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* About `purify-flag'
@ 2013-02-27 12:18 Xue Fuqiao
  2013-02-27 14:11 ` Stefan Monnier
  0 siblings, 1 reply; 3+ messages in thread
From: Xue Fuqiao @ 2013-02-27 12:18 UTC (permalink / raw)
  To: emacs-devel

In (info "(elisp) Pure Storage"):

 -- Variable: purify-flag
[...]
     This flag is `t' while loading all of the basic functions for
     building Emacs initially (allowing those functions to be shareable
     and non-collectible).

What does "shareable and non-collectible" mean here?

-- 
Best regards, Xue Fuqiao.
http://www.emacswiki.org/emacs/XueFuqiao



^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: About `purify-flag'
  2013-02-27 12:18 About `purify-flag' Xue Fuqiao
@ 2013-02-27 14:11 ` Stefan Monnier
  2013-02-27 14:23   ` Xue Fuqiao
  0 siblings, 1 reply; 3+ messages in thread
From: Stefan Monnier @ 2013-02-27 14:11 UTC (permalink / raw)
  To: Xue Fuqiao; +Cc: emacs-devel

> In (info "(elisp) Pure Storage"):
>  -- Variable: purify-flag
> [...]
>      This flag is `t' while loading all of the basic functions for
>      building Emacs initially (allowing those functions to be shareable
>      and non-collectible).

> What does "shareable and non-collectible" mean here?

Basically, the idea is that the "pure space" will never be written to,
so the OS can use the same VM memory pages for the pure space of several
Emacs processes.  I.e. the "pure space" can be shared among
Emacs processes.

Non-collectible means that they will never be garbage collected (the GC
never even looks at them).


        Stefan



^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: About `purify-flag'
  2013-02-27 14:11 ` Stefan Monnier
@ 2013-02-27 14:23   ` Xue Fuqiao
  0 siblings, 0 replies; 3+ messages in thread
From: Xue Fuqiao @ 2013-02-27 14:23 UTC (permalink / raw)
  To: Stefan Monnier; +Cc: emacs-devel

On Wed, 27 Feb 2013 09:11:08 -0500
Stefan Monnier <monnier@iro.umontreal.ca> wrote:

> > In (info "(elisp) Pure Storage"):
> >  -- Variable: purify-flag
> > [...]
> >      This flag is `t' while loading all of the basic functions for
> >      building Emacs initially (allowing those functions to be shareable
> >      and non-collectible).
> > What does "shareable and non-collectible" mean here?

> Basically, the idea is that the "pure space" will never be written to,
> so the OS can use the same VM memory pages for the pure space of several
> Emacs processes.  I.e. the "pure space" can be shared among
> Emacs processes.
> Non-collectible means that they will never be garbage collected (the GC
> never even looks at them).

Ah, I see, thanks.

>         Stefan

-- 
Best regards, Xue Fuqiao.
http://www.emacswiki.org/emacs/XueFuqiao



^ permalink raw reply	[flat|nested] 3+ messages in thread

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2013-02-27 12:18 About `purify-flag' Xue Fuqiao
2013-02-27 14:11 ` Stefan Monnier
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