Date: Tue, 25 Jul 2006 15:27:54 -0400 From: Michael Scheidell <scheidell@secnap.net> To: freebsd-hackers@freebsd.org Subject: Re: FBSD 5.5 and software timers Message-ID: <44C670BA.6060608@secnap.net> In-Reply-To: <44C6509E.4090708@secnap.net> References: <B3BCAF4246A8A84983A80DAB50FE72424C6970@secnap2.secnap.com> <20060725.093429.-1648696470.imp@bsdimp.com> <44C63DD2.9080705@freebsd.org> <44C6509E.4090708@secnap.net>
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Found it! library libc_r
Given POC:
int main( int argc, char **argv )
{
char execs1[256] = "/bin/date +A%Y%m%d%H%M.%S";
char execs2[256] = "/bin/date +B%Y%m%d%H%M.%S";
int a;
while ( 1) {
system( execs1 );
usleep( 500*1000);
system( execs2 );
}
return 0;
} /* main */
compile with:
cc -g -c nanotest.c
cc -g -o nanotest nanotest.o
everything works as expected.
time forward, back, doesn't matter (date prints out wallclock,
nanosleep() sleeps 500*1000*1000us (.5 seconds)
this breaks it:
cc -g -c nanotest.c
cc -g -o nanotest nanotest.o -lc_r
setting clock back 'hangs' during usleep (500*1000)
didn't hang on 5.4.
I will be writing up a bug report shortly.
--
Michael Scheidell, CTO
SECNAP Network Security / www.secnap.com
scheidell@secnap.net / 1+561-999-5000, x 1131
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