Re: Threads With Libpq

On 1 Aug 2012, at 14:32, dinesh kumar wrote:

> Respected All,
>
> This is my first request/post in PG-Generals. If it is not the place for these kind of queries, then please guide me where i need to be.
>
> I have a quick question regarding "pthread" with PostgreSQL 9.0 Libpq. I'm facing a problem with "Pthread" and libpq. Please find the below program behavoiur.
>
> Connection_To_PG()
> {
> /* Making a connection to PG 9.0 */
> }
>
> void* Independent_Thread1()
> {
> while(1)
> {
> sleep(5);
> /* Doing 1 Insert Operation on Table A*/
> }
> }
>
> void* Independent_Thread2()
> {
> while(1)
> {
> sleep(5);
> /*Doing 1 Insert Operation on Table B*/
> }
>
> main()
> {
> pthread Ind1,Ind2;
> Connection_TO_PG();
> pthread_create(&Ind1,NULL,&Independent_Thread1,NULL);
> pthread_create(&Ind2,NULL,&Independent_Thread2,NULL);
> if(pthread_join(Ind1,NULL)<0)
> {
> printf("Ind1 is completed");
> }
> if(pthread_join(Ind2,NULL)<0)
> {
> printf("Ind2 is completed");
> }
> }

You need a separate connection per thread or you need to synchronise your queries onto the single central connection, meaning that other threads need to be blocked (from performing queries) while any thread is performing a query.

Alban Hertroys

--
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