bug#70522: 29.2.50; eglot-shutdown sends SIGKILL before LSP server can exit gracefully

bug#70522: 29.2.50; eglot-shutdown sends SIGKILL before LSP server can exit gracefully

[Aaron Zeng]

1. emacs -Q
2. M-x eglot in some file (I tested with OCaml-LSP and another language
server, the latter is internal to my site)
3. M-x eglot-shutdown

This messages:

[jsonrpc] Server exited with status 9

Which is a little confusing.  One would expect the language server to
exit with status 0, and not end up with "killed" in the events buffer,
if the server exited successfully upon user request.

I installed the following patch locally at my site, and it seems to fix
the issue (now the server exits with status 0).  I think it also better
matches the docstring of `jsonrpc-shutdown'.

diff --git a/jsonrpc.el b/jsonrpc.el
--- a/jsonrpc.el
+++ b/jsonrpc.el
@@ -598,8 +598,8 @@ With optional CLEANUP, kill any associat
        while (not (process-get proc 'jsonrpc-sentinel-cleanup-started))
        unless (zerop i) do
        (jsonrpc--warn "Sentinel for %s still hasn't run, deleting it!" proc)
+       (delete-process proc)
        do
-       (delete-process proc)
        (accept-process-output nil 0.1))
     (when cleanup
       (kill-buffer (process-buffer (jsonrpc--process conn)))


In GNU Emacs 29.2.50 (build 2, x86_64-pc-linux-gnu, X toolkit, cairo
 version 1.15.12, Xaw scroll bars) of 2024-04-15 built on
 psr-qws-hydra382
Windowing system distributor 'The X.Org Foundation', version 11.0.12011000
System Description: Rocky Linux 8.9 (Green Obsidian)

Configured using:
 'configure --config-cache --with-x-toolkit=lucid --without-gpm
 --without-gconf --without-selinux --without-imagemagick --with-modules
 --with-gif=no --with-cairo --with-rsvg --without-compress-install
 --prefix=/j/office/app/emacs/store/20240415-155142'

Configured features:
CAIRO DBUS FREETYPE GLIB GMP GNUTLS GSETTINGS HARFBUZZ JPEG JSON
LIBSYSTEMD LIBXML2 MODULES NOTIFY INOTIFY PDUMPER PNG RSVG SECCOMP SOUND
SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS X11 XDBE XIM XINPUT2 XPM LUCID
ZLIB

Important settings:
  value of $LANG: en_US.utf8
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  show-paren-mode: t
  electric-indent-mode: t
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  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
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  line-number-mode: t
  indent-tabs-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message mailcap yank-media puny dired
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cl-loaddefs cl-lib sendmail rfc2047 rfc2045 ietf-drums mm-util
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composite emoji-zwj charscript charprop case-table epa-hook
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theme-loaddefs faces cus-face macroexp files window text-properties
overlay sha1 md5 base64 format env code-pages mule custom widget keymap
hashtable-print-readable backquote threads dbusbind inotify
dynamic-setting system-font-setting font-render-setting cairo x-toolkit
xinput2 x multi-tty make-network-process emacs)

Memory information:
((conses 16 38416 8673)
 (symbols 48 5185 0)
 (strings 32 14033 2273)
 (string-bytes 1 396649)
 (vectors 16 10266)
 (vector-slots 8 156275 9779)
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 (intervals 56 253 0)
 (buffers 976 10))

bug#70522: 29.2.50; eglot-shutdown sends SIGKILL before LSP server can exit gracefully

[Eli Zaretskii]

