Date: Sun, 06 Jul 1997 21:39:44 +0800 From: Peter Wemm <peter@spinner.dialix.com.au> To: =?KOI8-R?B?4c7E0sXKIP7F0s7P1w==?= <ache@nagual.pp.ru> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: sleep (was Re: Application os version compatibility?) Message-ID: <199707061339.VAA23239@spinner.dialix.com.au> In-Reply-To: Your message of "Sun, 06 Jul 1997 16:56:48 %2B0400." <Pine.BSF.3.96.970706165328.498A-100000@nagual.pp.ru>
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=?KOI8-R?B?4c7E0sXKIP7F0s7P1w==?= wrote:
> On 6 Jul 1997, Peter Wemm wrote:
>
> > Take programs using sleep() in 3.0. If you statically link a program under
> > 3.0, sleep() makes a call to either the nanosleep() or signanosleep() sysca
ll
> > (depending on the age of libc). If you try and run this program under 2.2
> > or 2.1, it'll get a SIGSYS and die when it tries to sleep. /bin/sleep is
> > the primary offender. On the other hand, a dynamically linked /bin/sleep
> > works on both systems because both branches provide their own implementatio
n
> > of sleep(3).
>
> Peter, why not remove special handling of ignored ALARMs in sleep() code?
> It is not compatible with world sleep() implementations and gives no
> advantages, but can cause potential incompatibility in future. I remember
> you agree with this statement too.
I'm not quite sure I follow you there.. I once talked about how using
plain nanosleep() as a replacement for sleep() is incompatable with some
things that depeneded on the SIGALRM eating semantics, and that one way
around it was to build make a merged sigprocmask/nanosleep syscall which
is basically "wait for specific signals or timeout, whichever comes first"
- this is what is in the tree at present. I also talked about using
another syscall to directly implement the sleep(3)/usleep(3) semantics,
perhaps called nsleep(), which has the same args as nanosleep() (ie:
requested and returned times). What were you thinking of?
> --
> Andrey A. Chernov
> <ache@null.net>
> http://www.nagual.pp.ru/~ache/
Cheers,
-Peter
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