Provide glthread/lock.h implementation in terms of Guile threads.

Fixes <http://bugs.gnu.org/14404>.
Thanks to Paul Eggert <eggert@cs.ucla.edu> for the suggestion.

* m4/gnulib-cache.m4: Avoid 'lock' module.
* m4/lock.m4, m4/threadlib.m4, lib/glthread/threadlib.c,
  lib/glthread/lock.c: Remove.
* lib/glthread/lock.h: Rewrite in terms of libguile/threads.h.
* m4/gnulib-common.m4, m4/gnulib-comp.m4, lib/Makefile.am,
  lib/unistd.in.h, maint.mk : Update, from Gnulib v0.1-92-g546ff82.

* configure.ac (GNULIB_LOCK): Define 'GNULIB_LOCK'.  Define
  'USE_POSIX_THREADS' when building with pthread support.
* Makefile.am (noinst_HEADERS): New variable.
  (BUILT_SOURCES): Add libguile/scmconfig.h.
  (libguile/scmconfig.h): New target.

5 files changed, 49 insertions, 2068 deletions

diff --git a/lib/Makefile.am b/lib/Makefile.am
index 8b643c72b..5d9c902fc 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -21,7 +21,7 @@
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --dir=. --local-dir=gnulib-local --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --lgpl=3 --no-conditional-dependencies --libtool --macro-prefix=gl --no-vc-files accept alignof alloca-opt announce-gen autobuild bind byteswap c-strcase canonicalize-lgpl ceil clock-time close connect copysign dirfd duplocale environ extensions flock floor fpieee frexp fstat fsync full-read full-write func gendocs getaddrinfo getlogin getpeername getsockname getsockopt git-version-gen gitlog-to-changelog gnu-web-doc-update gnupload havelib iconv_open-utf inet_ntop inet_pton isfinite isinf isnan ldexp lib-symbol-versions lib-symbol-visibility libunistring link listen localcharset locale log1p lstat maintainer-makefile malloc-gnu malloca mkdir mkstemp nl_langinfo nproc open pipe-posix pipe2 poll putenv readlink recv recvfrom regex rename rmdir select send sendto setenv setsockopt shutdown socket stat-time stdlib strftime striconveh string sys_stat time times trunc unistd verify vsnprintf warnings wchar
+# Reproduce by: gnulib-tool --import --dir=. --local-dir=gnulib-local --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=lock --lgpl=3 --no-conditional-dependencies --libtool --macro-prefix=gl --no-vc-files accept alignof alloca-opt announce-gen autobuild bind byteswap c-strcase canonicalize-lgpl ceil clock-time close connect copysign dirfd duplocale environ extensions flock floor fpieee frexp fstat fsync full-read full-write func gendocs getaddrinfo getlogin getpeername getsockname getsockopt git-version-gen gitlog-to-changelog gnu-web-doc-update gnupload havelib iconv_open-utf inet_ntop inet_pton isfinite isinf isnan ldexp lib-symbol-versions lib-symbol-visibility libunistring link listen localcharset locale log1p lstat maintainer-makefile malloc-gnu malloca mkdir mkstemp nl_langinfo nproc open pipe-posix pipe2 poll putenv readlink recv recvfrom regex rename rmdir select send sendto setenv setsockopt shutdown socket stat-time stdlib strftime striconveh string sys_stat time times trunc unistd verify vsnprintf warnings wchar
 
 AUTOMAKE_OPTIONS = 1.9.6 gnits subdir-objects
 
@@ -69,7 +69,6 @@ libgnu_la_LDFLAGS += $(LOG1P_LIBM)
 libgnu_la_LDFLAGS += $(LOG_LIBM)
 libgnu_la_LDFLAGS += $(LTLIBICONV)
 libgnu_la_LDFLAGS += $(LTLIBINTL)
-libgnu_la_LDFLAGS += $(LTLIBTHREAD)
 libgnu_la_LDFLAGS += $(LTLIBUNISTRING)
 libgnu_la_LDFLAGS += $(ROUND_LIBM)
 libgnu_la_LDFLAGS += $(SERVENT_LIB)
@@ -1050,12 +1049,6 @@ EXTRA_libgnu_la_SOURCES += localeconv.c
 
 ## end   gnulib module localeconv
 
-## begin gnulib module lock
-
-libgnu_la_SOURCES += glthread/lock.h glthread/lock.c
-
-## end   gnulib module lock
-
 ## begin gnulib module log
 
 
@@ -2799,14 +2792,6 @@ EXTRA_DIST += tempname.h
 
 ## end   gnulib module tempname
 
-## begin gnulib module threadlib
-
-libgnu_la_SOURCES += glthread/threadlib.c
-
-EXTRA_DIST += $(top_srcdir)/build-aux/config.rpath
-
-## end   gnulib module threadlib
-
 ## begin gnulib module time
 
