Date: Tue, 10 Jul 2012 17:02:03 +0300 From: Konstantin Belousov <kostikbel@gmail.com> To: Volodymyr Kostyrko <c.kworr@gmail.com> Cc: freebsd-hackers@freebsd.org, freebsd-standards@freebsd.org Subject: Re: kern/149857: [kqueue] kqueue not reporting EOF under certain circumstances Message-ID: <20120710140203.GA2338@deviant.kiev.zoral.com.ua> In-Reply-To: <4FFC1D2D.4020405@gmail.com> References: <4FFC1D2D.4020405@gmail.com>
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--dfOvyYudzT1RPUKx Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jul 10, 2012 at 03:16:45PM +0300, Volodymyr Kostyrko wrote: > Hi all. >=20 > http://www.freebsd.org/cgi/query-pr.cgi?pr=3Dkern/149857 >=20 > This PR is rather old. I just had submitted new test case, now in plain c. >=20 > It doesn't work exactly like python version, but the result is the same: >=20 > > clang test.c > > cat test.c | ./a.out > -1 916 0 0 0 > -1 0 32768 0 0 > > ./a.out < test.c > -1 916 0 0 0 > <- and here we have a complete hang in [kqread]. And what is your expectation ? The vnode filter never returns EOF when current file position at the end of file. It is documented that read filter returns when file offset if not at the end of file, thats all. In fact, EV_EOF is returned on forced unmoun= t. I do not see a bug in kqueue. On the other hand, your C code has at least two things that I cannot understand. First, EV_EOF is output flag, it makes absolutely no sense to set it in command. Second, it is mistery for me what do you check with if (kev.flags >> 15 =3D=3D 1) { test. --dfOvyYudzT1RPUKx Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (FreeBSD) iEYEARECAAYFAk/8NdsACgkQC3+MBN1Mb4iTxACgjIyAmfQzKZ1YJhjVqpcDeRtq cggAn1rOw71APAlZ1oyP+vvEyODsPtd2 =2fEs -----END PGP SIGNATURE----- --dfOvyYudzT1RPUKx--
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