Re: [PATCH] Refactoring of LWLock tranches

On Tue, Sep 15, 2015 at 12:44 PM, Ildus Kurbangaliev
<i(dot)kurbangaliev(at)postgrespro(dot)ru> wrote:
> On Mon, 14 Sep 2015 06:32:22 -0400
> Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>
>> On Sun, Sep 13, 2015 at 5:05 PM, Ildus Kurbangaliev
>> <i(dot)kurbangaliev(at)postgrespro(dot)ru> wrote:
>> > Yes, that is because I tried to go with current convention working
>> > with shmem in Postgres (there are one function that returns the
>> > size and others that initialize that memory). But I like your
>> > suggestion about API functions, in that case number of tranches and
>> > locks will be known during the initialization.
>>
>> I also want to leave the door open to tranches that are registered
>> after initialization. At that point, it's too late to put a tranche
>> in shared memory, but you can still use DSM.
>
> We can hold some extra space in LWLockTrancheArray, add some
> function for unregistering a tranche, and reuse free items in
> LWLockTrancheId later.

We could, but since that would be strictly more annoying and less
flexible than what we've already got, why would we?

--
Robert Haas
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