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 <1ba93b51-da78-8c37-f714-e354fab32b5a@qs.co.nz>
In-Reply-To: <1ba93b51-da78-8c37-f714-e354fab32b5a@qs.co.nz>
From: Silas McCroskey <inkswinc@gmail.com>
Date: Wed, 12 Feb 2020 16:21:04 -0800
Message-ID: <CAHjwAuxsW9J2faquv2djaedf9fT9OgFXc6FRfBH29vQBaRm6fA@mail.gmail.com>
Subject: Re: [9front] Mixfs: potential bug?
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X-Bullshit: rails cloud 

http://doc.cat-v.org/plan_9/4th_edition/papers/comp

The "Extensions" section goes over this compiler extension:

structs-within-structs declared without a name allow their members to
be accessed directly, so
qlock(s)
does the same thing as
qlock(s->Lock)
since the "locked" member used by qlock is accessible to both.

This is a compiler extension rather than pointer tricks, so it does
not depend on ordering within the struct (as displayed in the
Extensions section itself, where Lock is the last member of the outer
struct).

- sam-d

On Wed, Feb 12, 2020 at 4:07 PM Trevor Higgins
<plan9fullfrontal@qs.co.nz> wrote:
>
> Looking at the code for audio/mixfs (mixfs.c)
>
> The code uses qlock(s) where s is: struct Stream*.
>
> In the structure ,shouldn't the QLock member of the structure be the
> first member in the structure?
> If not so, then why does it not matter?
>
> Thanks.
>
> --
>