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Fix nREPL server ^C shutdown crash

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^C to a running `joltc --nrepl-server` aborted with "thread does not
own mutex" because the accept-loop thread absorbed SIGINT in its foreign
accept() call, where Chez can't run the keyboard-interrupt handler, and
run-main-pump's tight condition-wait loop wasn't interruptible anyway.

Block SIGINT in the primordial thread before starting the server so the
accept loop inherits a blocked mask, park in a single interruptible
condition-wait via the new park-until-interrupt, and run registered
shutdown hooks (newest-first, each isolated) from the keyboard-interrupt
handler before (exit 0). The stop fn now drops .nrepl-port via the new
jolt.host/delete-file seam — clojure.java.io/delete-file doesn't exist
in Jolt and silently no-ops, so .nrepl-port was never removed.
This commit is contained in:
Yogthos 2026-06-30 19:08:13 -04:00
parent 8c2bd60257
commit 46c9c7b4d9
3 changed files with 93 additions and 15 deletions
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18
jolt-core/jolt/main.clj
View file

@ -200,10 +200,22 @@
;; the GUI main loop: glimmer's run marshals its startup here via
;; jolt.host/call-on-main-thread — on macOS GTK quartz, g_application_run
;; must run on the main thread or AppKit aborts when it sets the main menu.
;; Block SIGINT in this (primordial) thread before starting the server so the
;; accept-loop future — and the conn-handler futures it spawns — inherit a
;; blocked SIGINT mask. Without this, ^C lands on the accept loop blocked in
;; c-accept (a foreign call), where Chez can't fire the keyboard-interrupt
;; handler, and the server hangs. park-until-interrupt unblocks SIGINT here
;; once its own ^C handler is installed, so ^C reaches this thread and the
;; shutdown hooks run cleanly.
(jolt.host/block-sigint)
(let [stop ((resolve 'jolt.nrepl/start) port (:nrepl-middleware resolved))]
;; park here until something calls jolt.host/stop-main-pump, then shut the
;; server down cleanly (close the socket, remove .nrepl-port) and return.
(jolt.host/run-main-pump)
;; register stop so ^C (handled by park-until-interrupt) closes the socket
;; and drops .nrepl-port on the way out.
(jolt.host/add-shutdown-hook stop)
;; park here until ^C (handled by park-until-interrupt's keyboard-interrupt-
;; handler, which runs the shutdown hooks and exits). The accept loop
;; inherited SIGINT-blocked above, so ^C is delivered to this thread.
(jolt.host/park-until-interrupt)
(when stop (stop))))))
(defn- usage []

24
jolt-core/jolt/nrepl.clj
View file

@ -29,9 +29,9 @@
(ffi/defcfn c-bind "bind" [:int :pointer :int] :int)
(ffi/defcfn c-listen "listen" [:int :int] :int)
(ffi/defcfn c-setsockopt "setsockopt" [:int :int :int :pointer :int] :int)
(ffi/defcfn c-accept "accept" [:int :pointer :pointer] :int :blocking)
(ffi/defcfn c-recv "recv" [:int :pointer :size_t :int] :ssize_t :blocking)
(ffi/defcfn c-send "send" [:int :pointer :size_t :int] :ssize_t :blocking)
(ffi/defcfn c-accept "accept" [:int :pointer :pointer] :int :blocking)
(ffi/defcfn c-recv "recv" [:int :pointer :size_t :int] :ssize_t :blocking)
(ffi/defcfn c-send "send" [:int :pointer :size_t :int] :ssize_t :blocking)
(ffi/defcfn c-close "close" [:int] :int)
(def ^:private AF-INET 2)
@ -243,18 +243,18 @@
(println (str "nREPL server started on port " port " (127.0.0.1) — .nrepl-port written"))
(when (seq middleware) (println (str ";; middleware: " (str/join " " middleware))))
(println ";; connect your editor; ^C to stop")
(future
;; A stop closes fd, which makes the blocking accept() return an error; the
;; @stopped check then breaks the loop instead of spinning on the dead fd.
(loop []
(future
;; A stop closes fd, which makes the blocking accept() return an error; the
;; @stopped check then breaks the loop instead of spinning on the dead fd.
(loop []
(let [conn (c-accept fd ffi/null ffi/null)]
(when-not @stopped
(when (>= conn 0)
(future (try (handle-conn conn handler)
(catch :default e (println "nrepl conn error:" (err-msg e)) (c-close conn)))))
(recur)))))
(fn stop []
(when (compare-and-set! stopped false true)
(c-close fd)
(try (io/delete-file ".nrepl-port" true) (catch :default _ nil)))
nil))))
(fn stop []
(when (compare-and-set! stopped false true)
(c-close fd)
(jolt.host/delete-file ".nrepl-port"))
nil))))