Re: [COMMITTERS] pgsql: Code cleanup in the wake of recent LWLock refactoring.

2016-02-12 17:35 GMT+01:00 Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>:

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> 2016-02-12 15:46 GMT+01:00 Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>:
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>> 2016-02-12 15:43 GMT+01:00 Robert Haas <robertmhaas(at)gmail(dot)com>:
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>>> On Fri, Feb 12, 2016 at 8:16 AM, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
>>> wrote:
>>> >> That's very strange. It looks to me like you did exactly the right
>>> >> thing. Can you provide any details on how it fails?
>>> >
>>> > Looks like some race conditions is there - but I didn't tested it
>>> deeper
>>>
>>> Well, OK, so I'm totally willing to work with you to help get this
>>> straightened out, but I'm not really going to go download orafce and
>>> debug it for you on company time. I'm fairly sure that won't win me
>>> any large awards.
>>>
>>
>> I'll do it - just need to finish some other. I hope so this night I'll
>> know more.
>>
>
> In _PG_init I am creating new tranche by
> RequestNamedLWLockTranche("orafce", 1);
>
> Immediately when I try to use this lock
>
> shmem_lock = sh_mem->shmem_lock = &(GetNamedLWLockTranche("orafce"))->lock;
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> I got a error
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> ERROR: XX000: requested tranche is not registered
> LOCATION: GetNamedLWLockTranche, lwlock.c:602
>
> Because the session initialization doesn't finish, then Orafce doesn't work
>

I am starting to understand - the new design is more strict. The Orafce is
designed to run without registration shared_preload_libraries (it is
possible, but not necessary). But - RequestNamedLWLockTranche is working
only for this use case. Then GetNamedLWLockTranche fails, and all other are
probably consequences because shared memory isn't well initialized. After
setting shared_preload_libraries all tests are running. But I cannot do it
generally.

What is your recommendation for this case? So I have not to use named locks?

Regards

Pavel

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>>
>> Regards
>>
>> Pavel
>>
>>>
>>> --
>>> Robert Haas
>>> EnterpriseDB: http://www.enterprisedb.com
>>> The Enterprise PostgreSQL Company
>>>
>>
>>
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