IRC, freenode, #hurd, 2010-07-31
<tschwinge> My idea was to have a separate libpthread package. What do you
think about that?
<youpi> in the long term, that can't work with glibc
<youpi> because of the thread stub stuff
libpthread dlopen, for example.
<youpi> it's not really possible to keep synchronized
<youpi> because you have to decide which package you unpack first
<youpi> (when upgrading)
<tschwinge> Hmm, how is that different if two shared libraries are in one
package vs. two packages? It isn't atomic either way? Aren't sonames /
versioned library packages solving that?
<tschwinge> ... for incompatible forward changes?
<youpi> that'd be a mess to maintain
<youpi> Drepper doesn't have this constraint and thus adds members of
private fields at will
<tschwinge> OK, but how is it different then if the libpthread is in the
Hurd package?
<youpi> I'm not saying it's better to have libpthread in the Hurd package
<tschwinge> OK.
<youpi> I'm saying it's useless to package it separately when Drepper makes
everything to have us put it along glibc
<tschwinge> Then, to goal is to have it in glibc?
<tschwinge> OK. :-)
<tschwinge> OK, I can accommodate to that. Isn't not that we'd want to
switch libpthread to something else so quickly.
<tschwinge> So our official goal is to have libpthread in glibc, at least
for Debian purposese?
<youpi> for any port purpose
<tschwinge> Ack.
<youpi> provided you're using glibc, you're deemed to ship libpthread with
it
<youpi> because of the strong relations Drepper puts between them
<youpi> (just to remind: we already have bugs just because our current
libpthread isn't bound enough to glibc: dlopen()ing a library depending
on libpthread doesn't work, for instance)
<pinotree> yeah, pthread-stubs is linked to almost everywhere -lpthread
isn't used
<pinotree> (would be nice to not have those issues anymore...)
<tschwinge> So -- what do we need to put it into glibc? We can make
libpthread a Git submodule (or move the code; but it's shared also for
Neal's viengoos, so perhaps the submodule is better?), plus some glibc
make foo, plus some other adaptions (stubs, etc.)
<tschwinge> Does that sound about right, or am I missing something
fundamental?
<youpi> I actually don't know what a git submodule permits :)
<youpi> looks like a good thing for this, yes
<tschwinge> Unfortunately I can't allocate much time at the moment to work
on this. :-/
<youpi> well, as long as I know where we're going, I can know how to
package stuff in Debian
<tschwinge> That sounds like a plan to me. libpthread -> glibc as
submodule.
<youpi> (note: actually, the interface between glibc and the libpthread is
the responsibility of the libpthread: it gives a couple of .c files to be
shipped in libc.so)
IRC, freenode, #hurd, 2012-04-21
<youpi> had you tried to build libpthread as a glibc addon?
<tschwinge> youpi: No, I only know about libpthread in Hurd build system,
and libpthread stand-alone (with the Auto* stuff that I added), but not
yet as a glibc add-on.
<youpi> k
<youpi> I'm trying it atm
<tschwinge> Oh, OK.
<youpi> that should fix the no-add-needed issue in gcc/binutils, as well as
the pthread_threads assertion errors in threaded plugins
<youpi> (once I add forward.c, but that part should not be hard)
<pinotree> that means also less use of pthread-stubs^
<pinotree> ?
<youpi> tschwinge: do you remember whether sysdeps/mach/bits/spin* are used
by anybody?
<youpi> they are half-finished (no __PTHREAD_SPIN_LOCK_INITIALIZER), and
come in the way when building in glibc
<youpi> pinotree: rid of pthread-stubs yes
<pinotree> \o/
<tschwinge> youpi: You mean sysdeps/mach/i386/machine-lock.h? No idea
about that one, sorry.
<youpi> I'm talking about libpthread
<youpi> not glibc
<tschwinge> Oh.
<tschwinge> sysdeps/i386/bits/spin-lock.h:# define
__PTHREAD_SPIN_LOCK_INITIALIZER ((__pthread_spinlock_t) 0)
<tschwinge> Anyway, no idea about that either.
<youpi> that one is meant to be used with the spin-lock.h just below
<youpi> +-inline
<youpi> also, I guess signal/ was for the l4 port?
<tschwinge> youpi: I guess so.
<youpi> tschwinge: I have an issue with sysdeps pt files:
sysdeps/hurd/pt-getspecific.c is not looked for by libc ; symlinking into
sysdeps/mach/hurd/pt-getspecific.c works
<youpi> we don't have a non-mach sysdeps directory?
<pinotree> youpi: if you add sysdeps/mach/hurd/Implies containing only
"hurd", does sysdeps/hurd work?
<youpi> ah, right
<pinotree> youpi: did it work? (and, it was needed in sysdeps/mach/hurd, or
in libpthread/sysdeps/mach/hurd?)
<youpi> pinotree: it worked, it was for libpthread
<youpi> good: I got libpthread built and forward working
IRC, freenode, #hurd, 2012-04-23
<youpi> phew
<youpi> confirmed that moving libpthread to glibc fixes the gcc/binutils
no-add-needed issue
IRC, freenode, #hurd, 2012-08-07
<tschwinge> Also, the Savannah hurd/glibc.git one does not/not yet include
libpthread.
