Tom Lane wrote:
> Andrew Dunstan <andrew@dunslane.net> writes:
>
>> 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.
>>
>
> That can only be a solution if postmaster child processes will inherit
> the lock. (The nasty scenario is where the postmaster has died but one
> or more backends are still alive --- a new postmaster attempting to
> start MUST detect that and refuse to start.) Does fork/exec preserve
> lock ownership on Windows?
>
>
>
I don't think so, no. But we could have the children explicitly acquire
a shared lock, so if the postmaster at startup tried to grab an
exclusive lock that would fail if any child were still alive.
cheers
andrew