Messages in this thread | | | Date | Tue, 25 Dec 2012 17:58:03 +0100 | From | Oleg Nesterov <> | Subject | Re: [PATCH 1/4] signalfd: add ability to return siginfo in a raw format |
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On 12/25, Pavel Emelyanov wrote: > > On 12/25/2012 07:27 PM, Oleg Nesterov wrote: > > > > I guess that probably you actually need DUMP, not DEQUEUE. but the > > latter is not trivial. However, perhaps we can do this assuming that > > all other threads are sleeping and nobody can do dequeue_signal(). > > Say, we can play with ppos/llseek. If *ppos is not zero, > > signalfd_dequeue() could dump the nth entry from list or return 0. > > This would be perfect, but isn't it better to preserve the pos > semantics -- we do know size of entry we're about to copy, we can > treat pos as offset in bytes, not in elements.
nr-of-records looks better (more flexible) than nr-of-bytes to me. And perhaps we can also encode private-or-shared into ppos. But I will not argue in any case.
Oleg.
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