Понедельник, 25 ноября 2013, 8:31 +09:00 от Michael Paquier <michael.paqu...@gmail.com>: >On Mon, Nov 25, 2013 at 2:10 AM, Alexey Vasiliev < leopard...@inbox.ru > wrote: >> Воскресенье, 24 ноября 2013, 14:06 +01:00 от Andres Freund >> < and...@anarazel.de >: >> >> Hi, >> >> >> On 2013-11-24 16:27:06 +0400, Олексій Васильєв wrote: >>> This is part where I try to connect to database: >>> https://github.com/le0pard/pg_web/blob/master/src/pg_web.c#L92-L132 , but >>> SPI functions give error in log (it is commented): >>> >>> 2013-11-24 02:57:43 UTC ERROR: stack depth limit exceeded >>> 2013-11-24 02:57:43 UTC HINT: Increase the configuration parameter >>> "max_stack_depth" (currently 2048kB), after ensuring the platform's stack >>> depth limit is adequate. >>> 2013-11-24 02:57:43 UTC CONTEXT: SQL statement "SELECT COUNT(*) FROM >>> pg_class;" >>> >>> Because I doing something in wrong way. I will appreciate for any help: >>> where I doing wrong, link to the article how to do it, just a tip, pull >>> request - anything. Google search and PostgreSQL sources reading so far >>> helped me to this point. >> >> At the very least you're calling InitPostgres() instead of >> BackgroundWorkerInitializeConnection() which you have commented out. And >> the latter should only be called once in every worker. >> >> Greetings, >> >> Andres Freund >> >> >> Fixed by using PQconnectdb from "libpq-fe.h". Thanks. >You should not need an extra PQconnectdb to connect to a database >using a background worker for your case as far as I understood. By >using that you are requiring a connection to database without using >the internal infrastructure in place, meaning that your bgworker is >not connected to the database server from the inside but from the >outside, like a normal client would do. Aren't to trying to have a >background worker connected to a database when it is initialized with >BgWorkerStart_PostmasterStart? Bgworkers using this start-up mode are >not eligible to initialize database connections. Please use either >BgWorkerStart_ConsistentState or BgWorkerStart_RecoveryFinished and >BackgroundWorkerInitializeConnection will allow a connection to >database without any extra work. >-- >Michael Thanks, I just try this. This work if I working with database in loop inside bgw_main function. But if I create threads inside bgw_main and try to connect to database - I have errors "stack depth limit exceeded" . The code:
https://github.com/le0pard/pg_web/blob/master/src/pg_web.c#L195 - connect to database https://github.com/le0pard/pg_web/blob/master/src/pg_web.c#L100-L131 - "http_event_handler" function execute in threads, because it handle http requests. And this code not work. BTW, I need connect to database depend from request url, so execute BackgroundWorkerInitializeConnection at the beginning not enough. Thanks again. -- Alexey Vasiliev
