When using the OSSP UUID library, cache its uuid_t state object. The original coding in contrib/uuid-ossp created and destroyed a uuid_t object (or, in some cases, even two of them) each time it was called. This is not the intended usage: you're supposed to keep the uuid_t object around so that the library can cache its state across uses. (Other UUID libraries seem to keep equivalent state behind-the-scenes in static variables, but OSSP chose differently.) Aside from being quite inefficient, creating a new uuid_t loses knowledge of the previously generated UUID, which in theory could result in duplicate V1-style UUIDs being created on sufficiently fast machines.
On at least some platforms, creating a new uuid_t also draws some entropy from /dev/urandom, leaving less for the rest of the system. This seems sufficiently unpleasant to justify back-patching this change. Branch ------ REL8_4_STABLE Details ------- http://git.postgresql.org/pg/commitdiff/fd785441ffc11969b658625fe66f162589f07bdb Modified Files -------------- contrib/uuid-ossp/uuid-ossp.c | 74 ++++++++++++++++++++++++----------------- 1 file changed, 44 insertions(+), 30 deletions(-) -- Sent via pgsql-committers mailing list (pgsql-committers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-committers