<tschwinge> But that could easily be added as a Git submodule.
<tschwinge> youpi: To put libpthread into glibc it is literally enough to
make Savannah hurd/libpthread.git appear at [glibc]/libpthread?
<youpi> tschwinge: there are some patches needed in the rest of the tree
<youpi> see in debian, libpthread_clean.diff, tg-libpthread_depends.diff,
unsubmitted-pthread.diff, unsubmitted-pthread_posix_options.diff
<tschwinge> The libpthread in Debian glibc is
hurd/libpthread.git:b428baaa85c0adca9ef4884c637f289a0ab5e2d6 but with
25260994c812050a5d7addf125cdc90c911ca5c1 »Store self in __thread variable
instead of threadvar« reverted (why?), [...]
..., and 549aba4335946c26f2701c2b43be0e6148d27c09 »Fix libpthread.so symlink« cherry-picked.
<braunr> tschwinge: is there any plan to merge libpthread.git in glibc.git
upstream ?
<tschwinge> braunr, youpi: Has not yet been discussed with Roland, as far
as I know.
<youpi> has not
<youpi> libpthread.diff is supposed to be a verbatim copy of the repository
<youpi> and then there are a couple patches which don't (yet) make sense
upstream
IRC, OFTC, #debian-hurd, 2013-02-08
<tschwinge> I also have it on my (never-ending) agenda to add libpthread to
the tschwinge/Roger_Whittaker branch and/or propose it be added upstream
(as a Git submodule?).
<pinotree> imho a git submodule could be a solution, if glibc people would
accept it
<pinotree> if so, libpthread.git would need proper glibc/x.y branches to
follow glibc
<tschwinge> Yep.
<tschwinge> I though that would be the least invasive approach for glibc
upstream -- and quite convenient for us, too.
<pinotree> after all, git submodules don't track branches, but point to
specific commits, no?
<tschwinge> Correct.
<tschwinge> So we can do locally/in Debian whatever we want, and every once
in a while update the upstream glibc commit ID for libpthread.
<pinotree> so we could update the git submodule references in glibc when
we've tested enough libpthread changes
<tschwinge> Just like when committing patches upstream, just without
pestering them with all the patches/commits.
<tschwinge> Yep.
IRC, freenode, #hurd, 2012-11-16
<pinotree> *** $(common-objpfx)resolv/gai_suspend.o: uses
/usr/include/i386-gnu/bits/pthread.h
<pinotree> so the ones in the libpthread addon are not used...
<tschwinge> pinotree: The latter at leash should be useful information.
<pinotree> tschwinge: i'm afraid i didn't get you :) what are you referring
to?
<tschwinge> pinotree: s%leash%least -- what I mean was the it's actually a
real bug that not the in-tree libpthread addon include files are being
used.
<pinotree> tschwinge: ah sure -- basically, the stuff in
libpthread/sysdeps/generic are not used at all
<pinotree> (glibc only uses generic for glibc/sysdeps/generic)
<pinotree> tschwinge: i might have an idea how to fix it: moving the
contents from libpthread/sysdeps/generic to libpthread/sysdeps/pthread,
and that would depend on one of the latest libpthread patches i sent
libihash
IRC, freenode, #hurd, 2012-11-16
<pinotree> also, libpthread uses hurd's ihash
<tschwinge> Yes, I already thought a little bit about the ihash thing. I
besically see two options: move ihash into glibc ((probably?) not as a
public interface, though), or have libpthread use of of the hash
implementations that surely are already present in glibc.
<tschwinge> My notes say:
<tschwinge> * include/inline-hashtab.h
<tschwinge> * locale/programs/simple-hash.h
<tschwinge> * misc/hsearch_r.c
<tschwinge> * NNS; cf. f46f0abfee5a2b34451708f2462a1c3b1701facd
<tschwinge> No idea whether they're equivalent/usable.
<pinotree> interesting
<tschwinge> And no immediate recollection what NNS is;
f46f0abfee5a2b34451708f2462a1c3b1701facd is not a glibc commit after all.
;-)
<tschwinge> Oh, and: libiberty: `hashtab.c`
<pinotree> hmm, but then you would need to properly ifdef the libpthread
hash usage (iirc only for pthread keys) depending on whether it's in
glibc or standalone
<pinotree> but that shouldn't be an ussue, i guess
<pinotree> *issue
<tschwinge> No that'd be fine.
<tschwinge> My understanding is that the long-term goal (well, no so
long-term, actually) is to completely move libpthread into glibc.
<pinotree> ie have it buildable only ad glibc addon?
<tschwinge> Yes.
<tschwinge> No need for more than one mechanism for building it, I think.
<tschwinge> Hmm, this doesn't bring us any further:
https://www.google.com/search?q=f46f0abfee5a2b34451708f2462a1c3b1701facd
<pinotree> yay for acronyms ;)
<tschwinge> So, if someone figures out what NNS and this commit it are: one
beer. ;-)