hurd: Add hurd thread library

Contributed by

Agustina Arzille <avarzille@riseup.net>
Amos Jeffries <squid3@treenet.co.nz>
David Michael <fedora.dm0@gmail.com>
Marco Gerards <marco@gnu.org>
Marcus Brinkmann <marcus@gnu.org>
Neal H. Walfield <neal@gnu.org>
Pino Toscano <toscano.pino@tiscali.it>
Richard Braun <rbraun@sceen.net>
Roland McGrath <roland@gnu.org>
Samuel Thibault <samuel.thibault@ens-lyon.org>
Thomas DiModica <ricinwich@yahoo.com>
Thomas Schwinge <tschwinge@gnu.org>

	* htl: New directory.
	* sysdeps/htl: New directory.
	* sysdeps/hurd/htl: New directory.
	* sysdeps/i386/htl: New directory.
	* sysdeps/mach/htl: New directory.
	* sysdeps/mach/hurd/htl: New directory.
	* sysdeps/mach/hurd/i386/htl: New directory.
	* nscd/Depend, resolv/Depend, rt/Depend: Add htl dependency.
	* sysdeps/mach/hurd/i386/Implies: Add mach/hurd/i386/htl imply.
	* sysdeps/mach/hurd/i386/libpthread.abilist: New file.

50 files changed, 4126 insertions, 0 deletions

diff --git a/htl/Makefile b/htl/Makefile
new file mode 100644
index 0000000..3bde5f0
--- /dev/null
+++ b/htl/Makefile
@@ -0,0 +1,237 @@
+#
+#   Copyright (C) 1994-2018 Free Software Foundation, Inc.
+#
+#   This program is free software; you can redistribute it and/or
+#   modify it under the terms of the GNU General Public License as
+#   published by the Free Software Foundation; either version 2, or (at
+#   your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+#   General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program; if not, write to the Free Software
+#   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+subdir := htl
+
+srcdir = .
+
+MICROKERNEL := mach
+SYSDEPS := lockfile
+
+LCLHDRS :=
+
+libpthread-routines := pt-attr pt-attr-destroy pt-attr-getdetachstate	    \
+	pt-attr-getguardsize pt-attr-getinheritsched			    \
+	pt-attr-getschedparam pt-attr-getschedpolicy pt-attr-getscope	    \
+	pt-attr-getstack pt-attr-getstackaddr pt-attr-getstacksize	    \
+	pt-attr-init pt-attr-setdetachstate pt-attr-setguardsize	    \
+	pt-attr-setinheritsched pt-attr-setschedparam			    \
+	pt-attr-setschedpolicy pt-attr-setscope pt-attr-setstack	    \
+	pt-attr-setstackaddr pt-attr-setstacksize			    \
+									    \
+	pt-barrier-destroy pt-barrier-init pt-barrier-wait		    \
+	pt-barrier pt-barrierattr-destroy pt-barrierattr-init		    \
+	pt-barrierattr-getpshared pt-barrierattr-setpshared		    \
+									    \
+	pt-destroy-specific pt-init-specific				    \
+	pt-key-create pt-key-delete					    \
+	pt-getspecific pt-setspecific					    \
+									    \
+	pt-once								    \
+									    \
+	pt-alloc							    \
+	pt-create							    \
+	pt-getattr							    \
+	pt-equal							    \
+	pt-dealloc							    \
+	pt-detach							    \
+	pt-exit								    \
+	pt-initialize							    \
+	pt-join								    \
+	pt-self								    \
+	pt-sigmask							    \
+	pt-spin-inlines							    \
+	pt-cleanup							    \
+	pt-setcancelstate						    \
+	pt-setcanceltype						    \
+	pt-testcancel							    \
+	pt-cancel							    \
+									    \
+	pt-mutexattr							    \
+	pt-mutexattr-destroy pt-mutexattr-init				    \
+	pt-mutexattr-getprioceiling pt-mutexattr-getprotocol		    \
+	pt-mutexattr-getpshared pt-mutexattr-gettype			    \
+	pt-mutexattr-setprioceiling pt-mutexattr-setprotocol		    \
+	pt-mutexattr-setpshared pt-mutexattr-settype			    \
+	pt-mutexattr-getrobust pt-mutexattr-setrobust			    \
+									    \
+	pt-mutex-init pt-mutex-destroy					    \
+	pt-mutex-lock pt-mutex-trylock pt-mutex-timedlock		    \
+	pt-mutex-unlock							    \
+	pt-mutex-transfer-np						    \
+	pt-mutex-getprioceiling pt-mutex-setprioceiling			    \
+	pt-mutex-consistent 						    \
+									    \
+	pt-rwlock-attr							    \
+	pt-rwlockattr-init pt-rwlockattr-destroy			    \
+	pt-rwlockattr-getpshared pt-rwlockattr-setpshared		    \
+									    \
+	pt-rwlock-init pt-rwlock-destroy				    \
+	pt-rwlock-rdlock pt-rwlock-tryrdlock				    \
+	pt-rwlock-trywrlock pt-rwlock-wrlock				    \
+	pt-rwlock-timedrdlock pt-rwlock-timedwrlock			    \
+	pt-rwlock-unlock						    \
+									    \
+	pt-cond								    \
+	pt-condattr-init pt-condattr-destroy				    \
+	pt-condattr-getclock pt-condattr-getpshared			    \
+	pt-condattr-setclock pt-condattr-setpshared			    \
+									    \
+	pt-cond-destroy pt-cond-init					    \
+	pt-cond-brdcast							    \
+	pt-cond-signal							    \
+	pt-cond-wait							    \
+	pt-cond-timedwait						    \
+	pt-hurd-cond-wait						    \
+	pt-hurd-cond-timedwait						    \
+									    \
+	pt-stack-alloc							    \
+	pt-thread-alloc							    \
+	pt-thread-start							    \
+	pt-thread-terminate						    \
+	pt-startup							    \
+									    \
+	pt-getconcurrency pt-setconcurrency				    \
+									    \
+	pt-block							    \
+	pt-timedblock							    \
+	pt-wakeup							    \
+	pt-docancel							    \
+	pt-sysdep							    \
+	pt-setup							    \
+	pt-machdep							    \
+	pt-spin								    \
+									    \
+	pt-sigstate-init						    \
+	pt-sigstate-destroy						    \
+	pt-sigstate							    \
+									    \
+	pt-atfork							    \
+	old_pt-atfork							    \
+	pt-kill								    \
+	pt-getcpuclockid						    \
+									    \
+	pt-getschedparam pt-setschedparam pt-setschedprio		    \
+	pt-yield							    \
+									    \
+	sem-close sem-destroy sem-getvalue sem-init sem-open		    \
+	sem-post sem-timedwait sem-trywait sem-unlink			    \
+	sem-wait							    \
+									    \
+	shm-directory							    \
+									    \
+	cthreads-compat							    \
+	$(SYSDEPS)
+
+libpthread-static-only-routines = pt-atfork
+
+headers :=				\
+              pthread.h				\
+	      semaphore.h			\
+						\
+              bits/pthread.h			\
+              bits/pthread-np.h			\
+              bits/pthreadtypes.h		\
+              bits/pthreadtypes-arch.h		\
+              bits/thread-shared-types.h	\
+              bits/types/struct___pthread_mutex.h	\
+              bits/types/struct___pthread_cond.h	\
+              bits/types/struct___pthread_condattr.h	\
+              bits/types/__pthread_spinlock_t.h	\
+              bits/spin-lock-inline.h		\
+              bits/cancelation.h		\
+              bits/types/struct___pthread_attr.h	\
+              bits/types/struct___pthread_barrierattr.h	\
+              bits/types/struct___pthread_barrier.h	\
+              bits/types/__pthread_key.h		\
+              bits/types/struct___pthread_once.h	\
+              bits/types/struct___pthread_mutexattr.h	\
+              bits/types/struct___pthread_rwlock.h	\
+              bits/types/struct___pthread_rwlockattr.h	\
+	      bits/semaphore.h
+
+distribute :=
+
+routines := forward libc_pthread_init alloca_cutoff
+shared-only-routines = forward
+
+extra-libs := libpthread
+extra-libs-others := $(extra-libs)
+install-lib := libpthread.so
+
+include ../Makeconfig
+
+CFLAGS-lockfile.c = -D_IO_MTSAFE_IO
+
+all: # Make this the default target; it will be defined in Rules.
+
+subdir_install: $(inst_libdir)/libpthread2.a
+
+# XXX: If $(inst_libdir)/libpthread2.a is installed and
+# $(inst_libdir)/libpthread is not, we can have some issues.
+.PHONY: $(inst_libdir)/libpthread.a $(inst_libdir)/libpthread_pic.a
+
+# XXX: These rules are a hack.  But it is better than messing with
+# ../Makeconf at the moment.  Note that the linker scripts
+# $(srcdir)/libpthread.a and $(srcdir)/libpthread_pic.a get overwritten
+# when building in $(srcdir) and not a seperate build directory.
+$(inst_libdir)/libpthread2.a: $(inst_libdir)/libpthread.a
+	mv $< $@
+	$(INSTALL_DATA) $(srcdir)/libpthread.a $<
+
+$(inst_libdir)/libpthread2_pic.a: $(inst_libdir)/libpthread_pic.a
+	mv $< $@
+	$(INSTALL_DATA) $(srcdir)/libpthread_pic.a $<
+
+libc-link.so = $(common-objpfx)libc.so
+
+extra-B-pthread.so = -B$(common-objpfx)htl/
+
+include ../Rules
+
+ifeq (yes,$(build-shared))
+# What we install as libpthread.so for programs to link against is in fact a
+# link script.  It contains references for the various libraries we need.
+# The libpthread.so object is not complete since some functions are only
+# defined in libpthread_nonshared.a.
+# We need to use absolute paths since otherwise local copies (if they exist)
+# of the files are taken by the linker.
+install: $(inst_libdir)/libpthread.so
+
+$(inst_libdir)/libpthread.so: $(common-objpfx)format.lds \
+			      $(objpfx)libpthread.so$(libpthread.so-version) \
+			      $(inst_libdir)/$(patsubst %,$(libtype.oS),\
+							$(libprefix)pthread) \
+			      $(+force)
+	(echo '/* GNU ld script';\
+	 echo '   Use the shared library, but some functions are only in';\
+	 echo '   the static library, so try that secondarily.  */';\
+	 cat $<; \
+	 echo 'GROUP ( $(slibdir)/libpthread.so$(libpthread.so-version)' \
+	      '$(libdir)/$(patsubst %,$(libtype.oS),$(libprefix)pthread)'\
+	      ')' \
+	) > $@.new
+	mv -f $@.new $@
+
+$(addprefix $(objpfx), \
+  $(filter-out $(tests-static) $(xtests-static) $(tests-reverse) \
+    $(tests-nolibpthread), \
+    $(tests) $(xtests) $(test-srcs))): $(objpfx)libpthread.so \
+				       $(objpfx)libpthread_nonshared.a
+endif
+
+generated += libpthread_nonshared.a
diff --git a/htl/Versions b/htl/Versions
new file mode 100644
index 0000000..6a63a1b
--- /dev/null
+++ b/htl/Versions
@@ -0,0 +1,156 @@
+libc {
+  GLIBC_2.21 {
+    pthread_attr_destroy; pthread_attr_getdetachstate;
+    pthread_attr_getinheritsched; pthread_attr_getschedparam;
+    pthread_attr_getschedpolicy; pthread_attr_getscope; pthread_attr_init;
+    pthread_attr_setdetachstate; pthread_attr_setinheritsched;
+    pthread_attr_setschedparam; pthread_attr_setschedpolicy;
+    pthread_attr_setscope;
+    pthread_condattr_destroy; pthread_condattr_init;
+    pthread_cond_broadcast; pthread_cond_destroy;
+    pthread_cond_init; pthread_cond_signal; pthread_cond_wait;
+    pthread_cond_timedwait;
+    pthread_equal;
+    pthread_exit; pthread_getschedparam; pthread_setschedparam;
+    pthread_mutex_destroy; pthread_mutex_init;
+    pthread_mutex_lock; pthread_mutex_trylock; pthread_mutex_unlock;
+    pthread_self; pthread_setcancelstate; pthread_setcanceltype;
+    __pthread_get_cleanup_stack;
+  }
+  GLIBC_2.22 {
+    __register_atfork;
+  }
+  GLIBC_PRIVATE {
+    __libc_alloca_cutoff;
+    __libc_pthread_init;
+  }
+}
+
+libpthread {
+  GLIBC_2.2.6 {
+    _IO_flockfile; _IO_ftrylockfile; _IO_funlockfile;
+  }
+  GLIBC_2.12 {
+    __pthread_errorcheck_mutexattr; __pthread_recursive_mutexattr;
+
+    __pthread_get_cleanup_stack;
+
+    __pthread_mutex_transfer_np;
+
+    _pthread_mutex_destroy; _pthread_mutex_init;
+    _pthread_mutex_lock; _pthread_mutex_trylock; _pthread_mutex_unlock;
+    _pthread_rwlock_destroy; _pthread_rwlock_init;
+
+    _cthread_init_routine;
+
+    cthread_detach;
+    cthread_fork;
+    cthread_keycreate;
+    cthread_getspecific;
+    cthread_setspecific;
+    __mutex_lock_solid;
+    __mutex_unlock_solid;
+    _cthreads_flockfile;
+    _cthreads_ftrylockfile;
+    _cthreads_funlockfile;
+
+    flockfile; ftrylockfile; funlockfile;
+
+    pthread_atfork;
+
+    pthread_attr_destroy; pthread_attr_getdetachstate;
+    pthread_attr_getguardsize; pthread_attr_getinheritsched;
+    pthread_attr_getschedparam; pthread_attr_getschedpolicy;
+    pthread_attr_getscope; pthread_attr_getstack; pthread_attr_getstackaddr;
+    pthread_attr_getstacksize; pthread_attr_init; pthread_attr_setdetachstate;
+    pthread_attr_setguardsize; pthread_attr_setinheritsched;
+    pthread_attr_setschedparam; pthread_attr_setschedpolicy;
+    pthread_attr_setscope; pthread_attr_setstack; pthread_attr_setstackaddr;
+    pthread_attr_setstacksize;
+
+    pthread_barrier_destroy; pthread_barrier_init; pthread_barrier_wait;
+    pthread_barrierattr_destroy; pthread_barrierattr_getpshared;
+    pthread_barrierattr_init; pthread_barrierattr_setpshared;
+
+    pthread_cancel;
+
+    pthread_cond_broadcast; pthread_cond_destroy; pthread_cond_init;
+    pthread_cond_signal; pthread_cond_timedwait; pthread_cond_wait;
+
+    pthread_condattr_destroy; pthread_condattr_getclock;
+    pthread_condattr_getpshared; pthread_condattr_init;
+    pthread_condattr_setclock; pthread_condattr_setpshared;
+
+    pthread_create; pthread_detach; pthread_equal; pthread_exit;
+
+    pthread_getattr_np;
+
+    pthread_getconcurrency; pthread_getcpuclockid;
+    pthread_getschedparam; pthread_getspecific;
+
+    pthread_join;
+
+    pthread_key_create; pthread_key_delete;
+    __pthread_key_create;
+
+    pthread_kill;
+    __pthread_kill;
+
+    pthread_mutex_destroy; pthread_mutex_getprioceiling;
+    pthread_mutex_init; pthread_mutex_lock; pthread_mutex_setprioceiling;
+    pthread_mutex_timedlock; pthread_mutex_transfer_np;
+    pthread_mutex_trylock; pthread_mutex_unlock;
+
+    pthread_mutexattr_destroy; pthread_mutexattr_getprioceiling;
+    pthread_mutexattr_getprotocol; pthread_mutexattr_getpshared;
+    pthread_mutexattr_gettype; pthread_mutexattr_init;
+    pthread_mutexattr_setprioceiling; pthread_mutexattr_setprotocol;
+    pthread_mutexattr_setpshared; pthread_mutexattr_settype;
+
+    pthread_once;
+
+    pthread_rwlock_destroy; pthread_rwlock_init; pthread_rwlock_rdlock;
+    pthread_rwlock_timedrdlock; pthread_rwlock_timedwrlock;
+    pthread_rwlock_tryrdlock; pthread_rwlock_trywrlock;
+    pthread_rwlock_unlock; pthread_rwlock_wrlock;
+
+    pthread_rwlockattr_destroy; pthread_rwlockattr_getpshared;
+    pthread_rwlockattr_init; pthread_rwlockattr_setpshared;
+
+    pthread_self;
+    __pthread_self;
+
+    pthread_setcancelstate; pthread_setcanceltype;
+    pthread_setconcurrency; pthread_setschedparam;
+    pthread_setschedprio; pthread_setspecific;
+
+    pthread_sigmask;
+    pthread_testcancel;
+    pthread_yield;
+
+    sem_close; sem_destroy; sem_getvalue; sem_init; sem_open; sem_post;
+    sem_timedwait; sem_trywait; sem_unlink; sem_wait;
+
+    pthread_spin_destroy; pthread_spin_init; pthread_spin_lock;
+    pthread_spin_trylock; pthread_spin_unlock;
+    __pthread_spin_destroy; __pthread_spin_init;
+    __pthread_spin_lock; __pthread_spin_trylock; __pthread_spin_unlock;
+    _pthread_spin_lock;
+  }
+  GLIBC_2.21 {
+    pthread_hurd_cond_wait_np;
+    pthread_hurd_cond_timedwait_np;
+  }
+  GLIBC_PRIVATE {
+    __shm_directory;
+    __pthread_threads;
+
+    __cthread_detach;
+    __cthread_fork;
+    __cthread_keycreate;
+    __cthread_getspecific;
+    __cthread_setspecific;
+    __pthread_getattr_np;
+    __pthread_attr_getstack;
+  }
+}
diff --git a/htl/alloca_cutoff.c b/htl/alloca_cutoff.c
new file mode 100644
index 0000000..4c183bd
--- /dev/null
+++ b/htl/alloca_cutoff.c
@@ -0,0 +1,26 @@
+/* Allocate a new thread structure.
