @@ ParallelSlotsWaitCompletion(ParallelSlotArray *sa)
 		if (!consumeQueryResult(&sa->slots[i]))
 			return false;
 		/* Mark connection as idle */
-		sa->slots[i].inUse = false;
-		ParallelSlotClearHandler(&sa->slots[i]);
+		ParallelSlotSetIdle(&sa->slots[i]);
 	}
 
 	return true;
diff --git a/src/include/fe_utils/parallel_slot.h b/src/include/fe_utils/parallel_slot.h
index 7770a20de34..4a5fbfb3d8c 100644
--- a/src/include/fe_utils/parallel_slot.h
+++ b/src/include/fe_utils/parallel_slot.h
@@ -58,6 +58,13 @@ ParallelSlotClearHandler(ParallelSlot *slot)
 	slot->handler_context = NULL;
 }
 
+static inline void
+ParallelSlotSetIdle(ParallelSlot *slot)
+{
+	slot->inUse = false;
+	ParallelSlotClearHandler(slot);
+}
+
 extern ParallelSlot *ParallelSlotsGetIdle(ParallelSlotArray *sa,
 										  const char *dbname);