 BUILT_SOURCES += time.h
diff --git a/lib/glthread/lock.c b/lib/glthread/lock.c
deleted file mode 100644
index 0454cc251..000000000
--- a/lib/glthread/lock.c
+++ /dev/null
@@ -1,1057 +0,0 @@
-/* Locking in multithreaded situations.
-   Copyright (C) 2005-2014 Free Software Foundation, Inc.
-
-   This program 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, 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 Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public License
-   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
-
-/* Written by Bruno Haible <bruno@clisp.org>, 2005.
-   Based on GCC's gthr-posix.h, gthr-posix95.h, gthr-solaris.h,
-   gthr-win32.h.  */
-
-#include <config.h>
-
-#include "glthread/lock.h"
-
-/* ========================================================================= */
-
-#if USE_POSIX_THREADS
-
-/* -------------------------- gl_lock_t datatype -------------------------- */
-
-/* ------------------------- gl_rwlock_t datatype ------------------------- */
-
-# if HAVE_PTHREAD_RWLOCK
-
-#  if !defined PTHREAD_RWLOCK_INITIALIZER
-
-int
-glthread_rwlock_init_multithreaded (gl_rwlock_t *lock)
-{
-  int err;
-
-  err = pthread_rwlock_init (&lock->rwlock, NULL);
-  if (err != 0)
-    return err;
-  lock->initialized = 1;
-  return 0;
-}
-
-int
-glthread_rwlock_rdlock_multithreaded (gl_rwlock_t *lock)
-{
-  if (!lock->initialized)
-    {
-      int err;
-
-      err = pthread_mutex_lock (&lock->guard);
-      if (err != 0)
-        return err;
-      if (!lock->initialized)
-        {
-          err = glthread_rwlock_init_multithreaded (lock);
-          if (err != 0)
-            {
-              pthread_mutex_unlock (&lock->guard);
-              return err;
-            }
-        }
-      err = pthread_mutex_unlock (&lock->guard);
-      if (err != 0)
-        return err;
-    }
-  return pthread_rwlock_rdlock (&lock->rwlock);
-}
-
-int
-glthread_rwlock_wrlock_multithreaded (gl_rwlock_t *lock)
-{
-  if (!lock->initialized)
-    {
-      int err;
-
-      err = pthread_mutex_lock (&lock->guard);
-      if (err != 0)
-        return err;
-      if (!lock->initialized)
-        {
-          err = glthread_rwlock_init_multithreaded (lock);
-          if (err != 0)
-            {
-              pthread_mutex_unlock (&lock->guard);
-              return err;
-            }
-        }
-      err = pthread_mutex_unlock (&lock->guard);
-      if (err != 0)
-        return err;
-    }
-  return pthread_rwlock_wrlock (&lock->rwlock);
-}
-
-int
-glthread_rwlock_unlock_multithreaded (gl_rwlock_t *lock)
-{
-  if (!lock->initialized)
-    return EINVAL;
-  return pthread_rwlock_unlock (&lock->rwlock);
-}
-
-int
-glthread_rwlock_destroy_multithreaded (gl_rwlock_t *lock)
-{
-  int err;
-
-  if (!lock->initialized)
-    return EINVAL;
-  err = pthread_rwlock_destroy (&lock->rwlock);
-  if (err != 0)
-    return err;
-  lock->initialized = 0;
-  return 0;
-}
-
-#  endif
-
-# else
-
-int
-glthread_rwlock_init_multithreaded (gl_rwlock_t *lock)
-{
-  int err;
-
-  err = pthread_mutex_init (&lock->lock, NULL);
-  if (err != 0)
-    return err;
-  err = pthread_cond_init (&lock->waiting_readers, NULL);
-  if (err != 0)
-    return err;
-  err = pthread_cond_init (&lock->waiting_writers, NULL);
-  if (err != 0)
-    return err;
-  lock->waiting_writers_count = 0;
-  lock->runcount = 0;
-  return 0;
-}
-
-int
-glthread_rwlock_rdlock_multithreaded (gl_rwlock_t *lock)
-{
-  int err;
-
-  err = pthread_mutex_lock (&lock->lock);
-  if (err != 0)
-    return err;
-  /* Test whether only readers are currently running, and whether the runcount
-     field will not overflow.  */
-  /* POSIX says: "It is implementation-defined whether the calling thread
-     acquires the lock when a writer does not hold the lock and there are
-     writers blocked on the lock."  Let's say, no: give the writers a higher
-     priority.  */
-  while (!(lock->runcount + 1 > 0 && lock->waiting_writers_count == 0))
-    {
-      /* This thread has to wait for a while.  Enqueue it among the
-         waiting_readers.  */
-      err = pthread_cond_wait (&lock->waiting_readers, &lock->lock);
-      if (err != 0)
-        {
-          pthread_mutex_unlock (&lock->lock);
-          return err;
-        }
-    }
-  lock->runcount++;
-  return pthread_mutex_unlock (&lock->lock);
-}
-
-int
-glthread_rwlock_wrlock_multithreaded (gl_rwlock_t *lock)
-{
-  int err;
-
-  err = pthread_mutex_lock (&lock->lock);
-  if (err != 0)
-    return err;
-  /* Test whether no readers or writers are currently running.  */
-  while (!(lock->runcount == 0))
-    {
-      /* This thread has to wait for a while.  Enqueue it among the
-         waiting_writers.  */
-      lock->waiting_writers_count++;
-      err = pthread_cond_wait (&lock->waiting_writers, &lock->lock);
-      if (err != 0)
-        {
-          lock->waiting_writers_count--;
-          pthread_mutex_unlock (&lock->lock);
-          return err;
-        }
-      lock->waiting_writers_count--;
-    }
-  lock->runcount--; /* runcount becomes -1 */
-  return pthread_mutex_unlock (&lock->lock);
-}
-
-int
-glthread_rwlock_unlock_multithreaded (gl_rwlock_t *lock)
-{
-  int err;
-
-  err = pthread_mutex_lock (&lock->lock);
-  if (err != 0)
-    return err;
-  if (lock->runcount < 0)
-    {
-      /* Drop a writer lock.  */
-      if (!(lock->runcount == -1))
-        {
-          pthread_mutex_unlock (&lock->lock);
-          return EINVAL;
-        }
-      lock->runcount = 0;
-    }
-  else
-    {
-      /* Drop a reader lock.  */
-      if (!(lock->runcount > 0))
-        {
-          pthread_mutex_unlock (&lock->lock);
-          return EINVAL;
-        }
-      lock->runcount--;
-    }
-  if (lock->runcount == 0)
-    {
-      /* POSIX recommends that "write locks shall take precedence over read
-         locks", to avoid "writer starvation".  */
-      if (lock->waiting_writers_count > 0)
-        {
-          /* Wake up one of the waiting writers.  */
-          err = pthread_cond_signal (&lock->waiting_writers);
-          if (err != 0)
-            {
-              pthread_mutex_unlock (&lock->lock);
-              return err;
-            }
-        }
-      else
-        {
-          /* Wake up all waiting readers.  */
-          err = pthread_cond_broadcast (&lock->waiting_readers);
-          if (err != 0)
-            {
-              pthread_mutex_unlock (&lock->lock);
-              return err;
-            }
-        }
-    }
-  return pthread_mutex_unlock (&lock->lock);
-}
-
-int
-glthread_rwlock_destroy_multithreaded (gl_rwlock_t *lock)
-{
-  int err;
-
-  err = pthread_mutex_destroy (&lock->lock);
-  if (err != 0)
-    return err;
-  err = pthread_cond_destroy (&lock->waiting_readers);
-  if (err != 0)
-    return err;
-  err = pthread_cond_destroy (&lock->waiting_writers);
-  if (err != 0)
-    return err;
-  return 0;
-}
-
-# endif
-
-/* --------------------- gl_recursive_lock_t datatype --------------------- */
-
-# if HAVE_PTHREAD_MUTEX_RECURSIVE
-
-#  if defined PTHREAD_RECURSIVE_MUTEX_INITIALIZER || defined PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
-
-int
-glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock)
-{
-  pthread_mutexattr_t attributes;
-  int err;
-
-  err = pthread_mutexattr_init (&attributes);
-  if (err != 0)
-    return err;
-  err = pthread_mutexattr_settype (&attributes, PTHREAD_MUTEX_RECURSIVE);
-  if (err != 0)
-    {
-      pthread_mutexattr_destroy (&attributes);
-      return err;
-    }
-  err = pthread_mutex_init (lock, &attributes);
-  if (err != 0)
-    {
-      pthread_mutexattr_destroy (&attributes);
-      return err;
-    }
-  err = pthread_mutexattr_destroy (&attributes);
-  if (err != 0)
-    return err;
-  return 0;
-}
-
-#  else
-
-int
-glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock)
-{
-  pthread_mutexattr_t attributes;
-  int err;
-
-  err = pthread_mutexattr_init (&attributes);
-  if (err != 0)
-    return err;
-  err = pthread_mutexattr_settype (&attributes, PTHREAD_MUTEX_RECURSIVE);
-  if (err != 0)
-    {
-      pthread_mutexattr_destroy (&attributes);
-      return err;
-    }
-  err = pthread_mutex_init (&lock->recmutex, &attributes);
-  if (err != 0)
-    {
-      pthread_mutexattr_destroy (&attributes);
-      return err;
-    }
-  err = pthread_mutexattr_destroy (&attributes);
-  if (err != 0)
-    return err;
-  lock->initialized = 1;
-  return 0;
-}
-
-int
-glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock)
-{
-  if (!lock->initialized)
-    {
-      int err;
-
-      err = pthread_mutex_lock (&lock->guard);
-      if (err != 0)
-        return err;
-      if (!lock->initialized)
-        {
-          err = glthread_recursive_lock_init_multithreaded (lock);
-          if (err != 0)
-            {
-              pthread_mutex_unlock (&lock->guard);
-              return err;
-            }
-        }
-      err = pthread_mutex_unlock (&lock->guard);
-      if (err != 0)
-        return err;
-    }
-  return pthread_mutex_lock (&lock->recmutex);
-}
-
-int
-glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock)
-{
-  if (!lock->initialized)
-    return EINVAL;
-  return pthread_mutex_unlock (&lock->recmutex);
-}
-
-int
-glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock)
-{
-  int err;
-
-  if (!lock->initialized)
-    return EINVAL;
-  err = pthread_mutex_destroy (&lock->recmutex);
-  if (err != 0)
-    return err;
-  lock->initialized = 0;
-  return 0;
-}
-
-#  endif
-
-# else
-
-int
-glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock)
-{
-  int err;
-
-  err = pthread_mutex_init (&lock->mutex, NULL);
-  if (err != 0)
-    return err;
-  lock->owner = (pthread_t) 0;
-  lock->depth = 0;
-  return 0;
-}
-
-int
-glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock)
-{
-  pthread_t self = pthread_self ();
-  if (lock->owner != self)
-    {
-      int err;
-
-      err = pthread_mutex_lock (&lock->mutex);
-      if (err != 0)
-        return err;
-      lock->owner = self;
-    }
-  if (++(lock->depth) == 0) /* wraparound? */
-    {
-      lock->depth--;
-      return EAGAIN;
-    }
-  return 0;
-}
-
-int
-glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock)
-{
-  if (lock->owner != pthread_self ())
-    return EPERM;
-  if (lock->depth == 0)
-    return EINVAL;
-  if (--(lock->depth) == 0)
-    {
-      lock->owner = (pthread_t) 0;
-      return pthread_mutex_unlock (&lock->mutex);
-    }
-  else
-    return 0;
-}
-
-int
-glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock)
-{
