Run function in background.

Run function in background.

[Oleksandr Gavenko]

I need use auto update for GNU Global:

   $ global -u

There described how this done:

   http://www.emacswiki.org/emacs/GnuGlobal

But this:

   (defun gtags-root-dir ()
     "Returns GTAGS root directory or nil if doesn't exist."
     (with-temp-buffer
       (if (zerop (call-process "global" nil t nil "-pr"))
           (buffer-substring (point-min) (1- (point-max)))
         nil)))

   (defun gtags-update ()
     "Make GTAGS incremental update"
     (call-process "global" nil nil nil "-u"))

   (defun gtags-update-hook ()
     (when (gtags-root-dir)
       (gtags-update)))

   (add-hook 'after-save-hook #'gtags-update-hook)

cause freezing Emacs for about 2-3 sec. How run this in background
so I can still complete Emacs editing?

Write sh script and start-process-shell-command for asynchronous job?

Re: Run function in background.

[Oleksandr Gavenko]

On 01.06.2011 13:19, Oleksandr Gavenko wrote:
> I need use auto update for GNU Global:
>
> $ global -u
>
> There described how this done:
>
> http://www.emacswiki.org/emacs/GnuGlobal
>
> But this:
>
> (defun gtags-root-dir ()
> "Returns GTAGS root directory or nil if doesn't exist."
> (with-temp-buffer
> (if (zerop (call-process "global" nil t nil "-pr"))
> (buffer-substring (point-min) (1- (point-max)))
> nil)))
>
> (defun gtags-update ()
> "Make GTAGS incremental update"
> (call-process "global" nil nil nil "-u"))
>
> (defun gtags-update-hook ()
> (when (gtags-root-dir)
> (gtags-update)))
>
> (add-hook 'after-save-hook #'gtags-update-hook)
>
> cause freezing Emacs for about 2-3 sec. How run this in background
> so I can still complete Emacs editing?
>
> Write sh script and start-process-shell-command for asynchronous job?
>
I write:

(defun gtags-update ()
   (start-process-shell-command "/bin/sh" nil "if global -pr; then 
global -u; fi")
   )

(add-hook 'after-save-hook #'gtags-update)
; (remove-hook 'after-save-hook #'gtags-update)

Seems this help but how in general case when I need run elisp code
in background (synchronization issue is not essential).

Re: Run function in background.

[Deniz Dogan]

On 2011-06-01 12:40, Oleksandr Gavenko wrote:
> On 01.06.2011 13:19, Oleksandr Gavenko wrote:
>> I need use auto update for GNU Global:
>>
>> $ global -u
>>
>> There described how this done:
>>
>> http://www.emacswiki.org/emacs/GnuGlobal
>>
>> But this:
>>
>> (defun gtags-root-dir ()
>> "Returns GTAGS root directory or nil if doesn't exist."
>> (with-temp-buffer
>> (if (zerop (call-process "global" nil t nil "-pr"))
>> (buffer-substring (point-min) (1- (point-max)))
>> nil)))
>>
>> (defun gtags-update ()
>> "Make GTAGS incremental update"
>> (call-process "global" nil nil nil "-u"))
>>
>> (defun gtags-update-hook ()
>> (when (gtags-root-dir)
>> (gtags-update)))
>>
>> (add-hook 'after-save-hook #'gtags-update-hook)
>>
>> cause freezing Emacs for about 2-3 sec. How run this in background
>> so I can still complete Emacs editing?
>>
>> Write sh script and start-process-shell-command for asynchronous job?
>>
> I write:
>
> (defun gtags-update ()
>   (start-process-shell-command "/bin/sh" nil "if global -pr; then 
> global -u; fi")
>   )
>
> (add-hook 'after-save-hook #'gtags-update)
> ; (remove-hook 'after-save-hook #'gtags-update)
>
> Seems this help but how in general case when I need run elisp code
> in background (synchronization issue is not essential).
>

Read: (info "(elisp) Asynchronous Processes")

I haven't really tested this, but I think something like this should work:

(defun gtags-process-sentinel (process event)
   (when (string= event "finished\n"))
     (kill-buffer (process-buffer process))))

(defun gtags-update ()
   "Make GTAGS incremental update."
   (let ((gtags-process (start-process "Global" "*Global output*" "dir")))
     (set-process-sentinel gtags-process 'gtags-process-sentinel)))

/Deniz