Re: [HACKERS] libpqrcv_PQexec() seems to violate latch protocol

Andres Freund <andres@anarazel.de> writes:
> The function  in $subject does:

>             ResetLatch(&MyProc->procLatch);
>             rc = WaitLatchOrSocket(&MyProc->procLatch,
>                                    WL_POSTMASTER_DEATH | WL_SOCKET_READABLE |
>                                    WL_LATCH_SET,
>                                    PQsocket(streamConn),
>                                    0,
>                                    WAIT_EVENT_LIBPQWALRECEIVER);

Yeah, this is certainly broken.

> Afaict, the ResetLatch() really should just instead be in the if (rc & WL_LATCH_SET) block.

And, to be specific, it should be before the CHECK_FOR_INTERRUPTS call,
since that is the useful work that we want to be sure occurs after
any latch-setting event.
        regards, tom lane