[[!meta copyright="Copyright © 2012, 2013 Free Software Foundation, Inc."]] [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable id="license" text="Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled [[GNU Free Documentation License|/fdl]]."]]"""]] [[!meta title="libpthread as glibc addon"]] [[!tag open_issue_glibc open_issue_libpthread]] This page lists all the notes, issues, etc, only about compiling libpthread as addon for glibc, *not* for general libpthread issues. # Building To build libpthread as glibc addon, copy libpthread inside the glibc tree, and then tell glibc's configure to use it: $ cp /path/to/libpthread libpthread $ ./configure [...] --enable-add-ons=[...],libpthread Currently, it is build like that in Debian since eglibc 2.13-31. # Issues and notes ### `bits/` headers not used Recompiling glibc (e.g. on a Debian system) and running the `check-local-headers` test, `check-local-headers.out` shows: *** $(common-objpfx)elf/tst-thrlock.o: uses /usr/include/i386-gnu/bits/pthread.h *** $(common-objpfx)elf/tst-thrlock.o: uses /usr/include/i386-gnu/bits/thread-attr.h *** $(common-objpfx)elf/tst-thrlock.o: uses /usr/include/i386-gnu/bits/mutex-attr.h *** $(common-objpfx)elf/tst-thrlock.o: uses /usr/include/i386-gnu/bits/mutex.h *** $(common-objpfx)elf/tst-thrlock.o: uses /usr/include/i386-gnu/bits/condition-attr.h *** $(common-objpfx)elf/tst-thrlock.o: uses /usr/include/i386-gnu/bits/condition.h *** $(common-objpfx)elf/tst-thrlock.o: uses /usr/include/i386-gnu/bits/rwlock-attr.h *** $(common-objpfx)elf/tst-thrlock.o: uses /usr/include/i386-gnu/bits/rwlock.h *** $(common-objpfx)elf/tst-thrlock.o: uses /usr/include/i386-gnu/bits/barrier-attr.h *** $(common-objpfx)elf/tst-thrlock.o: uses /usr/include/i386-gnu/bits/barrier.h *** $(common-objpfx)elf/tst-thrlock.o: uses /usr/include/i386-gnu/bits/thread-specific.h *** $(common-objpfx)elf/tst-thrlock.o: uses /usr/include/i386-gnu/bits/once.h *** $(common-objpfx)elf/tst-thrlock.o: uses /usr/include/i386-gnu/bits/cancelation.h *** $(common-objpfx)elf/tst-thrlock.o: uses /usr/include/i386-gnu/bits/pthread-np.h This happens because these headers are in the `bits/` subdirectory in `sysdeps/generic` -- a `generic` sysdep is used only for the top-level `sysdeps` directory in glibc. ### Use of hurd's libihash libpthread makes use of the ihash hurd library, as also glibc's `check-local-headers` test shows: *** $(common-objpfx)libpthread/pt-alloc.o: uses /usr/include/hurd/ihash.h Possible alternatives: [[hurd/libihash]]. ### Executable stack Running glibc's `check-execstack` test gives in `check-execstack.out`: $BUILDDIR/libpthread/libpthread.so.phdr: *** executable stack signaled ### Extra PLT references Running glibc's `check-localplt` test gives in `check-localplt.out`: Extra PLT reference: libpthread.so: pthread_detach Extra PLT reference: libpthread.so: pthread_mutex_lock Extra PLT reference: libpthread.so: pthread_mutexattr_settype Extra PLT reference: libpthread.so: pthread_rwlock_rdlock Extra PLT reference: libpthread.so: _pthread_spin_lock Extra PLT reference: libpthread.so: pthread_attr_setstacksize Extra PLT reference: libpthread.so: pthread_attr_getstacksize Extra PLT reference: libpthread.so: pthread_attr_getstackaddr Extra PLT reference: libpthread.so: pthread_attr_setstackaddr Extra PLT reference: libpthread.so: pthread_exit Extra PLT reference: libpthread.so: pthread_getspecific Extra PLT reference: libpthread.so: __mutex_lock_solid Extra PLT reference: libpthread.so: pthread_mutex_unlock Extra PLT reference: libpthread.so: pthread_setcanceltype Extra PLT reference: libpthread.so: pthread_key_create Extra PLT reference: libpthread.so: pthread_cond_wait Extra PLT reference: libpthread.so: pthread_rwlock_wrlock Extra PLT reference: libpthread.so: pthread_once Extra PLT reference: libpthread.so: pthread_cond_broadcast Extra PLT reference: libpthread.so: pthread_setspecific Extra PLT reference: libpthread.so: __pthread_get_cleanup_stack Extra PLT reference: libpthread.so: pthread_rwlock_unlock Extra PLT reference: libpthread.so: pthread_create Extra PLT reference: libpthread.so: pthread_mutex_init Extra PLT reference: libpthread.so: pthread_mutexattr_init Extra PLT reference: libpthread.so: __mutex_unlock_solid Extra PLT reference: libpthread.so: pthread_mutexattr_destroy Extra PLT reference: libpthread.so: pthread_setcancelstate ### `bits/posix_opt.h` `bits/posix_opt.h` is the glibc header defining the various supported/unsupported `_POSIX_*` defines (e.g. `_POSIX_THREADS`, etc). Currently, glibc's `sysdeps/mach/hurd/bits/posix_opt.h` is patched in Debian to add all the defines advertizing thread-related support. An idea to avoid this would be to follow what is done in NPTL, and do the following: - in glibc: leave `sysdeps/mach/hurd/bits/posix_opt.h` with *no* thread-related macros at all. - in libpthread: provide `sysdeps/mach/hurd/bits/posix_opt.h` which would be a copy of glibc's `sysdeps/mach/hurd/bits/posix_opt.h` with also the thread macros. This approach would have the drawback that changes in the glibc header must be mirrored also in the libpthread version, but with the advantage that defines according to supported features in libpthread can be added in libpthread's own version (and glibc would pick it automatically). ### Tests The (few) existing tests are not built (thus neither run) just like other tests in glibc. ### `gai_misc.h` A pthread version of `gai_misc.h` must be provided by libpthread (just like NPTL provides one), either in `sysdeps/mach/hurd` or `sysdeps/pthread` (better). Currently, it is provided in glibc itself in Debian.