Date: Mon, 7 Feb 2011 22:20:34 +0200 From: Kostik Belousov <kostikbel@gmail.com> To: Jung-uk Kim <jkim@freebsd.org> Cc: davidxu@freebsd.org, freebsd-threads@freebsd.org Subject: Re: [RFC] Implement pthread_getthreadid_np(3) and pthread_getunique_np(3) Message-ID: <20110207202034.GS78089@deviant.kiev.zoral.com.ua> In-Reply-To: <201102071331.54198.jkim@FreeBSD.org> References: <201102041409.12314.jkim@FreeBSD.org> <201102050224.23377.jkim@FreeBSD.org> <20110205095810.GW78089@deviant.kiev.zoral.com.ua> <201102071331.54198.jkim@FreeBSD.org>
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--yQifGgTvVVJcdOYJ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Feb 07, 2011 at 01:31:42PM -0500, Jung-uk Kim wrote: > On Saturday 05 February 2011 04:58 am, Kostik Belousov wrote: > > On Sat, Feb 05, 2011 at 02:24:09AM -0500, Jung-uk Kim wrote: > > > On Friday 04 February 2011 04:33 pm, Kostik Belousov wrote: > > > > On Fri, Feb 04, 2011 at 02:09:10PM -0500, Jung-uk Kim wrote: > > > > > Our pthread_t is not an integral type and it causes a lot of > > > > > trouble porting some software, which relies on Linux's > > > > > gettid() or similar syscalls: > > > > > > > > > > http://www.kernel.org/doc/man-pages/online/pages/man2/gettid. > > > > >2.ht ml > > > > > > > > > > For example: > > > > > > > > > > http://docs.freebsd.org/cgi/mid.cgi?201102032111.13479.jkim > > > > > > > > > > To solve this problem, I implemented two functions: > > > > > > > > > > http://people.freebsd.org/~jkim/thr_tid.diff > > > > > > > > > > Basically, they are AIX's pthread_getthreadid_np(3) and > > > > > pthread_getunique_np(3) look-alikes: > > > > > > > > > > http://publib.boulder.ibm.com/infocenter/iseries/v5r4/topic/a > > > > >pis/ users_22.htm > > > > > http://publib.boulder.ibm.com/infocenter/iseries/v5r4/topic/a > > > > >pis/ users_23.htm > > > > > > > > > > Please let me know what you think. > > > > > > > > Why do you need new functions available in stubs ? > > > > > > Oops, my bad. Fixed: > > > > > > http://people.freebsd.org/~jkim/thr_tid2.diff > > > > > > > Also, would it be better to return proper id even if threading > > > > is not initialized, instead of EINVAL ? > > > > > > Because I want it to be fast and cause no side-effect, no. > > > > You can allocate static lwpid_t self_tid variable, and in case > > threading is not initialized yet, and self_tid =3D=3D 0, do > > self_tid =3D thr_self(). Otherwise, if threading is initialized and > > self_tid !=3D 0, return self_tid. > > > > BTW, what should be the behaviour of new functions after fork() ? > > Is it undefined ? >=20 > Please ignore this RFC. I found (undocumented) thr_self(2) works just=20 > like pthread_getthreadid_np(3) and I don't have immediate need for=20 > pthread_getunique_np(3). I think that making thr_* private libthr syscalls part of the public namespace was unfortunate. If you need the functionality of pthread_getthreadid_np(3), then please introduce it, as discussed above, and use. We already have somewhat sad experience with kse, when static binaries where broken. Using thr_self() directly in such important application as jdk/jre might cause similar problem in future (I hope not). Also, you said that pthread_getthreadid_np(3) was taken from AIX, am I remember right ? This is additional argument for use it instead of single-implementation interface. --yQifGgTvVVJcdOYJ Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (FreeBSD) iEYEARECAAYFAk1QVBIACgkQC3+MBN1Mb4hN9gCfXtpo7h85Ab/kZsWjAGeTVP4w h5IAoKn5wRLjHLt7oPFthFPtOe0ZH/13 =i677 -----END PGP SIGNATURE----- --yQifGgTvVVJcdOYJ--
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