Re: thread safety on clients - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: thread safety on clients
Date
Msg-id 200912110131.nBB1VSV07199@momjian.us
Whole thread Raw
In response to Re: thread safety on clients  (Greg Smith <greg@2ndquadrant.com>)
Responses Re: thread safety on clients  (Bruce Momjian <bruce@momjian.us>)
List pgsql-hackers
Greg Smith wrote:
> Bruce Momjian wrote:
> > Peter Eisentraut wrote:
> >   
> >>> if i remove the -j option then it runs without a problem
> >>>       
> >> Possibly related to the incomplete removal of the enable-thread-safety
> >> option that I just posted about.
> >>     
> >
> > I thought about that but I can't figure out how that would affect
> > pgbench.
> >   
> The "-j" option is the recent addition to pgbench that causes it to 
> launch multiple client threads when enabled, each handling a subset of 
> the transactions.  There's blocks of codes in pgbench.c now that depend 
> on having sane values for thread safety in libpq.  That it may be 
> detecting the wrong thing and operating in an unsafe way after the 
> recent change is what Peter's suggesting.  This is good, actually, 
> because I don't think we had many client-side thread-safety tests 
> floating around to catch problems in this area before.

I can reproduce the crash here so I can see if I can find the cause.

However, the failure is happening in the _server_.  Threading is
unrelated to the server itself, only the client.  I suppose the first
test for me will be to test CVS before the thread change was made.

The failure is in heap_fill_tuple(), and I am unclear how that assert
could be getting triggered:
CONTEXT:  automatic analyze of table "test.public.pgbench_accounts"TRAP: FailedAssertion("!((data - start) ==
data_size)",File: "heaptuple.c", Line: 255)TRAP: FailedAssertion("!((data - start) == data_size)", File: "heaptuple.c",
Line:255)TRAP: FailedAssertion("!((data - start) == data_size)", File: "heaptuple.c", Line: 255)LOG:  server process
(PID6076) was terminated by signal 6: Abort trapLOG:  terminating any other active server processes
 

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + If your life is a hard drive, Christ can be your backup. +


pgsql-hackers by date:

Previous
From: Greg Smith
Date:
Subject: Re: Adding support for SE-Linux security
Next
From: Andrew Dunstan
Date:
Subject: Re: YAML Was: CommitFest status/management