+   Copyright (C) 2015-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <alloca.h>
+
+int
+__libc_alloca_cutoff (size_t size)
+{
+  return size <= 65536;
+}
+libc_hidden_def (__libc_alloca_cutoff)
diff --git a/htl/configure b/htl/configure
new file mode 100644
index 0000000..5983490
--- /dev/null
+++ b/htl/configure
@@ -0,0 +1,2 @@
+libc_add_on_canonical=libpthread
+libc_add_on_subdirs=.
diff --git a/htl/configure.in b/htl/configure.in
new file mode 100644
index 0000000..4e140b1
--- /dev/null
+++ b/htl/configure.in
@@ -0,0 +1,4 @@
+GLIBC_PROVIDES
+
+libc_add_on_canonical=libpthread
+libc_add_on_subdirs=.
diff --git a/htl/cthreads-compat.c b/htl/cthreads-compat.c
new file mode 100644
index 0000000..042ed64
--- /dev/null
+++ b/htl/cthreads-compat.c
@@ -0,0 +1,101 @@
+/* Compatibility routines for cthreads.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <assert.h>
+#include <pthreadP.h>
+
+#define	CTHREAD_KEY_INVALID (__cthread_key_t) -1
+
+void
+__cthread_detach (__cthread_t thread)
+{
+  int err;
+
+  err = pthread_detach ((pthread_t) thread);
+  assert_perror (err);
+}
+weak_alias (__cthread_detach, cthread_detach)
+
+__cthread_t
+__cthread_fork (__cthread_fn_t func, void *arg)
+{
+  pthread_t thread;
+  int err;
+
+  err = pthread_create (&thread, NULL, func, arg);
+  assert_perror (err);
+
+  return (__cthread_t) thread;
+}
+weak_alias (__cthread_fork, cthread_fork)
+
+int
+__cthread_keycreate (__cthread_key_t *key)
+{
+  error_t err;
+
+  err = pthread_key_create (key, 0);
+  if (err)
+    {
+      errno = err;
+      *key = CTHREAD_KEY_INVALID;
+      err = -1;
+    }
+
+  return err;
+}
+weak_alias (__cthread_keycreate, cthread_keycreate)
+
+int
+__cthread_getspecific (__cthread_key_t key, void **val)
+{
+  *val = pthread_getspecific (key);
+  return 0;
+}
+weak_alias (__cthread_getspecific, cthread_getspecific)
+
+int
+__cthread_setspecific (__cthread_key_t key, void *val)
+{
+  error_t err;
+
+  err = pthread_setspecific (key, (const void *) val);
+  if (err)
+    {
+      errno = err;
+      err = -1;
+    }
+
+  return err;
+}
+weak_alias (__cthread_setspecific, cthread_setspecific)
+
+void
+__mutex_lock_solid (void *lock)
+{
+  __pthread_mutex_lock (lock);
+}
+
+void
+__mutex_unlock_solid (void *lock)
+{
+  if (__pthread_spin_trylock (lock) != 0)
+    /* Somebody already got the lock, that one will manage waking up others */
+    return;
+  __pthread_mutex_unlock (lock);
+}
diff --git a/htl/forward.c b/htl/forward.c
new file mode 100644
index 0000000..cb36ae2
--- /dev/null
+++ b/htl/forward.c
@@ -0,0 +1,283 @@
+/* Libc stubs for pthread functions.  Hurd pthread version.
+   Copyright (C) 2002-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library;  if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <dlfcn.h>
+#include <stdlib.h>
+#include <shlib-compat.h>
+#include <pthread-functions.h>
+#include <libc-lock.h>
+#include <fork.h>
+
+/* Pointers to the libc functions.  */
+struct pthread_functions __libc_pthread_functions attribute_hidden;
+int __libc_pthread_functions_init attribute_hidden;
+
+
+#define FORWARD2(name, rettype, decl, params, defaction) \
+rettype									      \
+name decl								      \
+{									      \
+  if (!__libc_pthread_functions_init)					      \
+    defaction;								      \
+									      \
+  return PTHFCT_CALL (ptr_##name, params);				      \
+}
+
+/* Same as FORWARD2, only without return.  */
+#define FORWARD_NORETURN(name, rettype, decl, params, defaction) \
+rettype									      \
+name decl								      \
+{									      \
+  if (!__libc_pthread_functions_init)					      \
+    defaction;								      \
+									      \
+  PTHFCT_CALL (ptr_##name, params);					      \
+}
+
+#define FORWARD(name, decl, params, defretval) \
+  FORWARD2 (name, int, decl, params, return defretval)
+
+FORWARD (pthread_attr_destroy, (pthread_attr_t *attr), (attr), 0)
+
+FORWARD (pthread_attr_init, (pthread_attr_t *attr), (attr), 0)
+
+FORWARD (pthread_attr_getdetachstate,
+	 (const pthread_attr_t *attr, int *detachstate), (attr, detachstate),
+	 0)
+FORWARD (pthread_attr_setdetachstate, (pthread_attr_t *attr, int detachstate),
+	 (attr, detachstate), 0)
+
+FORWARD (pthread_attr_getinheritsched,
+	 (const pthread_attr_t *attr, int *inherit), (attr, inherit), 0)
+FORWARD (pthread_attr_setinheritsched, (pthread_attr_t *attr, int inherit),
+	 (attr, inherit), 0)
+
+FORWARD (pthread_attr_getschedparam,
+	 (const pthread_attr_t *attr, struct sched_param *param),
+	 (attr, param), 0)
+FORWARD (pthread_attr_setschedparam,
+	 (pthread_attr_t *attr, const struct sched_param *param),
+	 (attr, param), 0)
+
+FORWARD (pthread_attr_getschedpolicy,
+	 (const pthread_attr_t *attr, int *policy), (attr, policy), 0)
+FORWARD (pthread_attr_setschedpolicy, (pthread_attr_t *attr, int policy),
+	 (attr, policy), 0)
+
+FORWARD (pthread_attr_getscope,
+	 (const pthread_attr_t *attr, int *scope), (attr, scope), 0)
+FORWARD (pthread_attr_setscope, (pthread_attr_t *attr, int scope),
+	 (attr, scope), 0)
+
+
+FORWARD (pthread_condattr_destroy, (pthread_condattr_t *attr), (attr), 0)
+FORWARD (pthread_condattr_init, (pthread_condattr_t *attr), (attr), 0)
+
+
+FORWARD (pthread_cond_broadcast, (pthread_cond_t *cond), (cond), 0)
+FORWARD (pthread_cond_destroy, (pthread_cond_t *cond), (cond), 0)
+FORWARD (pthread_cond_init,
+	 (pthread_cond_t *cond, const pthread_condattr_t *cond_attr),
+	 (cond, cond_attr), 0)
+FORWARD (pthread_cond_signal, (pthread_cond_t *cond), (cond), 0)
+FORWARD (pthread_cond_wait, (pthread_cond_t *cond, pthread_mutex_t *mutex),
+	 (cond, mutex), 0)
+FORWARD (pthread_cond_timedwait,
+	 (pthread_cond_t *cond, pthread_mutex_t *mutex,
+	  const struct timespec *abstime), (cond, mutex, abstime), 0)
+
+FORWARD (pthread_equal, (pthread_t thread1, pthread_t thread2),
+	 (thread1, thread2), 1)
+
+
+/* Use an alias to avoid warning, as pthread_exit is declared noreturn.  */
+FORWARD_NORETURN (__pthread_exit, void, (void *retval), (retval),
+		  exit (EXIT_SUCCESS))
+strong_alias (__pthread_exit, pthread_exit);
+
+
+FORWARD (pthread_getschedparam,
+	 (pthread_t target_thread, int *policy, struct sched_param *param),
+	 (target_thread, policy, param), 0)
+FORWARD (pthread_setschedparam,
+	 (pthread_t target_thread, int policy,
+	  const struct sched_param *param), (target_thread, policy, param), 0)
+
+
+FORWARD (pthread_mutex_destroy, (pthread_mutex_t *mutex), (mutex), 0)
+
+FORWARD (pthread_mutex_init,
+	 (pthread_mutex_t *mutex, const pthread_mutexattr_t *mutexattr),
+	 (mutex, mutexattr), 0)
+
+FORWARD (pthread_mutex_lock, (pthread_mutex_t *mutex), (mutex), 0)
+
+FORWARD (pthread_mutex_unlock, (pthread_mutex_t *mutex), (mutex), 0)
+
+
+FORWARD2 (pthread_self, pthread_t, (void), (), return 0)
+
+
+FORWARD (__pthread_setcancelstate, (int state, int *oldstate),
+	 (state, oldstate), 0)
+strong_alias (__pthread_setcancelstate, pthread_setcancelstate);
+
+FORWARD (pthread_setcanceltype, (int type, int *oldtype), (type, oldtype), 0)
+
+struct __pthread_cancelation_handler *dummy_list;
+FORWARD2 (__pthread_get_cleanup_stack, struct __pthread_cancelation_handler **,
+	  (void), (), return &dummy_list);
+
+
+/* Fork interaction */
+
+struct atfork
+{
+  void (*prepare) (void);
+  void (*parent) (void);
+  void (*child) (void);
+  void *dso_handle;
+  struct atfork *prev;
+  struct atfork *next;
+};
+
+/* TODO: better locking */
+__libc_lock_define_initialized (static, atfork_lock);
+static struct atfork *fork_handlers, *fork_last_handler;
+
+static void
+atfork_pthread_prepare (void)
+{
+  struct atfork *handlers, *last_handler;
+
+  __libc_lock_lock (atfork_lock);
+  handlers = fork_handlers;
+  last_handler = fork_last_handler;
+  __libc_lock_unlock (atfork_lock);
+
+  if (last_handler == NULL)
+    return;
+
+  while (1)
+    {
+      if (last_handler->prepare != NULL)
+	last_handler->prepare ();
+      if (last_handler == handlers)
+	break;
+      last_handler = last_handler->prev;
+    }
+}
+text_set_element (_hurd_atfork_prepare_hook, atfork_pthread_prepare);
+
+static void
+atfork_pthread_parent (void)
+{
+  struct atfork *handlers;
+
+  __libc_lock_lock (atfork_lock);
+  handlers = fork_handlers;
+  __libc_lock_unlock (atfork_lock);
+
+  while (handlers != NULL)
+    {
+      if (handlers->parent != NULL)
+	handlers->parent ();
+      handlers = handlers->next;
+    }
+}
+text_set_element (_hurd_atfork_parent_hook, atfork_pthread_parent);
+
+static void
+atfork_pthread_child (void)
+{
+  struct atfork *handlers;
+
+  __libc_lock_lock (atfork_lock);
+  handlers = fork_handlers;
+  __libc_lock_unlock (atfork_lock);
+
+  while (handlers != NULL)
+    {
+      if (handlers->child != NULL)
+	handlers->child ();
+      handlers = handlers->next;
+    }
+}
+text_set_element (_hurd_atfork_child_hook, atfork_pthread_child);
+
+int
+__register_atfork (void (*prepare) (void),
+		   void (*parent) (void),
+		   void (*child) (void),
+		   void *dso_handle)
+{
+  struct atfork *new = malloc (sizeof (*new));
+  if (new == NULL)
+    return errno;
+
+  new->prepare = prepare;
+  new->parent = parent;
+  new->child = child;
+  new->dso_handle = dso_handle;
+  new->prev = NULL;
+
+  __libc_lock_lock (atfork_lock);
+  new->next = fork_handlers;
+  if (fork_handlers != NULL)
+    fork_handlers->prev = new;
+  fork_handlers = new;
+  if (fork_last_handler == NULL)
+    fork_last_handler = new;
+  __libc_lock_unlock (atfork_lock);
+
+  return 0;
+}
+libc_hidden_def (__register_atfork)
+
+void
+__unregister_atfork (void *dso_handle)
+{
+  struct atfork **handlers, *prev = NULL, *next;
+  __libc_lock_lock (atfork_lock);
+  handlers = &fork_handlers;
+  while (*handlers != NULL)
+    {
+      if ((*handlers)->dso_handle == dso_handle)
+	{
+	  /* Drop this handler from the list.  */
+	  if (*handlers == fork_last_handler)
+	    {
+	      /* Was last, new last is prev, if any.  */
+	      fork_last_handler = prev;
+	    }
+
+	  next = (*handlers)->next;
+	  if (next != NULL)
+	    next->prev = prev;
+	  *handlers = next;
+	}
+      else
+	{
+	  /* Just proceed to next handler.  */
+	  prev = *handlers;
+	  handlers = &prev->next;
+	}
+    }
+  __libc_lock_unlock (atfork_lock);
+}
diff --git a/htl/libc_pthread_init.c b/htl/libc_pthread_init.c
new file mode 100644
index 0000000..b6e9682
--- /dev/null
+++ b/htl/libc_pthread_init.c
@@ -0,0 +1,33 @@
+/* libc initialization for libpthread.  Hurd pthread version.
