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Re: Typecasting Pointers on a 64 bit System

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On 11/14/2011 04:15 PM, Ian Collins wrote:
> On 11/15/11 08:48 AM, James Kuyper wrote:
>> On 11/14/2011 02:28 PM, Ian Collins wrote:
>>> On 11/15/11 08:10 AM, William Ahern wrote:
>> ....
>>>> Pass-by-reference and threads aren't
>>>> known to play well. IMHO the OP had sensible intuition to pass the
>>>> descriptor by value. It may not be pretty in C, but neither is threaded
>>>> programming.
>>>
>>> As long as the address is still valid when a thread dereferences it,
>>> what's the problem?
>>
>> The possibility that the address might NOT still be valid at the time of
>> use. This has already been pointed out, and is explicitly considered
>> (but somehow ignored as unimportant) in your own response.
> 
> I had assumed a competent programmer would be aware of the issue.  I had 
> further assumed a programmer writing threaded applications to be 
> competent.  If either of those assumptions are untrue, the programmer's 
> foray into threaded programming will be brief and painful.

That second assumption seems unjustified to me, and I would say the same
about your assumption that the painful foray will be short. I've seen an
incompetent programmer spend several long painful months trying to deal
with problems caused by a much simpler misunderstanding (and I'm not
talking about Bill Cunningham). If the particular programmer I'm
thinking of had bothered spending 5 minutes asking me questions, that
waste could have been avoided, but I had no idea that he was wasting his
time that way. He was under orders to ask me questions if he ran into
trouble, but never did so - he never gave a coherent explanation of why
he didn't.

However, neither assumption seems to be relevant here. As long as this
is an issue that the programmer needs to be aware of, the need for such
awareness IS the problem that you're asking about.

>> A relevant response would give reasons justifying your treatment of that
>> possibility as unimportant.
> 
> Where did I say it was unimportant?

You asked "what's the problem?" in the same sentence where you conceded
both the existence and relevance of the problem you were asking about.
The simplest explanation I could come up with for such a seemingly
bizarre combination was that you considered the problem you mentioned to
be unimportant, and were challenging people to come up with a more
important one, with the expectation that they would not succeed. I'll
concede that there might be other reasons for writing a sentence with
that structure, but the variety of those other possible reasons is
great, and the probability that any particular one of them is justified
is small. It would improve my understanding of the point of your message
if you could explain your reason for posting such a question.

