Re: ERROR: invalid spinlock number: 0 - Mailing list pgsql-hackers

From Michael Paquier
Subject Re: ERROR: invalid spinlock number: 0
Date
Msg-id YCyg+XrLMcYWpNOT@paquier.xyz
Whole thread Raw
In response to Re: ERROR: invalid spinlock number: 0  (Fujii Masao <masao.fujii@oss.nttdata.com>)
Responses Re: ERROR: invalid spinlock number: 0
List pgsql-hackers
On Tue, Feb 16, 2021 at 11:47:52PM +0900, Fujii Masao wrote:
> On 2021/02/16 15:50, Michael Paquier wrote:
>> +   /*
>> +    * Read "writtenUpto" without holding a spinlock. So it may not be
>> +    * consistent with other WAL receiver's shared variables protected by a
>> +    * spinlock. This is OK because that variable is used only for
>> +    * informational purpose and should not be used for data integrity checks.
>> +    */
>> What about the following?
>> "Read "writtenUpto" without holding a spinlock.  Note that it may not
>> be consistent with the other shared variables of the WAL receiver
>> protected by a spinlock, but this should not be used for data
>> integrity checks."
>
> Sounds good. Attached is the updated version of the patch.

Thanks, looks good to me.

>> I agree that what has been done with MyProc->waitStart in 46d6e5f is
>> not safe, and that initialization should happen once at postmaster
>> startup, with a write(0) when starting the backend.  There are two of
>> them in proc.c, one in twophase.c.  Do you mind if I add an open item
>> for this one?
>
> Yeah, please feel free to do that! BTW, I already posted the patch
> addressing that issue, at [1].

Okay, item added with a link to the original thread.
--
Michael

Attachment

pgsql-hackers by date:

Previous
From: Kyotaro Horiguchi
Date:
Subject: Re: Is it worth accepting multiple CRLs?
Next
From: John Naylor
Date:
Subject: Re: [POC] verifying UTF-8 using SIMD instructions