-  if (lock->owner != (pthread_t) 0)
-    return EBUSY;
-  return pthread_mutex_destroy (&lock->mutex);
-}
-
-# endif
-
-/* -------------------------- gl_once_t datatype -------------------------- */
-
-static const pthread_once_t fresh_once = PTHREAD_ONCE_INIT;
-
-int
-glthread_once_singlethreaded (pthread_once_t *once_control)
-{
-  /* We don't know whether pthread_once_t is an integer type, a floating-point
-     type, a pointer type, or a structure type.  */
-  char *firstbyte = (char *)once_control;
-  if (*firstbyte == *(const char *)&fresh_once)
-    {
-      /* First time use of once_control.  Invert the first byte.  */
-      *firstbyte = ~ *(const char *)&fresh_once;
-      return 1;
-    }
-  else
-    return 0;
-}
-
-#endif
-
-/* ========================================================================= */
-
-#if USE_PTH_THREADS
-
-/* Use the GNU Pth threads library.  */
-
-/* -------------------------- gl_lock_t datatype -------------------------- */
-
-/* ------------------------- gl_rwlock_t datatype ------------------------- */
-
-/* --------------------- gl_recursive_lock_t datatype --------------------- */
-
-/* -------------------------- gl_once_t datatype -------------------------- */
-
-static void
-glthread_once_call (void *arg)
-{
-  void (**gl_once_temp_addr) (void) = (void (**) (void)) arg;
-  void (*initfunction) (void) = *gl_once_temp_addr;
-  initfunction ();
-}
-
-int
-glthread_once_multithreaded (pth_once_t *once_control, void (*initfunction) (void))
-{
-  void (*temp) (void) = initfunction;
-  return (!pth_once (once_control, glthread_once_call, &temp) ? errno : 0);
-}
-
-int
-glthread_once_singlethreaded (pth_once_t *once_control)
-{
-  /* We know that pth_once_t is an integer type.  */
-  if (*once_control == PTH_ONCE_INIT)
-    {
-      /* First time use of once_control.  Invert the marker.  */
-      *once_control = ~ PTH_ONCE_INIT;
-      return 1;
-    }
-  else
-    return 0;
-}
-
-#endif
-
-/* ========================================================================= */
-
-#if USE_SOLARIS_THREADS
-
-/* Use the old Solaris threads library.  */
-
-/* -------------------------- gl_lock_t datatype -------------------------- */
-
-/* ------------------------- gl_rwlock_t datatype ------------------------- */
-
-/* --------------------- gl_recursive_lock_t datatype --------------------- */
-
-int
-glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock)
-{
-  int err;
-
-  err = mutex_init (&lock->mutex, USYNC_THREAD, NULL);
-  if (err != 0)
-    return err;
-  lock->owner = (thread_t) 0;
-  lock->depth = 0;
-  return 0;
-}
-
-int
-glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock)
-{
-  thread_t self = thr_self ();
-  if (lock->owner != self)
-    {
-      int err;
-
-      err = mutex_lock (&lock->mutex);
-      if (err != 0)
-        return err;
-      lock->owner = self;
-    }
-  if (++(lock->depth) == 0) /* wraparound? */
-    {
-      lock->depth--;
-      return EAGAIN;
-    }
-  return 0;
-}
-
-int
-glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock)
-{
-  if (lock->owner != thr_self ())
-    return EPERM;
-  if (lock->depth == 0)
-    return EINVAL;
-  if (--(lock->depth) == 0)
-    {
-      lock->owner = (thread_t) 0;
-      return mutex_unlock (&lock->mutex);
-    }
-  else
-    return 0;
-}
-
-int
-glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock)
-{
-  if (lock->owner != (thread_t) 0)
-    return EBUSY;
-  return mutex_destroy (&lock->mutex);
-}
-
-/* -------------------------- gl_once_t datatype -------------------------- */
-
-int
-glthread_once_multithreaded (gl_once_t *once_control, void (*initfunction) (void))
-{
-  if (!once_control->inited)
-    {
-      int err;
-
-      /* Use the mutex to guarantee that if another thread is already calling
-         the initfunction, this thread waits until it's finished.  */
-      err = mutex_lock (&once_control->mutex);
-      if (err != 0)
-        return err;
-      if (!once_control->inited)
-        {
-          once_control->inited = 1;
-          initfunction ();
-        }
-      return mutex_unlock (&once_control->mutex);
-    }
-  else
-    return 0;
-}
-
-int
-glthread_once_singlethreaded (gl_once_t *once_control)
-{
-  /* We know that gl_once_t contains an integer type.  */
-  if (!once_control->inited)
-    {
-      /* First time use of once_control.  Invert the marker.  */
-      once_control->inited = ~ 0;
-      return 1;
-    }
-  else
-    return 0;
-}
-
-#endif
-
-/* ========================================================================= */
-
-#if USE_WINDOWS_THREADS
-
-/* -------------------------- gl_lock_t datatype -------------------------- */
-
-void
-glthread_lock_init_func (gl_lock_t *lock)
-{
-  InitializeCriticalSection (&lock->lock);
-  lock->guard.done = 1;
-}
-
-int
-glthread_lock_lock_func (gl_lock_t *lock)
-{
-  if (!lock->guard.done)
-    {
-      if (InterlockedIncrement (&lock->guard.started) == 0)
-        /* This thread is the first one to need this lock.  Initialize it.  */
-        glthread_lock_init (lock);
-      else
-        /* Yield the CPU while waiting for another thread to finish
-           initializing this lock.  */
-        while (!lock->guard.done)
-          Sleep (0);
-    }
-  EnterCriticalSection (&lock->lock);
-  return 0;
-}
-
-int
-glthread_lock_unlock_func (gl_lock_t *lock)
-{
-  if (!lock->guard.done)
-    return EINVAL;
-  LeaveCriticalSection (&lock->lock);
-  return 0;
-}
-
-int
-glthread_lock_destroy_func (gl_lock_t *lock)
-{
-  if (!lock->guard.done)
-    return EINVAL;
-  DeleteCriticalSection (&lock->lock);
-  lock->guard.done = 0;
-  return 0;
-}
-
-/* ------------------------- gl_rwlock_t datatype ------------------------- */
-
-/* In this file, the waitqueues are implemented as circular arrays.  */
-#define gl_waitqueue_t gl_carray_waitqueue_t
-
-static void
-gl_waitqueue_init (gl_waitqueue_t *wq)
-{
-  wq->array = NULL;
-  wq->count = 0;
-  wq->alloc = 0;
-  wq->offset = 0;
-}
-
-/* Enqueues the current thread, represented by an event, in a wait queue.
-   Returns INVALID_HANDLE_VALUE if an allocation failure occurs.  */
-static HANDLE
-gl_waitqueue_add (gl_waitqueue_t *wq)
-{
-  HANDLE event;
-  unsigned int index;
-
-  if (wq->count == wq->alloc)
-    {
-      unsigned int new_alloc = 2 * wq->alloc + 1;
-      HANDLE *new_array =
-        (HANDLE *) realloc (wq->array, new_alloc * sizeof (HANDLE));
-      if (new_array == NULL)
-        /* No more memory.  */
-        return INVALID_HANDLE_VALUE;
-      /* Now is a good opportunity to rotate the array so that its contents
-         starts at offset 0.  */
-      if (wq->offset > 0)
-        {
-          unsigned int old_count = wq->count;
-          unsigned int old_alloc = wq->alloc;
-          unsigned int old_offset = wq->offset;
-          unsigned int i;
-          if (old_offset + old_count > old_alloc)
-            {
-              unsigned int limit = old_offset + old_count - old_alloc;
-              for (i = 0; i < limit; i++)
-                new_array[old_alloc + i] = new_array[i];
-            }
-          for (i = 0; i < old_count; i++)
-            new_array[i] = new_array[old_offset + i];
-          wq->offset = 0;
-        }
-      wq->array = new_array;
-      wq->alloc = new_alloc;
-    }
-  /* Whether the created event is a manual-reset one or an auto-reset one,
-     does not matter, since we will wait on it only once.  */
-  event = CreateEvent (NULL, TRUE, FALSE, NULL);
-  if (event == INVALID_HANDLE_VALUE)
-    /* No way to allocate an event.  */
-    return INVALID_HANDLE_VALUE;
-  index = wq->offset + wq->count;
-  if (index >= wq->alloc)
-    index -= wq->alloc;
-  wq->array[index] = event;
-  wq->count++;
-  return event;
-}
-
-/* Notifies the first thread from a wait queue and dequeues it.  */
-static void
-gl_waitqueue_notify_first (gl_waitqueue_t *wq)
-{
-  SetEvent (wq->array[wq->offset + 0]);
-  wq->offset++;
-  wq->count--;
-  if (wq->count == 0 || wq->offset == wq->alloc)
-    wq->offset = 0;
-}
-
-/* Notifies all threads from a wait queue and dequeues them all.  */
-static void
-gl_waitqueue_notify_all (gl_waitqueue_t *wq)
-{
-  unsigned int i;
-
-  for (i = 0; i < wq->count; i++)
-    {
-      unsigned int index = wq->offset + i;
-      if (index >= wq->alloc)
-        index -= wq->alloc;
-      SetEvent (wq->array[index]);
-    }
-  wq->count = 0;
-  wq->offset = 0;
-}
-
-void
-glthread_rwlock_init_func (gl_rwlock_t *lock)
-{
-  InitializeCriticalSection (&lock->lock);
-  gl_waitqueue_init (&lock->waiting_readers);
-  gl_waitqueue_init (&lock->waiting_writers);
-  lock->runcount = 0;
-  lock->guard.done = 1;
-}
-
-int
-glthread_rwlock_rdlock_func (gl_rwlock_t *lock)
-{
-  if (!lock->guard.done)
-    {
-      if (InterlockedIncrement (&lock->guard.started) == 0)
-        /* This thread is the first one to need this lock.  Initialize it.  */
-        glthread_rwlock_init (lock);
-      else
-        /* Yield the CPU while waiting for another thread to finish
-           initializing this lock.  */
-        while (!lock->guard.done)
-          Sleep (0);
-    }
-  EnterCriticalSection (&lock->lock);
-  /* Test whether only readers are currently running, and whether the runcount
-     field will not overflow.  */
-  if (!(lock->runcount + 1 > 0))
-    {
-      /* This thread has to wait for a while.  Enqueue it among the
-         waiting_readers.  */
-      HANDLE event = gl_waitqueue_add (&lock->waiting_readers);
-      if (event != INVALID_HANDLE_VALUE)
-        {
-          DWORD result;
-          LeaveCriticalSection (&lock->lock);
-          /* Wait until another thread signals this event.  */
-          result = WaitForSingleObject (event, INFINITE);
-          if (result == WAIT_FAILED || result == WAIT_TIMEOUT)
-            abort ();
-          CloseHandle (event);
-          /* The thread which signalled the event already did the bookkeeping:
-             removed us from the waiting_readers, incremented lock->runcount.  */
-          if (!(lock->runcount > 0))
-            abort ();
-          return 0;
-        }
-      else
-        {
-          /* Allocation failure.  Weird.  */
-          do
-            {
-              LeaveCriticalSection (&lock->lock);
-              Sleep (1);
-              EnterCriticalSection (&lock->lock);
-            }
-          while (!(lock->runcount + 1 > 0));
-        }
-    }
-  lock->runcount++;
-  LeaveCriticalSection (&lock->lock);
-  return 0;
-}
-
-int
-glthread_rwlock_wrlock_func (gl_rwlock_t *lock)
-{
