On Thu, Jun 22, 2017 at 9:48 AM, Michael Paquier <michael.paqu...@gmail.com> wrote: > On Thu, Jun 22, 2017 at 1:29 AM, Kuntal Ghosh > <kuntalghosh.2...@gmail.com> wrote: >> On Wed, Jun 21, 2017 at 7:52 PM, Dilip Kumar <dilipbal...@gmail.com> wrote: >>> On Wed, Jun 21, 2017 at 7:47 PM, Kuntal Ghosh >>> <kuntalghosh.2...@gmail.com> wrote: >>>>> IMHO, It's not a good idea to use DSM call to verify the DSA handle. >>>>> >>>> Okay. Is there any particular scenario you've in mind where this may fail? >>> >>> It's not about failure, but about the abstraction. When we are using >>> the DSA we should not directly access the DSM which is under DSA. >>> >> Okay. I thought that I've found at least one usage of >> dsm_find_mapping() in the code. :-) >> >> But, I've some more doubts. >> 1. When should we use dsm_find_mapping()? (The first few lines of >> dsm_attach is same as dsm_find_mapping().) >> 2. As a user of dsa, how should we check whether my dsa handle is >> already attached? I guess this is required because, if a user tries to >> re-attach a dsa handle, it's punishing the user by throwing an error >> and the user wants to avoid such errors. > > From a logical point of view, there is nothing preventing the use of > dsm_find_mapping() on a DSA handle, still the API layering looks wrong > if you want to check for an existing mapping. So why not defining a > new API, like dsa_find_mapping() that just wraps dsm_find_mapping() > but has its own error handling? This would offer more flexibility for > the future. Yeah. That sounds reasonable. Or, dsa_attach can throw error conditionally.
-- Thanks & Regards, Kuntal Ghosh EnterpriseDB: http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
