From e0884c381d3c06c32bbfea6d50d3231f7b3dc213 Mon Sep 17 00:00:00 2001
From: Maxim Orlov <orlovmg@gmail.com>
Date: Thu, 21 Nov 2024 15:41:45 +0300
Subject: [PATCH] [PGPRO-7565] use 64-bit atomic access for MyPgXact xid/xmin

Switch to the pg_atomic_* calls for the xid/xmin.  This fixes a transient error
due to non-atomic reading of the xid/xmin values from shared memory on 32-bit
arch.

tags: 64xid
---
 src/dmq.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/dmq.c b/src/dmq.c
index 163e0a260b..6c72580c6a 100644
--- a/src/dmq.c
+++ b/src/dmq.c
@@ -1449,7 +1449,11 @@ dmq_receiver_loop(PG_FUNCTION_ARGS)
 		extra = dmq_receiver_start_hook(sender_name);
 
 	/* do not hold globalxmin. XXX: try to carefully release snaps */
+#ifdef PGPRO_EE
+	pg_atomic_write_u64(&MyPgXact->xmin, InvalidTransactionId);
+#else
 	MyPgXact->xmin = InvalidTransactionId;
+#endif
 
 	for (;;)
 	{