oauth: Remove stale events from the kqueue multiplexer If a socket is added to the kqueue, becomes readable/writable, and subsequently becomes non-readable/writable again, the kqueue itself will remain readable until either the socket registration is removed, or the stale event is cleared via a call to kevent().
In many simple cases, Curl itself will remove the socket registration quickly, but in real-world usage, this is not guaranteed to happen. The kqueue can then remain stuck in a permanently readable state until the request ends, which results in pointless wakeups for the client and wasted CPU time. Implement comb_multiplexer() to call kevent() and unstick any stale events that would cause unnecessary callbacks. This is called right after drive_request(), before we return control to the client to wait. Suggested-by: Thomas Munro <thomas.mu...@gmail.com> Co-authored-by: Thomas Munro <thomas.mu...@gmail.com> Reviewed-by: Thomas Munro <thomas.mu...@gmail.com> Backpatch-through: 18 Discussion: https://postgr.es/m/caoymi+ndzxjhawj9_jrsyf8umtocadamofjeggskw-ky7au...@mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/ff5b0824b3b0c58bbb322719628c42b7a4751dd9 Modified Files -------------- src/interfaces/libpq-oauth/oauth-curl.c | 67 ++++++++++++++++++++++++++++++--- 1 file changed, 61 insertions(+), 6 deletions(-)