-  if (!lock->guard.done)
-    {
-      if (InterlockedIncrement (&lock->guard.started) == 0)
-        /* This thread is the first one to need this lock.  Initialize it.  */
-        glthread_rwlock_init (lock);
-      else
-        /* Yield the CPU while waiting for another thread to finish
-           initializing this lock.  */
-        while (!lock->guard.done)
-          Sleep (0);
-    }
-  EnterCriticalSection (&lock->lock);
-  /* Test whether no readers or writers are currently running.  */
-  if (!(lock->runcount == 0))
-    {
-      /* This thread has to wait for a while.  Enqueue it among the
-         waiting_writers.  */
-      HANDLE event = gl_waitqueue_add (&lock->waiting_writers);
-      if (event != INVALID_HANDLE_VALUE)
-        {
-          DWORD result;
-          LeaveCriticalSection (&lock->lock);
-          /* Wait until another thread signals this event.  */
-          result = WaitForSingleObject (event, INFINITE);
-          if (result == WAIT_FAILED || result == WAIT_TIMEOUT)
-            abort ();
-          CloseHandle (event);
-          /* The thread which signalled the event already did the bookkeeping:
-             removed us from the waiting_writers, set lock->runcount = -1.  */
-          if (!(lock->runcount == -1))
-            abort ();
-          return 0;
-        }
-      else
-        {
-          /* Allocation failure.  Weird.  */
-          do
-            {
-              LeaveCriticalSection (&lock->lock);
-              Sleep (1);
-              EnterCriticalSection (&lock->lock);
-            }
-          while (!(lock->runcount == 0));
-        }
-    }
-  lock->runcount--; /* runcount becomes -1 */
-  LeaveCriticalSection (&lock->lock);
-  return 0;
-}
-
-int
-glthread_rwlock_unlock_func (gl_rwlock_t *lock)
-{
-  if (!lock->guard.done)
-    return EINVAL;
-  EnterCriticalSection (&lock->lock);
-  if (lock->runcount < 0)
-    {
-      /* Drop a writer lock.  */
-      if (!(lock->runcount == -1))
-        abort ();
-      lock->runcount = 0;
-    }
-  else
-    {
-      /* Drop a reader lock.  */
-      if (!(lock->runcount > 0))
-        {
-          LeaveCriticalSection (&lock->lock);
-          return EPERM;
-        }
-      lock->runcount--;
-    }
-  if (lock->runcount == 0)
-    {
-      /* POSIX recommends that "write locks shall take precedence over read
-         locks", to avoid "writer starvation".  */
-      if (lock->waiting_writers.count > 0)
-        {
-          /* Wake up one of the waiting writers.  */
-          lock->runcount--;
-          gl_waitqueue_notify_first (&lock->waiting_writers);
-        }
-      else
-        {
-          /* Wake up all waiting readers.  */
-          lock->runcount += lock->waiting_readers.count;
-          gl_waitqueue_notify_all (&lock->waiting_readers);
-        }
-    }
-  LeaveCriticalSection (&lock->lock);
-  return 0;
-}
-
-int
-glthread_rwlock_destroy_func (gl_rwlock_t *lock)
-{
-  if (!lock->guard.done)
-    return EINVAL;
-  if (lock->runcount != 0)
-    return EBUSY;
-  DeleteCriticalSection (&lock->lock);
-  if (lock->waiting_readers.array != NULL)
-    free (lock->waiting_readers.array);
-  if (lock->waiting_writers.array != NULL)
-    free (lock->waiting_writers.array);
-  lock->guard.done = 0;
-  return 0;
-}
-
-/* --------------------- gl_recursive_lock_t datatype --------------------- */
-
-void
-glthread_recursive_lock_init_func (gl_recursive_lock_t *lock)
-{
-  lock->owner = 0;
-  lock->depth = 0;
-  InitializeCriticalSection (&lock->lock);
-  lock->guard.done = 1;
-}
-
-int
-glthread_recursive_lock_lock_func (gl_recursive_lock_t *lock)
-{
-  if (!lock->guard.done)
-    {
-      if (InterlockedIncrement (&lock->guard.started) == 0)
-        /* This thread is the first one to need this lock.  Initialize it.  */
-        glthread_recursive_lock_init (lock);
-      else
-        /* Yield the CPU while waiting for another thread to finish
-           initializing this lock.  */
-        while (!lock->guard.done)
-          Sleep (0);
-    }
-  {
-    DWORD self = GetCurrentThreadId ();
-    if (lock->owner != self)
-      {
-        EnterCriticalSection (&lock->lock);
-        lock->owner = self;
-      }
-    if (++(lock->depth) == 0) /* wraparound? */
-      {
-        lock->depth--;
-        return EAGAIN;
-      }
-  }
-  return 0;
-}
-
-int
-glthread_recursive_lock_unlock_func (gl_recursive_lock_t *lock)
-{
-  if (lock->owner != GetCurrentThreadId ())
-    return EPERM;
-  if (lock->depth == 0)
-    return EINVAL;
-  if (--(lock->depth) == 0)
-    {
-      lock->owner = 0;
-      LeaveCriticalSection (&lock->lock);
-    }
-  return 0;
-}
-
-int
-glthread_recursive_lock_destroy_func (gl_recursive_lock_t *lock)
-{
-  if (lock->owner != 0)
-    return EBUSY;
-  DeleteCriticalSection (&lock->lock);
-  lock->guard.done = 0;
-  return 0;
-}
-
-/* -------------------------- gl_once_t datatype -------------------------- */
-
-void
-glthread_once_func (gl_once_t *once_control, void (*initfunction) (void))
-{
-  if (once_control->inited <= 0)
-    {
-      if (InterlockedIncrement (&once_control->started) == 0)
-        {
-          /* This thread is the first one to come to this once_control.  */
-          InitializeCriticalSection (&once_control->lock);
-          EnterCriticalSection (&once_control->lock);
-          once_control->inited = 0;
-          initfunction ();
-          once_control->inited = 1;
-          LeaveCriticalSection (&once_control->lock);
-        }
-      else
-        {
-          /* Undo last operation.  */
-          InterlockedDecrement (&once_control->started);
-          /* Some other thread has already started the initialization.
-             Yield the CPU while waiting for the other thread to finish
-             initializing and taking the lock.  */
-          while (once_control->inited < 0)
-            Sleep (0);
-          if (once_control->inited <= 0)
-            {
-              /* Take the lock.  This blocks until the other thread has
-                 finished calling the initfunction.  */
-              EnterCriticalSection (&once_control->lock);
-              LeaveCriticalSection (&once_control->lock);
-              if (!(once_control->inited > 0))
-                abort ();
-            }
-        }
-    }
-}
-
-#endif
-
-/* ========================================================================= */
diff --git a/lib/glthread/lock.h b/lib/glthread/lock.h
index 894b1fbaa..66c78a6cd 100644
--- a/lib/glthread/lock.h
+++ b/lib/glthread/lock.h
@@ -1,927 +1,38 @@
-/* Locking in multithreaded situations.
-   Copyright (C) 2005-2014 Free Software Foundation, Inc.
-
-   This program 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, 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 Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public License
-   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
-
-/* Written by Bruno Haible <bruno@clisp.org>, 2005.
-   Based on GCC's gthr-posix.h, gthr-posix95.h, gthr-solaris.h,
-   gthr-win32.h.  */
-
-/* This file contains locking primitives for use with a given thread library.
-   It does not contain primitives for creating threads or for other
-   synchronization primitives.
-
-   Normal (non-recursive) locks:
-     Type:                gl_lock_t
-     Declaration:         gl_lock_define(extern, name)
-     Initializer:         gl_lock_define_initialized(, name)
-     Initialization:      gl_lock_init (name);
-     Taking the lock:     gl_lock_lock (name);
-     Releasing the lock:  gl_lock_unlock (name);
-     De-initialization:   gl_lock_destroy (name);
-   Equivalent functions with control of error handling:
-     Initialization:      err = glthread_lock_init (&name);
-     Taking the lock:     err = glthread_lock_lock (&name);
-     Releasing the lock:  err = glthread_lock_unlock (&name);
-     De-initialization:   err = glthread_lock_destroy (&name);
-
-   Read-Write (non-recursive) locks:
-     Type:                gl_rwlock_t
-     Declaration:         gl_rwlock_define(extern, name)
-     Initializer:         gl_rwlock_define_initialized(, name)
-     Initialization:      gl_rwlock_init (name);
-     Taking the lock:     gl_rwlock_rdlock (name);
-                          gl_rwlock_wrlock (name);
-     Releasing the lock:  gl_rwlock_unlock (name);
-     De-initialization:   gl_rwlock_destroy (name);
-   Equivalent functions with control of error handling:
-     Initialization:      err = glthread_rwlock_init (&name);
-     Taking the lock:     err = glthread_rwlock_rdlock (&name);
-                          err = glthread_rwlock_wrlock (&name);
-     Releasing the lock:  err = glthread_rwlock_unlock (&name);
-     De-initialization:   err = glthread_rwlock_destroy (&name);
-
-   Recursive locks:
-     Type:                gl_recursive_lock_t
-     Declaration:         gl_recursive_lock_define(extern, name)
-     Initializer:         gl_recursive_lock_define_initialized(, name)
-     Initialization:      gl_recursive_lock_init (name);
-     Taking the lock:     gl_recursive_lock_lock (name);
-     Releasing the lock:  gl_recursive_lock_unlock (name);
-     De-initialization:   gl_recursive_lock_destroy (name);
-   Equivalent functions with control of error handling:
-     Initialization:      err = glthread_recursive_lock_init (&name);
-     Taking the lock:     err = glthread_recursive_lock_lock (&name);
-     Releasing the lock:  err = glthread_recursive_lock_unlock (&name);
-     De-initialization:   err = glthread_recursive_lock_destroy (&name);
-
-  Once-only execution:
-     Type:                gl_once_t
-     Initializer:         gl_once_define(extern, name)
-     Execution:           gl_once (name, initfunction);
-   Equivalent functions with control of error handling:
-     Execution:           err = glthread_once (&name, initfunction);
-*/
-
-
-#ifndef _LOCK_H
-#define _LOCK_H
-
-#include <errno.h>
+#ifndef SCM_GLTHREADS_H
+#define SCM_GLTHREADS_H
+
+/* Copyright (C) 2014 Free Software Foundation, Inc.
+ *
+ * This 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 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This 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 this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+/* This file implements Gnulib's glthreads/lock.h interface in terms of
+   Guile's locking API.  This allows Gnulib modules such as 'regex' to
+   be built with thread-safety support via Guile's locks (see
+   <http://bugs.gnu.org/14404>.)  */
+
+#include <libguile/threads.h>
 #include <stdlib.h>
 
