Improve ilist.h's support for deletion of slist elements during iteration. Previously one had to use slist_delete(), implying an additional scan of the list, making this infrastructure considerably less efficient than traditional Lists when deletion of element(s) in a long list is needed. Modify the slist_foreach_modify() macro to support deleting the current element in O(1) time, by keeping a "prev" pointer in addition to "cur" and "next". Although this makes iteration with this macro a bit slower, no real harm is done, since in any scenario where you're not going to delete the current list element you might as well just use slist_foreach instead. Improve the comments about when to use each macro.
Back-patch to 9.3 so that we'll have consistent semantics in all branches that provide ilist.h. Note this is an ABI break for callers of slist_foreach_modify(). Andres Freund and Tom Lane Branch ------ master Details ------- http://git.postgresql.org/pg/commitdiff/fa2fad3c06bfde03594ff38d53acdf9a60c56bb2 Modified Files -------------- src/backend/lib/ilist.c | 2 +- src/backend/postmaster/bgworker.c | 15 ++++--- src/backend/postmaster/pgstat.c | 7 +++ src/backend/postmaster/postmaster.c | 4 +- src/include/lib/ilist.h | 62 ++++++++++++++++++++++----- src/include/postmaster/bgworker_internals.h | 2 +- 6 files changed, 72 insertions(+), 20 deletions(-) -- Sent via pgsql-committers mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-committers