+   Copyright (C) 2002-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library;  if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <string.h>
+#include <pthread-functions.h>
+
+void
+__libc_pthread_init (const struct pthread_functions *functions)
+{
+#ifdef SHARED
+  /* We copy the content of the variable pointed to by the FUNCTIONS
+     parameter to one in libc.so since this means access to the array
+     can be done with one memory access instead of two.  */
+  memcpy (&__libc_pthread_functions, functions,
+	  sizeof (__libc_pthread_functions));
+  __libc_pthread_functions_init = 1;
+#endif
+}
diff --git a/htl/libpthread.a b/htl/libpthread.a
new file mode 100644
index 0000000..e5bd2cc
--- /dev/null
+++ b/htl/libpthread.a
@@ -0,0 +1,22 @@
+/* pthread initializer is weak in glibc.  It must be included if glibc
+   is to start threading. */
+EXTERN(_cthread_init_routine)
+
+/* Weak references in glibc that must be filled if glibc is to be
+   thread safe.  */
+EXTERN(cthread_detach)
+EXTERN(cthread_fork)
+EXTERN(cthread_keycreate)
+EXTERN(cthread_getspecific)
+EXTERN(cthread_setspecific)
+EXTERN(__mutex_lock_solid)
+EXTERN(__mutex_unlock_solid)
+/* For libio stream locking.  */
+EXTERN(_cthreads_flockfile)
+EXTERN(_cthreads_funlockfile)
+EXTERN(_cthreads_ftrylockfile)
+/* To get the sigthread stack layout on fork */
+EXTERN(pthread_getattr_np)
+EXTERN(pthread_attr_getstack)
+
+GROUP(-lpthread2 -lrt)
diff --git a/htl/libpthread_pic.a b/htl/libpthread_pic.a
new file mode 100644
index 0000000..33346b4
--- /dev/null
+++ b/htl/libpthread_pic.a
@@ -0,0 +1,22 @@
+/* pthread initializer is weak in glibc.  It must be included if glibc
+   is to start threading. */
+EXTERN(_cthread_init_routine)
+
+/* Weak references in glibc that must be filled if glibc is to be
+   thread safe.  */
+EXTERN(cthread_detach)
+EXTERN(cthread_fork)
+EXTERN(cthread_keycreate)
+EXTERN(cthread_getspecific)
+EXTERN(cthread_setspecific)
+EXTERN(__mutex_lock_solid)
+EXTERN(__mutex_unlock_solid)
+/* For libio stream locking.  */
+EXTERN(_cthreads_flockfile)
+EXTERN(_cthreads_funlockfile)
+EXTERN(_cthreads_ftrylockfile)
+/* To get the sigthread stack layout on fork */
+EXTERN(pthread_getattr_np)
+EXTERN(pthread_attr_getstack)
+
+GROUP(-lpthread2_pic)
diff --git a/htl/lockfile.c b/htl/lockfile.c
new file mode 100644
index 0000000..9069496
--- /dev/null
+++ b/htl/lockfile.c
@@ -0,0 +1,60 @@
+/* lockfile - Handle locking and unlocking of streams.  Hurd pthread version.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <cthreads.h>
+#include <pthread.h>		/* Must come before <stdio.h>! */
+#include <stdio.h>
+
+void
+_cthreads_flockfile (FILE *fp)
+{
+  _IO_lock_lock (*fp->_lock);
+}
+
+void
+_cthreads_funlockfile (FILE *fp)
+{
+  _IO_lock_unlock (*fp->_lock);
+}
+
+int
+_cthreads_ftrylockfile (FILE *fp)
+{
+  return __libc_lock_trylock_recursive (*fp->_lock);
+}
+
+#undef	_IO_flockfile
+#undef	_IO_funlockfile
+#undef	_IO_ftrylockfile
+#undef	flockfile
+#undef	funlockfile
+#undef	ftrylockfile
+
+void _IO_flockfile (FILE *)
+     __attribute__ ((alias ("_cthreads_flockfile")));
+void _IO_funlockfile (FILE *)
+     __attribute__ ((alias ("_cthreads_funlockfile")));
+int _IO_ftrylockfile (FILE *)
+     __attribute__ ((alias ("_cthreads_ftrylockfile")));
+
+void flockfile (FILE *)
+     __attribute__ ((alias ("_cthreads_flockfile")));
+void funlockfile (FILE *)
+     __attribute__ ((alias ("_cthreads_funlockfile")));
+int ftrylockfile (FILE *)
+     __attribute__ ((alias ("_cthreads_ftrylockfile")));
diff --git a/htl/pt-alloc.c b/htl/pt-alloc.c
new file mode 100644
index 0000000..adab790
--- /dev/null
+++ b/htl/pt-alloc.c
@@ -0,0 +1,214 @@
+/* Allocate a new thread structure.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <assert.h>
+#include <errno.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <pt-internal.h>
+
+/* This braindamage is necessary because the standard says that some
+   of the threads functions "shall fail" if "No thread could be found
+   corresponding to that specified by the given thread ID."  */
+
+/* Thread ID lookup table.  */
+struct __pthread **__pthread_threads;
+
+/* The size of the thread ID lookup table.  */
+int __pthread_max_threads;
+
+/* The total number of thread IDs currently in use, or on the list of
+   available thread IDs.  */
+int __pthread_num_threads;
+
+/* A lock for the table, and the other variables above.  */
+pthread_rwlock_t __pthread_threads_lock;
+
+/* List of thread structures corresponding to free thread IDs.  */
+struct __pthread *__pthread_free_threads;
+pthread_mutex_t __pthread_free_threads_lock;
+
+static inline error_t
+initialize_pthread (struct __pthread *new)
+{
+  error_t err;
+
+  err = __pthread_init_specific (new);
+  if (err)
+    return err;
+
+  new->nr_refs = 1;
+  new->cancel_lock = (pthread_mutex_t) PTHREAD_MUTEX_INITIALIZER;
+  new->cancel_hook = NULL;
+  new->cancel_hook_arg = NULL;
+  new->cancel_state = PTHREAD_CANCEL_ENABLE;
+  new->cancel_type = PTHREAD_CANCEL_DEFERRED;
+  new->cancel_pending = 0;
+
+  new->state_lock = (pthread_mutex_t) PTHREAD_MUTEX_INITIALIZER;
+  new->state_cond = (pthread_cond_t) PTHREAD_COND_INITIALIZER;
+
+  new->cancelation_handlers = 0;
+
+  memset (&new->res_state, '\0', sizeof (new->res_state));
+
+  new->tcb = NULL;
+
+  new->next = 0;
+  new->prevp = 0;
+
+  return 0;
+}
+
+
+/* Allocate a new thread structure and its pthread thread ID (but not
+   a kernel thread).  */
+int
+__pthread_alloc (struct __pthread **pthread)
+{
+  error_t err;
+
+  struct __pthread *new;
+  struct __pthread **threads;
+  struct __pthread **old_threads;
+  int max_threads;
+  int new_max_threads;
+
+  pthread_mutex_lock (&__pthread_free_threads_lock);
+  for (new = __pthread_free_threads; new; new = new->next)
+    {
+      /* There is no need to take NEW->STATE_LOCK: if NEW is on this
+         list, then it is protected by __PTHREAD_FREE_THREADS_LOCK
+         except in __pthread_dealloc where after it is added to the
+         list (with the lock held), it drops the lock and then sets
+         NEW->STATE and immediately stops using NEW.  */
+      if (new->state == PTHREAD_TERMINATED)
+	{
+	  __pthread_dequeue (new);
+	  break;
+	}
+    }
+  pthread_mutex_unlock (&__pthread_free_threads_lock);
+
+  if (new)
+    {
+      if (new->tcb)
+	{
+	  /* Drop old values */
+	  _dl_deallocate_tls (new->tcb, 1);
+	}
+
+      err = initialize_pthread (new);
+      if (!err)
+	*pthread = new;
+      return err;
+    }
+
+  /* Allocate a new thread structure.  */
+  new = malloc (sizeof (struct __pthread));
+  if (new == NULL)
+    return ENOMEM;
+
+  err = initialize_pthread (new);
+  if (err)
+    {
+      free (new);
+      return err;
+    }
+
+retry:
+  __pthread_rwlock_wrlock (&__pthread_threads_lock);
+
+  if (__pthread_num_threads < __pthread_max_threads)
+    {
+      /* We have a free slot.  Use the slot number plus one as the
+         thread ID for the new thread.  */
+      new->thread = 1 + __pthread_num_threads++;
+      __pthread_threads[new->thread - 1] = NULL;
+
+      __pthread_rwlock_unlock (&__pthread_threads_lock);
+
+      *pthread = new;
+      return 0;
+    }
+#ifdef PTHREAD_THREADS_MAX
+  else if (__pthread_num_threads >= PTHREAD_THREADS_MAX)
+    {
+      /* We have reached the limit on the number of threads per process.  */
+      __pthread_rwlock_unlock (&__pthread_threads_lock);
+
+      free (new);
+      return EAGAIN;
+    }
+#endif
+
+  /* We are going to enlarge the threads table.  Save its current
+     size.  We're going to release the lock before doing the necessary
+     memory allocation, since that's a potentially blocking operation.  */
+  max_threads = __pthread_max_threads;
+
+  __pthread_rwlock_unlock (&__pthread_threads_lock);
+
+  /* Allocate a new lookup table that's twice as large.  */
+  new_max_threads
+      = max_threads > 0 ? max_threads * 2 : _POSIX_THREAD_THREADS_MAX;
+  threads = malloc (new_max_threads * sizeof (struct __pthread *));
+  if (threads == NULL)
+    {
+      free (new);
+      return ENOMEM;
+    }
+
+  __pthread_rwlock_wrlock (&__pthread_threads_lock);
+
+  /* Check if nobody else has already enlarged the table.  */
+  if (max_threads != __pthread_max_threads)
+    {
+      /* Yep, they did.  */
+      __pthread_rwlock_unlock (&__pthread_threads_lock);
+
+      /* Free the newly allocated table and try again to allocate a slot.  */
+      free (threads);
+      goto retry;
+    }
+
+  /* Copy over the contents of the old table.  */
+  memcpy (threads, __pthread_threads,
+	  __pthread_max_threads * sizeof (struct __pthread *));
+
+  /* Save the location of the old table.  We want to deallocate its
+     storage after we released the lock.  */
+  old_threads = __pthread_threads;
+
+  /* Replace the table with the new one.  */
+  __pthread_max_threads = new_max_threads;
+  __pthread_threads = threads;
+
+  /* And allocate ourselves one of the newly created slots.  */
+  new->thread = 1 + __pthread_num_threads++;
+  __pthread_threads[new->thread - 1] = NULL;
+
+  __pthread_rwlock_unlock (&__pthread_threads_lock);
+
+  free (old_threads);
+
+  *pthread = new;
+  return 0;
+}
diff --git a/htl/pt-cancel.c b/htl/pt-cancel.c
new file mode 100644
index 0000000..9f87724
--- /dev/null
+++ b/htl/pt-cancel.c
@@ -0,0 +1,62 @@
+/* Cancel a thread.
+   Copyright (C) 2002-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+
+#include <pt-internal.h>
+
+int
+pthread_cancel (pthread_t t)
+{
+  int err = 0;
+  struct __pthread *p;
+
+  p = __pthread_getid (t);
+  if (p == NULL)
+    return ESRCH;
+
+  __pthread_mutex_lock (&p->cancel_lock);
+  if (p->cancel_pending)
+    {
+      __pthread_mutex_unlock (&p->cancel_lock);
+      return 0;
+    }
+
+  p->cancel_pending = 1;
+
+  if (p->cancel_state != PTHREAD_CANCEL_ENABLE)
+    {
+      __pthread_mutex_unlock (&p->cancel_lock);
+      return 0;
+    }
+
+  if (p->cancel_type == PTHREAD_CANCEL_ASYNCHRONOUS)
+    /* CANCEL_LOCK is unlocked by this call.  */
+    err = __pthread_do_cancel (p);
+  else
+    {
+      if (p->cancel_hook != NULL)
+	/* Thread blocking on a cancellation point.  Invoke hook to unblock.
+	   See __pthread_cond_timedwait_internal.  */
+	p->cancel_hook (p->cancel_hook_arg);
+
+      __pthread_mutex_unlock (&p->cancel_lock);
+    }
+
+  return err;
+}
diff --git a/htl/pt-cleanup.c b/htl/pt-cleanup.c
new file mode 100644
index 0000000..74c86b2
--- /dev/null
+++ b/htl/pt-cleanup.c
@@ -0,0 +1,27 @@
+/* Add a cancelation handler to the stack.
