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	<dbb7239e8c352e8db20ca68c849e381a@terzarima.net>
Date: Fri, 29 Oct 2010 19:58:27 +1100
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From: Bruce Ellis <bruce.ellis@gmail.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
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Subject: Re: [9fans] A little more ado about async Tclunk
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i don't believe that is possible in my implementation. will check.

brucee

On Fri, Oct 29, 2010 at 8:01 PM, Charles Forsyth <forsyth@terzarima.net> wr=
ote:
>>What you are saying is that the problem could be something like:
>
>>-> Tclunk
>>(do not wait for response)
>>-> Topen (the file is exclusive)
>
> no, because what actually happens is closer to
> =A0 =A0 =A0 =A0A: Topen
> =A0 =A0 =A0 =A0...
> =A0 =A0 =A0 =A0queue request to *another process* to send Tclunk
> =A0 =A0 =A0 =A0...
> =A0 =A0 =A0 =A0A: Topen
>
> leading to either case 1
> =A0 =A0 =A0 =A0A: Topen
> =A0 =A0 =A0 =A0B: Tclunk
> =A0 =A0 =A0 =A0A: Topen
>
> or case 2
> =A0 =A0 =A0 =A0A: Topen
> =A0 =A0 =A0 =A0A: Topen
> =A0 =A0 =A0 =A0B: Tclunk
>
> depending on the scheduling of the two processes A and B
>
> introducing that other process introduces a new race, that simply did not=
 exist before, because
> that other process didn't exist before. you always got case 1.
>
> and indeed, with the test i ran on the modified system usually it gets ca=
se 1
> because of timing, but eventually a case 2 shows up and the second open f=
ails.
>
>