By the way, At Mon, 06 Mar 2017 17:07:55 +0900 (Tokyo Standard Time), Kyotaro HORIGUCHI <horiguchi.kyot...@lab.ntt.co.jp> wrote in <20170306.170755.68410634.horiguchi.kyot...@lab.ntt.co.jp> > Ok, I think I understand the complete picture. > > At Mon, 06 Mar 2017 15:58:56 +0900 (Tokyo Standard Time), Kyotaro HORIGUCHI > <horiguchi.kyot...@lab.ntt.co.jp> wrote in > <20170306.155856.198084190.horiguchi.kyot...@lab.ntt.co.jp> > > > I can guess two ways to fix this. One is change the definition of > > > T_NAME. > > > > > > | #define T_NAME(l) \ > > > | ((l)->tranche < LWTRANCHE_FIRST_USER_DEFINED ? \ > > > | LWLockTrancheArray[(l)->tranche] : \ > > > | NamedLWLockTrancheArray[(l)->tranche - LWTRANCHE_FIRST_USER_DEFINED] > > > > > > It makes the patch small but I don't thing the shape is > > > desirable. > > > > > > Then, the other way is registering named tranches into the main > > > tranche array. The number and names of the requested named > > > tranches are known to postmaster so they can be allocated and > > > initialized at the time. > > > > > > The mapping of the shared memory is inherited to backends so > > > pointing to the addresses in shared memory will work in the > > > !EXEC_BACKEND case. I confirmed that the behavior is ensured also > > > in EXEC_BACKEND case. > > But this doesn't work for > LWLockNewTrancheId/LWLockRegisterTranche and it is valuable > interface. So the measure we can take is redefining T_NAME.
I realized that *I* have used the interface RequestNamedLWLockTranche in certain extensions but I completely forgot that and faintly recalled after being pointed by one of my colleagues.. Sorry for the off-topic. regards, -- Kyotaro Horiguchi NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers