Tom Lane wrote: > Alvaro Herrera <alvhe...@commandprompt.com> writes: > > Tom Lane wrote: > >> I guess I need to point out that those ereport calls already pose a far > >> more substantial risk of palloc failure than the DLNewElem represents. > > > Hmm, do they? I mean, don't they use ErrorContext, which is supposed to > > be preallocated? > > Well, we'd like to think that they pose an insignificant risk, but it's > hard to credit that DLNewElem isn't insignificant as well.
Yeah, actually as I said earlier, I haven't ever seen this. > If you're really intent on doing something about this, my inclination > would be to get rid of the dependence on DLNewElem altogether. Add > a Dlelem field to the Backend struct and use DLInitElem (compare > the way catcache uses that module). Hmm, yeah, I had seen that code. So it looks like this instead. -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc.
Index: src/backend/postmaster/postmaster.c =================================================================== RCS file: /home/alvherre/Code/cvs/pgsql/src/backend/postmaster/postmaster.c,v retrieving revision 1.551.2.1 diff -c -p -r1.551.2.1 postmaster.c *** src/backend/postmaster/postmaster.c 27 Jun 2008 01:53:31 -0000 1.551.2.1 --- src/backend/postmaster/postmaster.c 7 Apr 2009 02:25:51 -0000 *************** typedef struct bkend *** 142,147 **** --- 142,148 ---- long cancel_key; /* cancel key for cancels for this backend */ bool is_autovacuum; /* is it an autovacuum process? */ bool dead_end; /* is it going to send an error and quit? */ + Dlelem elem; /* self pointer into BackendList */ } Backend; static Dllist *BackendList; *************** CleanupBackend(int pid, *** 2343,2349 **** #endif DLRemove(curr); free(bp); - DLFreeElem(curr); break; } } --- 2344,2349 ---- *************** HandleChildCrash(int pid, int exitstatus *** 2390,2396 **** #endif DLRemove(curr); free(bp); - DLFreeElem(curr); /* Keep looping so we can signal remaining backends */ } else --- 2390,2395 ---- *************** BackendStartup(Port *port) *** 2857,2863 **** bn->cancel_key = MyCancelKey; bn->is_autovacuum = false; bn->dead_end = (port->canAcceptConnections != CAC_OK); ! DLAddHead(BackendList, DLNewElem(bn)); #ifdef EXEC_BACKEND if (!bn->dead_end) ShmemBackendArrayAdd(bn); --- 2856,2864 ---- bn->cancel_key = MyCancelKey; bn->is_autovacuum = false; bn->dead_end = (port->canAcceptConnections != CAC_OK); ! ! DLInitElem(&bn->elem, bn); ! DLAddHead(BackendList, &bn->elem); #ifdef EXEC_BACKEND if (!bn->dead_end) ShmemBackendArrayAdd(bn);
-- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