-/* ========================================================================= */
-
-#if USE_POSIX_THREADS
-
-/* Use the POSIX threads library.  */
-
-# include <pthread.h>
-
-# ifdef __cplusplus
-extern "C" {
-# endif
-
-# if PTHREAD_IN_USE_DETECTION_HARD
-
-/* The pthread_in_use() detection needs to be done at runtime.  */
-#  define pthread_in_use() \
-     glthread_in_use ()
-extern int glthread_in_use (void);
-
-# endif
-
-# if USE_POSIX_THREADS_WEAK
-
-/* Use weak references to the POSIX threads library.  */
-
-/* Weak references avoid dragging in external libraries if the other parts
-   of the program don't use them.  Here we use them, because we don't want
-   every program that uses libintl to depend on libpthread.  This assumes
-   that libpthread would not be loaded after libintl; i.e. if libintl is
-   loaded first, by an executable that does not depend on libpthread, and
-   then a module is dynamically loaded that depends on libpthread, libintl
-   will not be multithread-safe.  */
-
-/* The way to test at runtime whether libpthread is present is to test
-   whether a function pointer's value, such as &pthread_mutex_init, is
-   non-NULL.  However, some versions of GCC have a bug through which, in
-   PIC mode, &foo != NULL always evaluates to true if there is a direct
-   call to foo(...) in the same function.  To avoid this, we test the
-   address of a function in libpthread that we don't use.  */
-
-#  pragma weak pthread_mutex_init
-#  pragma weak pthread_mutex_lock
-#  pragma weak pthread_mutex_unlock
-#  pragma weak pthread_mutex_destroy
-#  pragma weak pthread_rwlock_init
-#  pragma weak pthread_rwlock_rdlock
-#  pragma weak pthread_rwlock_wrlock
-#  pragma weak pthread_rwlock_unlock
-#  pragma weak pthread_rwlock_destroy
-#  pragma weak pthread_once
-#  pragma weak pthread_cond_init
-#  pragma weak pthread_cond_wait
-#  pragma weak pthread_cond_signal
-#  pragma weak pthread_cond_broadcast
-#  pragma weak pthread_cond_destroy
-#  pragma weak pthread_mutexattr_init
-#  pragma weak pthread_mutexattr_settype
-#  pragma weak pthread_mutexattr_destroy
-#  ifndef pthread_self
-#   pragma weak pthread_self
-#  endif
-
-#  if !PTHREAD_IN_USE_DETECTION_HARD
-#   pragma weak pthread_cancel
-#   define pthread_in_use() (pthread_cancel != NULL)
-#  endif
-
-# else
-
-#  if !PTHREAD_IN_USE_DETECTION_HARD
-#   define pthread_in_use() 1
-#  endif
-
-# endif
-
-/* -------------------------- gl_lock_t datatype -------------------------- */
-
-typedef pthread_mutex_t gl_lock_t;
-# define gl_lock_define(STORAGECLASS, NAME) \
-    STORAGECLASS pthread_mutex_t NAME;
-# define gl_lock_define_initialized(STORAGECLASS, NAME) \
-    STORAGECLASS pthread_mutex_t NAME = gl_lock_initializer;
-# define gl_lock_initializer \
-    PTHREAD_MUTEX_INITIALIZER
-# define glthread_lock_init(LOCK) \
-    (pthread_in_use () ? pthread_mutex_init (LOCK, NULL) : 0)
-# define glthread_lock_lock(LOCK) \
-    (pthread_in_use () ? pthread_mutex_lock (LOCK) : 0)
-# define glthread_lock_unlock(LOCK) \
-    (pthread_in_use () ? pthread_mutex_unlock (LOCK) : 0)
-# define glthread_lock_destroy(LOCK) \
-    (pthread_in_use () ? pthread_mutex_destroy (LOCK) : 0)
-
-/* ------------------------- gl_rwlock_t datatype ------------------------- */
-
-# if HAVE_PTHREAD_RWLOCK
-
-#  ifdef PTHREAD_RWLOCK_INITIALIZER
-
-typedef pthread_rwlock_t gl_rwlock_t;
-#   define gl_rwlock_define(STORAGECLASS, NAME) \
-      STORAGECLASS pthread_rwlock_t NAME;
-#   define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
-      STORAGECLASS pthread_rwlock_t NAME = gl_rwlock_initializer;
-#   define gl_rwlock_initializer \
-      PTHREAD_RWLOCK_INITIALIZER
-#   define glthread_rwlock_init(LOCK) \
-      (pthread_in_use () ? pthread_rwlock_init (LOCK, NULL) : 0)
-#   define glthread_rwlock_rdlock(LOCK) \
-      (pthread_in_use () ? pthread_rwlock_rdlock (LOCK) : 0)
-#   define glthread_rwlock_wrlock(LOCK) \
-      (pthread_in_use () ? pthread_rwlock_wrlock (LOCK) : 0)
-#   define glthread_rwlock_unlock(LOCK) \
-      (pthread_in_use () ? pthread_rwlock_unlock (LOCK) : 0)
-#   define glthread_rwlock_destroy(LOCK) \
-      (pthread_in_use () ? pthread_rwlock_destroy (LOCK) : 0)
-
-#  else
-
-typedef struct
-        {
-          int initialized;
-          pthread_mutex_t guard;   /* protects the initialization */
-          pthread_rwlock_t rwlock; /* read-write lock */
-        }
-        gl_rwlock_t;
-#   define gl_rwlock_define(STORAGECLASS, NAME) \
-      STORAGECLASS gl_rwlock_t NAME;
-#   define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
-      STORAGECLASS gl_rwlock_t NAME = gl_rwlock_initializer;
-#   define gl_rwlock_initializer \
-      { 0, PTHREAD_MUTEX_INITIALIZER }
-#   define glthread_rwlock_init(LOCK) \
-      (pthread_in_use () ? glthread_rwlock_init_multithreaded (LOCK) : 0)
-#   define glthread_rwlock_rdlock(LOCK) \
-      (pthread_in_use () ? glthread_rwlock_rdlock_multithreaded (LOCK) : 0)
-#   define glthread_rwlock_wrlock(LOCK) \
-      (pthread_in_use () ? glthread_rwlock_wrlock_multithreaded (LOCK) : 0)
-#   define glthread_rwlock_unlock(LOCK) \
-      (pthread_in_use () ? glthread_rwlock_unlock_multithreaded (LOCK) : 0)
-#   define glthread_rwlock_destroy(LOCK) \
-      (pthread_in_use () ? glthread_rwlock_destroy_multithreaded (LOCK) : 0)
-extern int glthread_rwlock_init_multithreaded (gl_rwlock_t *lock);
-extern int glthread_rwlock_rdlock_multithreaded (gl_rwlock_t *lock);
-extern int glthread_rwlock_wrlock_multithreaded (gl_rwlock_t *lock);
-extern int glthread_rwlock_unlock_multithreaded (gl_rwlock_t *lock);
-extern int glthread_rwlock_destroy_multithreaded (gl_rwlock_t *lock);
-
-#  endif
+#define gl_lock_define(klass, name)		\
+  klass scm_i_pthread_mutex_t name;
 
