On 2022-Jul-01, Andres Freund wrote:
> On 2022-07-01 19:55:16 +0200, Alvaro Herrera wrote:
> > On 2022-Jul-01, Andres Freund wrote:
> > > What is the reason for the || ProcDiePending || QueryCancelPending bit?
> > > What
> > > if there's dsm operations intentionally done while QueryCancelPending?
> >
> > That mirrors the test for the other block in that function, which was
> > added by 63efab4ca139, whose commit message explains:
> That whole approach seems quite wrong to me. At the absolute very least the
> code needs to check if interrupts are being processed in the current context
> before just giving up due to ProcDiePending || QueryCancelPending.
For the time being, I can just push the addition of the EINTR retry
without testing ProcDiePending || QueryCancelPending.
--
Álvaro Herrera Breisgau, Deutschland — https://www.EnterpriseDB.com/
"El sudor es la mejor cura para un pensamiento enfermo" (Bardia)
>From b7591beb919c3cfaa8090bda3977b7127de8de28 Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvhe...@alvh.no-ip.org>
Date: Fri, 1 Jul 2022 17:16:33 +0200
Subject: [PATCH v3] retry ftruncate
---
src/backend/storage/ipc/dsm_impl.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/src/backend/storage/ipc/dsm_impl.c b/src/backend/storage/ipc/dsm_impl.c
index 82b7978aeb..145a02204b 100644
--- a/src/backend/storage/ipc/dsm_impl.c
+++ b/src/backend/storage/ipc/dsm_impl.c
@@ -417,8 +417,19 @@ dsm_impl_posix_resize(int fd, off_t size)
{
int rc;
- /* Truncate (or extend) the file to the requested size. */
- rc = ftruncate(fd, size);
+ /*
+ * Truncate (or extend) the file to the requested size. If we're
+ * interrupted by a signal, retry; have caller handle any other error.
+ */
+ for (;;)
+ {
+ errno = 0;
+ rc = ftruncate(fd, size);
+ if (rc == 0)
+ break;
+ if (errno != EINTR)
+ return rc;
+ }
/*
* On Linux, a shm_open fd is backed by a tmpfs file. After resizing with
--
2.30.2