+   Copyright (C) 2002-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+
+#include <pt-internal.h>
+
+struct __pthread_cancelation_handler **
+__pthread_get_cleanup_stack (void)
+{
+  return &_pthread_self ()->cancelation_handlers;
+}
diff --git a/htl/pt-create.c b/htl/pt-create.c
new file mode 100644
index 0000000..f5c06ff
--- /dev/null
+++ b/htl/pt-create.c
@@ -0,0 +1,246 @@
+/* Thread creation.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <assert.h>
+#include <errno.h>
+#include <pthread.h>
+#include <signal.h>
+#include <resolv.h>
+
+#include <atomic.h>
+#include <hurd/resource.h>
+
+#include <pt-internal.h>
+
+#if IS_IN (libpthread)
+# include <ctype.h>
+#endif
+#ifdef HAVE_USELOCALE
+# include <locale.h>
+#endif
+
+/* The total number of pthreads currently active.  This is defined
+   here since it would be really stupid to have a threads-using
+   program that doesn't call `pthread_create'.  */
+unsigned int __pthread_total;
+
+
+/* The entry-point for new threads.  */
+static void
+entry_point (struct __pthread *self, void *(*start_routine) (void *), void *arg)
+{
+  ___pthread_self = self;
+  __resp = &self->res_state;
+
+#if IS_IN (libpthread)
+  /* Initialize pointers to locale data.  */
+  __ctype_init ();
+#endif
+#ifdef HAVE_USELOCALE
+  /* A fresh thread needs to be bound to the global locale.  */
+  uselocale (LC_GLOBAL_LOCALE);
+#endif
+
+  __pthread_startup ();
+
+  pthread_exit (start_routine (arg));
+}
+
+/* Create a thread with attributes given by ATTR, executing
+   START_ROUTINE with argument ARG.  */
+int
+pthread_create (pthread_t * thread, const pthread_attr_t * attr,
+		void *(*start_routine) (void *), void *arg)
+{
+  int err;
+  struct __pthread *pthread;
+
+  err = __pthread_create_internal (&pthread, attr, start_routine, arg);
+  if (!err)
+    *thread = pthread->thread;
+  else if (err == ENOMEM)
+    err = EAGAIN;
+
+  return err;
+}
+
+/* Internal version of pthread_create.  See comment in
+   pt-internal.h.  */
+int
+__pthread_create_internal (struct __pthread **thread,
+			   const pthread_attr_t * attr,
+			   void *(*start_routine) (void *), void *arg)
+{
+  int err;
+  struct __pthread *pthread;
+  const struct __pthread_attr *setup;
+  sigset_t sigset;
+  size_t stacksize;
+
+  /* Allocate a new thread structure.  */
+  err = __pthread_alloc (&pthread);
+  if (err)
+    goto failed;
+
+  /* Use the default attributes if ATTR is NULL.  */
+  setup = attr ? attr : &__pthread_default_attr;
+
+  stacksize = setup->__stacksize;
+  if (stacksize == 0)
+    {
+      struct rlimit rlim;
+      __getrlimit (RLIMIT_STACK, &rlim);
+      if (rlim.rlim_cur != RLIM_INFINITY)
+	stacksize = rlim.rlim_cur;
+      if (stacksize == 0)
+	stacksize = PTHREAD_STACK_DEFAULT;
+    }
+
+  /* Initialize the thread state.  */
+  pthread->state = (setup->__detachstate == PTHREAD_CREATE_DETACHED
+		    ? PTHREAD_DETACHED : PTHREAD_JOINABLE);
+
+  if (setup->__stackaddr)
+    {
+      pthread->stackaddr = setup->__stackaddr;
+
+      /* If the user supplied a stack, it is not our responsibility to
+         setup a stack guard.  */
+      pthread->guardsize = 0;
+      pthread->stack = 0;
+    }
+  else
+    {
+      /* Allocate a stack.  */
+      err = __pthread_stack_alloc (&pthread->stackaddr,
+				   ((setup->__guardsize + __vm_page_size - 1)
+				    / __vm_page_size) * __vm_page_size
+				   + stacksize);
+      if (err)
+	goto failed_stack_alloc;
+
+      pthread->guardsize = setup->__guardsize;
+      pthread->stack = 1;
+    }
+
+  pthread->stacksize = stacksize;
+
+  /* Allocate the kernel thread and other required resources.  */
+  err = __pthread_thread_alloc (pthread);
+  if (err)
+    goto failed_thread_alloc;
+
+  pthread->tcb = _dl_allocate_tls (NULL);
+  if (pthread->tcb == NULL)
+    {
+      err = ENOMEM;
+      goto failed_thread_tls_alloc;
+    }
+  pthread->tcb->tcb = pthread->tcb;
+
+  /* And initialize the rest of the machine context.  This may include
+     additional machine- and system-specific initializations that
+     prove convenient.  */
+  err = __pthread_setup (pthread, entry_point, start_routine, arg);
+  if (err)
+    goto failed_setup;
+
+  /* Initialize the system-specific signal state for the new
+     thread.  */
+  err = __pthread_sigstate_init (pthread);
+  if (err)
+    goto failed_sigstate;
+
+  /* If the new thread is joinable, add a reference for the caller.  */
+  if (pthread->state == PTHREAD_JOINABLE)
+    pthread->nr_refs++;
+
+  /* Set the new thread's signal mask and set the pending signals to
+     empty.  POSIX says: "The signal mask shall be inherited from the
+     creating thread.  The set of signals pending for the new thread
+     shall be empty."  If the currnet thread is not a pthread then we
+     just inherit the process' sigmask.  */
+  if (__pthread_num_threads == 1)
+    err = sigprocmask (0, 0, &sigset);
+  else
+    err = __pthread_sigstate (_pthread_self (), 0, 0, &sigset, 0);
+  assert_perror (err);
+
+  err = __pthread_sigstate (pthread, SIG_SETMASK, &sigset, 0, 1);
+  assert_perror (err);
+
+  /* Increase the total number of threads.  We do this before actually
+     starting the new thread, since the new thread might immediately
+     call `pthread_exit' which decreases the number of threads and
+     calls `exit' if the number of threads reaches zero.  Increasing
+     the number of threads from within the new thread isn't an option
+     since this thread might return and call `pthread_exit' before the
+     new thread runs.  */
+  atomic_increment (&__pthread_total);
+
+  /* Store a pointer to this thread in the thread ID lookup table.  We
+     could use __thread_setid, however, we only lock for reading as no
+     other thread should be using this entry (we also assume that the
+     store is atomic).  */
+  __pthread_rwlock_rdlock (&__pthread_threads_lock);
+  __pthread_threads[pthread->thread - 1] = pthread;
+  __pthread_rwlock_unlock (&__pthread_threads_lock);
+
+  /* At this point it is possible to guess our pthread ID.  We have to
+     make sure that all functions taking a pthread_t argument can
+     handle the fact that this thread isn't really running yet.  Since
+     the new thread might be passed its ID through pthread_create (to
+     avoid calling pthread_self), read it before starting the thread.  */
+  *thread = pthread;
+
+  /* Schedule the new thread.  */
+  err = __pthread_thread_start (pthread);
+  if (err)
+    goto failed_starting;
+
+
+  return 0;
+
+failed_starting:
+  /* If joinable, a reference was added for the caller.  */
+  if (pthread->state == PTHREAD_JOINABLE)
+    __pthread_dealloc (pthread);
+
+  __pthread_setid (pthread->thread, NULL);
+  atomic_decrement (&__pthread_total);
+failed_sigstate:
+  __pthread_sigstate_destroy (pthread);
+failed_setup:
+  _dl_deallocate_tls (pthread->tcb, 1);
+  pthread->tcb = NULL;
+failed_thread_tls_alloc:
+  __pthread_thread_terminate (pthread);
+
+  /* __pthread_thread_terminate has taken care of deallocating the stack and
+     the thread structure.  */
+  goto failed;
+failed_thread_alloc:
+  if (pthread->stack)
+    __pthread_stack_dealloc (pthread->stackaddr,
+			     ((setup->__guardsize + __vm_page_size - 1)
+			      / __vm_page_size) * __vm_page_size + stacksize);
+failed_stack_alloc:
+  __pthread_dealloc (pthread);
+failed:
+  return err;
+}
diff --git a/htl/pt-dealloc.c b/htl/pt-dealloc.c
new file mode 100644
index 0000000..15e251e
--- /dev/null
+++ b/htl/pt-dealloc.c
@@ -0,0 +1,68 @@
+/* Deallocate a thread structure.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <assert.h>
+#include <pthread.h>
+#include <stdlib.h>
+
+#include <pt-internal.h>
+
+#include <atomic.h>
+
+/* List of thread structures corresponding to free thread IDs.  */
+extern struct __pthread *__pthread_free_threads;
+extern pthread_mutex_t __pthread_free_threads_lock;
+
+
+/* Deallocate the thread structure for PTHREAD.  */
+void
+__pthread_dealloc (struct __pthread *pthread)
+{
+  assert (pthread->state != PTHREAD_TERMINATED);
+
+  if (!atomic_decrement_and_test (&pthread->nr_refs))
+    return;
+
+  /* Withdraw this thread from the thread ID lookup table.  */
+  __pthread_setid (pthread->thread, NULL);
+
+  /* Mark the thread as terminated.  We broadcast the condition
+     here to prevent pthread_join from waiting for this thread to
+     exit where it was never really started.  Such a call to
+     pthread_join is completely bogus, but unfortunately allowed
+     by the standards.  */
+  __pthread_mutex_lock (&pthread->state_lock);
+  if (pthread->state != PTHREAD_EXITED)
+    __pthread_cond_broadcast (&pthread->state_cond);
+  __pthread_mutex_unlock (&pthread->state_lock);
+
+  /* We do not actually deallocate the thread structure, but add it to
+     a list of re-usable thread structures.  */
+  __pthread_mutex_lock (&__pthread_free_threads_lock);
+  __pthread_enqueue (&__pthread_free_threads, pthread);
+  __pthread_mutex_unlock (&__pthread_free_threads_lock);
+
+  /* Setting PTHREAD->STATE to PTHREAD_TERMINATED makes this TCB
+     available for reuse.  After that point, we can no longer assume
+     that PTHREAD is valid.
+
+     Note that it is safe to not lock this update to PTHREAD->STATE:
+     the only way that it can now be accessed is in __pthread_alloc,
+     which reads this variable.  */
+  pthread->state = PTHREAD_TERMINATED;
+}
diff --git a/htl/pt-detach.c b/htl/pt-detach.c
new file mode 100644
index 0000000..773ed10
--- /dev/null
+++ b/htl/pt-detach.c
@@ -0,0 +1,79 @@
+/* Detach a thread.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <pthread.h>
+#include <stddef.h>
+
+#include <pt-internal.h>
+
+/* Indicate that the storage for THREAD can be reclaimed when it
+   terminates.  */
+int
+pthread_detach (pthread_t thread)
+{
+  struct __pthread *pthread;
+  int err = 0;
+
+  /* Lookup the thread structure for THREAD.  */
+  pthread = __pthread_getid (thread);
+  if (pthread == NULL)
+    return ESRCH;
+
+  __pthread_mutex_lock (&pthread->state_lock);
+
+  switch (pthread->state)
+    {
+    case PTHREAD_JOINABLE:
+      /* THREAD still running.  Mark it as detached such that its
+         resources can be reclaimed as soon as the thread exits.  */
+      pthread->state = PTHREAD_DETACHED;
+
+      /* Broadcast the condition.  This will make threads that are
+         waiting to join THREAD continue with hopefully disastrous
+         consequences instead of blocking indefinitely.  */
+      pthread_cond_broadcast (&pthread->state_cond);
+      __pthread_mutex_unlock (&pthread->state_lock);
+
+      __pthread_dealloc (pthread);
+      break;
+
+    case PTHREAD_EXITED:
+      __pthread_mutex_unlock (&pthread->state_lock);
+
+      /* THREAD has already exited.  PTHREAD remained after the thread
+         exited in order to provide the exit status, but it turns out
+         it won't be needed.  */
+      __pthread_dealloc (pthread);
+      break;
+
+    case PTHREAD_TERMINATED:
+      /* Pretend THREAD wasn't there in the first place.  */
+      __pthread_mutex_unlock (&pthread->state_lock);
+      err = ESRCH;
+      break;
+
+    default:
+      /* Thou shalt not detach non-joinable threads!  */
+      __pthread_mutex_unlock (&pthread->state_lock);
+      err = EINVAL;
+      break;
+    }
+
+  return err;
+}
diff --git a/htl/pt-exit.c b/htl/pt-exit.c
new file mode 100644
index 0000000..8f3d755
--- /dev/null
+++ b/htl/pt-exit.c
@@ -0,0 +1,111 @@
+/* Thread termination.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <assert.h>
+#include <errno.h>
+#include <pthread.h>
+#include <stdlib.h>
+
+#include <pt-internal.h>
+
+#include <atomic.h>
+
+
+/* Terminate the current thread and make STATUS available to any
+   thread that might join it.  */
+void
+__pthread_exit (void *status)
+{
+  struct __pthread *self = _pthread_self ();
+  struct __pthread_cancelation_handler **handlers;
+  int oldstate;
+
+  /* Run any cancelation handlers.  According to POSIX, the
+     cancellation cleanup handlers should be called with cancellation
+     disabled.  */
+  pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &oldstate);
+
+  for (handlers = __pthread_get_cleanup_stack ();
+       *handlers != NULL;
+       *handlers = (*handlers)->__next)
+    (*handlers)->__handler ((*handlers)->__arg);
+
+  pthread_setcancelstate (oldstate, &oldstate);
+
+  /* Decrease the number of threads.  We use an atomic operation to
+     make sure that only the last thread calls `exit'.  */
+  if (atomic_decrement_and_test (&__pthread_total))
+    /* We are the last thread.  */
+    exit (0);
+
+  /* Note that after this point the process can be terminated at any
+     point if another thread calls `pthread_exit' and happens to be
+     the last thread.  */
+
+  __pthread_mutex_lock (&self->state_lock);
+
+  if (self->cancel_state == PTHREAD_CANCEL_ENABLE && self->cancel_pending)
+    status = PTHREAD_CANCELED;
+
+  switch (self->state)
+    {
+    default:
+      assert (!"Consistency error: unexpected self->state");
+      abort ();
+      break;
+
+    case PTHREAD_DETACHED:
+      __pthread_mutex_unlock (&self->state_lock);
+
+      break;
+
+    case PTHREAD_JOINABLE:
+      /* We need to stay around for a while since another thread
+         might want to join us.  */
+      self->state = PTHREAD_EXITED;
+
+      /* We need to remember the exit status.  A thread joining us
+         might ask for it.  */
+      self->status = status;
+
+      /* Broadcast the condition.  This will wake up threads that are
+         waiting to join us.  */
+      __pthread_cond_broadcast (&self->state_cond);
+      __pthread_mutex_unlock (&self->state_lock);
+
+      break;
+    }
+
+  /* Destroy any thread specific data.  */
+  __pthread_destroy_specific (self);
+
+  /* Destroy any signal state.  */
+  __pthread_sigstate_destroy (self);
+
+  /* Self terminating requires TLS, so defer the release of the TCB until
+     the thread structure is reused.  */
+
+  /* Release kernel resources, including the kernel thread and the stack,
+     and drop the self reference.  */
+  __pthread_thread_terminate (self);
+
+  /* NOTREACHED */
+  abort ();
+}
+
+strong_alias (__pthread_exit, pthread_exit);
diff --git a/htl/pt-getattr.c b/htl/pt-getattr.c
new file mode 100644
index 0000000..b1ec5e0
--- /dev/null
+++ b/htl/pt-getattr.c
@@ -0,0 +1,51 @@
+/* Thread attributes retrieval.