-# else
-
-typedef struct
-        {
-          pthread_mutex_t lock; /* protects the remaining fields */
-          pthread_cond_t waiting_readers; /* waiting readers */
-          pthread_cond_t waiting_writers; /* waiting writers */
-          unsigned int waiting_writers_count; /* number of waiting writers */
-          int runcount; /* number of readers running, or -1 when a writer runs */
-        }
-        gl_rwlock_t;
-# define gl_rwlock_define(STORAGECLASS, NAME) \
-    STORAGECLASS gl_rwlock_t NAME;
-# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
-    STORAGECLASS gl_rwlock_t NAME = gl_rwlock_initializer;
-# define gl_rwlock_initializer \
-    { PTHREAD_MUTEX_INITIALIZER, PTHREAD_COND_INITIALIZER, PTHREAD_COND_INITIALIZER, 0, 0 }
-# define glthread_rwlock_init(LOCK) \
-    (pthread_in_use () ? glthread_rwlock_init_multithreaded (LOCK) : 0)
-# define glthread_rwlock_rdlock(LOCK) \
-    (pthread_in_use () ? glthread_rwlock_rdlock_multithreaded (LOCK) : 0)
-# define glthread_rwlock_wrlock(LOCK) \
-    (pthread_in_use () ? glthread_rwlock_wrlock_multithreaded (LOCK) : 0)
-# define glthread_rwlock_unlock(LOCK) \
-    (pthread_in_use () ? glthread_rwlock_unlock_multithreaded (LOCK) : 0)
-# define glthread_rwlock_destroy(LOCK) \
-    (pthread_in_use () ? glthread_rwlock_destroy_multithreaded (LOCK) : 0)
-extern int glthread_rwlock_init_multithreaded (gl_rwlock_t *lock);
-extern int glthread_rwlock_rdlock_multithreaded (gl_rwlock_t *lock);
-extern int glthread_rwlock_wrlock_multithreaded (gl_rwlock_t *lock);
-extern int glthread_rwlock_unlock_multithreaded (gl_rwlock_t *lock);
-extern int glthread_rwlock_destroy_multithreaded (gl_rwlock_t *lock);
-
-# endif
-
-/* --------------------- gl_recursive_lock_t datatype --------------------- */
-
-# if HAVE_PTHREAD_MUTEX_RECURSIVE
-
-#  if defined PTHREAD_RECURSIVE_MUTEX_INITIALIZER || defined PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
-
-typedef pthread_mutex_t gl_recursive_lock_t;
-#   define gl_recursive_lock_define(STORAGECLASS, NAME) \
-      STORAGECLASS pthread_mutex_t NAME;
-#   define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
-      STORAGECLASS pthread_mutex_t NAME = gl_recursive_lock_initializer;
-#   ifdef PTHREAD_RECURSIVE_MUTEX_INITIALIZER
-#    define gl_recursive_lock_initializer \
-       PTHREAD_RECURSIVE_MUTEX_INITIALIZER
-#   else
-#    define gl_recursive_lock_initializer \
-       PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
-#   endif
-#   define glthread_recursive_lock_init(LOCK) \
-      (pthread_in_use () ? glthread_recursive_lock_init_multithreaded (LOCK) : 0)
-#   define glthread_recursive_lock_lock(LOCK) \
-      (pthread_in_use () ? pthread_mutex_lock (LOCK) : 0)
-#   define glthread_recursive_lock_unlock(LOCK) \
-      (pthread_in_use () ? pthread_mutex_unlock (LOCK) : 0)
-#   define glthread_recursive_lock_destroy(LOCK) \
-      (pthread_in_use () ? pthread_mutex_destroy (LOCK) : 0)
-extern int glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock);
-
-#  else
-
-typedef struct
-        {
-          pthread_mutex_t recmutex; /* recursive mutex */
-          pthread_mutex_t guard;    /* protects the initialization */
-          int initialized;
-        }
-        gl_recursive_lock_t;
-#   define gl_recursive_lock_define(STORAGECLASS, NAME) \
-      STORAGECLASS gl_recursive_lock_t NAME;
-#   define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
-      STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer;
-#   define gl_recursive_lock_initializer \
-      { PTHREAD_MUTEX_INITIALIZER, PTHREAD_MUTEX_INITIALIZER, 0 }
-#   define glthread_recursive_lock_init(LOCK) \
-      (pthread_in_use () ? glthread_recursive_lock_init_multithreaded (LOCK) : 0)
-#   define glthread_recursive_lock_lock(LOCK) \
-      (pthread_in_use () ? glthread_recursive_lock_lock_multithreaded (LOCK) : 0)
-#   define glthread_recursive_lock_unlock(LOCK) \
-      (pthread_in_use () ? glthread_recursive_lock_unlock_multithreaded (LOCK) : 0)
-#   define glthread_recursive_lock_destroy(LOCK) \
-      (pthread_in_use () ? glthread_recursive_lock_destroy_multithreaded (LOCK) : 0)
-extern int glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock);
-extern int glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock);
-extern int glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock);
-extern int glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock);
-
-#  endif
-
-# else
-
-/* Old versions of POSIX threads on Solaris did not have recursive locks.
-   We have to implement them ourselves.  */
-
-typedef struct
-        {
-          pthread_mutex_t mutex;
-          pthread_t owner;
-          unsigned long depth;
-        }
-        gl_recursive_lock_t;
-#  define gl_recursive_lock_define(STORAGECLASS, NAME) \
-     STORAGECLASS gl_recursive_lock_t NAME;
-#  define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
-     STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer;
-#  define gl_recursive_lock_initializer \
-     { PTHREAD_MUTEX_INITIALIZER, (pthread_t) 0, 0 }
-#  define glthread_recursive_lock_init(LOCK) \
-     (pthread_in_use () ? glthread_recursive_lock_init_multithreaded (LOCK) : 0)
-#  define glthread_recursive_lock_lock(LOCK) \
-     (pthread_in_use () ? glthread_recursive_lock_lock_multithreaded (LOCK) : 0)
-#  define glthread_recursive_lock_unlock(LOCK) \
-     (pthread_in_use () ? glthread_recursive_lock_unlock_multithreaded (LOCK) : 0)
-#  define glthread_recursive_lock_destroy(LOCK) \
-     (pthread_in_use () ? glthread_recursive_lock_destroy_multithreaded (LOCK) : 0)
-extern int glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock);
-extern int glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock);
-extern int glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock);
-extern int glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock);
-
-# endif
-
-/* -------------------------- gl_once_t datatype -------------------------- */
-
-typedef pthread_once_t gl_once_t;
-# define gl_once_define(STORAGECLASS, NAME) \
-    STORAGECLASS pthread_once_t NAME = PTHREAD_ONCE_INIT;
-# define glthread_once(ONCE_CONTROL, INITFUNCTION) \
-    (pthread_in_use ()                                                         \
-     ? pthread_once (ONCE_CONTROL, INITFUNCTION)                               \
-     : (glthread_once_singlethreaded (ONCE_CONTROL) ? (INITFUNCTION (), 0) : 0))
-extern int glthread_once_singlethreaded (pthread_once_t *once_control);
-
-# ifdef __cplusplus
-}
-# endif
+#define glthread_lock_init(lock) scm_i_pthread_mutex_init ((lock), NULL)
+#define glthread_lock_destroy    scm_i_pthread_mutex_destroy
+#define glthread_lock_lock       scm_i_pthread_mutex_lock
+#define glthread_lock_unlock     scm_i_pthread_mutex_unlock
 
