Proposal: a revoke() system call

[Poul-Henning Kamp]

In message <20080707162733.V63144 at fledge.watson.org>, Robert Watson writes:

>>> achieve something of the same end by opening /dev/null and then dup2()'ing 
>>> to the file descriptor you want to revoke, perhaps?  Right now there's a 
>>> known
>>
>> That's a great idea. I haven't thought about it. It should do everything.
>
>Right, and possibly this means that no additional kernel support is required 
>-- we just make it a libc or libutil interface.

I can't see how that could possibly work...

If you do a dup2(), the original fd is closed, and that still does not
release all threads that may be sleeing on it in device drivers.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.