+   Copyright (C) 2008-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <assert.h>
+#include <errno.h>
+#include <pthread.h>
+
+#include <pt-internal.h>
+
+/* Initialize thread attribute *ATTR with attributes corresponding to the
+   already running thread THREAD.  It shall be called on an uninitialized ATTR
+   and destroyed with pthread_attr_destroy when no longer needed.  */
+int
+__pthread_getattr_np (pthread_t thread, pthread_attr_t *attr)
+{
+  struct __pthread *pthread;
+
+  pthread = __pthread_getid (thread);
+  if (pthread == NULL)
+    return ESRCH;
+
+  /* Some attributes (schedparam, inheritsched, contentionscope and schedpolicy)
+     are not supported yet, so fill them with our default values.  */
+  *attr = __pthread_default_attr;
+
+  attr->__stackaddr = pthread->stackaddr +
+      ((pthread->guardsize + __vm_page_size - 1)
+       / __vm_page_size * __vm_page_size);
+  attr->__stacksize = pthread->stacksize;
+  attr->__guardsize = pthread->guardsize;
+  attr->__detachstate = (pthread->state == PTHREAD_DETACHED
+			 ? PTHREAD_CREATE_DETACHED : PTHREAD_CREATE_JOINABLE);
+
+  return 0;
+}
+weak_alias (__pthread_getattr_np, pthread_getattr_np)
diff --git a/htl/pt-initialize.c b/htl/pt-initialize.c
new file mode 100644
index 0000000..201810f
--- /dev/null
+++ b/htl/pt-initialize.c
@@ -0,0 +1,83 @@
+/* Initialize pthreads library.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <assert.h>
+#include <string.h>
+
+#include <pt-internal.h>
+#include <set-hooks.h>
+
+#include <pthread.h>
+#include <pthread-functions.h>
+
+#if IS_IN (libpthread)
+static const struct pthread_functions pthread_functions = {
+  .ptr_pthread_attr_destroy = __pthread_attr_destroy,
+  .ptr_pthread_attr_init = __pthread_attr_init,
+  .ptr_pthread_attr_getdetachstate = __pthread_attr_getdetachstate,
+  .ptr_pthread_attr_setdetachstate = __pthread_attr_setdetachstate,
+  .ptr_pthread_attr_getinheritsched = __pthread_attr_getinheritsched,
+  .ptr_pthread_attr_setinheritsched = __pthread_attr_setinheritsched,
+  .ptr_pthread_attr_getschedparam = __pthread_attr_getschedparam,
+  .ptr_pthread_attr_setschedparam = __pthread_attr_setschedparam,
+  .ptr_pthread_attr_getschedpolicy = __pthread_attr_getschedpolicy,
+  .ptr_pthread_attr_setschedpolicy = __pthread_attr_setschedpolicy,
+  .ptr_pthread_attr_getscope = __pthread_attr_getscope,
+  .ptr_pthread_attr_setscope = __pthread_attr_setscope,
+  .ptr_pthread_condattr_destroy = __pthread_condattr_destroy,
+  .ptr_pthread_condattr_init = __pthread_condattr_init,
+  .ptr_pthread_cond_broadcast = __pthread_cond_broadcast,
+  .ptr_pthread_cond_destroy = __pthread_cond_destroy,
+  .ptr_pthread_cond_init = __pthread_cond_init,
+  .ptr_pthread_cond_signal = __pthread_cond_signal,
+  .ptr_pthread_cond_wait = __pthread_cond_wait,
+  .ptr_pthread_cond_timedwait = __pthread_cond_timedwait,
+  .ptr_pthread_equal = __pthread_equal,
+  .ptr___pthread_exit = __pthread_exit,
+  .ptr_pthread_getschedparam = __pthread_getschedparam,
+  .ptr_pthread_setschedparam = __pthread_setschedparam,
+  .ptr_pthread_mutex_destroy = _pthread_mutex_destroy,
+  .ptr_pthread_mutex_init = _pthread_mutex_init,
+  .ptr_pthread_mutex_lock = __pthread_mutex_lock,
+  .ptr_pthread_mutex_trylock = __pthread_mutex_trylock,
+  .ptr_pthread_mutex_unlock = __pthread_mutex_unlock,
+  .ptr_pthread_self = __pthread_self,
+  .ptr___pthread_setcancelstate = __pthread_setcancelstate,
+  .ptr_pthread_setcanceltype = __pthread_setcanceltype,
+  .ptr___pthread_get_cleanup_stack = __pthread_get_cleanup_stack,
+  .ptr_pthread_once = __pthread_once,
+  .ptr_pthread_rwlock_rdlock = __pthread_rwlock_rdlock,
+  .ptr_pthread_rwlock_wrlock = __pthread_rwlock_wrlock,
+  .ptr_pthread_rwlock_unlock = __pthread_rwlock_unlock,
+  .ptr___pthread_key_create = __pthread_key_create,
+  .ptr___pthread_getspecific = __pthread_getspecific,
+  .ptr___pthread_setspecific = __pthread_setspecific,
+  .ptr__IO_flockfile = _cthreads_flockfile,
+  .ptr__IO_funlockfile = _cthreads_funlockfile,
+  .ptr__IO_ftrylockfile = _cthreads_ftrylockfile,
+};
+#endif /* IS_IN (libpthread) */
+
+/* Initialize the pthreads library.  */
+void
+___pthread_init (void)
+{
+#if IS_IN (libpthread)
+  __libc_pthread_init (&pthread_functions);
+#endif
+}
diff --git a/htl/pt-internal.h b/htl/pt-internal.h
new file mode 100644
index 0000000..22afc1f
--- /dev/null
+++ b/htl/pt-internal.h
@@ -0,0 +1,324 @@
+/* Internal defenitions for pthreads library.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef _PT_INTERNAL_H
+#define _PT_INTERNAL_H	1
+
+#include <pthread.h>
+#include <stddef.h>
+#include <sched.h>
+#include <signal.h>
+#include <assert.h>
+#include <bits/types/res_state.h>
+
+#include <atomic.h>
+
+#include <pt-key.h>
+
+#include <pt-sysdep.h>
+#include <pt-machdep.h>
+
+#if IS_IN (libpthread)
+# include <ldsodefs.h>
+#endif
+
+/* Thread state.  */
+enum pthread_state
+{
+  /* The thread is running and joinable.  */
+  PTHREAD_JOINABLE = 0,
+  /* The thread is running and detached.  */
+  PTHREAD_DETACHED,
+  /* A joinable thread exited and its return code is available.  */
+  PTHREAD_EXITED,
+  /* The thread structure is unallocated and available for reuse.  */
+  PTHREAD_TERMINATED
+};
+
+#ifndef PTHREAD_KEY_MEMBERS
+# define PTHREAD_KEY_MEMBERS
+#endif
+
+#ifndef PTHREAD_SYSDEP_MEMBERS
+# define PTHREAD_SYSDEP_MEMBERS
+#endif
+
+#if !(IS_IN (libpthread))
+/* Type of the TCB.  */
+typedef struct
+{
+  void *tcb;			/* Points to this structure.  */
+  void *dtv;			/* Vector of pointers to TLS data.  */
+  thread_t self;		/* This thread's control port.  */
+} tcbhead_t;
+#endif /* ! IS_IN (libpthread) */
+
+/* This structure describes a POSIX thread.  */
+struct __pthread
+{
+  /* Thread ID.  */
+  pthread_t thread;
+
+  unsigned int nr_refs;		/* Detached threads have a self reference only,
+				   while joinable threads have two references.
+				   These are used to keep the structure valid at
+				   thread destruction.  Detaching/joining a thread
+				   drops a reference.  */
+
+  /* Cancellation.  */
+  pthread_mutex_t cancel_lock;	/* Protect cancel_xxx members.  */
+  void (*cancel_hook) (void *);	/* Called to unblock a thread blocking
+				   in a cancellation point (namely,
+				   __pthread_cond_timedwait_internal).  */
+  void *cancel_hook_arg;
+  int cancel_state;
+  int cancel_type;
+  int cancel_pending;
+  struct __pthread_cancelation_handler *cancelation_handlers;
+
+  /* Thread stack.  */
+  void *stackaddr;
+  size_t stacksize;
+  size_t guardsize;
+  int stack;			/* Nonzero if the stack was allocated.  */
+
+  /* Exit status.  */
+  void *status;
+
+  /* Thread state.  */
+  enum pthread_state state;
+  pthread_mutex_t state_lock;	/* Locks the state.  */
+  pthread_cond_t state_cond;	/* Signalled when the state changes.  */
+
+  /* Resolver state.  */
+  struct __res_state res_state;
+
+  /* Thread context.  */
+  struct pthread_mcontext mcontext;
+
+  PTHREAD_KEY_MEMBERS
+
+  PTHREAD_SYSDEP_MEMBERS
+
+  tcbhead_t *tcb;
+
+  /* Queue links.  Since PREVP is used to determine if a thread has been
+     awaken, it must be protected by the queue lock.  */
+  struct __pthread *next, **prevp;
+};
+
+/* Enqueue an element THREAD on the queue *HEAD.  */
+static inline void
+__pthread_enqueue (struct __pthread **head, struct __pthread *thread)
+{
+  assert (thread->prevp == 0);
+
+  thread->next = *head;
+  thread->prevp = head;
+  if (*head)
+    (*head)->prevp = &thread->next;
+  *head = thread;
+}
+
+/* Dequeue the element THREAD from the queue it is connected to.  */
+static inline void
+__pthread_dequeue (struct __pthread *thread)
+{
+  assert (thread);
+  assert (thread->prevp);
+
+  if (thread->next)
+    thread->next->prevp = thread->prevp;
+  *thread->prevp = thread->next;
+  thread->prevp = 0;
+}
+
+/* Iterate over QUEUE storing each element in ELEMENT.  */
+#define __pthread_queue_iterate(queue, element)				\
+  for (struct __pthread *__pdi_next = (queue);				\
+       ((element) = __pdi_next)						\
+	 && ((__pdi_next = __pdi_next->next),				\
+	     1);							\
+       )
+
+/* Iterate over QUEUE dequeuing each element, storing it in
+   ELEMENT.  */
+#define __pthread_dequeuing_iterate(queue, element)			\
+  for (struct __pthread *__pdi_next = (queue);				\
+       ((element) = __pdi_next)						\
+	 && ((__pdi_next = __pdi_next->next),				\
+	     ((element)->prevp = 0),					\
+	     1);							\
+       )
+
+/* The total number of threads currently active.  */
+extern unsigned int __pthread_total;
+
+/* The total number of thread IDs currently in use, or on the list of
+   available thread IDs.  */
+extern int __pthread_num_threads;
+
+/* Concurrency hint.  */
+extern int __pthread_concurrency;
+
+/* Array of __pthread structures and its lock.  Indexed by the pthread
+   id minus one.  (Why not just use the pthread id?  Because some
+   brain-dead users of the pthread interface incorrectly assume that 0
+   is an invalid pthread id.)  */
+extern struct __pthread **__pthread_threads;
+extern pthread_rwlock_t __pthread_threads_lock;
+
+#define __pthread_getid(thread) \
+  ({ struct __pthread *__t;                                                  \
+     __pthread_rwlock_rdlock (&__pthread_threads_lock);                      \
+     __t = __pthread_threads[thread - 1];                                    \
+     __pthread_rwlock_unlock (&__pthread_threads_lock);                      \
+     __t; })
+
+#define __pthread_setid(thread, pthread) \
+  __pthread_rwlock_wrlock (&__pthread_threads_lock);                         \
+  __pthread_threads[thread - 1] = pthread;                                   \
+  __pthread_rwlock_unlock (&__pthread_threads_lock);
+
+/* Similar to pthread_self, but returns the thread descriptor instead
+   of the thread ID.  */
+#ifndef _pthread_self
+extern struct __pthread *_pthread_self (void);
+#endif
+
+
+/* Initialize the pthreads library.  */
+extern void ___pthread_init (void);
+
+/* Internal version of pthread_create.  Rather than return the new
+   tid, we return the whole __pthread structure in *PTHREAD.  */
+extern int __pthread_create_internal (struct __pthread **__restrict pthread,
+				      const pthread_attr_t *__restrict attr,
+				      void *(*start_routine) (void *),
+				      void *__restrict arg);
+
+/* Allocate a new thread structure and a pthread thread ID (but not a
+   kernel thread or a stack).  THREAD has one reference.  */
+extern int __pthread_alloc (struct __pthread **thread);
+
+/* Deallocate the thread structure.  This is the dual of
+   __pthread_alloc (N.B. it does not call __pthread_stack_dealloc nor
+   __pthread_thread_terminate).  THREAD loses one reference and is
+   released if the reference counter drops to 0.  */
+extern void __pthread_dealloc (struct __pthread *thread);
+
+
+/* Allocate a stack of size STACKSIZE.  The stack base shall be
+   returned in *STACKADDR.  */
+extern int __pthread_stack_alloc (void **stackaddr, size_t stacksize);
+
+/* Deallocate the stack STACKADDR of size STACKSIZE.  */
+extern void __pthread_stack_dealloc (void *stackaddr, size_t stacksize);
+
+
+/* Setup thread THREAD's context.  */
+extern int __pthread_setup (struct __pthread *__restrict thread,
+			    void (*entry_point) (struct __pthread *,
+						 void *(*)(void *),
+						 void *),
+			    void *(*start_routine) (void *),
+			    void *__restrict arg);
+
+
+/* Allocate a kernel thread (and any miscellaneous system dependent
+   resources) for THREAD; it must not be placed on the run queue.  */
+extern int __pthread_thread_alloc (struct __pthread *thread);
+
+/* Start THREAD making it eligible to run.  */
+extern int __pthread_thread_start (struct __pthread *thread);
+
+/* Terminate the kernel thread associated with THREAD, and deallocate its
+   stack as well as any other kernel resource associated with it.
+   In addition, THREAD looses one reference.
+
+   This function can be called by any thread, including the target thread.
+   Since some resources that are destroyed along the kernel thread are
+   stored in thread-local variables, the conditions required for this
+   function to behave correctly are a bit unusual : as long as the target
+   thread hasn't been started, any thread can terminate it, but once it
+   has started, no other thread can terminate it, so that thread-local
+   variables created by that thread are correctly released.  */
+extern void __pthread_thread_terminate (struct __pthread *thread);
+
+
+/* Called by a thread just before it calls the provided start
+   routine.  */
+extern void __pthread_startup (void);
+
+/* Block THREAD.  */
+extern void __pthread_block (struct __pthread *thread);
+
+/* Block THREAD until *ABSTIME is reached.  */
+extern error_t __pthread_timedblock (struct __pthread *__restrict thread,
+				     const struct timespec *__restrict abstime,
+				     clockid_t clock_id);
+
+/* Wakeup THREAD.  */
+extern void __pthread_wakeup (struct __pthread *thread);
+
+
+/* Perform a cancelation.  The CANCEL_LOCK member of the given thread must
+   be locked before calling this function, which must unlock it.  */
+extern int __pthread_do_cancel (struct __pthread *thread);
+
+
+/* Initialize the thread specific data structures.  THREAD must be the
+   calling thread.  */
+extern error_t __pthread_init_specific (struct __pthread *thread);
+
+/* Call the destructors on all of the thread specific data in THREAD.
