279c8e176b
Host-value protocol dispatch (a protocol extended to Number/String/… called on a host value) recomputed the candidate type-tag list and walked the registry — up to ~15 map lookups plus an array alloc — on every call. It now caches (most-specific-host-tag, protocol, method) -> fn, guarded by a registry generation that bumps in register-protocol-method; re-extending a protocol invalidates the cache. The single-lookup fast paths (deftype protocol dispatch, direct multimethod dispatch) are untouched — they're already cheap, so no cache overhead there. The multimethod hierarchy-fallback cache (narrower: only derive-based dispatch) is deferred. Test in test/integration/dispatch-cache-test.janet covers correctness under re-extension in all three modes. Conformance 218/218; battery 3916.
33 lines
1.6 KiB
Text
33 lines
1.6 KiB
Text
# Protocol host-value dispatch cache (jolt-4ay).
|
|
#
|
|
# Host-value protocol dispatch used to recompute the candidate type-tag list and
|
|
# walk the registry on every call. It's now a generation-guarded cache keyed by
|
|
# (most-specific-host-tag, protocol, method); registering a protocol impl bumps
|
|
# the registry generation and invalidates it. This pins correctness: the cache
|
|
# must never hide a re-extension.
|
|
|
|
(use ../../src/jolt/api)
|
|
|
|
(var failures 0)
|
|
(defn- check [label got want]
|
|
(unless (= got want)
|
|
(++ failures)
|
|
(printf "FAIL [%s] got %q want %q" label got want)))
|
|
|
|
(each mode [{:compile? true} {} {:aot-core? false}]
|
|
(def ctx (init mode))
|
|
(eval-string ctx "(defprotocol P (m [x]))")
|
|
(eval-string ctx "(extend-protocol P Number (m [x] (* x 2)))")
|
|
(check (string mode " host dispatch") (eval-string ctx "(m 5)") 10)
|
|
(check (string mode " cache hit (same class)") (eval-string ctx "(m 7)") 14)
|
|
# Re-extend: registry generation bumps, cache must invalidate.
|
|
(eval-string ctx "(extend-protocol P Number (m [x] (+ x 100)))")
|
|
(check (string mode " sees re-extension") (eval-string ctx "(m 5)") 105)
|
|
# Extending a different host class bumps gen too; number impl re-resolves.
|
|
(eval-string ctx "(extend-protocol P String (m [x] (str \"s:\" x)))")
|
|
(check (string mode " other class") (eval-string ctx "(m \"hi\")") "s:hi")
|
|
(check (string mode " number after other-class extend") (eval-string ctx "(m 3)") 103))
|
|
|
|
(if (pos? failures)
|
|
(do (printf "dispatch-cache: %d failure(s)" failures) (os/exit 1))
|
|
(print "dispatch-cache: all cases passed (compile, interpret, aot-core off)"))
|