Avoid potential deadlock in InitCatCachePhase2(). Opening a catcache's index could require reading from that cache's own catalog, which of course would acquire AccessShareLock on the catalog. So the original coding here risks locking index before heap, which could deadlock against another backend trying to get exclusive locks in the normal order. Because InitCatCachePhase2 is only called when a backend has to start up without a relcache init file, the deadlock was seldom seen in the field. (And by the same token, there's no need to worry about any performance disadvantage; so not much point in trying to distinguish exactly which catalogs have the risk.)
Bug report, diagnosis, and patch by Nikhil Sontakke. Additional commentary by me. Back-patch to all supported branches. Branch ------ REL8_3_STABLE Details ------- http://git.postgresql.org/pg/commitdiff/cf73547075f3632da3beef345eb50646bf142edf Modified Files -------------- src/backend/utils/cache/catcache.c | 9 +++++++++ src/backend/utils/cache/relcache.c | 10 ++++++++++ 2 files changed, 19 insertions(+), 0 deletions(-) -- Sent via pgsql-committers mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-committers