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Typecasting Pointers on a 64 bit System Quentin Pope <qp19433@hotmail.NOSPAM.com> - 2011-11-10 20:21 +0000
  Re: Typecasting Pointers on a 64 bit System Lauri Alanko <la@iki.fi> - 2011-11-10 20:29 +0000
    Re: Typecasting Pointers on a 64 bit System Kaz Kylheku <kaz@kylheku.com> - 2011-11-10 20:51 +0000
      Re: Typecasting Pointers on a 64 bit System Kaz Kylheku <kaz@kylheku.com> - 2011-11-10 20:58 +0000
      Re: Typecasting Pointers on a 64 bit System James Kuyper <jameskuyper@verizon.net> - 2011-11-10 16:08 -0500
        Re: Typecasting Pointers on a 64 bit System Kaz Kylheku <kaz@kylheku.com> - 2011-11-10 21:35 +0000
          Re: Typecasting Pointers on a 64 bit System James Kuyper <jameskuyper@verizon.net> - 2011-11-10 17:18 -0500
            Re: Typecasting Pointers on a 64 bit System Kaz Kylheku <kaz@kylheku.com> - 2011-11-10 23:14 +0000
              Re: Typecasting Pointers on a 64 bit System Richard Damon <news.x.richarddamon@xoxy.net> - 2011-11-10 19:36 -0500
  Re: Typecasting Pointers on a 64 bit System Ben Pfaff <blp@cs.stanford.edu> - 2011-11-10 12:32 -0800
    Re: Typecasting Pointers on a 64 bit System James Kuyper <jameskuyper@verizon.net> - 2011-11-10 15:44 -0500
    Re: Typecasting Pointers on a 64 bit System Keith Thompson <kst-u@mib.org> - 2011-11-10 12:58 -0800
      Re: Typecasting Pointers on a 64 bit System blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-11-17 15:53 +0000
  Re: Typecasting Pointers on a 64 bit System Kaz Kylheku <kaz@kylheku.com> - 2011-11-10 20:45 +0000
    Re: Typecasting Pointers on a 64 bit System Kaz Kylheku <kaz@kylheku.com> - 2011-11-10 21:00 +0000
  Re: Typecasting Pointers on a 64 bit System Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-11-10 15:14 -0700
  Re: Typecasting Pointers on a 64 bit System Ian Collins <ian-news@hotmail.com> - 2011-11-11 11:22 +1300
    Re: Typecasting Pointers on a 64 bit System William Ahern <william@wilbur.25thandClement.com> - 2011-11-14 11:10 -0800
      Re: Typecasting Pointers on a 64 bit System Ian Collins <ian-news@hotmail.com> - 2011-11-15 08:28 +1300
        Re: Typecasting Pointers on a 64 bit System James Kuyper <jameskuyper@verizon.net> - 2011-11-14 14:48 -0500
          Re: Typecasting Pointers on a 64 bit System Ian Collins <ian-news@hotmail.com> - 2011-11-15 10:15 +1300
            Re: Typecasting Pointers on a 64 bit System jacob navia <jacob@spamsink.net> - 2011-11-14 22:18 +0100
              Re: Typecasting Pointers on a 64 bit System Ian Collins <ian-news@hotmail.com> - 2011-11-15 10:26 +1300
            Re: Typecasting Pointers on a 64 bit System James Kuyper <jameskuyper@verizon.net> - 2011-11-14 16:46 -0500
              Re: Typecasting Pointers on a 64 bit System Ian Collins <ian-news@hotmail.com> - 2011-11-15 10:58 +1300
                Re: Typecasting Pointers on a 64 bit System James Kuyper <jameskuyper@verizon.net> - 2011-11-14 17:15 -0500
                Re: Typecasting Pointers on a 64 bit System blp@cs.stanford.edu (Ben Pfaff) - 2011-11-14 14:18 -0800
                Re: Typecasting Pointers on a 64 bit System Ian Collins <ian-news@hotmail.com> - 2011-11-15 11:29 +1300
                Re: Typecasting Pointers on a 64 bit System James Kuyper <jameskuyper@verizon.net> - 2011-11-14 18:14 -0500
                Re: Typecasting Pointers on a 64 bit System Seebs <usenet-nospam@seebs.net> - 2011-11-14 23:01 +0000
                Re: Typecasting Pointers on a 64 bit System Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-11-16 10:39 +0200
                Re: Typecasting Pointers on a 64 bit System Seebs <usenet-nospam@seebs.net> - 2011-11-16 20:18 +0000
                Re: Typecasting Pointers on a 64 bit System Fritz Wuehler <fritz@spamexpire-201111.rodent.frell.theremailer.net> - 2011-11-17 02:54 +0100
                Re: Typecasting Pointers on a 64 bit System pete <pfiland@mindspring.com> - 2011-11-16 21:29 -0500
                Re: Typecasting Pointers on a 64 bit System Seebs <usenet-nospam@seebs.net> - 2011-11-17 02:31 +0000
                Re: Typecasting Pointers on a 64 bit System Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-11-18 14:31 +0200
                Re: Typecasting Pointers on a 64 bit System Kaz Kylheku <kaz@kylheku.com> - 2011-11-17 02:44 +0000
                Re: Typecasting Pointers on a 64 bit System Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-11-16 21:33 -0700
                Re: Typecasting Pointers on a 64 bit System "io_x" <a@b.c.invalid> - 2011-11-17 04:01 +0100
                Re: Typecasting Pointers on a 64 bit System blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-11-17 15:46 +0000
                Re: Typecasting Pointers on a 64 bit System Seebs <usenet-nospam@seebs.net> - 2011-11-17 18:48 +0000
                Re: Typecasting Pointers on a 64 bit System blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-11-18 14:48 +0000
                Re: Typecasting Pointers on a 64 bit System Ian Collins <ian-news@hotmail.com> - 2011-11-15 14:37 +1300
                Re: Typecasting Pointers on a 64 bit System Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-11-16 10:23 +0200
                Re: Typecasting Pointers on a 64 bit System James Kuyper <jameskuyper@verizon.net> - 2011-11-16 06:53 -0500
                Re: Typecasting Pointers on a 64 bit System James Kuyper <jameskuyper@verizon.net> - 2011-11-16 11:15 -0500
                Re: Typecasting Pointers on a 64 bit System Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-11-16 17:08 +0000
                Re: Typecasting Pointers on a 64 bit System Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-11-18 15:09 +0200
                Re: Typecasting Pointers on a 64 bit System Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-11-18 14:24 +0200
                Re: Typecasting Pointers on a 64 bit System James Kuyper <jameskuyper@verizon.net> - 2011-11-18 10:08 -0500
                Re: Typecasting Pointers on a 64 bit System Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-11-18 17:52 +0200
            Re: Typecasting Pointers on a 64 bit System Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-11-14 15:45 -0700
  Re: Typecasting Pointers on a 64 bit System "christian.bau" <christian.bau@cbau.wanadoo.co.uk> - 2011-11-10 15:19 -0800
    Re: Typecasting Pointers on a 64 bit System Kaz Kylheku <kaz@kylheku.com> - 2011-11-10 23:41 +0000
      Re: Typecasting Pointers on a 64 bit System Keith Thompson <kst-u@mib.org> - 2011-11-10 20:48 -0800
      Re: Typecasting Pointers on a 64 bit System "christian.bau" <christian.bau@cbau.wanadoo.co.uk> - 2011-11-14 03:39 -0800
        Re: Typecasting Pointers on a 64 bit System Lauri Alanko <la@iki.fi> - 2011-11-14 13:08 +0000
          Re: Typecasting Pointers on a 64 bit System James Kuyper <jameskuyper@verizon.net> - 2011-11-14 09:21 -0500
        Re: Typecasting Pointers on a 64 bit System Keith Thompson <kst-u@mib.org> - 2011-11-14 12:54 -0800

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