await & asleep

Scott Long scottl at
Wed Jul 27 16:35:28 GMT 2005

Daniel Eischen wrote:
> On Wed, 27 Jul 2005, Norbert Koch wrote:
>>>>The functions await() and asleep() in kern_synch.c
>>>>are marked as EXPERIMENTAL/UNTESTED.
>>>>Is this comment still valid? Does anyone have used
>>>>those functions successfully? Should I better not
>>>>use them in my device driver code for RELENG_4?
>>>>How do I correctly cancel a request (as I should do
>>>>according to the man page): "asleep (NULL, 0, NULL, 0)"?
>>>The await family was removed in 5.x and beyond, so trying to
>>>use them in 4.x will make your driver very unportable.  There
>>>are better ways than await to handle delayed events.
> Well, there's tsleep() and wakeup() for FreeBSD < 5.0.  Other
> than that, what else can you do?  These functions are deprecated
> in 5.x and 6.x in favor of condvar(9) and mutex(9), so you should
> really use those instead of tsleep() and wakeup().
> It seems the kernel in -current is still using tsleep() and
> wakeup() in some places.  I thought we got rid of all these...

????  Can you explain why tsleep and wakeup should no longer be
used?  I wasn't aware that they were formally deprecated.


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