> Cc: app-emacs-dev <app-emacs-dev@janestreet.com>
> From: Aaron Zeng <azeng@janestreet.com>
> Date: Mon, 22 Apr 2024 17:39:32 -0400
> 
> 1. emacs -Q
> 2. M-x eglot in some file (I tested with OCaml-LSP and another language
> server, the latter is internal to my site)
> 3. M-x eglot-shutdown
> 
> This messages:
> 
> [jsonrpc] Server exited with status 9
> 
> Which is a little confusing.  One would expect the language server to
> exit with status 0, and not end up with "killed" in the events buffer,
> if the server exited successfully upon user request.
> 
> I installed the following patch locally at my site, and it seems to fix
> the issue (now the server exits with status 0).  I think it also better
> matches the docstring of `jsonrpc-shutdown'.
> 
> diff --git a/jsonrpc.el b/jsonrpc.el
> --- a/jsonrpc.el
> +++ b/jsonrpc.el
> @@ -598,8 +598,8 @@ With optional CLEANUP, kill any associat
>         while (not (process-get proc 'jsonrpc-sentinel-cleanup-started))
>         unless (zerop i) do
>         (jsonrpc--warn "Sentinel for %s still hasn't run, deleting it!" proc)
> +       (delete-process proc)
>         do
> -       (delete-process proc)
>         (accept-process-output nil 0.1))
>      (when cleanup
>        (kill-buffer (process-buffer (jsonrpc--process conn)))

Thanks.

Daniel, could you please look into this issue?

bug#70522: 29.2.50; eglot-shutdown sends SIGKILL before LSP server can exit gracefully

[Daniel Pettersson]

[-- Attachment #1: Type: text/plain, Size: 736 bytes --]

Eli Zaretskii <eliz@gnu.org> writes:

> Daniel, could you please look into this issue?

Change makes sense, the only "risk" is that jsonrpc users populate the
*Warnings* buffer with an warning that they should take action upon and
solve, so I think this is an no brainer.

Nice job!

I have done some adhock testing of eglot and dape. Was not able to
produce the warning, which means that eglot and dape are using the
function as intended (at least when interacting with the servers I
tested with).

When the function is touched I would like to do some small additions to
the documentation of the function, would be nice if the docstring
mention the undocumented behavior and an small comment to make it a bit
easier to follow along. 


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: documentation changes --]
[-- Type: text/x-patch, Size: 1024 bytes --]

diff --git a/lisp/jsonrpc.el b/lisp/jsonrpc.el
index 5037d8c5b2b..111e58cefe2 100644
--- a/lisp/jsonrpc.el
+++ b/lisp/jsonrpc.el
@@ -591,15 +591,18 @@ jsonrpc-running-p
 (cl-defmethod jsonrpc-shutdown ((conn jsonrpc-process-connection)
                                 &optional cleanup)
   "Wait for JSONRPC connection CONN to shutdown.
-With optional CLEANUP, kill any associated buffers."
+With optional CLEANUP, kill any associated buffers.
+If CONN is not shutdown within an reasonable amount of time, warn
+and delete process."
   (unwind-protect
       (cl-loop
        with proc = (jsonrpc--process conn) for i from 0
        while (not (process-get proc 'jsonrpc-sentinel-cleanup-started))
        unless (zerop i) do
        (jsonrpc--warn "Sentinel for %s still hasn't run, deleting it!" proc)
-       do
        (delete-process proc)
+       do
+       ;; Let sentinel have a chance to run
        (accept-process-output nil 0.1))
     (when cleanup
       (kill-buffer (process-buffer (jsonrpc--process conn)))

[-- Attachment #3: Type: text/plain, Size: 10 bytes --]


/ Daniel

bug#70522: 29.2.50; eglot-shutdown sends SIGKILL before LSP server can exit gracefully

[Eli Zaretskii]

> From: Daniel Pettersson <daniel@dpettersson.net>
> Cc: Aaron Zeng <azeng@janestreet.com>,  70522@debbugs.gnu.org,
>   app-emacs-dev@janestreet.com,  João Távora
>  <joaotavora@gmail.com>
> Date: Tue, 23 Apr 2024 18:58:06 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Daniel, could you please look into this issue?
> 
> Change makes sense, the only "risk" is that jsonrpc users populate the
> *Warnings* buffer with an warning that they should take action upon and
> solve, so I think this is an no brainer.
> 
> Nice job!
> 
> I have done some adhock testing of eglot and dape. Was not able to
> produce the warning, which means that eglot and dape are using the
> function as intended (at least when interacting with the servers I
> tested with).
> 
> When the function is touched I would like to do some small additions to
> the documentation of the function, would be nice if the docstring
> mention the undocumented behavior and an small comment to make it a bit
> easier to follow along. 

Thanks, installed on master, and closing the bug.