I was looking at backpatching this to pg13. That made me realize that
commit dc7420c2c927 changed things in 14; and before that commit, the
bitmask that is checked is PROCARRAY_FLAGS_VACUUM, which has a
definition independently from whatever proc.h says. As far as I can
tell, there's no problem with the patches I post here (the backpatched
version for pg13 and p14). But's it's something to be aware of; and if
we do want to add the additional bits to the bitmask, we should do that
in a separate master-only commit.
--
Álvaro Herrera Breisgau, Deutschland — https://www.EnterpriseDB.com/
>From 6595af9af208de33ab431b502e2f178f7d0f8007 Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvhe...@alvh.no-ip.org>
Date: Sat, 14 May 2022 16:51:23 +0200
Subject: [PATCH] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS
This is a slight, convenient semantics change from what commit
0f0cfb494004 introduced that lets us simplify the coding in the one
place where it is used.
---
src/backend/storage/ipc/procarray.c | 11 ++++++-----
src/include/storage/proc.h | 7 +++----
2 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index 6ff8d8699b..447b6e3de7 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -1916,12 +1916,13 @@ ProcArrayInstallRestoredXmin(TransactionId xmin, PGPROC *proc)
TransactionIdIsNormal(xid) &&
TransactionIdPrecedesOrEquals(xid, xmin))
{
- /* Install xmin */
+ /*
+ * Install xmin and propagate the vacuumFlags that affect how the
+ * value is interpreted by vacuum.
+ */
MyPgXact->xmin = TransactionXmin = xmin;
-
- /* Flags being copied must be valid copy-able flags. */
- Assert((pgxact->vacuumFlags & (~PROC_COPYABLE_FLAGS)) == 0);
- MyPgXact->vacuumFlags = pgxact->vacuumFlags;
+ MyPgXact->vacuumFlags = (MyPgXact->vacuumFlags & ~PROC_XMIN_FLAGS) |
+ (pgxact->vacuumFlags & PROC_XMIN_FLAGS);
result = true;
}
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index 9cf9684b41..7c85b5645b 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -63,11 +63,10 @@ struct XidCache
(PROC_IN_VACUUM | PROC_IN_ANALYZE | PROC_VACUUM_FOR_WRAPAROUND)
/*
- * Flags that are valid to copy from another proc, the parallel leader
- * process in practice. Currently, a flag that is set during parallel
- * vacuum is allowed.
+ * Xmin-related flags. Make sure any flags that affect how the process' Xmin
+ * value is interpreted by VACUUM are included here.
*/
-#define PROC_COPYABLE_FLAGS (PROC_IN_VACUUM)
+#define PROC_XMIN_FLAGS (PROC_IN_VACUUM)
/*
* We allow a small number of "weak" relation locks (AccessShareLock,
--
2.30.2
>From 35197d187fe3e7c9e4bd563396c9c7459e39a7ff Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvhe...@alvh.no-ip.org>
Date: Sat, 14 May 2022 16:51:23 +0200
Subject: [PATCH] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS
This is a slight, convenient semantics change from what commit
0f0cfb494004 introduced that lets us simplify the coding in the one
place where it is used.
---
src/backend/storage/ipc/procarray.c | 11 ++++++-----
src/include/storage/proc.h | 7 +++----
2 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index 127be9c017..08053a7e8f 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -2686,12 +2686,13 @@ ProcArrayInstallRestoredXmin(TransactionId xmin, PGPROC *proc)
TransactionIdIsNormal(xid) &&
TransactionIdPrecedesOrEquals(xid, xmin))
{
- /* Install xmin */
+ /*
+ * Install xmin and propagate the statusFlags that affect how the
+ * value is interpreted by vacuum.
+ */
MyProc->xmin = TransactionXmin = xmin;
-
- /* Flags being copied must be valid copy-able flags. */
- Assert((proc->statusFlags & (~PROC_COPYABLE_FLAGS)) == 0);
- MyProc->statusFlags = proc->statusFlags;
+ MyProc->statusFlags = (MyProc->statusFlags & ~PROC_XMIN_FLAGS) |
+ (proc->statusFlags & PROC_XMIN_FLAGS);
ProcGlobal->statusFlags[MyProc->pgxactoff] = MyProc->statusFlags;
result = true;
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index 11b514c9ae..1464fad9b9 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -66,11 +66,10 @@ struct XidCache
(PROC_IN_VACUUM | PROC_IN_SAFE_IC | PROC_VACUUM_FOR_WRAPAROUND)
/*
- * Flags that are valid to copy from another proc, the parallel leader
- * process in practice. Currently, flags that are set during parallel
- * vacuum and parallel index creation are allowed.
+ * Xmin-related flags. Make sure any flags that affect how the process' Xmin
+ * value is interpreted by VACUUM are included here.
*/
-#define PROC_COPYABLE_FLAGS (PROC_IN_VACUUM | PROC_IN_SAFE_IC)
+#define PROC_XMIN_FLAGS (PROC_IN_VACUUM | PROC_IN_SAFE_IC)
/*
* We allow a small number of "weak" relation locks (AccessShareLock,
--
2.30.2