 #endif
-
-/* ========================================================================= */
-
-#if USE_PTH_THREADS
-
-/* Use the GNU Pth threads library.  */
-
-# include <pth.h>
-
-# ifdef __cplusplus
-extern "C" {
-# endif
-
-# if USE_PTH_THREADS_WEAK
-
-/* Use weak references to the GNU Pth threads library.  */
-
-#  pragma weak pth_mutex_init
-#  pragma weak pth_mutex_acquire
-#  pragma weak pth_mutex_release
-#  pragma weak pth_rwlock_init
-#  pragma weak pth_rwlock_acquire
-#  pragma weak pth_rwlock_release
-#  pragma weak pth_once
-
-#  pragma weak pth_cancel
-#  define pth_in_use() (pth_cancel != NULL)
-
-# else
-
-#  define pth_in_use() 1
-
-# endif
-
-/* -------------------------- gl_lock_t datatype -------------------------- */
-
-typedef pth_mutex_t gl_lock_t;
-# define gl_lock_define(STORAGECLASS, NAME) \
-    STORAGECLASS pth_mutex_t NAME;
-# define gl_lock_define_initialized(STORAGECLASS, NAME) \
-    STORAGECLASS pth_mutex_t NAME = gl_lock_initializer;
-# define gl_lock_initializer \
-    PTH_MUTEX_INIT
-# define glthread_lock_init(LOCK) \
-    (pth_in_use () && !pth_mutex_init (LOCK) ? errno : 0)
-# define glthread_lock_lock(LOCK) \
-    (pth_in_use () && !pth_mutex_acquire (LOCK, 0, NULL) ? errno : 0)
-# define glthread_lock_unlock(LOCK) \
-    (pth_in_use () && !pth_mutex_release (LOCK) ? errno : 0)
-# define glthread_lock_destroy(LOCK) \
-    ((void)(LOCK), 0)
-
-/* ------------------------- gl_rwlock_t datatype ------------------------- */
-
-typedef pth_rwlock_t gl_rwlock_t;
-#  define gl_rwlock_define(STORAGECLASS, NAME) \
-     STORAGECLASS pth_rwlock_t NAME;
-#  define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
-     STORAGECLASS pth_rwlock_t NAME = gl_rwlock_initializer;
-#  define gl_rwlock_initializer \
-     PTH_RWLOCK_INIT
-#  define glthread_rwlock_init(LOCK) \
-     (pth_in_use () && !pth_rwlock_init (LOCK) ? errno : 0)
-#  define glthread_rwlock_rdlock(LOCK) \
-     (pth_in_use () && !pth_rwlock_acquire (LOCK, PTH_RWLOCK_RD, 0, NULL) ? errno : 0)
-#  define glthread_rwlock_wrlock(LOCK) \
-     (pth_in_use () && !pth_rwlock_acquire (LOCK, PTH_RWLOCK_RW, 0, NULL) ? errno : 0)
-#  define glthread_rwlock_unlock(LOCK) \
-     (pth_in_use () && !pth_rwlock_release (LOCK) ? errno : 0)
-#  define glthread_rwlock_destroy(LOCK) \
-     ((void)(LOCK), 0)
-
-/* --------------------- gl_recursive_lock_t datatype --------------------- */
-
-/* In Pth, mutexes are recursive by default.  */
-typedef pth_mutex_t gl_recursive_lock_t;
-#  define gl_recursive_lock_define(STORAGECLASS, NAME) \
-     STORAGECLASS pth_mutex_t NAME;
-#  define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
-     STORAGECLASS pth_mutex_t NAME = gl_recursive_lock_initializer;
-#  define gl_recursive_lock_initializer \
-     PTH_MUTEX_INIT
-#  define glthread_recursive_lock_init(LOCK) \
-     (pth_in_use () && !pth_mutex_init (LOCK) ? errno : 0)
-#  define glthread_recursive_lock_lock(LOCK) \
-     (pth_in_use () && !pth_mutex_acquire (LOCK, 0, NULL) ? errno : 0)
-#  define glthread_recursive_lock_unlock(LOCK) \
-     (pth_in_use () && !pth_mutex_release (LOCK) ? errno : 0)
-#  define glthread_recursive_lock_destroy(LOCK) \
-     ((void)(LOCK), 0)
-
-/* -------------------------- gl_once_t datatype -------------------------- */
-
-typedef pth_once_t gl_once_t;
-# define gl_once_define(STORAGECLASS, NAME) \
-    STORAGECLASS pth_once_t NAME = PTH_ONCE_INIT;
-# define glthread_once(ONCE_CONTROL, INITFUNCTION) \
-    (pth_in_use ()                                                             \
-     ? glthread_once_multithreaded (ONCE_CONTROL, INITFUNCTION)                \
-     : (glthread_once_singlethreaded (ONCE_CONTROL) ? (INITFUNCTION (), 0) : 0))
-extern int glthread_once_multithreaded (pth_once_t *once_control, void (*initfunction) (void));
-extern int glthread_once_singlethreaded (pth_once_t *once_control);
-
-# ifdef __cplusplus
-}
-# endif
-
-#endif
-
-/* ========================================================================= */
-
-#if USE_SOLARIS_THREADS
-
-/* Use the old Solaris threads library.  */
-
-# include <thread.h>
-# include <synch.h>
-
-# ifdef __cplusplus
-extern "C" {
-# endif
-
-# if USE_SOLARIS_THREADS_WEAK
-
-/* Use weak references to the old Solaris threads library.  */
-
-#  pragma weak mutex_init
-#  pragma weak mutex_lock
-#  pragma weak mutex_unlock
-#  pragma weak mutex_destroy
-#  pragma weak rwlock_init
-#  pragma weak rw_rdlock
-#  pragma weak rw_wrlock
-#  pragma weak rw_unlock
-#  pragma weak rwlock_destroy
-#  pragma weak thr_self
-
-#  pragma weak thr_suspend
-#  define thread_in_use() (thr_suspend != NULL)
-
-# else
-
-#  define thread_in_use() 1
-
-# endif
-
-/* -------------------------- gl_lock_t datatype -------------------------- */
-
-typedef mutex_t gl_lock_t;
-# define gl_lock_define(STORAGECLASS, NAME) \
-    STORAGECLASS mutex_t NAME;
-# define gl_lock_define_initialized(STORAGECLASS, NAME) \
-    STORAGECLASS mutex_t NAME = gl_lock_initializer;
-# define gl_lock_initializer \
-    DEFAULTMUTEX
-# define glthread_lock_init(LOCK) \
-    (thread_in_use () ? mutex_init (LOCK, USYNC_THREAD, NULL) : 0)
-# define glthread_lock_lock(LOCK) \
-    (thread_in_use () ? mutex_lock (LOCK) : 0)
-# define glthread_lock_unlock(LOCK) \
-    (thread_in_use () ? mutex_unlock (LOCK) : 0)
-# define glthread_lock_destroy(LOCK) \
-    (thread_in_use () ? mutex_destroy (LOCK) : 0)
-
-/* ------------------------- gl_rwlock_t datatype ------------------------- */
-
-typedef rwlock_t gl_rwlock_t;
-# define gl_rwlock_define(STORAGECLASS, NAME) \
-    STORAGECLASS rwlock_t NAME;
-# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
-    STORAGECLASS rwlock_t NAME = gl_rwlock_initializer;
-# define gl_rwlock_initializer \
-    DEFAULTRWLOCK
-# define glthread_rwlock_init(LOCK) \
-    (thread_in_use () ? rwlock_init (LOCK, USYNC_THREAD, NULL) : 0)
-# define glthread_rwlock_rdlock(LOCK) \
-    (thread_in_use () ? rw_rdlock (LOCK) : 0)
-# define glthread_rwlock_wrlock(LOCK) \
-    (thread_in_use () ? rw_wrlock (LOCK) : 0)
-# define glthread_rwlock_unlock(LOCK) \
-    (thread_in_use () ? rw_unlock (LOCK) : 0)
-# define glthread_rwlock_destroy(LOCK) \
-    (thread_in_use () ? rwlock_destroy (LOCK) : 0)
-
-/* --------------------- gl_recursive_lock_t datatype --------------------- */
-
-/* Old Solaris threads did not have recursive locks.
-   We have to implement them ourselves.  */
-
-typedef struct
-        {
-          mutex_t mutex;
-          thread_t owner;
-          unsigned long depth;
-        }
-        gl_recursive_lock_t;
-# define gl_recursive_lock_define(STORAGECLASS, NAME) \
-    STORAGECLASS gl_recursive_lock_t NAME;
-# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
-    STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer;
-# define gl_recursive_lock_initializer \
-    { DEFAULTMUTEX, (thread_t) 0, 0 }
-# define glthread_recursive_lock_init(LOCK) \
-    (thread_in_use () ? glthread_recursive_lock_init_multithreaded (LOCK) : 0)
-# define glthread_recursive_lock_lock(LOCK) \
-    (thread_in_use () ? glthread_recursive_lock_lock_multithreaded (LOCK) : 0)
-# define glthread_recursive_lock_unlock(LOCK) \
-    (thread_in_use () ? glthread_recursive_lock_unlock_multithreaded (LOCK) : 0)
-# define glthread_recursive_lock_destroy(LOCK) \
-    (thread_in_use () ? glthread_recursive_lock_destroy_multithreaded (LOCK) : 0)
-extern int glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock);
-extern int glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock);
-extern int glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock);
-extern int glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock);
-
-/* -------------------------- gl_once_t datatype -------------------------- */
-
-typedef struct
-        {
-          volatile int inited;
-          mutex_t mutex;
-        }
-        gl_once_t;
-# define gl_once_define(STORAGECLASS, NAME) \
-    STORAGECLASS gl_once_t NAME = { 0, DEFAULTMUTEX };
-# define glthread_once(ONCE_CONTROL, INITFUNCTION) \
-    (thread_in_use ()                                                          \
-     ? glthread_once_multithreaded (ONCE_CONTROL, INITFUNCTION)                \
-     : (glthread_once_singlethreaded (ONCE_CONTROL) ? (INITFUNCTION (), 0) : 0))
-extern int glthread_once_multithreaded (gl_once_t *once_control, void (*initfunction) (void));
-extern int glthread_once_singlethreaded (gl_once_t *once_control);
-
-# ifdef __cplusplus
-}
-# endif
-
-#endif
-
-/* ========================================================================= */
-
-#if USE_WINDOWS_THREADS
-
-# define WIN32_LEAN_AND_MEAN  /* avoid including junk */
-# include <windows.h>
-
-# ifdef __cplusplus
-extern "C" {
-# endif
-
-/* We can use CRITICAL_SECTION directly, rather than the native Windows Event,
-   Mutex, Semaphore types, because
-     - we need only to synchronize inside a single process (address space),
-       not inter-process locking,
-     - we don't need to support trylock operations.  (TryEnterCriticalSection
-       does not work on Windows 95/98/ME.  Packages that need trylock usually
-       define their own mutex type.)  */
-
-/* There is no way to statically initialize a CRITICAL_SECTION.  It needs
-   to be done lazily, once only.  For this we need spinlocks.  */
-
-typedef struct { volatile int done; volatile long started; } gl_spinlock_t;
-
-/* -------------------------- gl_lock_t datatype -------------------------- */
-
-typedef struct
-        {
-          gl_spinlock_t guard; /* protects the initialization */
-          CRITICAL_SECTION lock;
-        }
-        gl_lock_t;
-# define gl_lock_define(STORAGECLASS, NAME) \
-    STORAGECLASS gl_lock_t NAME;
-# define gl_lock_define_initialized(STORAGECLASS, NAME) \
-    STORAGECLASS gl_lock_t NAME = gl_lock_initializer;
-# define gl_lock_initializer \
-    { { 0, -1 } }
-# define glthread_lock_init(LOCK) \
-    (glthread_lock_init_func (LOCK), 0)
-# define glthread_lock_lock(LOCK) \
-    glthread_lock_lock_func (LOCK)
-# define glthread_lock_unlock(LOCK) \
-    glthread_lock_unlock_func (LOCK)
-# define glthread_lock_destroy(LOCK) \
-    glthread_lock_destroy_func (LOCK)
-extern void glthread_lock_init_func (gl_lock_t *lock);
-extern int glthread_lock_lock_func (gl_lock_t *lock);
-extern int glthread_lock_unlock_func (gl_lock_t *lock);
-extern int glthread_lock_destroy_func (gl_lock_t *lock);
-
-/* ------------------------- gl_rwlock_t datatype ------------------------- */
-
-/* It is impossible to implement read-write locks using plain locks, without
-   introducing an extra thread dedicated to managing read-write locks.
-   Therefore here we need to use the low-level Event type.  */
-
-typedef struct
-        {
-          HANDLE *array; /* array of waiting threads, each represented by an event */
-          unsigned int count; /* number of waiting threads */
-          unsigned int alloc; /* length of allocated array */
-          unsigned int offset; /* index of first waiting thread in array */
-        }
-        gl_carray_waitqueue_t;
-typedef struct
-        {
-          gl_spinlock_t guard; /* protects the initialization */
-          CRITICAL_SECTION lock; /* protects the remaining fields */
-          gl_carray_waitqueue_t waiting_readers; /* waiting readers */
-          gl_carray_waitqueue_t waiting_writers; /* waiting writers */
-          int runcount; /* number of readers running, or -1 when a writer runs */
-        }
-        gl_rwlock_t;
-# define gl_rwlock_define(STORAGECLASS, NAME) \
-    STORAGECLASS gl_rwlock_t NAME;
-# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
-    STORAGECLASS gl_rwlock_t NAME = gl_rwlock_initializer;
-# define gl_rwlock_initializer \
-    { { 0, -1 } }
-# define glthread_rwlock_init(LOCK) \
-    (glthread_rwlock_init_func (LOCK), 0)
