Horton

Re: BUG #19006: Assert(BufferIsPinned) in BufferGetBlockNumber() is triggered for forwarded buffer

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Thomas Munro <thomas.munro@gmail.com>, Xuneng Zhou <xunengzhou@gmail.com>, exclusion@gmail.com, pgsql-bugs@lists.postgresql.org
Date: 2025-08-06T08:40:33Z
Lists: pgsql-bugs

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Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Fix rare bug in read_stream.c's split IO handling.

On Tue, Aug 05, 2025 at 12:43:06AM -0400, Tom Lane wrote:
> I've not looked at the issue actually being fixed, but a drive-by
> comment: these loops
> 
> +	for (int i = 0; i < stream->forwarded_buffers; ++i)
> +		Assert(BufferGetBlockNumber(stream->buffers[stream->next_buffer_index + i]) ==
> +			   stream->pending_read_blocknum + i);
> 
> should be wrapped in "#ifdef USE_ASSERT_CHECKING".  Maybe the
> compiler is smart enough to throw away the useless looping logic
> in a production build, or maybe it isn't.

I'd bet it is usually not that smart..  Embedding these in an extra
#ifdef is a sound defense IMO.
--
Michael