+   THREAD must be the calling thread.  */
+extern void __pthread_destroy_specific (struct __pthread *thread);
+
+
+/* Initialize newly create thread *THREAD's signal state data
+   structures.  */
+extern error_t __pthread_sigstate_init (struct __pthread *thread);
+
+/* Destroy the signal state data structures associcated with thread
+   *THREAD.  */
+extern void __pthread_sigstate_destroy (struct __pthread *thread);
+
+/* Modify thread *THREAD's signal state.  */
+extern error_t __pthread_sigstate (struct __pthread *__restrict thread, int how,
+				   const sigset_t *__restrict set,
+				   sigset_t *__restrict oset,
+				   int clear_pending);
+
+
+/* Default thread attributes.  */
+extern const struct __pthread_attr __pthread_default_attr;
+
+/* Default barrier attributes.  */
+extern const struct __pthread_barrierattr __pthread_default_barrierattr;
+
+/* Default mutex attributes.  */
+extern const struct __pthread_mutexattr __pthread_default_mutexattr;
+
+/* Default rdlock attributes.  */
+extern const struct __pthread_rwlockattr __pthread_default_rwlockattr;
+
+/* Default condition attributes.  */
+extern const struct __pthread_condattr __pthread_default_condattr;
+
+#endif /* pt-internal.h */
diff --git a/htl/pt-join.c b/htl/pt-join.c
new file mode 100644
index 0000000..329163d
--- /dev/null
+++ b/htl/pt-join.c
@@ -0,0 +1,75 @@
+/* Wait for thread termination.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <pthread.h>
+#include <stddef.h>
+
+#include <pt-internal.h>
+
+/* Make calling thread wait for termination of thread THREAD.  Return
+   the exit status of the thread in *STATUS.  */
+int
+pthread_join (pthread_t thread, void **status)
+{
+  struct __pthread *pthread;
+  int err = 0;
+
+  /* Lookup the thread structure for THREAD.  */
+  pthread = __pthread_getid (thread);
+  if (pthread == NULL)
+    return ESRCH;
+
+  __pthread_mutex_lock (&pthread->state_lock);
+  pthread_cleanup_push ((void (*)(void *)) __pthread_mutex_unlock,
+			&pthread->state_lock);
+
+  /* Rely on pthread_cond_wait being a cancellation point to make
+     pthread_join one too.  */
+  while (pthread->state == PTHREAD_JOINABLE)
+    __pthread_cond_wait (&pthread->state_cond, &pthread->state_lock);
+
+  pthread_cleanup_pop (0);
+
+  switch (pthread->state)
+    {
+    case PTHREAD_EXITED:
+      /* THREAD has already exited.  Salvage its exit status.  */
+      if (status != NULL)
+	*status = pthread->status;
+
+      __pthread_mutex_unlock (&pthread->state_lock);
+
+      __pthread_dealloc (pthread);
+      break;
+
+    case PTHREAD_TERMINATED:
+      /* Pretend THREAD wasn't there in the first place.  */
+      __pthread_mutex_unlock (&pthread->state_lock);
+      err = ESRCH;
+      break;
+
+    default:
+      /* Thou shalt not join non-joinable threads!  */
+      __pthread_mutex_unlock (&pthread->state_lock);
+      err = EINVAL;
+      break;
+    }
+
+  return err;
+}
diff --git a/htl/pt-self.c b/htl/pt-self.c
new file mode 100644
index 0000000..0f932ac
--- /dev/null
+++ b/htl/pt-self.c
@@ -0,0 +1,33 @@
+/* Get calling thread's ID.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+
+#include <pt-internal.h>
+
+/* Return the thread ID of the calling thread.  */
+pthread_t
+__pthread_self (void)
+{
+  struct __pthread *self = _pthread_self ();
+  assert (self != NULL);
+
+  return self->thread;
+}
+
+strong_alias (__pthread_self, pthread_self);
diff --git a/htl/pt-setcancelstate.c b/htl/pt-setcancelstate.c
new file mode 100644
index 0000000..de5c688
--- /dev/null
+++ b/htl/pt-setcancelstate.c
@@ -0,0 +1,46 @@
+/* Set the cancel state for the calling thread.
+   Copyright (C) 2002-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+
+#include <pt-internal.h>
+
+int
+__pthread_setcancelstate (int state, int *oldstate)
+{
+  struct __pthread *p = _pthread_self ();
+
+  switch (state)
+    {
+    default:
+      return EINVAL;
+    case PTHREAD_CANCEL_ENABLE:
+    case PTHREAD_CANCEL_DISABLE:
+      break;
+    }
+
+  __pthread_mutex_lock (&p->cancel_lock);
+  if (oldstate != NULL)
+    *oldstate = p->cancel_state;
+  p->cancel_state = state;
+  __pthread_mutex_unlock (&p->cancel_lock);
+
+  return 0;
+}
+
+strong_alias (__pthread_setcancelstate, pthread_setcancelstate);
diff --git a/htl/pt-setcanceltype.c b/htl/pt-setcanceltype.c
new file mode 100644
index 0000000..0f29a43
--- /dev/null
+++ b/htl/pt-setcanceltype.c
@@ -0,0 +1,46 @@
+/* Set the cancel type for the calling thread.
+   Copyright (C) 2002-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+
+#include <pt-internal.h>
+
+int
+__pthread_setcanceltype (int type, int *oldtype)
+{
+  struct __pthread *p = _pthread_self ();
+
+  switch (type)
+    {
+    default:
+      return EINVAL;
+    case PTHREAD_CANCEL_DEFERRED:
+    case PTHREAD_CANCEL_ASYNCHRONOUS:
+      break;
+    }
+
+  __pthread_mutex_lock (&p->cancel_lock);
+  if (oldtype != NULL)
+    *oldtype = p->cancel_type;
+  p->cancel_type = type;
+  __pthread_mutex_unlock (&p->cancel_lock);
+
+  return 0;
+}
+
+strong_alias (__pthread_setcanceltype, pthread_setcanceltype);
diff --git a/htl/pt-sigmask.c b/htl/pt-sigmask.c
new file mode 100644
index 0000000..f55c508
--- /dev/null
+++ b/htl/pt-sigmask.c
@@ -0,0 +1,31 @@
+/* Get or set a thread's signal mask.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+#include <signal.h>
+
+#include <pt-internal.h>
+
+int
+pthread_sigmask (int how, const sigset_t *set, sigset_t *oset)
+{
+  struct __pthread *self = _pthread_self ();
+
+  /* Do not clear SELF's pending signals.  */
+  return __pthread_sigstate (self, how, set, oset, 0);
+}
diff --git a/htl/pt-spin-inlines.c b/htl/pt-spin-inlines.c
new file mode 100644
index 0000000..3797235
--- /dev/null
+++ b/htl/pt-spin-inlines.c
@@ -0,0 +1,33 @@
+/* Spin locks non-inline functions.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+/* <bits/types/__pthread_spinlock_t.h> declares some extern inline functions.  These
+   functions are declared additionally here for use when inlining is
+   not possible.  */
+
+#define _FORCE_INLINES
+#define __PT_SPIN_INLINE	/* empty */
+
+#include <pthread.h>
+
+/* Weak aliases for the spin lock functions.  */
+weak_alias (__pthread_spin_destroy, pthread_spin_destroy);
+weak_alias (__pthread_spin_init, pthread_spin_init);
+weak_alias (__pthread_spin_trylock, pthread_spin_trylock);
+weak_alias (__pthread_spin_lock, pthread_spin_lock);
+weak_alias (__pthread_spin_unlock, pthread_spin_unlock);
diff --git a/htl/pt-testcancel.c b/htl/pt-testcancel.c
new file mode 100644
index 0000000..783a6a6
--- /dev/null
+++ b/htl/pt-testcancel.c
@@ -0,0 +1,35 @@
+/* Add an explicit cancelation point.
+   Copyright (C) 2002-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+
+#include <pt-internal.h>
+
+void
+pthread_testcancel (void)
+{
+  struct __pthread *p = _pthread_self ();
+  int cancelled;
+
+  __pthread_mutex_lock (&p->cancel_lock);
+  cancelled = (p->cancel_state == PTHREAD_CANCEL_ENABLE) && p->cancel_pending;
+  __pthread_mutex_unlock (&p->cancel_lock);
+
+  if (cancelled)
+    pthread_exit (PTHREAD_CANCELED);
+}
diff --git a/htl/pt-yield.c b/htl/pt-yield.c
new file mode 100644
index 0000000..0dee959
--- /dev/null
+++ b/htl/pt-yield.c
@@ -0,0 +1,26 @@
+/* Yield the processor to another thread or process.
+   Copyright (C) 2010-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+#include <sched.h>
+
+int
+pthread_yield (void)
+{
+  return sched_yield ();
+}
diff --git a/htl/shlib-versions b/htl/shlib-versions
new file mode 100644
index 0000000..98e07a6
--- /dev/null
+++ b/htl/shlib-versions
@@ -0,0 +1 @@
+libpthread=0.3
diff --git a/htl/tests/Makefile b/htl/tests/Makefile
new file mode 100644
index 0000000..7177ad1
--- /dev/null
+++ b/htl/tests/Makefile
@@ -0,0 +1,40 @@
+ifdef INSTALL_ROOT
+INSTALL_ROOT_CPPFLAGS = -isystem $(INSTALL_ROOT)/include
+INSTALL_ROOT_LDFLAGS = -L$(INSTALL_ROOT)/lib -Wl,-rpath,$(INSTALL_ROOT)/lib
+endif
+
+CFLAGS=-Wall -g
+
+LDLIBS = -lpthread
+
+CHECK_SRC := test-1.c test-2.c test-3.c test-6.c test-7.c test-8.c	\
+	test-9.c test-10.c test-11.c test-12.c test-13.c test-14.c	\
+	test-15.c test-16.c test-17.c test-__pthread_destroy_specific-skip.c
+
+CHECK_OBJS := $(addsuffix .o,$(basename $(notdir $(CHECK_SRC))))
+CHECK_PROGS := $(basename $(notdir $(CHECK_SRC))) \
+	$(addsuffix -static, $(basename $(CHECK_SRC)))
+
+%.o: %.c
+	$(CC) $(INSTALL_ROOT_CPPFLAGS) $(CPPFLAGS) $(CFLAGS) $< -c -o $@
+
+%: %.o
+	$(CC) $(INSTALL_ROOT_LDFLAGS) $(LDFLAGS) $< -o $@ $(LDLIBS)
+
+%-static: %.o
+	$(CC) -static $(INSTALL_ROOT_LDFLAGS) $(LDFLAGS) $< -o $@ $(LDLIBS)
+
+check: $(CHECK_OBJS) $(CHECK_PROGS)
+	for i in $(CHECK_PROGS); do		\
+	  echo -n Running $$i...\ ;		\
+	  if ./$$i 2>&1 > $$i.out;		\
+	  then					\
+	    echo Success.;			\
+	  else					\
+	    echo Failure.;			\
+	  fi					\
+	done
+
+clean:
+	rm -f $(CHECK_OBJS) $(CHECK_PROGS) \
+	  $(addsuffix .out,$(basename $(notdir $(CHECK_PROGS))))
\ No newline at end of file
diff --git a/htl/tests/README b/htl/tests/README
new file mode 100644
index 0000000..230f1b2
--- /dev/null
+++ b/htl/tests/README
@@ -0,0 +1,6 @@
+Testing of installed package:
+
+    $ [libpthread]/configure --prefix=[install_root]
+    $ make
+    $ make install
+    $ make -C [libpthread]/tests/ INSTALL_ROOT=[install_root] clean check
diff --git a/htl/tests/test-1.c b/htl/tests/test-1.c
new file mode 100644
index 0000000..25263ee
--- /dev/null
+++ b/htl/tests/test-1.c
@@ -0,0 +1,68 @@
+/* Test mutexes.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <assert.h>
+#include <unistd.h>
+#include <error.h>
+#include <errno.h>
+#include <stdio.h>
+
+#define THREADS 500
+
+void *
+foo (void *arg)
+{
+  pthread_mutex_t *mutex = arg;
+  pthread_mutex_lock (mutex);
+  pthread_mutex_unlock (mutex);
+  return mutex;
+}
+
+int
+main (int argc, char **argv)
+{
+  int i;
+  error_t err;
+  pthread_t tid[THREADS];
+  pthread_mutex_t mutex[THREADS];
+
+  for (i = 0; i < THREADS; i++)
+    {
+      pthread_mutex_init (&mutex[i], 0);
+      pthread_mutex_lock (&mutex[i]);
+      err = pthread_create (&tid[i], 0, foo, &mutex[i]);
+      if (err)
+	error (1, err, "pthread_create");
+      sched_yield ();
+    }
+
+  for (i = THREADS - 1; i >= 0; i--)
+    {
+      void *ret;
+      pthread_mutex_unlock (&mutex[i]);
+      err = pthread_join (tid[i], &ret);
+      if (err)
+	error (1, err, "pthread_join");
+      assert (ret == &mutex[i]);
+    }
+
+  return 0;
+}
diff --git a/htl/tests/test-10.c b/htl/tests/test-10.c
new file mode 100644
index 0000000..31d3449
--- /dev/null
+++ b/htl/tests/test-10.c
@@ -0,0 +1,62 @@
+/* Test error checking mutexes.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <assert.h>
+#include <error.h>
+#include <errno.h>
+
+int
+main (int argc, char **argv)
+{
+  error_t err;
+  pthread_mutexattr_t mattr;
+  pthread_mutex_t mutex;
+
+  err = pthread_mutexattr_init (&mattr);
+  if (err)
+    error (1, err, "pthread_mutexattr_init");
+
+  err = pthread_mutexattr_settype (&mattr, PTHREAD_MUTEX_ERRORCHECK);
+  if (err)
+    error (1, err, "pthread_mutexattr_settype");
+
+  err = pthread_mutex_init (&mutex, &mattr);
+  if (err)
+    error (1, err, "pthread_mutex_init");
+
+  err = pthread_mutexattr_destroy (&mattr);
+  if (err)
+    error (1, err, "pthread_mutexattr_destroy");
+
+  err = pthread_mutex_lock (&mutex);
+  assert (err == 0);
+
+  err = pthread_mutex_lock (&mutex);
+  assert (err == EDEADLK);
+
+  err = pthread_mutex_unlock (&mutex);
+  assert (err == 0);
+
+  err = pthread_mutex_unlock (&mutex);
+  assert (err == EPERM);
+
+  return 0;
+}
diff --git a/htl/tests/test-11.c b/htl/tests/test-11.c
new file mode 100644
index 0000000..f8c7a42
--- /dev/null
+++ b/htl/tests/test-11.c
@@ -0,0 +1,159 @@
+/* Test rwlocks.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <assert.h>
+#include <error.h>
+#include <errno.h>
+
+#define THREADS 1
+
+int a;
+int b;
+
+/* Get a read lock and assert that a == b.  */
+void *
+test1 (void *arg)
+{
+  error_t err;
+  pthread_rwlock_t *lock = arg;
+  int i;
+
+  for (i = 0; i < 200; i++)
+    {
+      err = pthread_rwlock_rdlock (lock);
+      assert (err == 0);
+
+      assert (a == b);
+
+      sched_yield ();
+
+      assert (a == b);
+