-# define glthread_rwlock_rdlock(LOCK) \
-    glthread_rwlock_rdlock_func (LOCK)
-# define glthread_rwlock_wrlock(LOCK) \
-    glthread_rwlock_wrlock_func (LOCK)
-# define glthread_rwlock_unlock(LOCK) \
-    glthread_rwlock_unlock_func (LOCK)
-# define glthread_rwlock_destroy(LOCK) \
-    glthread_rwlock_destroy_func (LOCK)
-extern void glthread_rwlock_init_func (gl_rwlock_t *lock);
-extern int glthread_rwlock_rdlock_func (gl_rwlock_t *lock);
-extern int glthread_rwlock_wrlock_func (gl_rwlock_t *lock);
-extern int glthread_rwlock_unlock_func (gl_rwlock_t *lock);
-extern int glthread_rwlock_destroy_func (gl_rwlock_t *lock);
-
-/* --------------------- gl_recursive_lock_t datatype --------------------- */
-
-/* The native Windows documentation says that CRITICAL_SECTION already
-   implements a recursive lock.  But we need not rely on it: It's easy to
-   implement a recursive lock without this assumption.  */
-
-typedef struct
-        {
-          gl_spinlock_t guard; /* protects the initialization */
-          DWORD owner;
-          unsigned long depth;
-          CRITICAL_SECTION lock;
-        }
-        gl_recursive_lock_t;
-# define gl_recursive_lock_define(STORAGECLASS, NAME) \
-    STORAGECLASS gl_recursive_lock_t NAME;
-# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
-    STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer;
-# define gl_recursive_lock_initializer \
-    { { 0, -1 }, 0, 0 }
-# define glthread_recursive_lock_init(LOCK) \
-    (glthread_recursive_lock_init_func (LOCK), 0)
-# define glthread_recursive_lock_lock(LOCK) \
-    glthread_recursive_lock_lock_func (LOCK)
-# define glthread_recursive_lock_unlock(LOCK) \
-    glthread_recursive_lock_unlock_func (LOCK)
-# define glthread_recursive_lock_destroy(LOCK) \
-    glthread_recursive_lock_destroy_func (LOCK)
-extern void glthread_recursive_lock_init_func (gl_recursive_lock_t *lock);
-extern int glthread_recursive_lock_lock_func (gl_recursive_lock_t *lock);
-extern int glthread_recursive_lock_unlock_func (gl_recursive_lock_t *lock);
-extern int glthread_recursive_lock_destroy_func (gl_recursive_lock_t *lock);
-
-/* -------------------------- gl_once_t datatype -------------------------- */
-
-typedef struct
-        {
-          volatile int inited;
-          volatile long started;
-          CRITICAL_SECTION lock;
-        }
-        gl_once_t;
-# define gl_once_define(STORAGECLASS, NAME) \
-    STORAGECLASS gl_once_t NAME = { -1, -1 };
-# define glthread_once(ONCE_CONTROL, INITFUNCTION) \
-    (glthread_once_func (ONCE_CONTROL, INITFUNCTION), 0)
-extern void glthread_once_func (gl_once_t *once_control, void (*initfunction) (void));
-
-# ifdef __cplusplus
-}
-# endif
-
-#endif
-
-/* ========================================================================= */
-
-#if !(USE_POSIX_THREADS || USE_PTH_THREADS || USE_SOLARIS_THREADS || USE_WINDOWS_THREADS)
-
-/* Provide dummy implementation if threads are not supported.  */
-
-/* -------------------------- gl_lock_t datatype -------------------------- */
-
-typedef int gl_lock_t;
-# define gl_lock_define(STORAGECLASS, NAME)
-# define gl_lock_define_initialized(STORAGECLASS, NAME)
-# define glthread_lock_init(NAME) 0
-# define glthread_lock_lock(NAME) 0
-# define glthread_lock_unlock(NAME) 0
-# define glthread_lock_destroy(NAME) 0
-
-/* ------------------------- gl_rwlock_t datatype ------------------------- */
-
-typedef int gl_rwlock_t;
-# define gl_rwlock_define(STORAGECLASS, NAME)
-# define gl_rwlock_define_initialized(STORAGECLASS, NAME)
-# define glthread_rwlock_init(NAME) 0
-# define glthread_rwlock_rdlock(NAME) 0
-# define glthread_rwlock_wrlock(NAME) 0
-# define glthread_rwlock_unlock(NAME) 0
-# define glthread_rwlock_destroy(NAME) 0
-
-/* --------------------- gl_recursive_lock_t datatype --------------------- */
-
-typedef int gl_recursive_lock_t;
-# define gl_recursive_lock_define(STORAGECLASS, NAME)
-# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME)
-# define glthread_recursive_lock_init(NAME) 0
-# define glthread_recursive_lock_lock(NAME) 0
-# define glthread_recursive_lock_unlock(NAME) 0
-# define glthread_recursive_lock_destroy(NAME) 0
-
-/* -------------------------- gl_once_t datatype -------------------------- */
-
-typedef int gl_once_t;
-# define gl_once_define(STORAGECLASS, NAME) \
-    STORAGECLASS gl_once_t NAME = 0;
-# define glthread_once(ONCE_CONTROL, INITFUNCTION) \
-    (*(ONCE_CONTROL) == 0 ? (*(ONCE_CONTROL) = ~ 0, INITFUNCTION (), 0) : 0)
-
-#endif
-
-/* ========================================================================= */
-
-/* Macros with built-in error handling.  */
-
-/* -------------------------- gl_lock_t datatype -------------------------- */
-
-#define gl_lock_init(NAME) \
-   do                                  \
-     {                                 \
-       if (glthread_lock_init (&NAME)) \
-         abort ();                     \
-     }                                 \
-   while (0)
-#define gl_lock_lock(NAME) \
-   do                                  \
-     {                                 \
-       if (glthread_lock_lock (&NAME)) \
-         abort ();                     \
-     }                                 \
-   while (0)
-#define gl_lock_unlock(NAME) \
-   do                                    \
-     {                                   \
-       if (glthread_lock_unlock (&NAME)) \
-         abort ();                       \
-     }                                   \
-   while (0)
-#define gl_lock_destroy(NAME) \
-   do                                     \
-     {                                    \
-       if (glthread_lock_destroy (&NAME)) \
-         abort ();                        \
-     }                                    \
-   while (0)
-
-/* ------------------------- gl_rwlock_t datatype ------------------------- */
-
-#define gl_rwlock_init(NAME) \
-   do                                    \
-     {                                   \
-       if (glthread_rwlock_init (&NAME)) \
-         abort ();                       \
-     }                                   \
-   while (0)
-#define gl_rwlock_rdlock(NAME) \
-   do                                      \
-     {                                     \
-       if (glthread_rwlock_rdlock (&NAME)) \
-         abort ();                         \
-     }                                     \
-   while (0)
-#define gl_rwlock_wrlock(NAME) \
-   do                                      \
-     {                                     \
-       if (glthread_rwlock_wrlock (&NAME)) \
-         abort ();                         \
-     }                                     \
-   while (0)
-#define gl_rwlock_unlock(NAME) \
-   do                                      \
-     {                                     \
-       if (glthread_rwlock_unlock (&NAME)) \
-         abort ();                         \
-     }                                     \
-   while (0)
-#define gl_rwlock_destroy(NAME) \
-   do                                       \
-     {                                      \
-       if (glthread_rwlock_destroy (&NAME)) \
-         abort ();                          \
-     }                                      \
-   while (0)
-
-/* --------------------- gl_recursive_lock_t datatype --------------------- */
-
-#define gl_recursive_lock_init(NAME) \
-   do                                            \
-     {                                           \
-       if (glthread_recursive_lock_init (&NAME)) \
-         abort ();                               \
-     }                                           \
-   while (0)
-#define gl_recursive_lock_lock(NAME) \
-   do                                            \
-     {                                           \
-       if (glthread_recursive_lock_lock (&NAME)) \
-         abort ();                               \
-     }                                           \
-   while (0)
-#define gl_recursive_lock_unlock(NAME) \
-   do                                              \
-     {                                             \
-       if (glthread_recursive_lock_unlock (&NAME)) \
-         abort ();                                 \
-     }                                             \
-   while (0)
-#define gl_recursive_lock_destroy(NAME) \
-   do                                               \
-     {                                              \
-       if (glthread_recursive_lock_destroy (&NAME)) \
-         abort ();                                  \
-     }                                              \
-   while (0)
-
-/* -------------------------- gl_once_t datatype -------------------------- */
-
-#define gl_once(NAME, INITFUNCTION) \
-   do                                           \
-     {                                          \
-       if (glthread_once (&NAME, INITFUNCTION)) \
-         abort ();                              \
-     }                                          \
-   while (0)
-
-/* ========================================================================= */
-
-#endif /* _LOCK_H */
diff --git a/lib/glthread/threadlib.c b/lib/glthread/threadlib.c
deleted file mode 100644
index 37a5762d8..000000000
--- a/lib/glthread/threadlib.c
+++ /dev/null
@@ -1,73 +0,0 @@
-/* Multithreading primitives.
-   Copyright (C) 2005-2014 Free Software Foundation, Inc.
-
-   This program 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, 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 Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public License
-   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
-
-/* Written by Bruno Haible <bruno@clisp.org>, 2005.  */
-
-#include <config.h>
-
-/* ========================================================================= */
-
-#if USE_POSIX_THREADS
-
-/* Use the POSIX threads library.  */
-
-# include <pthread.h>
-# include <stdlib.h>
-
-# if PTHREAD_IN_USE_DETECTION_HARD
-
-/* The function to be executed by a dummy thread.  */
-static void *
-dummy_thread_func (void *arg)
-{
-  return arg;
-}
-
-int
-glthread_in_use (void)
-{
-  static int tested;
-  static int result; /* 1: linked with -lpthread, 0: only with libc */
-
-  if (!tested)
-    {
-      pthread_t thread;
-
-      if (pthread_create (&thread, NULL, dummy_thread_func, NULL) != 0)
-        /* Thread creation failed.  */
-        result = 0;
-      else
-        {
-          /* Thread creation works.  */
-          void *retval;
-          if (pthread_join (thread, &retval) != 0)
-            abort ();
-          result = 1;
-        }
-      tested = 1;
-    }
-  return result;
-}
-
-# endif
-
-#endif
-
-/* ========================================================================= */
-
-/* This declaration is solely to ensure that after preprocessing
-   this file is never empty.  */
-typedef int dummy;
diff --git a/lib/unistd.in.h b/lib/unistd.in.h
index 988090814..842025024 100644
--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -21,9 +21,23 @@
 #endif
 @PRAGMA_COLUMNS@
 
+#ifdef _GL_INCLUDING_UNISTD_H
+/* Special invocation convention:
+   - On Mac OS X 10.3.9 we have a sequence of nested includes
+     <unistd.h> -> <signal.h> -> <pthread.h> -> <unistd.h>
+     In this situation, the functions are not yet declared, therefore we cannot
+     provide the C++ aliases.  */
+
+#@INCLUDE_NEXT@ @NEXT_UNISTD_H@
+
+#else
+/* Normal invocation convention.  */
+
 /* The include_next requires a split double-inclusion guard.  */
 #if @HAVE_UNISTD_H@
+# define _GL_INCLUDING_UNISTD_H
 # @INCLUDE_NEXT@ @NEXT_UNISTD_H@
+# undef _GL_INCLUDING_UNISTD_H
 #endif
 
 /* Get all possible declarations of gethostname().  */
@@ -1539,4 +1553,5 @@ _GL_CXXALIASWARN (write);
 _GL_INLINE_HEADER_END
 
 #endif /* _@GUARD_PREFIX@_UNISTD_H */
+#endif /* _GL_INCLUDING_UNISTD_H */
 #endif /* _@GUARD_PREFIX@_UNISTD_H */