A out of date comment of WaitForWALToBecomeAvailable
Hi,
The following comment looks out of date now. should we fix it as following?
*
- * If the record is not immediately available, the function returns false
+ * If the record is not immediately available, the function returns XLREAD_FAIL
* if we're not in standby mode. In standby mode, waits for it to become
* available.
*
..
static XLogPageReadResult
WaitForWALToBecomeAvailable(XLogRecPtr RecPtr, bool randAccess, ..)Thanks
On Fri, Jan 30, 2026 at 10:29:41AM +0800, Andy Fan wrote:
The following comment looks out of date now. should we fix it as following?
Yes, the code returns XLREAD_FAIL is we cannot find a record when not
in standby mode. Thanks for the report.
--
Michael
At 2026-01-30 13:13:37, "Michael Paquier" <michael@paquier.xyz> wrote:
Hi,
On Fri, Jan 30, 2026 at 10:29:41AM +0800, Andy Fan wrote:
The following comment looks out of date now. should we fix it as following?
Yes, the code returns XLREAD_FAIL is we cannot find a record when not
in standby mode. Thanks for the report.
Thanks for double check. patch attached.
Attachments:
v1-0001-Fix-out-of-date-comment-in-WaitForWALToBecomeAvai.patchapplication/octet-stream; name=v1-0001-Fix-out-of-date-comment-in-WaitForWALToBecomeAvai.patch; x-cm-securityLevel=0Download+1-2
Hi Andy,
Thanks for the patch.
On Fri, Jan 30, 2026 at 6:23 PM Andy Fan <zhihuifan1213@163.com> wrote:
At 2026-01-30 13:13:37, "Michael Paquier" <michael@paquier.xyz> wrote:
Hi,
On Fri, Jan 30, 2026 at 10:29:41AM +0800, Andy Fan wrote:
The following comment looks out of date now. should we fix it as following?
Yes, the code returns XLREAD_FAIL is we cannot find a record when not
in standby mode. Thanks for the report.Thanks for double check. patch attached.
WaitForWALToBecomeAvailable can also return XLREAD_WOULDBLOCK when the
caller set nonblocking. The comment only talks about XLREAD_FAIL vs
“waits in standby,” so it still doesn’t describe that third outcome.
That omission pre-dates this patch, should we expand the comment
mention the nonblocking case as well?
--
Best,
Xuneng
On Mon, Feb 02, 2026 at 10:37:43AM +0800, Xuneng Zhou wrote:
WaitForWALToBecomeAvailable can also return XLREAD_WOULDBLOCK when the
caller set nonblocking. The comment only talks about XLREAD_FAIL vs
“waits in standby,” so it still doesn’t describe that third outcome.
That omission pre-dates this patch, should we expand the comment
mention the nonblocking case as well?
The outcome related to XLREAD_WOULDBLOCK is implied in the last
sentence of the comment block standing at the top of the function,
which seems OK to me.
--
Michael
Hi All,
[[PGP Signed Part:Undecided]]
On Mon, Feb 02, 2026 at 10:37:43AM +0800, Xuneng Zhou wrote:WaitForWALToBecomeAvailable can also return XLREAD_WOULDBLOCK when the
caller set nonblocking. The comment only talks about XLREAD_FAIL vs
“waits in standby,” so it still doesn’t describe that third outcome.
That omission pre-dates this patch, should we expand the comment
mention the nonblocking case as well?The outcome related to XLREAD_WOULDBLOCK is implied in the last
sentence of the comment block standing at the top of the function,
which seems OK to me.
Thank you for the double check, I personally prefer to keep
XLREAD_WOULDBLOCK as it it.
--
Best Regards
Andy Fan