+      err = pthread_rwlock_unlock (lock);
+      assert (err == 0);
+    }
+
+  return 0;
+}
+
+int
+main (int argc, char **argv)
+{
+  error_t err;
+  pthread_rwlockattr_t attr;
+  pthread_rwlock_t lock;
+  int pshared;
+
+  int i;
+  pthread_t tid[THREADS];
+  void *ret;
+
+  err = pthread_rwlockattr_init (&attr);
+  if (err)
+    error (1, err, "pthread_rwlockattr_init");
+
+  err = pthread_rwlockattr_getpshared (&attr, &pshared);
+  if (err)
+    error (1, err, "pthread_rwlockattr_getpshared");
+
+  /* Assert the default state as mandated by POSIX.  */
+  assert (pshared == PTHREAD_PROCESS_PRIVATE);
+
+  err = pthread_rwlockattr_setpshared (&attr, pshared);
+  if (err)
+    error (1, err, "pthread_rwlockattr_setpshared");
+
+  err = pthread_rwlock_init (&lock, &attr);
+  if (err)
+    error (1, err, "pthread_rwlock_init");
+
+  err = pthread_rwlockattr_destroy (&attr);
+  if (err)
+    error (1, err, "pthread_rwlockattr_destroy");
+
+  /* Now test the lock.  */
+
+  for (i = 0; i < THREADS; i++)
+    {
+      err = pthread_create (&tid[i], 0, test1, &lock);
+      if (err)
+	error (1, err, "pthread_create");
+    }
+
+  for (i = 0; i < 10; i++)
+    {
+      sched_yield ();
+
+      /* Get a write lock.  */
+      pthread_rwlock_wrlock (&lock);
+      /* Increment a and b giving other threads a chance to run in
+         between.  */
+      sched_yield ();
+      a++;
+      sched_yield ();
+      b++;
+      sched_yield ();
+      /* Unlock.  */
+      pthread_rwlock_unlock (&lock);
+    }
+
+  for (i = 0; i < THREADS; i++)
+    {
+      err = pthread_join (tid[i], &ret);
+      if (err)
+	error (1, err, "pthread_join");
+    }
+
+  /* Read lock it.  */
+  err = pthread_rwlock_tryrdlock (&lock);
+  assert (err == 0);
+
+  /* Try to write lock it.  It should fail with EBUSY.  */
+  err = pthread_rwlock_trywrlock (&lock);
+  assert (err == EBUSY);
+
+  /* Drop the read lock.  */
+  err = pthread_rwlock_unlock (&lock);
+  assert (err == 0);
+
+  /* Get a write lock.  */
+  err = pthread_rwlock_trywrlock (&lock);
+  assert (err == 0);
+
+  /* Fail trying to acquire another write lock.  */
+  err = pthread_rwlock_trywrlock (&lock);
+  assert (err == EBUSY);
+
+  /* Try to get a read lock which should also fail.  */
+  err = pthread_rwlock_tryrdlock (&lock);
+  assert (err == EBUSY);
+
+  /* Unlock it.  */
+  err = pthread_rwlock_unlock (&lock);
+  assert (err == 0);
+
+
+  err = pthread_rwlock_destroy (&lock);
+  if (err)
+    error (1, err, "pthread_rwlock_destroy");
+
+  return 0;
+}
diff --git a/htl/tests/test-12.c b/htl/tests/test-12.c
new file mode 100644
index 0000000..9676446
--- /dev/null
+++ b/htl/tests/test-12.c
@@ -0,0 +1,45 @@
+/* Test concurrency level.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <assert.h>
+#include <error.h>
+#include <errno.h>
+
+int
+main (int argc, char **argv)
+{
+  int i;
+  int err;
+
+  i = pthread_getconcurrency ();
+  assert (i == 0);
+
+  err = pthread_setconcurrency (-1);
+  assert (err == EINVAL);
+
+  err = pthread_setconcurrency (4);
+  assert (err == 0);
+
+  i = pthread_getconcurrency ();
+  assert (i == 4);
+
+  return 0;
+}
diff --git a/htl/tests/test-13.c b/htl/tests/test-13.c
new file mode 100644
index 0000000..d142149
--- /dev/null
+++ b/htl/tests/test-13.c
@@ -0,0 +1,82 @@
+/* Test condition attributes and pthread_cond_timedwait.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <stdio.h>
+#include <assert.h>
+#include <error.h>
+#include <errno.h>
+#include <sys/time.h>
+
+int
+main (int argc, char **argv)
+{
+  error_t err;
+  int i;
+  pthread_condattr_t attr;
+  pthread_cond_t cond;
+  struct timespec ts;
+  pthread_mutex_t m = PTHREAD_MUTEX_INITIALIZER;
+  struct timeval before, after;
+  int diff;
+
+  err = pthread_condattr_init (&attr);
+  if (err)
+    error (1, err, "pthread_condattr_init");
+
+  err = pthread_condattr_getpshared (&attr, &i);
+  if (err)
+    error (1, err, "pthread_condattr_getpshared");
+  assert (i == PTHREAD_PROCESS_PRIVATE);
+
+  err = pthread_condattr_setpshared (&attr, PTHREAD_PROCESS_PRIVATE);
+  assert (err == 0);
+
+  err = pthread_cond_init (&cond, &attr);
+  if (err)
+    error (1, err, "pthread_cond_init");
+
+  err = pthread_condattr_destroy (&attr);
+  if (err)
+    error (1, err, "pthread_condattr_destroy");
+
+  gettimeofday (&before, 0);
+  ts.tv_sec = before.tv_sec + 1;
+  ts.tv_nsec = before.tv_usec * 1000;
+
+  printf ("Starting wait @ %d\n", (int) before.tv_sec);
+
+  pthread_mutex_lock (&m);
+  err = pthread_cond_timedwait (&cond, &m, &ts);
+
+  gettimeofday (&after, 0);
+
+  printf ("End wait @ %d (err = %d)\n", (int) after.tv_sec, err);
+
+  assert (err == ETIMEDOUT);
+
+  diff = after.tv_sec * 1000000 + after.tv_usec
+      - before.tv_sec * 1000000 - before.tv_usec;
+
+  if (diff < 900000 || diff > 1100000)
+    error (1, EGRATUITOUS, "pthread_cond_timedwait waited %d us", diff);
+
+  return 0;
+}
diff --git a/htl/tests/test-14.c b/htl/tests/test-14.c
new file mode 100644
index 0000000..6e7cef1
--- /dev/null
+++ b/htl/tests/test-14.c
@@ -0,0 +1,60 @@
+/* Test pthread_mutex_timedlock.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <stdio.h>
+#include <assert.h>
+#include <error.h>
+#include <errno.h>
+#include <sys/time.h>
+
+int
+main (int argc, char **argv)
+{
+  error_t err;
+  struct timespec ts;
+  pthread_mutex_t m = PTHREAD_MUTEX_INITIALIZER;
+  struct timeval before, after;
+  int diff;
+
+  gettimeofday (&before, 0);
+  ts.tv_sec = before.tv_sec + 1;
+  ts.tv_nsec = before.tv_usec * 1000;
+
+  printf ("Starting wait @ %d\n", (int) before.tv_sec);
+
+  pthread_mutex_lock (&m);
+  /* A default mutex shall dead lock if locked twice.  As such we do
+     not need spawn a second thread.  */
+  err = pthread_mutex_timedlock (&m, &ts);
+  assert (err == ETIMEDOUT);
+
+  gettimeofday (&after, 0);
+
+  printf ("End wait @ %d\n", (int) after.tv_sec);
+
+  diff = after.tv_sec * 1000000 + after.tv_usec
+      - before.tv_sec * 1000000 - before.tv_usec;
+
+  if (diff < 900000 || diff > 1100000)
+    error (1, EGRATUITOUS, "pthread_mutex_timedlock waited %d us", diff);
+
+  return 0;
+}
diff --git a/htl/tests/test-15.c b/htl/tests/test-15.c
new file mode 100644
index 0000000..baf866a
--- /dev/null
+++ b/htl/tests/test-15.c
@@ -0,0 +1,102 @@
+/* Test pthread_rwlock_timedrdlock and pthread_rwlock_timedwrlock.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <stdio.h>
+#include <assert.h>
+#include <error.h>
+#include <errno.h>
+#include <sys/time.h>
+
+#define THREADS 10
+
+pthread_rwlock_t rwlock;
+
+void *
+test (void *arg)
+{
+  error_t err;
+  int foo = (int) arg;
+  struct timespec ts;
+  struct timeval before, after;
+  int diff;
+
+  gettimeofday (&before, 0);
+  ts.tv_sec = before.tv_sec + 1;
+  ts.tv_nsec = before.tv_usec * 1000;
+
+  printf ("Thread %d starting wait @ %d\n", pthread_self (),
+	  (int) before.tv_sec);
+
+  if (foo % 2 == 0)
+    err = pthread_rwlock_timedrdlock (&rwlock, &ts);
+  else
+    err = pthread_rwlock_timedwrlock (&rwlock, &ts);
+
+  assert (err == ETIMEDOUT);
+
+  gettimeofday (&after, 0);
+
+  printf ("Thread %d ending wait @ %d\n", pthread_self (), (int) after.tv_sec);
+
+  diff = after.tv_sec * 1000000 + after.tv_usec
+      - before.tv_sec * 1000000 - before.tv_usec;
+
+  if (diff < 900000 || diff > 1100000)
+    error (1, EGRATUITOUS, "pthread_mutex_timedlock waited %d us", diff);
+
+  return 0;
+}
+
+int
+main (int argc, char **argv)
+{
+  error_t err;
+  int i;
+  pthread_t tid[THREADS];
+
+  err = pthread_rwlock_init (&rwlock, 0);
+  if (err)
+    error (1, err, "pthread_rwlock_init");
+
+  /* Lock it so all the threads will block.  */
+  err = pthread_rwlock_wrlock (&rwlock);
+  assert (err == 0);
+
+  for (i = 0; i < THREADS; i++)
+    {
+      err = pthread_create (&tid[i], 0, test, (void *) i);
+      if (err)
+	error (1, err, "pthread_create");
+    }
+
+  for (i = 0; i < THREADS; i++)
+    {
+      void *ret;
+
+      err = pthread_join (tid[i], &ret);
+      if (err)
+	error (1, err, "pthread_join");
+
+      assert (ret == 0);
+    }
+
+  return 0;
+}
diff --git a/htl/tests/test-16.c b/htl/tests/test-16.c
new file mode 100644
index 0000000..519aa84
--- /dev/null
+++ b/htl/tests/test-16.c
@@ -0,0 +1,87 @@
+/* Test pthread_kill.c.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <signal.h>
+#include <stdio.h>
+#include <assert.h>
+#include <error.h>
+#include <errno.h>
+#include <hurd/signal.h>
+
+pthread_t testthread;
+
+int i;
+
+void *
+test (void *arg)
+{
+  error_t err;
+
+  printf ("test: %d\n", pthread_self ());
+
+  err = pthread_kill (pthread_self (), SIGINFO);
+  if (err)
+    error (1, err, "pthread_kill");
+
+  /* To avoid using condition variables in a signal handler.  */
+  while (i == 0)
+    sched_yield ();
+
+  return 0;
+}
+
+static void
+handler (int sig)
+{
+  assert (pthread_equal (pthread_self (), testthread));
+  printf ("handler: %d\n", pthread_self ());
+  i = 1;
+}
+
+int
+main (int argc, char **argv)
+{
+  error_t err;
+  struct sigaction sa;
+  void *ret;
+
+  printf ("main: %d\n", pthread_self ());
+
+  sa.sa_handler = handler;
+  sa.sa_mask = 0;
+  sa.sa_flags = 0;
+
+  err = sigaction (SIGINFO, &sa, 0);
+  if (err)
+    error (1, err, "sigaction");
+
+  err = pthread_create (&testthread, 0, test, 0);
+  if (err)
+    error (1, err, "pthread_create");
+
+  err = pthread_join (testthread, &ret);
+  if (err)
+    error (1, err, "pthread_join");
+
+  assert (ret == 0);
+
+  return 0;
+}
diff --git a/htl/tests/test-17.c b/htl/tests/test-17.c
new file mode 100644
index 0000000..ffc90b5
--- /dev/null
+++ b/htl/tests/test-17.c
@@ -0,0 +1,73 @@
+/* Test that the key reuse inside libpthread does not cause thread
+   specific values to persist.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE 1
+
+#include <pthread.h>
+#include <stdio.h>
+#include <assert.h>
+#include <errno.h>
+
+void
+work (int iter)
+{
+  error_t err;
+  pthread_key_t key1;
+  pthread_key_t key2;
+  void *value1;
+  void *value2;
+
+  printf ("work/%d: start\n", iter);
+  err = pthread_key_create (&key1, NULL);
+  assert (err == 0);
+  err = pthread_key_create (&key2, NULL);
+  assert (err == 0);
+
+  value1 = pthread_getspecific (key1);
+  value2 = pthread_getspecific (key2);
+  printf ("work/%d: pre-setspecific: %p,%p\n", iter, value1, value2);
+  assert (value1 == NULL);
+  assert (value2 == NULL);
+  err = pthread_setspecific (key1, (void *) (0x100 + iter));
+  assert (err == 0);
+  err = pthread_setspecific (key2, (void *) (0x200 + iter));
+  assert (err == 0);
+
+  value1 = pthread_getspecific (key1);
+  value2 = pthread_getspecific (key2);
+  printf ("work/%d: post-setspecific: %p,%p\n", iter, value1, value2);
+  assert (value1 == (void *) (0x100 + iter));
+  assert (value2 == (void *) (0x200 + iter));
+
+  err = pthread_key_delete (key1);
+  assert (err == 0);
+  err = pthread_key_delete (key2);
+  assert (err == 0);
+}
+
+int
+main (int argc, char *argv[])
+{
+  int i;
+
+  for (i = 0; i < 8; ++i)
+    work (i + 1);
+
+  return 0;
+}
diff --git a/htl/tests/test-2.c b/htl/tests/test-2.c
new file mode 100644
index 0000000..1194a34
--- /dev/null
+++ b/htl/tests/test-2.c
@@ -0,0 +1,56 @@
+/* Test detachability.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <assert.h>
+#include <error.h>
+#include <errno.h>
+#include <unistd.h>
+
+void *
+thread (void *arg)
+{
+  while (1)
+    sched_yield ();
+}
+
+int
+main (int argc, char **argv)
+{
+  int err;
+  pthread_t tid;
+  void *ret;
+
+  err = pthread_create (&tid, 0, thread, 0);
+  if (err)
+    error (1, err, "pthread_create");
+
+  err = pthread_detach (tid);
+  if (err)
+    error (1, err, "pthread_detach");
+
+  err = pthread_detach (tid);
+  assert (err == EINVAL);
+
+  err = pthread_join (tid, &ret);
+  assert (err == EINVAL);
+
+  return 0;
+}
diff --git a/htl/tests/test-3.c b/htl/tests/test-3.c
new file mode 100644
index 0000000..beed473
--- /dev/null
+++ b/htl/tests/test-3.c
@@ -0,0 +1,71 @@
+/* Test the thread attribute get and set methods.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <sched.h>
+#include <assert.h>
+#include <errno.h>
+
+int
+main (int argc, char *argv[])
+{
+  error_t err;
+  pthread_attr_t attr;
+
+  int i;
+  struct sched_param sp;
+  void *p;
+  size_t sz;
+
+  err = pthread_attr_init (&attr);
+  assert_perror (err);
+
+  err = pthread_attr_destroy (&attr);
+  assert_perror (err);
+
+  err = pthread_attr_init (&attr);
+  assert_perror (err);
+
+#define TEST1(foo, rv, v) \
+	err = pthread_attr_get##foo (&attr, rv); \
+	assert_perror (err); \
+	\
+	err = pthread_attr_set##foo (&attr, v); \
+	assert_perror (err);
+
+#define TEST(foo, rv, v) TEST1(foo, rv, v)
+
+  TEST (inheritsched, &i, i);
+  TEST (schedparam, &sp, &sp);
+  TEST (schedpolicy, &i, i);
+  TEST (scope, &i, i);
+  TEST (stackaddr, &p, p);
+  TEST (detachstate, &i, i);
+  TEST (guardsize, &sz, sz);
+  TEST (stacksize, &sz, sz);
+
+  err = pthread_attr_getstack (&attr, &p, &sz);
+  assert_perror (err);
+
+  err = pthread_attr_setstack (&attr, p, sz);
+  assert_perror (err);
+
+  return 0;
+}
diff --git a/htl/tests/test-4.c b/htl/tests/test-4.c
new file mode 100644
index 0000000..b8c24b7
--- /dev/null
+++ b/htl/tests/test-4.c
@@ -0,0 +1,102 @@
+/* Test the stack guard.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <assert.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+size_t stacksize;
+
+void *
+thr (void *arg)
+{
+  int i;
+  char *foo;
+
+  foo = alloca (3 * stacksize / 4);
+  for (i = 0; i < sizeof foo; i++)
+    foo[i] = -1;
+
+  return (void *) 1;
+}
+
+int
+main (int argc, char *argv[])
+{
+  error_t err;
+  pid_t child;
+
+  child = fork ();
+  switch (child)
+    {
+    case -1:
+      error (1, errno, "fork");
+      break;
+
+    case 0:
+      {
+	pthread_attr_t attr;
+	pthread_t tid;
+	void *ret;
+
+	err = pthread_attr_init (&attr);
+	assert_perror (err);
+
+	err = pthread_attr_getstacksize (&attr, &stacksize);
+	assert_perror (err);
+
+	err = pthread_attr_setguardsize (&attr, stacksize / 2);
+	if (err == ENOTSUP)
+	  {
+	    printf ("Stack guard attribute not supported.\n");
+	    return 1;
+	  }
+	assert_perror (err);
+
+	err = pthread_create (&tid, &attr, thr, 0);
+	assert_perror (err);
+
+	err = pthread_attr_destroy (&attr);
+	assert_perror (err);
+
+	err = pthread_join (tid, &ret);
+	/* Should never be successful.  */
+	printf ("Thread did not segfault!?!\n");
+	assert_perror (err);
+	return 0;
+      }
+
+    default:
+      {
+	pid_t pid;
+	int status;
+
+	pid = waitpid (child, &status, 0);
+	printf ("pid = %d; child = %d; status = %d\n", pid, child, status);
+	assert (pid == child);
+	assert (status != 0);
+      }
+    }
+
+  return 0;
+}
diff --git a/htl/tests/test-5.c b/htl/tests/test-5.c
new file mode 100644
index 0000000..ef9691c
--- /dev/null
+++ b/htl/tests/test-5.c
@@ -0,0 +1,91 @@
+/* Test signals.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+#include <error.h>
+#include <assert.h>
+#include <sys/resource.h>
+#include <sys/wait.h>
+
+void *
+thr (void *arg)
+{
+  *(int *) 0 = 0;
+  return 0;
+}
+
+int foobar;
+
+int
+main (int argc, char *argv[])
+{
+  error_t err;
+  pid_t child;
+
+  struct rlimit limit;
+
+  limit.rlim_cur = 0;
+  limit.rlim_max = 0;
+
+  err = setrlimit (RLIMIT_CORE, &limit);
+  if (err)
+    error (1, err, "setrlimit");
+
+  child = fork ();
+  switch (child)
+    {
+    case -1:
+      error (1, errno, "fork");
+      break;
+
+    case 0:
+      {
+	pthread_t tid;
+	void *ret;
+
+	err = pthread_create (&tid, 0, thr, 0);
+	if (err)
+	  error (1, err, "pthread_create");
+
+	err = pthread_join (tid, &ret);
+	assert_perror (err);
+
+	/* Should have never returned.  Our parent expects us to fail
+	   thus we succeed and indicate the error.  */
+	return 0;
+      }
+
+    default:
+      {
+	pid_t pid;
+	int status;
+
+	pid = waitpid (child, &status, 0);
+	printf ("pid = %d; child = %d; status = %d\n", pid, child, status);
+	assert (pid == child);
+	assert (status != 0);
+      }
+    }
+
+  return 0;
+}
diff --git a/htl/tests/test-6.c b/htl/tests/test-6.c
new file mode 100644
index 0000000..e25d419
--- /dev/null
+++ b/htl/tests/test-6.c
@@ -0,0 +1,114 @@
+/* Test barriers.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <stdio.h>
+#include <error.h>
+#include <assert.h>
+#include <errno.h>
+
+#define THREADS 500
+#define WAITS 3
+
+void *
+dowait (void *arg)
+{
+  pthread_barrier_t *barrier = arg;
+  int ret;
+
+  ret = pthread_barrier_wait (barrier);
+  printf ("%d ", pthread_self ());
+  return (void *) ret;
+}
+
+int
+main (int argc, char **argv)
+{
+  pthread_barrierattr_t attr;
+  pthread_barrier_t barrier;
+
+  int i, j;
+  error_t err;
+  pthread_t tid[THREADS];
+
+  int havesyncs;
+
+  err = pthread_barrierattr_init (&attr);
+  if (err)
+    error (1, err, "pthread_barrierattr_init");
+
+  err = pthread_barrierattr_getpshared (&attr, &i);
+  if (err)
+    error (1, err, "pthread_barrierattr_getpshared");
+  assert (i == PTHREAD_PROCESS_PRIVATE || i == PTHREAD_PROCESS_SHARED);
+
+  err = pthread_barrierattr_setpshared (&attr, PTHREAD_PROCESS_PRIVATE);
+  if (err)
+    error (1, err, "pthread_barrierattr_setpshared");
+
+  err = pthread_barrier_init (&barrier, &attr, THREADS + 1);
+  if (err)
+    error (1, err, "pthread_barrier_init");
+
+  for (j = 0; j < WAITS; j++)
+    {
+
+      for (i = 0; i < THREADS; i++)
+	{
+	  err = pthread_create (&tid[i], 0, dowait, &barrier);
+	  if (err)
+	    error (1, err, "pthread_create (%d)", i);
+	}
+
+      printf ("Manager will now call pthread_barrier_wait.\n");
+
+      havesyncs
+	  = pthread_barrier_wait (&barrier) == PTHREAD_BARRIER_SERIAL_THREAD
+	  ? 1 : 0;
+
+      for (i = THREADS - 1; i >= 0; i--)
+	{
+	  void *ret;
+	  err = pthread_join (tid[i], &ret);
+	  if (err)
+	    error (1, err, "pthread_join");
+
+	  switch ((int) ret)
+	    {
+	    case 0:
+	      break;
+
+	    case PTHREAD_BARRIER_SERIAL_THREAD:
+	      havesyncs++;
+	      break;
+
+	    default:
+	      assert (!"Unknown value returned from pthread_barrier_wait.");
+	      break;
+	    }
+	}
+
+      printf ("\n");
+
+      assert (havesyncs == 1);
+    }
+
+  return 0;
+}
diff --git a/htl/tests/test-7.c b/htl/tests/test-7.c
new file mode 100644
index 0000000..4823de2
--- /dev/null
+++ b/htl/tests/test-7.c
@@ -0,0 +1,89 @@
+/* Test Thread-Specific Data.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <assert.h>
+#include <stdio.h>
+#include <error.h>
+#include <errno.h>
+
+#define THREADS 10
+#define KEYS 400
+
+pthread_key_t key[KEYS];
+
+void *
+thr (void *arg)
+{
+  error_t err;
+  int i;
+
+  for (i = 0; i < KEYS; i++)
+    {
+      printf ("pthread_getspecific(%d).\n", key[i]);
+      assert (pthread_getspecific (key[i]) == NULL);
+      printf ("pthread_setspecific(%d, %d).\n", key[i], pthread_self ());
+      err = pthread_setspecific (key[i], (void *) pthread_self ());
+      printf ("pthread_setspecific(%d, %d) => %d.\n", key[i], pthread_self (),
+	      err);
+      assert_perror (err);
+    }
+
+  return 0;
+}
+
+int
+main (int argc, char **argv)
+{
+  error_t err;
+  int i;
+  pthread_t tid[THREADS];
+
+  void des (void *val)
+  {
+    assert ((pthread_t) val == pthread_self ());
+  }
+
+  assert (pthread_getspecific ((pthread_key_t) 0) == NULL);
+  assert (pthread_setspecific ((pthread_key_t) 0, (void *) 0x1) == EINVAL);
+
+  for (i = 0; i < KEYS; i++)
+    err = pthread_key_create (&key[i], des);
+
+  for (i = 0; i < THREADS; i++)
+    {
+      err = pthread_create (&tid[i], 0, thr, 0);
+      if (err)
+	error (1, err, "pthread_create (%d)", i);
+    }
+
+  for (i = 0; i < THREADS; i++)
+    {
+      void *ret;
+
+      err = pthread_join (tid[i], &ret);
+      if (err)
+	error (1, err, "pthread_join");
+
+      assert (ret == 0);
+    }
+
+  return 0;
+}
diff --git a/htl/tests/test-8.c b/htl/tests/test-8.c
new file mode 100644
index 0000000..9cf74a7
--- /dev/null
+++ b/htl/tests/test-8.c
@@ -0,0 +1,78 @@
+/* Test pthread_once.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <assert.h>
+#include <error.h>
+#include <errno.h>
+
+#define THREADS 10
+
+pthread_once_t inc_var_once = PTHREAD_ONCE_INIT;
+int var;
+
+void
+inc_var (void)
+{
+  var++;
+}
+
+void *
+thr (void *arg)
+{
+  int i;
+
+  for (i = 0; i < 500; i++)
+    pthread_once (&inc_var_once, inc_var);
+
+  return 0;
+}
+
+int
+main (int argc, char **argv)
+{
+  error_t err;
+  int i;
+  pthread_t tid[THREADS];
+
+  for (i = 0; i < THREADS; i++)
+    {
+      err = pthread_create (&tid[i], 0, thr, 0);
+      if (err)
+	error (1, err, "pthread_create (%d)", i);
+    }
+
+  assert (thr (0) == 0);
+
+  for (i = 0; i < THREADS; i++)
+    {
+      void *ret;
+
+      err = pthread_join (tid[i], &ret);
+      if (err)
+	error (1, err, "pthread_join");
+
+      assert (ret == 0);
+    }
+
+  assert (var == 1);
+
+  return 0;
+}
diff --git a/htl/tests/test-9.c b/htl/tests/test-9.c
new file mode 100644
index 0000000..ad6bc36
--- /dev/null
+++ b/htl/tests/test-9.c
@@ -0,0 +1,104 @@
+/* Test recursive mutexes.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <pthread.h>
+#include <assert.h>
+#include <error.h>
+#include <errno.h>
+
+#define THREADS 10
+
+int foo;
+
+void *
+thr (void *arg)
+{
+  int i;
+
+  pthread_mutex_lock (arg);
+
+  foo = pthread_self ();
+
+  for (i = 0; i < 500; i++)
+    pthread_mutex_lock (arg);
+  for (i = 0; i < 500; i++)
+    pthread_mutex_unlock (arg);
+
+  assert (foo == pthread_self ());
+
+  pthread_mutex_unlock (arg);
+
+  return 0;
+}
+
+int
+main (int argc, char **argv)
+{
+  error_t err;
+  int i;
+  pthread_t tid[THREADS];
+  pthread_mutexattr_t mattr;
+  pthread_mutex_t mutex;
+
+  err = pthread_mutexattr_init (&mattr);
+  if (err)
+    error (1, err, "pthread_mutexattr_init");
+
+  err = pthread_mutexattr_settype (&mattr, PTHREAD_MUTEX_RECURSIVE);
+  if (err)
+    error (1, err, "pthread_mutexattr_settype");
+
+  err = pthread_mutex_init (&mutex, &mattr);
+  if (err)
+    error (1, err, "pthread_mutex_init");
+
+  err = pthread_mutexattr_destroy (&mattr);
+  if (err)
+    error (1, err, "pthread_mutexattr_destroy");
+
+  pthread_mutex_lock (&mutex);
+  pthread_mutex_lock (&mutex);
+  pthread_mutex_unlock (&mutex);
+  pthread_mutex_unlock (&mutex);
+
+  for (i = 0; i < THREADS; i++)
+    {
+      err = pthread_create (&tid[i], 0, thr, &mutex);
+      if (err)
+	error (1, err, "pthread_create (%d)", i);
+    }
+
+  for (i = 0; i < THREADS; i++)
+    {
+      void *ret;
+
+      err = pthread_join (tid[i], &ret);
+      if (err)
+	error (1, err, "pthread_join");
+
+      assert (ret == 0);
+    }
+
+  err = pthread_mutex_destroy (&mutex);
+  if (err)
+    error (1, err, "pthread_mutex_destroy");
+
+  return 0;
+}
diff --git a/htl/tests/test-__pthread_destroy_specific-skip.c b/htl/tests/test-__pthread_destroy_specific-skip.c
new file mode 100644
index 0000000..c54ccad
--- /dev/null
+++ b/htl/tests/test-__pthread_destroy_specific-skip.c
@@ -0,0 +1,100 @@
+/* Check that __pthread_destroy_specific works correctly if it has to skip
+   unused slots.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+
+#include <error.h>
+#include <pthread.h>
+#include <stdio.h>
+
+
+#define N_k 42
+
+static volatile int v;
+
+static void
+d (void *x)
+{
+  int *i = (int *) x;
+
+  if (v != *i)
+    error (1, 0, "FAILED %d %d", v, *i);
+  v += 2;
+
+  printf ("%s %d\n", __FUNCTION__, *i);
+  fflush (stdout);
+}
+
+static void *
+test (void *x)
+{
+  pthread_key_t k[N_k];
+  static int k_v[N_k];
+
+  int err, i;
+
+  for (i = 0; i < N_k; i += 1)
+    {
+      err = pthread_key_create (&k[i], &d);
+      if (err != 0)
+	error (1, err, "pthread_key_create %d", i);
+    }
+
+  for (i = 0; i < N_k; i += 1)
+    {
+      k_v[i] = i;
+      err = pthread_setspecific (k[i], &k_v[i]);
+      if (err != 0)
+	error (1, err, "pthread_setspecific %d", i);
+    }
+
+  /* Delete every even key.  */
+  for (i = 0; i < N_k; i += 2)
+    {
+      err = pthread_key_delete (k[i]);
+      if (err != 0)
+	error (1, err, "pthread_key_delete %d", i);
+    }
+
+  v = 1;
+  pthread_exit (NULL);
+
+  return NULL;
+}
+
+
+int
+main (void)
+{
+  pthread_t tid;
+  int err;
+
+  err = pthread_create (&tid, 0, test, NULL);
+  if (err != 0)
+    error (1, err, "pthread_create");
+
+  err = pthread_join (tid, NULL);
+  if (err)
+    error (1, err, "pthread_join");
+
+  if (v != N_k + 1)
+    error (1, 0, "FAILED END %d %d", v, N_k + 1);
+
+  return 0;
+}