Messages in this thread |  | | Date | Wed, 13 Oct 2004 21:28:26 -0600 | From | Robert Hancock <> | Subject | Re: select, jiffies, and SIGALRM |
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I see calls to getitimer, so I'm assuming it's also using setitimer. SIGALRM is what you get when those timers go off - if it's not handling that, that's a bug, but presumably the timer is in there for a reason..
----- Original Message ----- From: "Vx Glenn" <VxGlenn@gmail.com> Newsgroups: fa.linux.kernel To: <linux-net@vger.kernel.org>; <linux-kernel@vger.kernel.org> Sent: Wednesday, October 13, 2004 10:13 AM Subject: select, jiffies, and SIGALRM
> Hi all, > > I am seeing an issue relating to the jiffies counter wrapping around > at 0x7FFFFFFF. > > This is a legacy application, and when it runs on 32-bit Unix-Like > OS's, the application silently dies without leaving core after 248 > days. > > I was able to manipulate the jiffies counter and run the application. > I was able to reproduce the problem. I captured an strace log, and I > see that SIGALRM (alarm clock) is raised after select times out > (because of no data). > > I can add a signal handler to intercept the SIGALRM. But my question > is, why should the signal be raised? > > ---[ strace.log ]--- > select(1024, [3 4 5 6], NULL, NULL, {0, 320000}) = 0 (Timeout) > getitimer(ITIMER_REAL, {it_interval={2147157, 520}, it_value={0, 684895}}) > = 0 > adjtimex({modes=32769, offset=0, freq=0, maxerror=16384000, > esterror=16384000, status=64, constant=2, precision=1, > tolerance=33554432, time={1097551596, 43475}}) = 5 > getitimer(ITIMER_REAL, {it_interval={2147157, 520}, it_value={0, 684895}}) > = 0 > select(1024, [3 4 5 6], NULL, NULL, {1, 0}) = ? ERESTARTNOHAND (To be > restarted) > --- SIGALRM (Alarm clock) @ 0 (0) --- > Process 4881 detached > ---[ eof strace.log ]--- > > > Anyone have any ideas? > > > -- > You're not your Job; > You're not the contents of your wallet. > You're the all singing all dancing crap of the world > - > 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/
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