Alvaro Herrera wrote:
> Andrew Dunstan wrote:
>
>
>> I have verified that it does indeed work. Underneath the hood it uses
>> the native call LockFileEx() see win32io.c in Perl source. I suggest we
>> should switch from this flaky use of Global namespace to having the
>> postmaster acquire an explicit lock on a file in the datadir.
>>
>
> Does it work for all backends to grab a lock, so that if they continue
> to live after postmaster has died, then the new postmaster cannot start?
>
> I guess the postmaster could try-acquire an exclusive lock and all other
> processes would acquire a shared lock.
>
I think we'd need to have the postmaster grab an exclusive lock to start
with, to make sure nothing else has the lock, then swap to a shared lock
before any backends are created. That might leave a tiny window on
postmaster start, but I think it would be good enough.
cheers
andrew
