Messages in this thread | | | From | Christoph Rohland <> | Subject | Re: [PATCH] 'select' failure or signal should not update timeout | Date | 21 Jul 2002 18:00:35 +0200 |
| |
Hi Linus,
On Sat, 20 Jul 2002, Linus Torvalds wrote: > The thing is, nobody should really ever use timeouts, because the > notion of "I want to sleep X seconds" is simply not _useful_ if the > process also just got delayed by a page-out event as it said so. > What does "X seconds" mean at that point? It's ambiguous - and the > kernel will (quite naturally) just always assume that it is "X > seconds from when the kernel got notified". > > A _useful_ interface would be to say "I want to sleep to at most > time X" or "to at least time X". Those are unambiguous things to > say, and are not open to interpretation.
Yes, so everybody really using select assumes it's _at least_ X seconds... So where's the problem? I always know it's at least in a multiprocess environment. (At least as long as I do not want to fiddle with scheduling and priorities)
> The Linux behaviour of modifying the timeout is a half-assed try for > restartability, but the problem is that (a) nobody else does that or > expects it to happen, despite the man-pages originally claiming that > they were supposed to and (b) it inherently has rounding problems > and other ambiguities - making it even less useful.
Yes, and probably select is one of the calls you most of the time use because of portability. So IMHO a linuxism isn't worth the effort.
Greetings Christoph
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |