Re: WSAStartup() in libpq

Magnus Hagander <magnus(at)hagander(dot)net> writes:
> On Thu, Mar 08, 2007 at 10:10:28AM -0500, Tom Lane wrote:
>> Also, isn't the WSACleanup() in freePGconn in the wrong place? Seems
>> like it shouldn't be done until after we've closed the socket. I'd
>> be inclined to put it at the bottom of the routine.

> Certainly looks wrong. It's interesting how this could have worked
> *before*.

Because the calls in DllMain covered us (ie, the WSA usage count never
got to be less than one). If we remove them, we'd better get this pair
right.

One thing that bothers me a bit is that if we just move the call to the
bottom, then freePGconn won't do it at all if passed a NULL pointer.
Now (assuming a non-broken app) the only way that can happen is if
makeEmptyPGconn runs out of memory. If the client gets back a null
pointer from a connection attempt, it's probably a 50-50 proposition
whether it will think it ought to do PQfinish with it. So it'd be good
if we could keep the usage count straight either way. I propose the
invariant "a WSA usage count is associated with a non-null PGconn
structure". That would mean that doing WSACleanup only at the bottom
of freePGconn is correct, but also that makeEmptyPGconn needs to do
WSACleanup in its (two) failure paths.

regards, tom lane