Date: Tue, 8 Jan 2013 07:36:13 -0800 From: Adrian Chadd <adrian@freebsd.org> To: Richard Sharpe <rsharpe@richardsharpe.com> Cc: Daniel Eischen <deischen@freebsd.org>, freebsd-hackers@freebsd.org Subject: Re: Is it possible to block pending queued RealTime signals (AIO originating)? Message-ID: <CAJ-VmomN5G70ftbV-uETYwUV7U6zLq%2BUKdav%2BM_B9HYB7HuEpQ@mail.gmail.com> In-Reply-To: <1357626412.6752.24.camel@localhost.localdomain> References: <1357608470.6752.22.camel@localhost.localdomain> <Pine.GSO.4.64.1301072215400.14726@sea.ntplx.net> <1357626412.6752.24.camel@localhost.localdomain>
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.. or you could abstract it out a bit and use freebsd's aio_waitcomplete() or kqueue aio notification. It'll then behave much saner. adrian On 7 January 2013 22:26, Richard Sharpe <rsharpe@richardsharpe.com> wrote: > On Mon, 2013-01-07 at 22:24 -0500, Daniel Eischen wrote: >> On Mon, 7 Jan 2013, Richard Sharpe wrote: >> >> > Hi folks, >> > >> > I am running into a problem with AIO in Samba 3.6.x under FreeBSD 8.0 >> > and I want to check if the assumptions made by the original coder are >> > correct. >> > >> > Essentially, the code queues a number of AIO requests (up to 100) and >> > specifies an RT signal to be sent upon completion with siginfo_t. >> > >> > These are placed into an array. >> > >> > The code assumes that when handling one of these signals, if it has >> > already received N such siginfo_t structures, it can BLOCK further >> > instances of the signal while these structures are drained by the main >> > code in Samba. >> > >> > However, my debugging suggests that if a bunch of signals have already >> > been queued, you cannot block those undelivered but already queued >> > signals. >> > >> > I am certain that they are all being delivered to the main thread and >> > that they keep coming despite the code trying to stop them at 64 (they >> > get all the way up to the 100 that were queued.) >> > >> > Can someone confirm whether I have this correct or not? >> >> If true, could they not use sigwaitinfo() from a separate >> thread instead and just bypass having to use a signal >> handler altogether? That thread can either call sigwaitinfo() >> when it is ready to receive more signals, or block on a >> semaphore/CV/whatever while events are being processed. > > So, I guess that what I want is something that will continue to work for > both Linux and FreeBSD with minimal code divergence ... > > I guess I need to write a simpler program to check what the deal is. > > > > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org"
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