Re: mutex question

[Jason Thorpe <thorpej%me.com@localhost>]

> On Jul 6, 2018, at 4:48 PM, Phil Nelson <phil%NetBSD.org@localhost> wrote:
> 
> Hello,
> 
>    The FreeBSD 802.11 code is using a call to mtx_sleep().  The define is:
> 
> #define mtx_sleep(chan, mtx, pri, wmesg, timo)                          \
>        _sleep((chan), &(mtx)->lock_object, (pri), (wmesg),             \
>            tick_sbt * (timo), 0, C_HARDCLOCK)

In NetBSD, you could use mtsleep(), but the best way to do this is with kcondvar_t's.  Each "wait channel" really become a discrete condition variable that is initialized separately, and you'd use cv_wait() for non-timeout sleeps and cv_timedwait() for timeout sleeps.  The "pri" argument is unneeded because the priority comes from the LWP that's sleeping, and the condvars do priority inheritance / boosting via turnstiles as needed.


> 
> 
> Just in case I can save time by getting an answer by asking before digging deep ...
> does anyone know what I should translate this to in NetBSD?   Our mutex routines
> do not appear to have any similar call.
> 
> --Phil

-- thorpej