From: "alin.s" <alinsoar@voila.fr>
To: Emacs-devel@gnu.org
Subject: Re: Watchpoints for emacs lisp.
Date: Sat, 15 May 2010 06:06:11 -0700 (PDT) [thread overview]
Message-ID: <28568286.post@talk.nabble.com> (raw)
In-Reply-To: <m28w7l49oj.fsf@gmail.com>
Helmut Eller-2 wrote:
>
> * alin.s [2010-05-15 13:56+0200] writes:
>
>> Suppose that we have the symbol
>>
>> X = ( 3 . ( 4 . some_cons ) )
>>
>> and
>>
>> Y = some_cons.
>>
>> Suppose that I have set the watch bit on X, but not on Y.
>>
>> In these conditions, modifying Y will not stop into the watchpoint of X.
>>
>> That means that setting a watchpoint on a symbol X, should be a recursive
>> operation, id est, setting recursively a :watch: field for all the
>> cons-cells, symbols, strings, etc, which are present in X.
>>
>> That means that we need to insert a watch field in all lisp data
>> strucutures, not only n symbol, etc
>>
>> Is that algorithm right ?
>
> Can't you use the MMU for this? Protect the page(s) the watched object
> is on; in the SIGSEGV handler set the QUIT flag and store some info in a
> global place so that the debugger can figure out which object triggered
> the watchpoint.
>
> Helmut
>
>
>
>
Probably it works. But GC would call the handler lots of times, and this
might be inconvenient.
I can set the flag :watch to 1 for that objects, and when the handler is
called, it passed the address of the object that generated the segv. it has
just to check the :watch flag first and decides so whether the debugger is
called.
Depending on the data segment, the handler knows whether a string, cons
cell, symbol , etc was modified.
Emacs is possible to run extremely slow with such a solution.
What the other think about it?
--
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next prev parent reply other threads:[~2010-05-15 13:06 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-10 16:28 Watchpoints for emacs lisp alin.s
2010-05-11 11:59 ` Richard Stallman
2010-05-11 12:54 ` alin.s
2010-05-11 13:43 ` Ken Raeburn
2010-05-11 14:10 ` Stefan Monnier
2010-05-11 15:37 ` alin.s
2010-05-15 11:16 ` alin.s
2010-05-15 11:24 ` alin.s
2010-05-15 11:44 ` alin.s
2010-05-15 11:56 ` alin.s
2010-05-15 12:43 ` Helmut Eller
2010-05-15 13:06 ` alin.s [this message]
2010-05-15 17:48 ` Stefan Monnier
2010-05-16 13:07 ` alin.s
2010-05-16 13:09 ` Lennart Borgman
2010-05-16 13:42 ` alin.s
2010-05-16 16:28 ` Lennart Borgman
2010-05-16 19:46 ` alin.s
2010-05-16 20:42 ` Stefan Monnier
2010-05-16 21:10 ` alin.s
2010-05-17 13:24 ` Stefan Monnier
2010-05-15 12:15 ` Andreas Schwab
2010-05-15 17:43 ` Stefan Monnier
2010-05-16 13:05 ` alin.s
2010-05-16 15:03 ` Chad Brown
2010-05-16 19:44 ` alin.s
2010-05-16 21:31 ` alin.s
2010-05-16 22:38 ` alin.s
2010-05-16 23:47 ` Lennart Borgman
2010-05-16 23:56 ` alin.s
2010-05-17 15:52 ` alin.s
2010-05-17 16:09 ` Lennart Borgman
2010-05-17 16:40 ` alin.s
2010-05-17 17:00 ` Lennart Borgman
2010-05-17 17:29 ` alin.s
2010-05-17 18:39 ` alin.s
2010-05-17 18:41 ` alin.s
2010-05-17 20:22 ` alin.s
2010-05-17 18:59 ` Eli Zaretskii
2010-05-17 19:04 ` Lennart Borgman
2010-05-17 19:00 ` Chad Brown
2010-05-18 8:22 ` Adrian Robert
2010-05-18 19:46 ` Chad Brown
2010-05-18 22:38 ` Andreas Schwab
2010-05-24 14:36 ` alin.s
2010-05-24 14:46 ` Ken Raeburn
2010-05-26 8:27 ` alin.s
2010-05-24 15:12 ` alin.s
2010-05-24 17:36 ` Jan Djärv
2010-05-24 17:47 ` Stefan Monnier
2010-05-26 10:38 ` alin.s
2010-05-26 13:46 ` Stefan Monnier
2010-05-26 16:49 ` alin.s
2010-05-27 14:08 ` alin.s
2010-05-27 22:05 ` Andreas Schwab
2010-05-28 20:09 ` alin.s
2010-07-06 12:26 ` alin.s
2010-08-10 11:00 ` Stefan Monnier
2010-05-29 4:25 ` tomas
2010-05-19 4:30 ` Ken Raeburn
2010-05-19 6:20 ` Adrian Robert
2010-05-17 19:56 ` Andreas Schwab
-- strict thread matches above, loose matches on Subject: below --
2010-05-11 13:54 A. Soare
2010-05-12 1:53 ` Ken Raeburn
2010-05-12 2:04 ` Stephen J. Turnbull
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