On Mon, Apr 29, 2024 at 01:44:24PM +0000, Joseph Myers wrote:
> > glibc 2.34 and later doesn't have separate libpthread (libpthread.so.0 is a
> > dummy shared library with just some symbol versions for compatibility, but
> > all the pthread_* APIs are in libc.so.6).
>
> I suspect this has caused link failures in the glibc testsuite for Hurd,
> which still has separate libpthread.
>
> https://sourceware.org/pipermail/libc-testresults/2024q2/012556.html
So like this then?
2024-04-30 Jakub Jelinek <jakub@redhat.com>
* gthr.h (GTHREAD_USE_WEAK): Don't redefine to 0 for glibc 2.34+
on GNU Hurd.
(cherry picked from commit 3146a92a77f1fccec71a880c7f890a1251aeab41)
glibc 2.34 and later doesn't have separate libpthread (libpthread.so.0 is a
dummy shared library with just some symbol versions for compatibility, but
all the pthread_* APIs are in libc.so.6).
So, we don't need to do the .weakref dances to check whether a program
has been linked with -lpthread or not, in dynamically linked apps those
will be always true anyway.
In -static linking, this fixes various issues people had when only linking
some parts of libpthread.a and getting weird crashes. A hack for that was
what e.g. some Fedora glibcs used, where libpthread.a was a library
containing just one giant *.o file which had all the normal libpthread.a
*.o files linked with -r together.
libstdc++-v3 actually does something like this already since r10-10928,
the following patch is meant to fix it even for libgfortran, libobjc and
whatever else uses gthr.h.
2024-04-25 Jakub Jelinek <jakub@redhat.com>
* gthr.h (GTHREAD_USE_WEAK): Redefine to 0 for GLIBC 2.34 or later.
2012-03-12 Richard Guenther <rguenther@suse.de>
* gthr.h (__GTHREAD_MUTEX_INIT_FUNCTION): Adjust specification.
* gthr-posix.h (__GTHREAD_MUTEX_INIT_FUNCTION): Define.
(__gthread_mutex_init_function): New function.
* gthr-single.h (__GTHREAD_MUTEX_INIT_FUNCTION): Define.
PR gcov/49484
* libgcov.c: Include gthr.h.
(__gcov_flush_mx): New global variable.
(init_mx, init_mx_once): New functions.
(__gcov_flush): Protect self with a mutex.
(__gcov_fork): Re-initialize mutex after forking.
* unwind-dw2-fde.c: Change condition under which to use
__GTHREAD_MUTEX_INIT_FUNCTION.
From-SVN: r185231
