Hi,
I noticed that we have Assert(ret != NULL) in palloc() but not in
palloc0() so for consistency I decided to add it. I also added an
assertion that the MCXT_ALLOC_NO_OOM flag is set if alloc() returns
NULL to palloc_extended().
I feel that this might be useful since while palloc() is much more
common the OOM which causes alloc() to incorrectly return NULL could in
theory happen in any of the three functions.
Andreas
From 7165657a4b62ac35e2c67b9e51035be2a5fbb93f Mon Sep 17 00:00:00 2001
From: Andreas Karlsson <andreas.karls...@percona.com>
Date: Sat, 1 Mar 2025 00:27:52 +0100
Subject: [PATCH] Add assertion for failed alloc to palloc0() and
palloc_extended()
The palloc() call asserts that the alloc function does not return NULL
so do the same in palloc0(). In palloc_extend() we can assert the same
as long as the MCXT_ALLOC_NO_OOM flag is not set, so let's do so.
---
src/backend/utils/mmgr/mcxt.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/src/backend/utils/mmgr/mcxt.c b/src/backend/utils/mmgr/mcxt.c
index aa6da0d0352..ce108788259 100644
--- a/src/backend/utils/mmgr/mcxt.c
+++ b/src/backend/utils/mmgr/mcxt.c
@@ -1356,7 +1356,8 @@ palloc0(Size size)
context->isReset = false;
ret = context->methods->alloc(context, size, 0);
-
+ /* We expect OOM to be handled by the alloc function */
+ Assert(ret != NULL);
VALGRIND_MEMPOOL_ALLOC(context, ret, size);
MemSetAligned(ret, 0, size);
@@ -1379,6 +1380,7 @@ palloc_extended(Size size, int flags)
ret = context->methods->alloc(context, size, flags);
if (unlikely(ret == NULL))
{
+ Assert(flags & MCXT_ALLOC_NO_OOM);
return NULL;
}
--
2.47.2
