[debbugs-tracker] bug#18396: closed (24.3.1; On windows, process-send-string can freeze Emacs)

[GNU bug Tracking System]

Your message dated Sat, 1 Nov 2014 16:37:57 +0100
with message-id <address@hidden>
and subject line No further updates
has caused the debbugs.gnu.org bug report #18396,
regarding 24.3.1; On windows, process-send-string can freeze Emacs
to be marked as done.

(If you believe you have received this mail in error, please contact
address@hidden)


-- 
18396: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=18396
GNU Bug Tracking System
Contact address@hidden with problems
> --- Begin Message ---
>
>
>
> Subject: 
>
> 24.3.1; On windows, process-send-string can freeze Emacs
>
>
>
>
> Date: 
>
> Wed, 03 Sep 2014 18:58:11 +0200
>
>
>
>
> Hi!
> A user's bug report[1] on my project Elpy has revealed an apparent bug
> in Emacs.
>
> [1] https://github.com/jorgenschaefer/elpy/issues/212#issuecomment-54015294
>
> Elpy starts a Python process using `start-process' with
> `process-connection-type' set to nil, `default-directory' set to "/",
> and an unchanged coding system. It then proceeds to talk with the
> subprocess using a JSON-RPC-based protocol.
>
> After some interactions, this freezes an Emacs under Windows. C-g does
> not lead to any reaction. Killing the subprocess unfreezes Emacs. The
> freeze happens more reliably the larger the data sent is.
>
> I asked the user to change the function that does the process
> communication to the following:
>
> (defun elpy-rpc--call (method-name params success error)
>   (let ((promise (elpy-promise success error)))
>     (with-current-buffer (elpy-rpc--get-rpc-buffer)
>       (setq elpy-rpc--call-id (1+ elpy-rpc--call-id))
>       (elpy-rpc--register-callback elpy-rpc--call-id promise)
>       (let ((proc (get-buffer-process (current-buffer)))
>             (text (json-encode `((id . ,elpy-rpc--call-id)
>                                  (method . ,method-name)
>                                  (params . ,params)))))
>         (message "Sending %s bytes ..." (length text))
>         (process-send-string proc text)
>         (process-send-string proc "\n")
>         (message "Sending %s bytes ... done." (length text))))
>     promise))
>
> This lead to the following output in *Messages*:
>
> Sending 978 bytes ... done.
> Sending 958 bytes ... done.
> Sending 959 bytes ... done.
> Sending 960 bytes ... done.
> Sending 961 bytes ... done.
> Sending 962 bytes ... done.
> Sending 958 bytes ...
>
> At this point, Emacs froze. Apparently, it did so in the middle of one
> of the two `process-send-string' calls. Killing the subprocess caused
> the following output:
>
> eldoc error: (file-error writing to process invalid argument elpy-rpc 
> [project:~/ python:pythonw])
>
> Elpy indeed is called from eldoc, and "elpy-rpc [project:~/
> python:pythonw]" is the process name.
>
> I'm a bit at a loss now as to how to continue debugging this. I do not
> use Windows myself. I'm sure the user is willing to do some debugging
> and reproduction cases there, but I wouldn't even know how to start or
> what to ask them to do (Windows doesn't have strace, does it?).
>
> Jorgen
>
>
>
> --- End Message ---
> --- Begin Message ---
>
>
>
> Subject: 
>
> No further updates
>
>
>
>
> Date: 
>
> Sat, 1 Nov 2014 16:37:57 +0100
>
>
>
>
> The user did not provide any further feedback after three weeks.
> Closing this bug report, assuming the problem was fixed.
>
> Thank you!
>
>
> --- End Message ---