Re: [INTERFACES] libpq + multiple connections ... - Mailing list pgsql-interfaces

From Roberto Joao Lopes Garcia
Subject Re: [INTERFACES] libpq + multiple connections ...
Date
Msg-id 3.0.5.32.19991129101959.007a1490@pop.hipernet.com.br
Whole thread Raw
In response to Re: [INTERFACES] libpq + multiple connections ...  ("E.E. Mellor" <eem21@cam.ac.uk>)
Responses Re: [INTERFACES] libpq + multiple connections ...  ("E.E. Mellor" <eem21@cam.ac.uk>)
List pgsql-interfaces
>> safely run two PQconnectdb() calls in parallel.  But you can open two
>> connections in sequence and then use them in parallel; 
>

So I could open, for exemple, 5 db connections (with PQconnectdb()) and
then create 5 threads and use those connections in eache thread. But how
about use PQreset() or PQfinish() inside the new created threads?

I used to test connection before send a query like bellow:

if(PQstatus(con)==CONNECTION_BAD) {  PQreset(con);  if(PQstatus(con)==CONNECTION_BAD) erro_fatal();
}

Should I protect the calls to those functions by an mutex?? Could it
work??? Which functions read or alter Qconnectdb()'s  static array??

I think it is important to mark wich  functions in Libpq is thread safe or
not.

Roberto




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