On 2015-05-15 AM 10:59, Amit Langote wrote: > On 2015-05-15 AM 10:39, Amit Langote wrote: >> On 2015-05-15 AM 05:01, Pavel Stehule wrote: >>> >>> I am trying to start bgworker from bgworker and create communication >>> between these process. I have a code based on test_shm_mq. This code fails >>> because BackendPidGetProc doesn't find related bgworker process, although >>> the registrant process is living >>> >> >> One reason for this may be that the worker was not started with the flag >> BGWORKER_SHMEM_ACCESS which is necessary to perform InitProcess() that would >> initialize a PGPROC entry for it. But if you'd used the same method for >> initializing workers as test_shm_mq_setup(), then it should have. >> > > It seems in addition, a BackgroundWorkerInitializeConnection() is also > necessary for the PGPROC entry of the worker to be visible to others. I do not > see that done anywhere in test_shm_mq(); so perhaps that's missing? >
And these conditions apply to the bgworker that started another bgworker, that is the registrant bgworker. I think such a pattern does not exist in existing code. That is, normally all workers are started by a user backend that has a valid shared PGPROC entry. Thanks, Amit -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
